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BLE on a chip to smartphone connection?

I'm trying to use the BLE option on my chip to talk to my smartphone. Any ideas or suggestions on how to go about this? Thanks!

Question by maddywantstocode    |  last reply



Bluetooth Low energy and Teensy microcontroller

Hi there! I was doing some research into how to use BLE in conjunction with a teensy 3.0 microcontroller to read various (up to five) sensors (temperature, pressure, etc), is there anyone with some advice on what module to start with or what ble setup would suit best? I'm new to bluetooth so I'd work with the most basic set up Thanks

Topic by enolan2  


Simple, efficient, low-cost, solar energy equipment

I am looking for a DIY simple, low-cost solar water heater and solar light that will work in any kind of weather and still be able to supply atleast some working heat and light. Please suggest.

Topic by rseni    |  last reply


Energy saving ideas???

I am on a fixed income and need homemade project ideas to cut my hydro bills down that have doubled in the last 3 years. Any low cost project plans would be helpful to me and my family. Thanks!

Question    |  last reply


The end of the energy crisis?

http://en.wikipedia.org/wiki/Energy_Catalyzer This is the wikipedia page to a cold fusion (low temperature fusion) device that uses powdered nickel as fuel to produce free energy... It's supposed to be totally eco-friendly and it's planned to be sold out as commercial cold fusion device. Just thought to share this with others on Instructables. I like it and am looking forward to seeing this in my hands when it's made commercial. How about you?

Topic by ZokiS    |  last reply


Thermodynamics

Is it possible to take a low heat spread over a large area and convert it into a high heat in a small area? For example a normal fireplace can't melt cast iron, but 2 or three create enough energy. Could you concentrate that? (thats just an example, I have a much more brilliant plan) Thanks

Topic by LinuxH4x0r    |  last reply


What are the cheaper possible methods of compressing a gas without using reciprocating or rotary compressor?

We are working on a project to compress a producer gas(N2: 50.9%, CO: 27.0%, H2: 14.0%, CO2: 4.5%, CH4: 3.0%, O2: 0.6%). It is just like a bio-gas. It can be used as a cooking gas or for any heating purpose. Any cheaper methods to compress such gas costing low price?

Question by akshay.tale    |  last reply


Using Your Body Energy!

Using a multimeter i tested myself out of curiosity using two differing metals and found i give off about 0.6 volts at about 20 milliamps, using a small capacitor it charges fine, I then used multiple ones in parallel and it also charges quick, when i disconnect it from myself then shift the capacitors into series i can flash a small led. Whats a good circuit for doing this automatic when a charge is built up? Also are there any other good low power things I could do with it? Solar power is great but wouldn't it be cool if we could also use our own ambient body energy to do low energy stuff!

Topic by Pseudoscience    |  last reply


Low-Footprint Lamp, DIY Wind Turbine, Energy Usage Meter

  Low-Footprint Lamp DIY Wind Turbine Energy Usage Monitor Build a Solar Tracker Stationary Bike Power Garden Rain Barrels DIY Solar Panel Recycled Window Greenhouse Pringles Wind Turbine Bike Wheel Generator Home Solar Panels Homemade Sun Jar Water Flow Sensor Solar Thermal Collector Energy Saving Tools  

Topic by randofo  


I have a problem in this code for Arduino UNO , Can you help me?

#include #include #define SOL_ADC A0     // Solar panel side voltage divider is connected to pin A0 #define BAT_ADC A1    // Battery side voltage divider is connected to pin A1 #define CURRENT_ADC A2  // ACS 712 current sensor is connected to pin A2 #define TEMP_ADC A3   // LM 35 Temperature is connected to pin A3 #define AVG_NUM 10    // number of iterations of the adc routine to average the adc readings #define BAT_MIN 10.5  // minimum battery voltage for 12V system #define BAT_MAX 15.0  // maximum battery voltage for 12V system #define BULK_CH_SP 14.4 // bulk charge set point for sealed lead acid battery // flooded type set it to 14.6V #define FLOAT_CH_SP 13.6  //float charge set point for lead acid battery #define LVD 11.5          //Low voltage disconnect setting for a 12V system #define PWM_PIN 3         // pin-3 is used to control the charging MOSFET //the default frequency is 490.20Hz #define LOAD_PIN 2       // pin-2 is used to control the load #define BAT_RED_LED 5 #define BAT_GREEN_LED 6 #define BAT_BLUE_LED 7 #define LOAD_RED_LED 8 #define LOAD_GREEN_LED 9 //-------------------------------------------------------------------------------------------------------------------------- ///////////////////////DECLARATION OF ALL BIT MAP ARRAY FOR FONTS//////////////////////////////////////////////////////////////// //-------------------------------------------------------------------------------------------------------------------------- byte solar[8] = //icon for solar panel {   0b11111,0b10101,0b11111,0b10101,0b11111,0b10101,0b11111,0b00000 }; byte battery[8] =  //icon for battery {   0b01110,0b11011,0b10001,0b10001,0b10001,0b10001,0b10001,0b11111 }; byte energy[8] =  // icon for power {   0b00010,0b00100,0b01000,0b11111,0b00010,0b00100,0b01000,0b00000 }; /*byte alarm[8] =  // icon for alarm { 0b00000,0b00100,0b01110,0b01110,0b01110,0b11111,0b00000,0b00100 };*/ byte temp[8] = //icon for termometer { 0b00100,0b01010,0b01010,0b01110,0b01110,0b11111,0b11111,0b01110 }; byte charge[8] = // icon for battery charge {   0b01010,0b11111,0b10001,0b10001,0b10001,0b01110,0b00100,0b00100, }; byte not_charge[8]= {   0b00000,0b10001,0b01010,0b00100,0b01010,0b10001,0b00000,0b00000, }; //-------------------------------------------------------------------------------------------------------------------------- ///////////////////////DECLARATION OF ALL GLOBAL VARIABLES////////////////////////////////////////////////////////////////// //-------------------------------------------------------------------------------------------------------------------------- float solar_volt=0; float bat_volt=0; float load_current=0; int temperature=0; int temp_change=0; float system_volt=0; float bulk_charge_sp=0; float float_charge_sp=0; float charge_status=0; float load_status=0; float error=0; float Ep=0; int duty =0; float lvd; float msec=0; float last_msec=0; float elasped_msec=0; float elasped_time=0; float ampSecs = 0; float ampHours=0; float watts=0; float wattSecs = 0; float wattHours=0; // Set the pins on the I2C chip used for LCD connections: //                    addr, en,rw,rs,d4,d5,d6,d7,bl,blpol LiquidCrystal_I2C lcd(0x27, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE);  // Set the LCD I2C address // In my case 0x27 //******************************************************* MAIN PROGRAM START ************************************************ void setup() { Serial.begin(9600); pinMode(BAT_RED_LED,OUTPUT); pinMode(BAT_GREEN_LED,OUTPUT); pinMode(BAT_BLUE_LED,OUTPUT); pinMode(LOAD_RED_LED ,OUTPUT); pinMode(LOAD_GREEN_LED,OUTPUT); pinMode(PWM_PIN,OUTPUT); pinMode(LOAD_PIN,OUTPUT); digitalWrite(PWM_PIN,LOW);  // default value of pwm duty cycle digitalWrite(LOAD_PIN,LOW);  // default load state is OFF lcd.begin(20,4);   // initialize the lcd for 16 chars 2 lines, turn on backlight lcd.backlight(); // finish with backlight on  lcd.createChar(1,solar); lcd.createChar(2, battery); lcd.createChar(3, energy); //lcd.createChar(4,alarm); lcd.createChar(5,temp); lcd.createChar(6,charge); lcd.createChar(7,not_charge); lcd.clear(); } void loop() { read_data();             // read different sensors data from analog pin of arduino system_voltage();        // detect the system voltage according to battery voltage setpoint();      // decide the charge set point according to system voltage charge_cycle();         // pwm charging of battery power();                // calculate the load power and energy load_control();         //control the load led_indication();       // led indica print_data();            // print in serial monitor lcd_display();           // lcd display } //************************************************************ PROGRAM END ************************************************* //------------------------------------------------------------------------------------------------------ ////////////////// READS AND AVERAGES THE ANALOG INPUTS (SOLRAR VOLTAGE,BATTERY VOLTAGE)//////////////// //------------------------------------------------------------------------------------------------------ int read_adc(int adc_parameter) {     int sum = 0;   int sample ;   for (int i=0; i   {                                        // loop through reading raw adc values AVG_NUM number of times      sample = analogRead(adc_parameter);    // read the input pin      sum += sample;                        // store sum for averaging     delayMicroseconds(50);              // pauses for 50 microseconds    }   return(sum / AVG_NUM);                // divide sum by AVG_NUM to get average and return it } //------------------------------------------------------------------------------------------------------------- ////////////////////////////////////READ THE DATA////////////////////////////////////////////////////////////// //------------------------------------------------------------------------------------------------------------- void read_data(void) {     //5V = ADC value 1024 => 1 ADC value = (5/1024)Volt= 0.0048828Volt     // Vout=Vin*R2/(R1+R2) => Vin = Vout*(R1+R2)/R2   R1=100 and R2=20      solar_volt = read_adc(SOL_ADC)*0.00488*(120/20);      bat_volt   = read_adc(BAT_ADC)*0.00488*(120/20);            load_current = (read_adc(CURRENT_ADC)*.0488 -25);      temperature = read_adc(TEMP_ADC)*0.00488*100;        }   //------------------------------------------------------------------------------------------------------------ /////////////////////////////////POWER AND ENERGY CALCULATION ////////////////////////////////////////////// //------------------------------------------------------------------------------------------------------------ void power(void) { msec = millis(); elasped_msec = msec - last_msec; //Calculate how long has past since last call of this function elasped_time = elasped_msec / 1000.0; // 1sec=1000 msec watts = load_current * bat_volt; //Watts now ampSecs = (load_current*elasped_time); //AmpSecs since last measurement wattSecs = ampSecs * bat_volt; //WattSecs since last measurement ampHours = ampHours + ampSecs/3600; // 1 hour=3600sec //Total ampHours since program started wattHours = wattHours + wattSecs/3600; // 1 hour=3600sec //Total wattHours since program started last_msec = msec; //Store 'now' for next time } //------------------------------------------------------------------------------------------------------------ /////////////////////////////////PRINT DATA IN SERIAL MONITOR///////////////////////////////////////////////// //------------------------------------------------------------------------------------------------------------   void print_data(void)   {     delay(100);     Serial.print("Solar Panel Voltage: ");     Serial.print(solar_volt);     Serial.println("V");     Serial.print("Battery Voltage: ");     Serial.print(bat_volt);     Serial.println("V");     Serial.print("Syestem Voltage: ");     Serial.print(system_volt);     Serial.println("V");     Serial.print("Charge Set Point:");     Serial.println(bulk_charge_sp);     Serial.print("Temperature:");     Serial.print(temperature);     Serial.println("C");     Serial.print("Load Current: ");     Serial.print(load_current);     Serial.println("A");     Serial.print("Power: ");     Serial.print(watts);     Serial.println("W");     Serial.print("Energy: ");     Serial.print(wattHours);     Serial.println("WH");     Serial.print("Duty Cycle :");     if (charge_status==1)     {     Serial.println("99%");     Serial.println("BULK CHARGING");     }     else if (charge_status==2)     {     Serial.print(Ep);     Serial.println("%");     Serial.println("FLOAT CHARGING");     }     else     {     Serial.println("0%");     Serial.println("NOT CHARGING");     }     if(load_status==1)     {      Serial.println("LOAD IS CONNECTED");     }     else     {      Serial.println("LOAD IS DISCONNECTED");       }        Serial.println("***************************"); } //---------------------------------------------------------------------------------------------------------------------- //////////////////////////////////SYSTEM VOLTAGE AUTO DETECT /////////////////////////////////////////////////////////// //---------------------------------------------------------------------------------------------------------------------- void system_voltage(void) {   if ((bat_volt >BAT_MIN) && (bat_volt < BAT_MAX))   {      system_volt = 12;   }   /*   else if  ((bat_volt > BAT_MIN*2 ) && (bat_volt < BAT_MAX*2))   {     system_volt=24;   }*/   else if ((bat_volt > BAT_MIN/2 ) && (bat_volt < BAT_MAX/2))   {     system_volt=6;   }   } //--------------------------------------------------------------------------------------------------------------------------- ////////////////////////////////////CHARGE SET POINT /////////////////////////////////////////////////////////////////////// //--------------------------------------------------------------------------------------------------------------------------- void setpoint(void) {   temp_change =temperature-25.0; // 25deg cel is taken as standard room temperature // temperature compensation = -5mv/degC/Cell   // If temperature is above the room temp ;Charge set point should reduced   // If temperature is bellow the room temp ;Charge set point should increased   if(system_volt ==12)   {      bulk_charge_sp = BULK_CH_SP-(0.030*temp_change) ;      float_charge_sp=FLOAT_CH_SP-(0.030*temp_change) ;      lvd =LVD;   }   else if(system_volt ==6)   {      bulk_charge_sp = (BULK_CH_SP/2)-(0.015*temp_change) ;      float_charge_sp= (FLOAT_CH_SP/2)-(0.015*temp_change) ;      lvd=LVD/2;   }   /*   else if (system_volt == 24)   {    bulk_charge_sp = (BULK_CH_SP*2)-(0.060*temp_change) ;    float_charge_sp= (FLOAT_CH_SP*2)-(0.060*temp_change) ;    lvd=LVD*2;   }   */   } //-------------------------------------------------------------------------------------------------------------------------------- ///////////////////////////////////////////////////PWM CHARGE CYCLE @500 HZ ////////////////////////////////////////////////// //------------------------------------------------------------------------------------------------------------------------------- void charge_cycle(void) {   if (solar_volt > bat_volt && bat_volt <= bulk_charge_sp)   {         if (bat_volt <= float_charge_sp) // charging start   {       charge_status = 1; // indicate the charger is in BULK mode      duty= 252.45;      analogWrite(PWM_PIN,duty); // 99 % duty cycle // rapid charging           }   else if (bat_volt >float_charge_sp && bat_volt <= bulk_charge_sp)   {         charge_status = 2; // indicate the charger is in FLOAT mode       error  = (bulk_charge_sp - bat_volt);      // duty cycle reduced when the battery voltage approaches the charge set point       Ep= error *100 ; //Ep= error* Kp // Assume  Kp=100             if(Ep < 0)        {         Ep=0;         }       else if(Ep>100)         {          Ep=100;         }       else if(Ep>0 && Ep <=100) // regulating        {          duty = (Ep*255)/100;        }        analogWrite(PWM_PIN,duty);    } }    else    {    charge_status=0;  // indicate the charger is OFF    duty=0;    analogWrite(PWM_PIN,duty);    } } //---------------------------------------------------------------------------------------------------------------------- /////////////////////////////////////////////LOAD CONTROL///////////////////////////////////////////////////// //----------------------------------------------------------------------------------------------------------------------    void load_control() { if (solar_volt < 5  ) // load will on when night {   if(bat_volt >lvd)   // check if battery is healthy   {   load_status=1;   digitalWrite(LOAD_PIN, HIGH); // load is ON   }   else if(bat_volt < lvd)   {     load_status=0;    digitalWrite(LOAD_PIN, LOW); //load is OFF   } } else // load will off during day {    load_status=0;    digitalWrite(LOAD_PIN, LOW); } } //------------------------------------------------------------------------------------------------- //////////////////////////LED INDICATION//////////////////////////////////// //------------------------------------------------------------------------------------------------- void led_indication(void) {   battery_led();           //Battery status led indication   load_led();              //Load led indication } //---------------------------------------------------------------------------------------------------------------------- /////////////////////////////////////////////BATTERY LED INDICATION///////////////////////////////////////////////////// //---------------------------------------------------------------------------------------------------------------------- void battery_led(void) {      if( (bat_volt > system_volt) && ( bat_volt   {         leds_off_all();       digitalWrite(BAT_GREEN_LED,LOW);  // battery voltage is healthy   }   else if(bat_volt >= bulk_charge_sp)   {       leds_off_all();       digitalWrite(BAT_BLUE_LED,LOW);  //battery is fully charged   }    else if(bat_volt < system_volt)   {       leds_off_all();       digitalWrite(BAT_RED_LED,LOW);  // battery voltage low   } } //---------------------------------------------------------------------------------------------------------------------- /////////////////////////////////////////////LOAD LED INDICATION///////////////////////////////////////////////////// //----------------------------------------------------------------------------------------------------------------------      void load_led()   {     if(load_status==1)     {       digitalWrite(LOAD_GREEN_LED,HIGH);     }     else if(load_status==0)     {       digitalWrite(LOAD_RED_LED,HIGH);     }    } //------------------------------------------------------------------------------------------------------ //////////////////////// TURN OFF ALL THE LED/////////////////////////////////////////////////////////// //------------------------------------------------------------------------------------------------------ void leds_off_all(void) {     digitalWrite(BAT_RED_LED,HIGH);   digitalWrite(BAT_GREEN_LED,HIGH);   digitalWrite(BAT_BLUE_LED,HIGH);   digitalWrite(LOAD_RED_LED, LOW);   digitalWrite(LOAD_GREEN_LED, LOW); } //------------------------------------------------------------------------------------------------------ //////////////////////// LCD DISPLAY/////////////////////////////////////////////////////////// //------------------------------------------------------------------------------------------------------ void lcd_display() { lcd.setCursor(0, 0); lcd.write(1); lcd.setCursor(2, 0); lcd.print(solar_volt); lcd.print("V"); lcd.setCursor(14, 0); lcd.write(5); lcd.setCursor(16, 0); lcd.print(temperature); lcd.write(0b11011111); lcd.print("C"); lcd.setCursor(0,1); lcd.write(2); lcd.setCursor(2, 1); lcd.print(bat_volt); lcd.print("V"); lcd.setCursor(14, 1); lcd.write(2); if((charge_status==1) | (charge_status== 2)) { lcd.write(6); } else { lcd.write(7); } lcd.setCursor(0,2); lcd.write(3); lcd.setCursor(2,2); lcd.print(load_current); lcd.print("A"); lcd.setCursor(13,2); lcd.print(watts); lcd.print("W"); lcd.setCursor(0,3); lcd.print("Energy:"); lcd.print(wattHours); lcd.print("WH");      }

Question by Fares Mareai    |  last reply


How to Generate low pressure air 0.8 psi for pallet gardens? Stirlinge engines, fluidyne? How?

My pallet garden project is a big success. It works great and it is becoming simpler and cheaper to do over time. It uses aquarium bubble pumps to produce low pressure air and this air is used to airlift pump water that circulates to the plants in the garden  in an endless loop.   I measured a few days ago and my bubble pump is producing 22 inches water pressure (0.8 psi) at the pump and 60 litres per hour of air at this pressure and this drives all the pallet gardens at a great distance (100 ft ) from the pump. I use a 3.5 watt air pump. I would just  love it if it could be off grid, and driven by solar heat in a low tech way.    Anyone want to try to do this?  Because then it is of great value in poor countries.   Just to give you an idea of how little heat you need to make this pressure.  If you heat air from 20 degrees C to 36 degrees C  (68 F to 97 F)  in a closed container, you get 0.8 psi pressure increase in the container!  That is the bar, and it would be really hard to set it lower than that!    I do not yet understand stirling engines or fluidyne pumps but I think they could do this.  If I try it, I will have cylinders of air alternatively heating and cooling  in the sun and valved to pump the air in one direction.  But if you are clever, I am sure you can do better than that with fluidyne or flutterwing wind power. I would love to see some comments and interest in this.   It IS working and people are going to be very interested as gardening season gets into full swing.    Playlists are http://www.youtube.com/playlist?list=PL00C41C26C91A76BB&feature=view_all for the pallet gardening and http://www.youtube.com/playlist?list=PLkzXlmAwZTZcHUq4YX8__3qLEJIIzTduW&feature=view_all for some amazing alternative wind, water and solar machines. Thanks Brian

Topic by gaiatechnician  


Which low boiling fluid to use (that won't corrode metals and plastics)?

I'm having a bit of a headache trying to chose and procure a working fluid to use in my solar device. It needs to be low boiling, but as my device so far is involving copper, aluminium and maybe some plastics and rubbers, it would also need to be as non corrosive as poss. Cheap and plentiful are also important, not so much for the prototype, but when these things are ultimately used, they need to be easy to assemble. The four options I'm aware of so far are: Methanol boils at 64.7 °C, I thought it would be easy to get but is turning out quite difficult and maybe expensive, also apparently eats through every material I plan to use. Ethanol Boiling Point: 78.4 °C, easier to get but still corrosive. Hexane Boiling Point: 69 °C, not corrosive (?) but not at all easy to get or cheap. Water Boiling Point: 100 °C, which may be a bit too high. The fluids will be boiling in a non-pressurised but sealed environment, so no atmospheric water will be able to get in or out. Help?

Topic by SolarFlower_org    |  last reply


Bluetooth 4.0 Low Energy module for independant wireless bracelet? Answered

Hi, I'd like to make a wireless bracelet linked to my phone via Bluetooth 4.0 Low Energy (BLE). BUT, i can't find lots of information about BLE module. In one hand, i found this special BLE Arduino : http://www.rfduino.com/rfd90101-teaser-kit.html but i think i won't power it with just a simple watch battery. Am i right? And if i have to power it with 2 AA battery, i won't build a bracelet... In the other hand, i've read an Instructable topic about a vibrating bracelet (almost the purpose of me) here : https://www.instructables.com/id/ViBracelet/ The person uses a Bluetooth Low Energy module , ConnectBlue part #: OLP425i-26. It seems to fit my needs, but also seems to be more difficult to program as it is not an arduino of something else. What do you think of that? I need advice... Thank you for your time. Chris

Question by ChristopheHvd    |  last reply


Does anyone know if it is possible to revive an automobile jumpstart jumpbox?

I'm constantly having car battery problems so I've purchased a Coleman Powermate Jumpstart system box. It was pretty pricey. It now has gone dead (won't charge) and i was wondering if anyone knows if it is possible to revive it . I have seen a few instructables about reviving batteries so i'm wondering if it can be revived. Thanx!

Question by kimxtc    |  last reply


Energy return on investment for various different energy sources

We're used to thinking about the cost per unit of energy (e.g. $/gallon of gasoline) with the implicit assumption that cost is a rough indicator of what is required to obtain that energy. The Oil Drum has a nice piece on Energy Return on Investment (EROI) and the implications of using low EROI energy sources. To dive right in, it's instructive to think about the EROI of domestic oil production as a function of time:100:1 in 193030:1 in 197011-18:1 in 2000EROI on the Web part 2 of 5, (Provisional Results Summary, Imported Oil, Natural Gas)Energy return on investment, sometimes called EROI and sometimes called EROEI, is thought by many, including myself, to be a critical issue for determining the past, present and future status of human society. It is usually considered in terms of energy return on energy investment, but it can also be considered in terms of energy return on monetary investment. While much of human progress has been attributed, rightfully, to technology, much of that technology has been a means of using more energy for human ends. This is true for fire, knife blades and spear points (energy concentrating devices), the development of agriculture and the increase in its productivity and, essentially all aspects of the industrial revolution.EROI is simply the energy delivered by an energy-obtaining activity compared to the energy required to get it. If the numerator and denominator are expressed in the same units (barrels per barrel, MegaJoules per MegaJoule) the result is a dimensionless ratio, i.e. 100:1 or 10:1). Obviously a higher ratio implies a more desirable fuel than a lower one, other things being equal (which is rarely the case). The concept is extremely simple in theory but often very difficult in execution, mostly because society generally maintains its records in monetary rather than energy terms. Another problem is that the U.S. Government has not supported such studies in a consistent fashion and it is my perception that the quality of some energy records as are kept by e.g. the U.S. Departments of Energy and of Commerce appear to be deteriorating in recent years. Thus deriving the energy cost of getting energy (or most other things) is generally somewhat, and oftentimes exceedingly, difficult. A second problem is that the usual measure of the quantity of a fuel, its heat value, often does not give a full assessment of that fuel's ability to do economic or other work. Most simply electricity and thermal heat from e.g. coal or oil have a great difference in their ability to do work, such as we are willing to trade three or four heat units of coal or oil in a thermal plant for one thermal unit of higher quality electricity. Thus if the input and output fuels are of different quality then it is often thought desirable to weight in some way the inputs and the outputs. A third problem is that it is important to consider boundaries: how large should we draw the boundaries of the energy analysis for the inputs? We will consider these issues in far more detail in later publications but there are many reasons why it is important to make summaries of EROI available at this time even though many uncertainties exist in the numbers that we present here, and indeed with any numbers that might be possible to generate.via jforbess

Topic by ewilhelm    |  last reply


How clouds act as an air pump to suck in air. Not how you think they do!

I have been thinking a long time about the biotic pump theory but I still don't understand it.  The math is too hard for me.   BUT it got me to thinking.   It is a point of major dispute in the meteorological world.   Does condensation cause low pressure?  2 russian nuclear physicists say yes,  almost everyone else says no!   So,  I thought and thought and thought.  Now I think I have a simple enough explanation And yes, they may not necessarily cause low pressure under the cloud (probably do)  but they definitely suck in air from elsewhere.  Imagine a fleet of huge doughnut shaped dirigible airships. They are sitting at 10,000 ft just floating there.   Now the commander tells everyone that they must now fly at 5000 ft.   So they turn on their propellers (in the hole in the doughnut) and drop down to 5000 ft by propelling air up  through the hole.   Now staying at 5000 ft is achieved by running the propellers at just fast enough.  So at 5000 ft they are pumping air from under the doughnuts to above them.   Now imagine a cumulus cloud.  Even though it is not fixed in size or shape and it does not have a propeller,  it is doing the exact same thing.  Air is being pumped up the middle and the clouds are sitting lower in the sky than they "should",  because they are sending that column of air up into the sky.   Here is my video to explain it visually.  https://www.youtube.com/watch?v=sPO8dWm_GIg

Topic by gaiatechnician    |  last reply



NGOs I can approach for sponsorship, regarding my solar project?

As I mentioned in the post for the Sunflower, I'm going to b spending the next year or two traveling around teaching people and communities how to generate and integrate solar energy into their local needs, pretty much for free. I've got a bit of money saved to pay for this if necessary, but was ideally hoping to get some kind of grant or sponsorship just to cover my cost of living, which would probabaly come to about £5000 / US$8000 over two years. I have a very low cost of living. Does anyone know of any NGOs / charities / etc I could approach for this? I'm not really needing or offering anything other than the cash to cover my expenses. I can name drop and put a logo on my website and all that, they wouldn't need to really do much of anything other than sling me the cash, safe in the knowledge that they were instrumental in bringing free solar energy to anyone who wants it. Cheers, Daniel.

Topic by SolarFlower_org    |  last reply


Version control in open source or free hardware projects. Standard methodology?

I have a pallet garden project that has morphed from 1 type of pallet garden into 3 types and with several methods of irrigation and water cycling.  Is there a standard method of versioning it?   I have it on youtube on a playlist.  Someone suggested  using Semantic Versioning http://semver.org/  on the videos in my playlist to help me and others keep track.   I do video's a lot because talking to the camera helps define problems for me and sometimes other people do suggest solutions.   http://www.youtube.com/playlist?list=PL00C41C26C91A76BB&feature;=view_all  The project continues to grow. I expect someone to come up with a Stirling or fluidyne method of using solar heat to compress the air in the next couple of months and if they don't I will do it myself.  (It is only 1 psi and 5 watts).   60 litres per hour works 3 pallet gardens together pretty easily.  I have 6 working at the same time right now.  2 vertical. 1 flat and 3 leaning pallet gardens.  I can double that as soon as I build some more.  Brian

Topic by gaiatechnician  


Electrical components

Is there any components that set the minimum energy to pass through? When the energy is lower than the fix amount , no energy will be passing through.  I'm trying to make a project. I'll put a dynamo on my bicycle, and it will be connected to 3 LEDs. When I cycle in low speed, only one LED will light up. When I increase my speed to certain level, 2 LEDs will light up and if it passes a certain speed all LED will light up. Any idea?

Topic by GohC    |  last reply


Boiling a fluid to make a inverse water wheel?

Ok, how about this; Submerge a waterwheel type structure with cups facing downwards on one side. Under the cups you have some kind of heating element. The fluid is methanol or some other low boiling fluid. A very small amount of heat from the element will produce bubbles, which rise and are caught in the cups, the wheel turns and can generate electricity or whatever. I'm using this principle in another application, but thought it could be quite an efficient means of generating electricity from heat. If the meths is sitting at forty something degrees and boils around 50, it shouldn't take hardly any energy to tip it over. And since you're effectively generating force from gravity (the weight of the fluid on the other side of the wheel) you're kind of getting ten times your force back. ie producing one litre of bubbles will give you 9.8 Newtons of force (for water, 8ish for meths). So (excuse my dodgy maths) 125 litres of bubbles in an hour would give you 1 kiloWatt hour? One cola bottle per minute, doesn't sound very much and that much energy could easily be produced through concentrated solar. Slight risk of explosion... How efficient do you think it would be, overall?

Topic by SolarFlower_org    |  last reply


"New " old material for experimentation.

This video is about Nitinol memory metal engines that are basically Stirling heat engines and work on a very low temperature difference. I first say this material while watching a video on the founder of 'The Venus Project'. He had small spring that he would stretch out of shape and the heat it - it would come back to its original form and shape. I thought it was neat but didn't see the potential of the material. This video is from a 1970 CNN broadcast  - when CNN was news instead of a propaganda machine. http://www.youtube.com/watch?v=7GfYlRakZ6Y The material is available on the web somewhere as others have purchased it since I showed them the video. At this point in time I am more of an information messenger and unable to partake in experimentation. So have at it guys and gals. God Bless

Topic by strmrnnr  


Energy efficient, waterless, Copper strip based cooling system

Energy efficient ,waterless Copper stripe based cooling system:The presented Idea is based on Heat exchange principle.As per sketch there will be a conveyor belt system and some copper stripes will be connected with this belt.Each copper strip will have a moveable hook.The conveyor belt will move with a motor.Each copper strip will be separated with each other and with conveyor belt with the help of Insulation (wooden insulation).Each copper strip will be connected with the machine for 15 to 20 seconds to absorb the heat and after that this copper strip will be removed and next copper strip will be ready to absorb the heat.The removed strip will be cooled down after some time and will be ready to couple with the machine again.In this way each copper stripe will work one by one to absorb the heat to cool the machine and each strip will get cool down due to convection .What I thought is that if I use a continuous water jet to cool the motor then the motor will remain cool so if I use the copper stripes then the same effect will be occured.It will work in this way that temperature will be not increased of machine if I couple the device with the machine. It will be low cost,low maintenance,waterless solution to cool the machines. It will consume almost nil energy

Topic by vikram_gupta11    |  last reply


How to assemble a low voltage, variable speed electric motor in a school laboratory, and how to measure its efficiency?

For a high school physics project, I am doing an investigation on how does the density of the transmission fluid affect the efficiency of a fluid coupling. I am planning to use honey based transmission fluid with varying amounts of water to dilute it, and alter and manipulate its density. For the turbines (blades of the fluid coupling) I need to construct a low voltage electric motor with variable speeds using materials easily available in a school laboratory (though I can use some other source for my materials as well).  I need to measure its efficiency. and by that I mean to actually compare the input and output energies (perhaps their voltages) using a low inertia dynamo as my output generator.

Question by diwakarchopra    |  last reply


How do you use a solar panel to light a 10w light bulb at night? And what kind of a solar panel would I need?

I want to make my own solar panel (a small one) for a school project, but I also want it to be useful for after the project as well. I need a small light to light something outside, but at night (because, obviously, I can see during the day). So apparently you need a battery to store the energy during the day, and a charge controller is really important. I've found a lot of useful sites and videos (and instructables) that show how to make solar panels, and a few that show how to connect the solar panel directly to a light bulb, but I can't seem to find anything that clearly explains the battery and charge controller part. Please note that I know nothing about the technology of solar panels, watts, volts, etc., and have never taken apart or made even a simple electronic device of any sort. The most experience I had with this stuff was when I made a small circuit with a light bulb, battery, and alligator clips sometime around the sixth grade, but I have no idea how all that works and all the numbers that you need to keep in mind (I did learn the basics a couple years back, but I've forgotten everything), so when I find brief explanations online that say you need a battery, charge controller, and you need to somehow calculate the correct capacity and voltage, I'm totally lost. Can someone please help me out and explain? Or at least provide a useful link or something? I've scoured the Internet, trust me. Unfortunately, I was unable to find anything clear or something in a "How-to" format. Also, I'm flexible on the 10w thing. A 10w light bulb was just the lowest I could find and I thought the lower the better. So what kind of a battery and solar panel (how many watts/volts, etc) would I need? Low cost is ideal.

Question by a Canadian    |  last reply


Bilge Pump vs Drip Irrigation for Low-Power Swamp Cooler

I'm building a small evaporative/swamp cooler for Burning Man that I would like to use as little power as possible (no solar panels). Traditional playa swamp cooler designs use a small pump to continuously irrigate the cooler pads. I'm thinking it might be more efficient to put the water in a reservoir that sits above the pads and gradually drips down on them. But since the pads need to be saturated for maximum evaporation, eventually the water will pool at the bottom and need to be pumped back to the reservoir by a pump controlled by a float switch. Which of these designs do you think would use less energy?

Topic by vagary    |  last reply


The low-down: Where have I been?

It may be a bit narcissistic for me to think anyone missed me or even noticed I was gone, but for those of you that did notice heres the low-down.Without a doubt, the time I spent working at Instructables last summer was the most fun I have ever had in my life. It was the perfect combination of working among smart creative individuals ( Eric, Christy, Tim, Paul, and Noah), having such an open ended job where I was actually paid to do what I love, and being in bright sunny free thinking northern California. The cherry on top of this summer of awesomeness was going to Burning Man (see pic below). It was something I had wanted to do ever since I had read about it online many years ago, and, as fate would have it, I ended up going the first year I was actually old enough to.I don't think I am ever going to forget driving Tim's manual truck (I don't know how to drive stick) on a deserted road in Nevada, at 3:30 am Sunday morning, the energy drinks wearing off and Tim sleeping peacefully in the passenger seat, while it rained intermittently, with only a vague idea where I was going, and doing this all with just a NY state learners permit. Nor will I forget getting my first sight of the playa, just as the sun was coming up, with all the massive metallic sculptures glistening on the horizion. The week that followed was just pure surreal amazingness. Anything I wrote about my first Burning Man experience wouldn't give it justice, but Tim describes it nicely in his Burning Man instructable.The most surprising thing about the summer though, was that by the end of it I actually looked forward to going back to school. I wanted to learn circuit building and other cool electrical engineering skills that I could incorporate into my future Instructables projects. I wanted to be able to post impressive electronic projects, instead of just minor circuit hacks like the tazer glove and capacitor charger. I wanted to master the movement of the electron.One plane trip from SFO to JFK later, I'm back home. The contrast between Frisco and NY was staggering. If there was one word to describe how NY looked to me at that time it would be "gray". The experience was like watching the Wizard of Oz in reverse, going from the bright, colorful, surreal land of Oz back to black and white Kansas. Don't get me wrong, I love my hometown. I am of the opinion that NYC is the single greatest city in the world (California wins as a state, but in terms of a single city nothing can compare to NY). If you don't agree with me, stand in the center of the Brooklyn Bridge and turn around to get a full 360 degree perspective. Your opinion will be swayed if not changed. Still, September 07 was a very gray month for me. It took me a few weeks to wade through the bureaucratic bullshit of Brooklyn Poly and finally get registered for classes. The classes I did get registered for were all prerequisites and nowhere near my area of interest. I know I am going to have to suck it up and complete them eventually (especially now that my school has merged with NYU, so I get to graduate with a much more impressive degree then the school I was originally accepted into), but at the time I was just too miserable and distracted to pay attention in class. It was even hard for me to respond to e-mails from summertime coworkers because hearing about the activities at the tower brought back memories of a happier time. I was in a state of near-complete mental shutdown, my creativity was shot, and I was depressed. I decided that I needed to take a break from school, so I took a leave of absence for the Spring semester. That leave of absence bought me a time period of 8 months to do whatever I wanted. I figure why not live out my weaboo fantasy, and travel to Japan. I can not say exactly when my obsession with Japanese culture began. Maybe it was subconsciously planted in my brain with the cherry tree in front of my childhood home, cultivated with anime, and brought to fruition when I actually started reading about their history and culture. Whatever the reason, it has been something I've always wanted to do, and what better time to "find myself" then while on a break from college (Its stereotypical-tastic!). There was only one obstacle standing between me and the romantic imagery I had of bathing in hot-springs and meditating in front of Shinto shrines ... money, at least a few thousand dollars of it. Japan aint cheap, and even if I was going to get a job to support me while I was there, I would still need a butt-load of money for the initial travel and living investment. (On that note if any of you Instructablites knows someone in Japan who you could get me in touch with regarding job opportunities or living quarters, or has some advice for living cheaply while there, I'm all ears) I spent most of January half-assedly looking for a job. I did not devote my whole ass to the task because, no matter how much I wanted to go to Japan, I wasn't too excited about the prospect of getting a minimum wage job which utilized none of my skills (I have very unique skills, so finding a job that used them would be next to impossible). It was looking as though my next few months would be filled with minimum wage menial labor. That is until I thought of throwing myself on the mercy of Eric and Christy, and asking for my old job back. I lacked the testicular fortitude to ask them directly, and so reverting to grade school mentality (the one that figures rejection will hurt less through proxy), I asked Tim to test the waters and see if my old job was still available (grade school version: Psst Tim, I've got a crush on Eric & Christy ::school girl giggles:: can you ask if they like me). Tim was kind enough to oblige. A few e-mails later I found out I could come back as long as I promised to return to school in September. (This was no problem because I had already made the same promise to my parents, and myself because I didn't want to loose my 20k a year scholarship).One plane trip at the end of February from JFK to OAK later, I'm back in California. My longterm goal for the next few months is to live as cheaply as possible, learn Japanese, and try to acquire some work that I can do while in Japan. Living cheaply has been easier then expected. I quit smoking (something I thought would be much harder then it was, but after two months of lukewarm-turkey I was able to eliminate my nicotine cravings entirely). I am able to feed myself almost entirely off the excess of others, with the occasional purchased produce being the exception. I bike for transportation (that same yellow road bike in the picture below). I'd say that overall, it took more effort to stop being a consumer-whore then it did to quit smoking, but it feels equally good to be free of both of those bad habits. Well thats my story. I should probably get back to work.New instructables coming soon ...

Topic by Tetranitrate    |  last reply


INSULATION.. Any way to make ATTIC and WALL INSULATION with recycle Items ???

Anyone knows any way of making cheap or free attic and wall insulation from recycle items? I know of a company that makes it out of recycle shreaded jeans. But then with what will I shread them and what will I wear after shreading them?...lol It will cost me Over $600.00 for a 30x60 ft attic and thats the cheapest being on sale now at Lowes and Home Depot installing it myself. The spray on foam insulation cost an arm and a leg.. Then again I will need them for making my other projects.. haha. I'm sure someone out there knows a way of making it or may have an idea of makin it with recycle material.. thanks.. This will be a a cool experiment or may I say a warm one.. =- }

Question by PitStoP    |  last reply


How to make a key beeper that can be activated by a cell phone?

Is there a device that that can be somehow activated by 'some' signal produces by today's cell phones (bluetooth, wifi, infra...) and then make a beep sound? Preferably it should be small, light, cheap, with low consumption of energy. It should work as a beeper to find a thing that it is attached to more quickly.  Any ideas?

Question by xsustek    |  last reply


Can LEDs be wired up to replace 12 VAC garden light bulbs?

How do I put them together? Some are wedge base and others are bi-pins. Can they be made water proof? Because they use less energy, can I string more of them using the same 300w transformer?

Question by yopauly    |  last reply


Solar Power Towers Efficiently Using Brayton Cycle

I want to point out a solar to electric generation concept that has yet to be seen anywhere, even though it originated back during the Carter Administration's ERDA programs of the late 70's. I’m talking about solar power towers that convert solar energy into electricity at the hundreds of mega-watt level. While power towers do exist today, and the world currently does have a handful of them as shown in Fig-1, none use the Brayton Cycle nor can they boast an energy conversion efficiency at the mid to upper thirty percent level.  A group of engineers got together at a think tank organization called Sanders Associates in Nashua, N.H., several decades ago, and designed a unique Brayton Cycle, 100 MW solar Power Tower concept for generating electricity. This was accomplished under ERDA (Energy Research Development Administration) who gave us a phase-2 follow-up contract that took our phase-1 design and built a working scale model at the 10 KW level. This model was tested at the Georgia Tech Solar Research Facility and "registered" ~37% electric solar conversion efficiency. The system used ambient air as its working fluid, and was to be located in open-spaced desert regions. Phase-2 was lost to competition using a closed-loop liquid sodium system that boiled water into superheated steam at 900F to run a turbine that generated ~21% overall electric conversion efficiency.  Apparently, at that time ERDA would rather haul water out to the desert than use ambient air to generate electricity? The politics of their decision is beyond reason and clashes with improving the world’s development of green technology energy.  ERDA shut out our better technological performer and safely locked it away for another day! ERDA's official reason for turning us down: "this technology uses excessively high temperatures (2500F versus 900F) that are dangerous to workman maintaining the equipment". But that was back in the 70’s, maybe we’ve learned to deal with high-temp heat by now?   Solar Energy Concept Using Low Pressure Storage Our solar power tower would collect the sun’s energy by locating its ceramic heat exchanger on top of a tall tower as shown in Fig-1. The tower was located in the center of a field of active sun-searching mirrors (heliostats, Figure-2). These mirrors reflected sunlight onto our ceramic honeycomb heat exchanger, producing a concentrated flux intensity level that heated it to around 2500F. At the same time, low pressure fans generating only a few psi pressure would suck the ambient air through the honeycomb, heating it to just under the 2500F and then passing it through energy storage silos which stored the heat down to ~150F. We purposely designed the energy storage charging phase of our hot air system to work at only a few psi above ambient as a safety feature. The sun effectively acts as the combustor of our jet engine or Brayton cycle engine. Once the sun heats the air, it passes through heat exchangers consisting of a labyrinth of underground silos that are temperature segregated. These silos receive our 2300F airflow and cool it down to about 150F, transferring this heat into solid salt containers which turn to liquid once they have absorbed sufficient heat. Figure-3 is a schematic of this underground energy storage facility and shows the airflow being heated by a fully charged set of silos containing liquid salt-bricks. This airflow direction is reversed when we charge the silo’s salt-bricks. The bricks are kept in specially insulated, high pressure silos (located underground for added insulation) that store the heat energy at one atmosphere for later use. These underground silos act as our energy storage batteries, and when needed would discharge their heat energy accordingly into the moving airflow. This energy storage concept permitted the generation of electricity at night and during overcast days. Two sets of storage systems are required for continuous operation. One would be charging at low pressure while the other is discharging at high pressure through the Brayton engine to generate electricity.   Electric Energy Generation at High Pressure Electricity would be created by turning an electric generator at high speed. The generator was turned by running a jet engine connected to it.  The engine’s combustor for heating the air is effectively the sun, hence the name Brayton cycle for generating our solar electricity (Figure-4). The heat from the molten salt containers would increase the energy of the high pressure air coming from the compressor, and would then force it through a typical turbine that turns this energy into high rotational speed to run the generator and make electricity. Our solar jet engine sucks in ambient air using its compressor, as all jet engines do, and blows it through a series of silos at high pressure whose stacked bricks are held at different temperature levels. We start our airflow through a silo held as low as 150F and work our way up to ~2300F as we pass through our last, hottest silo which acts to complete the effective solar combustion process. This air preheating technique dramatically improves our energy turnover capability and allowed us to convert solar energy into electricity at near 37% efficiency. During our electric energy generation phase, the silos of our Brayton system requires operating at many atmospheres of pressure just as in any jet engine combustor using petroleum-based JP-fuel.      

Topic by RT-101    |  last reply


Pumping Water in the Arctic!

As a small background to the project I am working on: I am currently doing my Masters of Architecture in Copenhagen, and we are designing devices to bring on our expedition to the North Pole, and I am harnessing salt water to pump through salt water batteries. My question is then: What kind of pump do I need to pump water up 2 meters? I don't need much water coming up at once, just needs to be constant. I am also looking for the most energy efficient way of doing this, any know of something? Any help is much appreciated! :) Thanks, AD

Topic by arctic_devices    |  last reply


Options to improve cooling and reduce consumption for portable coolers

I recently had to start learning how to service airconditioners on the fast and that learning got me thinking about my portable coolers.... Some of us like to go camping or on longer fishing trips, so there might be one of those 3-way fridges in use or a better cmpressor model. The one thing they all have in common is that they can only cool down to a difference in ambient temperatures. No matter which way we turn it the cooling produces heat and that needs to get away somehow. The other big thing is the cooling cycling - or the lack of it on a warm day. After some reading and thinking I came up with some ideas that might be applicable to your existing cooler if you are willing to mess around a bit. Let's start with the produced heat, shall we? Down here in Australia most people either have the fridge in their4WD or camper. In a car or small camper trailer there is often the problem of airflow, so the cooler might be doing overtime for no other reason than a lack of airflow. If you check online sites like Amozon and Ebay you quickly find fan systems meant to be installed inside the cooler to get lower temperatures and a quicker cooling of fresh goods. The thing is that the box is quite well insulated and the benefit of the airflow goes only as far as it can reach. And even if the box is quite empty and you would have a benefit of the cold air moving around it won't change the fact that "improved" cooling always comes with more heat in this case. But if we use one of these fan systems to actually improve the airflow on the hot side we not only get better cooling but also a reduce power consumption - something worth considering if you have no backup power generator.... This of course brings us to placement. As I have done the mistake myself you might be tempted to put a 3way cooler onto your seat. Opening it with the back free means the lid always gets stuck on the seat, do it the other way around and you block the airflow. If you do put it on the seat then make sure two things match: 1. The thing is secured properly. 2. The airflow from your aircon is able to reach the hot side of the cooler. Even permanent installations in a camper benefit from a good airflow. Often the fridge or freezer is built into some sort of bench and the airflow behind might be very limited. A simple solution here is to add a vent on top of the bench to allow the hot air to escape. A better one is to use a fan that is powered together with the heating element or compressor and drives the hot air to the outside. How to improve the cold side of the box or fridge? Well, to be honest there is not much that can be done unless you are prepared for some serious work. Depending on compartment size, contents and how full it is a little fan can help to keep the temperatures even but it won't help to get it cooler or reduce the cycling periods for the cooling. The only really working way that I found is to use a "battery" for the storage of the cold. The cooling works by checking the inside temp of the box and if above the set temp the cooling won't stop. This is all well and good while we have a constant supply of power but once we are on batteries it would be great to keep the active time to a minimum. A working solution is to build a container that fits around the cooling element. Smaller types often use an aluminium heatsink, bigger types might come with a compressor and an evaporator. In either case proper sealing is important! Most good models are fully waterproof, meaning even if you would fill them with water they would not leak in other areas than the door. But double check and if in doubt use a bit of silicone to make sure. Ok, but how do we "store" the cold coming from the device? Cold packs ;) These things contain a ready to use mix that holds cold temperatures quite well. Another really good alternative is alcohol or radiator coolant, although the last has limited capabilites in terms of holding capaity for the cold as it is desinged to exchange heat fast rather than to keep it. With a suitable sized and sealed box around the active cooling element we will need longer to actually see any cooling happen (with a warm "battery") but that can be compensated for by good planning or a frozen water bottle. If the cooling element is covered with a box of cooling gel then it has to cool this first before anything happens inside the box. But once it does the pack is already far below the normal temp it would have during normal operation. Remember the inside of the cold pack cools down first before the outside will get cold ;) So once the set temperature is reached the device will shut off. But since the cold pack is far below the set temp it will continue to cool our box until the core is warmer than the set temp. Quick thinkers will now say the benefit is lost as the time required to cool the "battery" down again is much longer than the normal cycle time - and they would be correct. But as we get much colder temps inside the gel box the overall running will still be less compared to normal operation. And since from the second cycle on the gel is only warming up to operating temp of the box it will be much faster than with a warm box. Another benefit might be the ease of cleaning and ice removal. Some peltier driven coolers have big cooling fins or a quite bad design for the heatsink allowing mould to grow where you can't remove it easy. If the box is made from stainless steel and flush with the back wall of the box we won't have that problem anymore. Ok, but how much is good or too much for the size and gel content? You got me there as it is bit tricky. You don't want to loose much usable space for starters and you don't want to wait hours for the gel to cool down if the box was not used. IMHO the size should fit the cooling element with about 20% to spare all around. If stainless steel is not an option than aluminium is the next best choice. Thin sheets can either be be cold formed with a hammer or "brazed" with a good torch and the right rods. Ok, before that route is there anything I should consider or do first? Depends ;) 3-way systems usually use a flame or heating elements to heat an ammoia solution. After years of neglect corrosion can form and reduce the amount of heat transfered into the system and reducing the efficiency this way. It might help to take the heating elements out once a year or so to clean them and the contact areas from any corrosion or dirt build up. With a fixed shedule for this you won't have the problem of never noticing a badly corroded heating element either - and this is the main failure on these systems.... Modifying your camper or making a few mods to your 4WD drawer system is not for the faint of heart and should be done with consideration. The last thing you want to do is rush things to find out it was not necessary. Before cutting holes check if you can't find the room for the fan in a different spot and use ducts to control the airflow - sometimes it is easier to blow air in than to get air out ;) When it comes to creating vents or connections for air to the outside always make sure it is waterproof and insect safe! If you can let the outlet go downwards so water won't run in, for 4WD trailers consider a flap to prevent water from going during a river crossing. Flyscreens will not only prevent insects from coming in but on the inside also prevent dust to go eerywhere - allow to the removal and cleaning! The salts used in these cold packs can be corrosive, so you have to make sure there are no leaks and that there is no steel to come into contact with gel - this includes screw ends hidden in through-holes. If in doubt use a coat of paint but keep it as thin as possible. Even on peltier systems it might be impossible to remove the heatsink without massive surgery on the internals. So before you take it all apart to gain access check if it is far easier to seal around the box opening and possible screw connections using silicone. The cooling battery can be screwed on and sealed with silicone as well as an easy escape route. Although for this to work you need to check if the material of the box allows for a proper bond with the silicone! Some materials just won't allow anything to stick at all, even after sanding them. So do a test first in an area where you would be able to cut the silicone away without causing damage. If you can rip or peel it off the surface you should not try to use a cooling battery screwed to the wall, only use a box that is fully sealed with the cooling element and has a seperate back - one complete unit around the cooling element. I have a 3-way system with a freezer compartment that does the cooling for the fridge too - what can I do? These units either provide good freezing with the fridge temps too low or good fridge cooling with no freezing capabilites - depending on the thermostat used. Our problem is that is next to impossible to add a cooling battery of the normal kind to these systems. The L-shaped freezer box can really only be added with a L-shaped cooling battery from underneath. Only if you don't need any freezing at all you could add a cooling battery to fit into the freezer box shape. In either case the benefit is somehow limited by the way the thermostat is used. If there is no temp control for freezing it should be fine. Warnings... Only peltier driven coolers are free from refrigerants. Every 3-way or compressor system uses refrigerant as evident by more or less piping and heating elements. Never attempt to screw anything into a cooling element containing refrigerant! Even if you think between the channels all will be fine it won't be! The material is just pressed to form the channels and any damage caould mean refrigerant leaking out! Use silicone instead and make sure all surfaces are properly cleaned before applying it, also wait until the silicone is really fully cured before putting any stress on it. As said, these cooling gels can be corrosive, especially if DC voltage is involved. Make sure that everything that is not aluminum or plastic is properly sealed before allowing ongoing contact with cooling gels. Do not attempt any of this if you have to ask yourself what tools you might need or how make a suitable container for the gel. If in doubt check Google on how to work with aluminium or stainless steel if there are not enough Instructables for it. The gel will expand a little bit if it freezes, this no problem in a metal container if you allow for a bit of flex or on the side added strength  - whatever suits you better. Another option is to get a few different cold packs (by the active ingredient) and to do a check in a little container. Freeze it and note whe level cold and warm. Little to no difference means nothing to worry in terms of expansion during freezing.

Topic by Downunder35m  


Low pressure pneumatic grid (1 to 4 psi) to use small wind, small hydro and small solar power?

I have used low pressure air and a simple "airlift pump"  to cycle water around a "pallet  Garden" since August.  This meant that very little water was being used but the plants were growing really well.   the air comes from an aquarium bubble pump and it is about 1 psi.  The pallet garden is almost 20 ft from the little bubble pump.   Recently I decided to do something similar in my greenhouse, but it is 120 ft from the little pump and there is no electrical socket close.  So reluctantly I bought another 120 ft of 1/4 inch tubing to send the air to the greenhouse.  I didn't expect it to work at that distance.  But it is working great. Why not use air instead of electricity to move the energy from "toy" windmills in gardens? Or from low head small water power?  I bet anyone could make a compressor to make 1 PSI.  It is orders of magnitude easier than making a direct water pump or converting the energy to electrical and then back again in a pump.  An airlift pump is just a vertical tube in the water.    How simple is that!   and it is darn cheap too.  You can use this for pumping water (Highest I ever got was 18 ft with 1 psi) or just bubbling air into a fishpond or to actually move the water in small water features.   Or of course in the pallet garden or in aquaponics.  And even thought this energy is useful at that scale it can never ever be made worthwhile to share it electrically.  But maybe your grid could extend to your neighbours garden too?  You could have an interconnector if you or they have a bit of excess pneumatic power!

Topic by gaiatechnician    |  last reply


What are some good options for solar powering a laptop?

I want to power a laptop with solar panels, the laptop will not have a monitor and will not run at night, so it has relatively small power demands (for a computer) - what kind of solar set-up should I be looking at? Keeping low-price options a high priority. Thanks

Question by action_owl    |  last reply


Coffee pot space heater

Ok, so this is my first post. I love this site! Anyway, I have a couple of old coffee pots that still heat the water, they just dont make coffee anymore. Im wondering if maybe i could make a very small and very low energy use space heater out of the parts. any ideas on how this might be accomplished would be great.

Topic by kithso    |  last reply


Westward Group Alternatives: Alternative Energy the Next Big Play?

Alternative energy plays have been around for decades, including Ballard Power Systems Inc. (NASDAQ/BLDP), a maker of hydrogen fuel cells that went public in 1993. The stock traded as high as $100.00 as a speculative investment opportunity in early 2000 but was unable to break into the automotive market. It is currently drifting at the $4.00 level. However, what Ballard was hoping for is now materializing for battery-powered automaker Tesla Motors, Inc. (NASDAQ/TSLA), which has built a superhighway of charging stations across the U.S. and is expanding into Europe and China. Tesla is a great story and a decent possible investment opportunity. Yet it’s not only vehicles that demand alternative sources of energy; we also see demand coming from numerous applications and, in some cases, manufacturing facilities. The demand for alternative energy can be based on wind, solar, or water and has led to the development of a strong solar industry as an investment opportunity. A small-cap that has been exciting the stock market while producing sizzling gains for speculators has been Plug Power Inc. (NASDAQ/PLUG), a developer of hydrogen fuel cells that power forklifts and other devices. The stock traded as low as $0.32 over the past 52 weeks, surging to $6.37 on Thursday morning after reporting strong results. Plug Power has been on my technical analysis screens for some time, as the stock consistently breaks higher. If interested, I would suggest investors look to this stock on weakness for a volatile speculative investment opportunity. Another possible investment opportunity that may interest investors in the alternative energy space is FuelCell Energy, Inc. (NASDAQ/FCEL), which has a market cap of $616 million. The stock has traded as low as $1.12 and as high as $4.74 over the past 52 weeks. The current price is halved at $2.37, so there’s a potential aggressive investment opportunity here. FuelCell is a developer of fuel cell solutions by way of its stationary “Direct FuelCell” power plants, built to deliver ultra-clean, efficient, and reliable green power. The process involves harnessing the energy of renewable biogas from wastewater treatment and food processing. Clients are varied and include commercial, industrial, government, and utility businesses. Sectors served include the food and beverage, manufacturing, hospital and prison, college and university, hospitality, utilities, and wastewater treatment areas. FuelCell says its energy produced is up to two times more efficient than fossil fuel plants. The company’s plants produce output ranging from 300 kilowatts (kW) to 2.8 megawatts (MW) and are expandable to more than 50 MW. There are currently more than 50 plants worldwide that have generated more than 300 million kilowatt hours (kWh) of electricity. FuelCell is expanding in Southeast Asia, including South Korea, Indonesia, Thailand, Malaysia, and Singapore, which the company sees as an investment opportunity. Revenues are estimated to rise 7.2% to $201.16 million in FY14 followed by 22.6% to an estimated $246.54 million in FY15, according to Thomson Financial. I suggest investors keep an eye on a company like FuelCell, as this volatile investment opportunity has tremendous upside if it can deliver results.

Topic by nicolcrisci  


"Knex War?" (The Math Bit)

Hey guy! Sharir1701 here and I just want to start off by saying that I'm not back into Knex warfare, but I have something to show you. About a year and a half ago, I posted this forum topic. There I explained why, in my opinion, just adding more rubber bands to a gun will not actually produce an overall better gun (past a certain, low point). I'm not getting back into that discussion, but I simply wanted to share something regarding that. Don't ask me how or why (I don't know, myself), but a few days ago I suddenly remembered that old assumption I made. Being a perfectionist, I hate leaving things unfinished or unexplained (particularly math and physics related inquiries). Back when I posted that topic, I had little to no formal Physics knowledge, and the beginnings of an understanding in mathematics. Now, I have a much broader understanding, much more knowledge, and an ability to explain and evaluate what I once couldn't. Anyway, what I'm trying to say is, back then, I didn't have the tools to prove my claims. I firmly believed in them, but I couldn't confirm them. It's nothing complicated, but, like I said, just something I'd like to share. I also want to point out that, although I personally don't enjoy spending days upon days perfecting a little plastic mechanism for firing (mostly) non-aerodynamic plastic projectiles, anymore, there still is a warm spot in my heart for the craft I once loved. More to the point - this is a small article just showing something I did in a few minutes the other day, that helps me to better understand how a Knex gun works. I hope that in writing this, more people that are still building guns, will think about more accurately calculating certain things about their guns to help improve their performance and hopefully produce more efficient guns. The final note I have is that I'm about to show you equations, all of which can be plugged with real, measurable numbers, to calculate to a high degree of accuracy, the forces at play. This means you can actually calculate the most efficient layout for a gun, and also that in designing your next, you will be able to use these equations, and many others, to find optimal solutions to your problems. So, what's all this fuss about? Well, basically, I just proved with a few, painfully easy equations that my conjecture about the forces in a gun, working on the pin, is true. I'll just get to it: First, Hooke's Law states that the force necessary to change the length of a spring or a (tense) rubber band is F=K*dX, where F is the force, dX is the distance you want to change, and K is a constant number, that each rubber band (or spring) has. You can quite easily measure both of these. For rubber bands connected parallel to each other (assuming they are the same type of rubber band, which ever is your chosen standard), this equation becomes F=K*dX*N, where N is the number of rubber bands used. dX and K are both constant in the regards of the pull of a pin on a standard Knex pin gun. Therefor, the amount of force required to cock a pin (pull it back to it's full length) is linearly correlated to the number of bands you put on your gun. Next, if we examine Newton's equation of work and energy, W=dE=F*dX, where W is the work, dE is the change in energy in your system (input from an external force, i.e. your hand), F is the force applied along a length of movement, and dX is that length. Let us define the base position of the pin (not cocked, minimum tension on the rubber bands, fully in the barrel, etc.) as having 0 energy. This then means that the work applied to the pin by cocking it is equal to all the potential energy it has. From this, plugging in the force, we get Ep=K*(dX)^2*N. Let us assume a perfect world, where we neglect the effects of friction and air resistance, and assume all the momentum of the pin is transferred into the bullet as it fires (I will briefly mention in the end, why everything we're neglecting here just strengthens my claim in reality, but let's continue for now). After being released (in other words, shot), the maximum velocity the pin reaches right before the end of it's journey can be found using the equation for kinetic energy Ek=1/2*M*(Vmax)^2, using the fact that (again, neglecting energy wasted as heat due to friction) the energy is conserved, as no external force is working on the system, which then means that Ep,start=Ek,end => K*(dX)^2*N=1/2*M*(Vmax)^2 => Vmax = sqrt(2*K*(dX)^2/M) * sqrt(N). The first sqrt term in the final equation is all one big constant (again, K is the ratio associated with the rubber band, dX is the distance the pin travels, and M is the mass of the pin), meaning we can conclude that (C for constant) Vmax=C*sqrt(N). Finally, force applied by a moving, massive object can be calculated using Newton's second law, F=dP/dT (P is the pin's momentum, T is the time it takes for the pin to go from velocity Vmax to 0, transferring all it's energy into the gun and the bullet, but as I said, let us assume all of it goes into the bullet), or F=M*dV/dT (M, mass of the pin, dV is the difference in velocity, Vmax-0, which is simply Vmax. This is because P=M*V, which means dP=M*dV, ignoring relativity). So, F=M*C/dT*sqrt(N). The time varies slightly, but insignificantly, so let us assume it is a constant. So that's it. The force exerted by the pin on the bullet is some constant (calculatable, as mentioned and as shown), times the sqrt of N, the number of rubber bands on the gun. So there you go. Just a little something I did out of the blue the other day and thought I would share a proof of my conjecture from what feels like eons ago. I hope you enjoyed. Finally, I would like to tell you guys, perhaps as a little tease, since I'm not sure if I will ever upload it, but I have made 1 more gun after I stopped posting. I have already slightly teased about it in my user info. I guess I'll tell you guys what it is if I'm already posting something here again :) Possibly my most enjoyable, most well received, and quite innovative gun of all time? The REMPAR-2. I built the REMPAR-3 (I was also going to call it S5 when I thought about posting it). In a brief summary, it's a pump action, chambering (or bolt action as I and many others falsely used to call it), magazine fed rifle, that's only 5 layers thick all over, except one tiny area where it's 8 layers thick (1.5 extra on either side), as a reinforcement, not necessary if you use less rubber bands. Oh, actually, there's another small necessary area where it's 7 layers thick, but it's tiny and doesn't make the gun look bulky at all, and who cares. Plus, the one is around the pump, which looks quite natural, and the other is "disguised" as a detachable sight (not really detachable) that also looks fine. It also looked fairly good for a gun that I made, it used (if I remember correctly) a grand total of 0 broken pieces, which is a big accomplishment for me (the mag has some broken white rods, but fuck off), and it worked flawlessly, reaching ranges over 80ft and being able to go at 2-4 rounds per second, depending on your skill level with it. In other words, I could shoot 4rps; My girlfriend, with no experience or practice, could do 2rps, which says something about the gun's comfortability and ease of use in my opinion. It shot blue rods up to an accuracy of about 5x5cm (2x2in) over 30ft, which is amazing for a Knex gun, and it was truly super comfortable. It wasn't even long at all, which is saying a lot, looking at some other people's attempts at 5-wide pump actions (I may also be guilty of an attempt several years ago). Being quite short and only 5 wide, it is also quite light. I'm sorry, I just really liked this gun, I think it was truly my best creation ever (of course, the S3 is by far the most innovative gun I've made, but it's mostly a concept gun, not meant for real effectiveness). I may post it in the future, but I'll make no promises. I suppose I won't leave you guys completely hanging and take a picture of it. Oh yes, there's also a neat, fun little thing I did, originally because I saw no other option, but then I actually really loved it. I'm talking about the mag-lock. It locks automatically (there's a band on it, but it ripped a long time ago, so...) and the mag cannot fall out. Then you pull on it with your middle finger, similar to a trigger, and the mag just drops right out. Love it :)

Topic by Sharir1701    |  last reply


hybrid go kart?

We r making hybrid go kart with 1 hp motor for hybrid go kart challenge which battery pack will be good choice 1.Lead acid 2.Ni metal hydride because of cost constraint we can't use li ion so if u know any other good batteries with low cost plz tell info: 48v 150 amps initial current energy efficient

Question by vpsingh92    |  last reply


Large Hadron Collider's First Operation

The Large Hadron Collider has been tested on 10, September, 2008.Look here on Wikipedia if you don't know what a Large Hadron Collider is.Proton beams have already been injected into the first metres of the LHC, to test the injection process, but the first attempt to circulate beams all the way around the LHC will be on the official start up day. If everything proceeds according to plan the beam will circulate all the way around the 27 km long LHC. Over the following months the LHC scientists and engineers will commission the LHC, running beams at higher energy with the intention of beginning collisions, using relatively low energy (5TeV) beams, towards the end of 2008.Continued on this link...

Topic by Plasmana    |  last reply


Voltage regulator for solar panel

I have built a solar panel as a fun little project, now it has come upon a big problem. The solar cells that I am using seem to have a higher amperage output and a lower voltage output in high intensity sun while having a high voltage and low amperage output in medium and low intensity sun. This poses a problem as my batteries were able to recharge during late winter and early spring but now are not able to recharge when there is the most energy to be captured during the summer. The average voltage during high intensity is about 11 while the voltage during medium or low is around 12.5 and 13. I want to know if there is a way to create a transformer to step up the voltage or create a voltage regulator that can withstand 13 amps so the battery can recharge properly. A link or any suggestions would help.

Topic by menace  


over 90W of flyback (back EMF) energy? how to dissipate it? Answered

Continuing my work on the flyback driver, I am investigating methods and practices to protect my MOSFETs from overvoltage conditions. I have measured peaks of as much as 350V across a 250V MOSFET while drawing an arc, and it does not matter what I do it seems like I simply cannot limit the back EMF transients to <250V. I am really impressed by the rugged nature of these MOSFETs, although I have popped quite a few of them. Seeing that they are being bombarded with almost 400V transients, it is a wonder they survive as long as they do. When I added a medium sized reverse biased zener diode in series with a 10 ohm 1 watt resistor, both went up in smoke, especially the resistor! The zener diode survived. I also tried a much larger screw mounted 30V zener diode w/o the resistor and it reached much over 100 degrees C after only a few seconds and I had very little output on the secondary. Judging by how quickly a 10 watt resistor heats up I assume that the back EMF very low impedance and has to be over 90W average!!! I'll need to try to use the integration feature on my scope to measure the average power dissipation accurately. In none of the configurations involving a resistor did I see the voltage clamped any lower than before. :(

Question by -max-    |  last reply


HELP - Energy production idea needing some tips and tricks

Good day to allI'm not quite sure this is the right forum for this so bear with me if it's not :PI'm looking for some info and ideas regarding a project that has been brewing in my head, but since i am no more than an initiate in all this mech and tech stuff i figured this would be a good place to find some help.I'm trying to create a low budget way to feed a 12v battery without having to use solar, hydric or wind power. Basically i want not to be dependant on atmosferic conditions so i wanted to use human generated mechanical thrust to generate enough electricity for some basic stuff. This project is to be put inside a yurt in the middle of a forest so one can have a few hours of light and maybe even enough power to charge a small laptop or a cell phone.This is my idea:I thought of using one of these old sewing tables connected to a small motor(instead of a sewing machine) in order to generate electricity which would then be stored in a battery , more or less the same process by wich a dynamo powers a bike's lamp but in a different scale.But to achieve this i still have many questions and doubts that i'm going to share with you all in the hope that some bright ideas might help me bring the project to life.-Question 1 I'm thinking the system should be composed of: Sewing table (Mechanical thrust) Motor (Generator) Some sort of electric rectifier (same function as the ones used with solar systems) 12v Battery Is this looking logical or have i missed something??-Question 2.a What kind of motor is suitable for energy production? I've been reading about this and if i understood right there are 2 kinds of motors. One kind that uses pre generated electric current to magnetize a coil wich in turn produces motion and another kind wich is built with permanent magnets. This later one would be the one i'm looking for, am i right?? Or could it be that not all PM motors can be used to produce energy from motion??-Question 2.b What kind of apliances use this kind of motors? I've just openned a broken vacuum cleaner to check it's motor but it has 2 sets of coils and no magnets, so i'm guessing it is the kind that needs electricity to magnetize one of the coils... LOW BUDGET is a key factor of this project and recycling the motor would be perfect.-Question 3 What about the rectifier... I'm guessing i should have some kind of apparatus which would normalize the energy that is going into the battery and also that prevents me from emptying the battery in order to preserve it. I'm wondering if a regular box like the ones used on solar systems would do the trick...-Question 4 I realized that these table's wheels can spin in both directions, and i'm guessing that this will have some kind of influence on the polarity of the energy produced by the engine and that this might pose some problems. Is this true?? And in case it is, any chance that the rectifier takes care of this or do i need to find a way to force the wheel to spin in only one direction?I still have many other questions but these are probably the bigger ones.I hope someone might help me with all this.Thank you very much in advance.

Topic by dameluz    |  last reply


Increasing Testosterone

As we age changes happen in our bodies. One of these changes is a decrease in the production of some hormones, one of which is important to men, namely: testosterone. It affects muscle mass, physical and mental energy, and sexual function. Selenium is found in Brazil nuts, and it is important in the production of testosterone. If you are showing any signs of low testosterone, try eating three or four raw Brazil nuts each day. Some suggest a person should not eat too many Brazil nuts. (Of course, I am not mentioning this because I had the problem. I am speaking for a friend. Uh huh. Yeah, that is it. Wink, wink.) Anyway, my "friend" began to notice improvements within a week. You can get Brazil nuts in bulk at many grocery stores, and they may be a simple and inexpensive aid to low testosterone problems. Other things that help low testosterone problems are reducing body weight by ten percent and regular exercise. 

Topic by Phil B    |  last reply


How to 'load' a CIS solar panel to maximize power output and efficiency? Answered

I have 4 decent CIS solar panels that, in series and in bright sun, will give ~16V, and can offer ~ 200mA shorted. However, if shorted, the voltage obviously sags to almost 0V, so basicly no power is delivered based on the fact that V*I=P at the other extreme, there is almost 4V open circuit, but essentially no current flow. Again, 0W of power delivery. The voltage and current figures above are just memory and I did log the data at various resistances awhile ago. My intention is to charge 3 lithium batteries in series to 12.6V, that will then feed power to a modified car charger (basic buck circuit for downconverting 9V-18V to 5V) Since the current is so low, can I maximize efficiency by connecting the cells directly to the battery pack without any additional circuitry other than a blocking diode? Or in order to speed up the charging do I need to add some complex control circuit that will intelligently match the impedance? If the battery charging speed is based on current, does that mean a direct connection is best?

Question by -max-    |  last reply


SWELTERING IN LOUISIANA Need Expert advice on a new heating and ac for our home.

My husband and I have bought into a house with our adult children? Our portion in a mother-in-law type aprtment that is two stories. Kitchen/living area downstairs and 2 bedrooms dwnstairs. Total about 1800 sq. We want a heating/ac unit that will stand up to Louisiana's hot humid conditions that in low energy useage and eviormentally friendly. Any suggestions? we are replacing window units.

Question    |  last reply


Global Warming Instructables

The Stay Warm Contest is requesting our warmest solutions to make it through the rather rough winter we've been having. In particular, they want to see our favorite low energy solutions. Therefore, may we post instructables about warming up the climate in an attempt to stay warm? Thanks, Purduecer p.s. (Since I know in advance that some of you won't appreciate the humor, you should know that this post is done in jest. You have been warned.)

Topic by purduecer    |  last reply


Play Guitar with cut off finger tip

I cut of my left middle finger tip, and wanted to protect it while healing, and wanted to extend my finger some way so as not to have to retrain my old brain and finger, so did what is shown on the MS Word attachment (Text  and photo's showing "how to" with low cost materials).  Now to get back to playing the guitar!!  Hope this helps someone else by saving time and energy on poor or expensive options.

Topic by phild2k    |  last reply