Large motors and electronics classes

Hello,Is it just me, or there's something wrong with "Large motors" and "Electronics class" by randofo? It looks like there's nothing in comparison to just yesterdady, whereas I bought a premium account just to download his classes. Another problem is that I can not enroll or download any classes.Can You help me?

Topic by Emerid   |  last reply


Electronic repair after a voltage spike or power surge

So far I was lucky and never got a lightning strike or other power failure to induce high voltages into my house and equippment. But over the time I got several requests from friends to take a look at things after literally all connected electronics in their house got fried. In some cases there is only a total write off as due to a lack of surge protectors inside all unwanted juice made it's way into vital components. Like a brand new Samsung TV where the replacement of the power board was the only option - which makes you wonder... But in other cases, like microwaves, induction cooktops, computers and such I had some good success with the repairs. Guess it comes down to purs luck on both sides, power surge was not too bad and simple components on the input side failed quickly enough to prevent damage to microprocessors or other sensitive parts. Right now I have an induction cooktop here again that failed after a mains transformer in street blew up during a thunderstorm. I can tell it was bad as everything in the area of fried parts has a vaporizsed metal film on the surface and not much is left that was a surge protection. I cleaned all up, replaced the varistors and missing parts of the traces on the circuit board but the cooktop is not performing the way it should anymore :( At some stage during cooking it turns off with a meaningless error code stating the input voltage was out of bounds. So my next attempt was to literally remove every single component from the filter and power supply board to measure for any possible connections between the traces. By doing so I noticed several points where I had a quite high but measurable resistance in areas where there should be none. Mostly on the direct input side where the varistors tried to save things. So I used my Dremel in a tin drill press to cut the circuit board aourd the affect areas (where possible with a drill, otherwise with a thin grinding disk).. Sure enough I was greeted by charcoal colored dust in several areas. After removing all material until the dust was "clean"  tried again and this time all seems to work fine. I would like to use this topic to offer some help and guidance in case you have devices that suffered a severe power surge of some sort. Many of us either have no insurance to replace those items or even if you do the device might be expensive enough to try a repair despite getting it replaced. Trust me, even it went up in smoke there is still a chance to fix it in some cases and if proper protective circuits were in place the repair could as cheap as a few Dollars for replacement parts. To get useful advice the following things should be included in your request: Some clear pictures showing a close up of the affected parts - if there is visibale damage to be seen. A brief description of what happened, e.g.: lightning strike directly into the house or outside power lines, generator or inverter failure or simply that the power company stuffed up and your entire street was affected. Of course you will need the means to take the device apart for investigation and also some basic soldering skills or somehow how has and can assist you. But if you are up to the challange I am willing to help if possible.

Topic by Downunder35m   |  last reply


phone charger

My wall phone charger is busting up could i just make a usb charger out of it, and howdo i go about doing that, the phone is a samsung

Topic by Rotten   |  last reply


HELP - Arduino - "Expected constructor, destructor, or type conversion before '(' token"

I have only just received this Arduino UNO and am trying to teach myself the language. I thought it wouldn't be that bad as I am already familiar with python, however, I was getting loads of errors (most of which I have managed to solve from searching through forums) and have landed on this one. I get this error - "exit status 1 - expected constructor, destructor, or type conversion before '(' token"This is my code...int ledPin = 0; //declares all different pins for different segments of displayint ledPin1 = 1; int ledPin2 = 2; int ledPin3 = 3; int ledPin4 = 4; int ledPin5 = 5; int ledPin6 = 6; int ledPin7 = 7;int inPin = 5; //declares analogRead pinint alphaValue = analogRead(inPin); map(alphaValue, 1, 1023, 1, 4) //maps 1-1023 to 1-4void setup() { // put your setup code here, to run once: pinMode(0, OUTPUT); //declares pin types pinMode(1, OUTPUT); pinMode(2, OUTPUT); pinMode(3, OUTPUT); pinMode(4, OUTPUT); pinMode(5, OUTPUT); pinMode(6, OUTPUT); pinMode(7, OUTPUT); pinMode(5, INPUT); #define low digitalWrite(ledPin, LOW); //defines 'low' digitalWrite(ledPin1, LOW); digitalWrite(ledPin2, LOW); digitalWrite(ledPin3, LOW); digitalWrite(ledPin4, LOW); digitalWrite(ledPin5, LOW); digitalWrite(ledPin6, LOW); digitalWrite(ledPin7, LOW); }void loop() { // put your main code here, to run repeatedly: if(alphaValue == 1){ low digitalWrite(ledPin, HIGH); digitalWrite(ledPin1, HIGH); digitalWrite(ledPin7, HIGH); digitalWrite(ledPin2, HIGH); digitalWrite(ledPin5, HIGH); digitalWrite(ledPin6, HIGH); } if (alphaValue == 2){ low digitalWrite(ledPin1, HIGH); digitalWrite(ledPin5, HIGH); digitalWrite(ledPin4, HIGH); digitalWrite(ledPin6, HIGH); digitalWrite(ledPin2, HIGH); } if(alphaValue == 3){ low digitalWrite(ledPin, HIGH); digitalWrite(ledPin1, HIGH); digitalWrite(ledPin5, HIGH); digitalWrite(ledPin4, HIGH); } if(alphaValue == 4){ low digitalWrite(ledPin, HIGH); digitalWrite(ledPin1, HIGH); digitalWrite(ledPin5, HIGH); digitalWrite(ledPin4, HIGH); digitalWrite(ledPin6, HIGH); digitalWrite(ledPin7, HIGH); digitalWrite(ledPin3, HIGH); } }

Topic by LOU_DEW747   |  last reply


Help! mouse is being stupid!

HELP! My mouse has a clicking problem. In that; whenever i try to click, it doesn't work, and i find myself having to click multiple times with some force in order to get a result, but it's not consistent. Sometimes, it works straight off, and sometimes it takes upwards of 20 clicks, in order to get my computer to do anything. The problem's also isolated to only the left button, the right one's fine. I reckon it's just dirt or something in the mouse, but it's really inconvenient. Any ideas on what i can do to fix it? can i fix it? To give you something pretty to look at, here's a brass cog: Thanks for all the replies. I've just had the case off, and cleaned the rollers. I looked at the switch and there was no dirt packed around it. I clicked the switch without the case on and it still didn't work, which leads me to believe that it's actually the switch that's damaged, and therefore it's not worth trying to fix.

Topic by Vendigroth   |  last reply


Pinterest image rotated, bug?

Anyone having issues with images rotating when they try to share in Pinterest? When I try to share, some of mine have their images rotated 90 degrees. Attached a screen shot. Anyone know a solution to this? I emailed support to see if they have some suggestions.

Topic by jpmarth   |  last reply


Arduino or Teensy coil winder - any code already out there?

I am in the process of deciding on a normal 8bit Arduino platform or a Teensy for my coil winder project.A found some interesting projects online, some with the code available too.But I was wondering if someone already implemented more than just winding a coil in such a project?At Krux.org is a nice winder based on a normal Arduino while the Alba winder uses a Teensy already to gain more precision and speed I guess.Misusing some printer or CNC code to be able to generate coils by G-code sounded nice at first but turned out to be more complex than actually required.My goal is actually rather simple despite the size and all, so let me try to explain what I want to be able to do:Have a modular winder setup so basically any winding task can be done with just two stepper motors.One for the spin, one to position the wire.Additions like limit switches and external counters are nice but usually not required for such a task if the the code is properly done.As a basic winder like all the examples out there it should be possible to just enter the wire diamter and number of turns and then push a button to wait for the finnished coil.In theory things like pitch or spacing can be calculated externally and then entered as a fictive wire diameter but of course this would be not user friendly enough ;)For special RF coils it is often required to keep an even turn spacing as well as creating a coil with many layers.So far I have been unable to find any usable code for this purpose that does not require glue, guides or at least waxing the wire.Although this seems to be simple enough, when adding things like a display and counters it soon starts to get messy with timings and steps.Is there anything out there that works properly on a 8bit processor with reasonable speed?Originally I wanted to use an OLED with touchscreen.This turned out to be too much for the timing on a Mega.Without messing around with timers and interrupts it seem a 20x4 LCD is the only option.Even then the refresh must be in sync with the tart of a new turn as otherwise the motors miss some steps here and there.These things run a 3D printer or little laser cutter with ease, so I am definately doing something wong with my approach here LOL

Topic by Downunder35m 


Chaining 4 74HC595 shift registers together

I have a question about chaining 4 shift registers together.I am going to be sending data to four shift registers and my question is this, when all four are loaded and latched if I send more data is it possible to only send data to the first register in the chain without the others losing their values?

Topic by mbcharney   |  last reply


Need Help Bypassing Surf Control "ACCESS DENIED" At School??

Hey guys it's me again, and I got a problem! Looking for some advice again! When I'm at school pretty much everything is blocked with this surf control and it says access denied. How and is there a way that I can bypass this?? NOTE: I HAVE ALREADY TRIED PROXY'S

Topic by rickick   |  last reply


Ethernet selector between 4 different sources

Hello, I'm trying to design a switch box to switch between 4 different ethernet sources and output to one cable. I've checked around and believe I have developed a way to do it, but I am unable to find a switch that uses 4 smaller independent switches. The concept seems pretty straight forward but I don't want to use 16 switches. Please let me know if there is a switch which controls 4 independent connections or if there is a better way that I'm over looking. I look forward to your input! Best Regards, Zach G

Topic by lossofworth   |  last reply


Calibrate Compass

I have compass cmps-12 and i want to use it or calibrate it with my raspberry pi 3 using python. I already check on website but im not find it how to make it work. Please anyone knows how to calibrate compass cmps using python on raspi3 i need your help. :(

Topic by alharis   |  last reply


What to do with old vacuum tubes?

I recently found a really old tv in a crawlspace at work and I brought it home and salvaged 13 vacuum tubes out of it. I figured I could make some sort of cool project out of them like maybe a mad scientist lamp with LEDs or something. But before I actually start using them I wanted to brainstorm some more ideas of possible projects. So if anybody has any good ideas of cool things to do with vacuum tubes, let me know. Also, just out of a nerdy curiosity I was wondering what exactly vacuum tubes are designed to do, does anyone know?

Topic by cannedham160   |  last reply


Edf jet longboard how much thrust is needed

Hello i want to create a longboard that is powerd by an edf jet engine just would like to know how much thrust whould i need to me

Topic by paul the maker   |  last reply


Solar Powered Electric Wheelchair

I would like to put a Challenge out there for anyone to come up with. You see, I am in a wheelchair and I would love to go hiking with my son, but my chair can only go so far before it needs to be plugged back into a socket. I hate this, because it keeps me from going most places I want to go outdoors. But it dawned on me that if I had a Solar Powered Option to my chair, nothing could hold me back from being outdoors again. Ok yah,  it would help if I could redesign the platform & wheels too, but that's not the most important part... I NEED POWER. So, if anyone feels like taking on a new challenge and you are into Solar Power perhaps you could help me in this way. Thank You for your time in reading this, I hope to plant seeds of inspiration with all of you! May Love Light Your Way, Blessings! 

Topic by CherishJames   |  last reply


Need a USB-Controlled lock box

Google led me here, and I have to say that I'm very impressed with the ingenuity of the people here! Hopefully someone here can help me. I'm trying to find a USB-controlled box. The box can be quite small, as it needs to contain just a single key. As for the USB part, I can go two ways: first, I would need the state of the box lid (i.e. open or closed) to be sent via USB to the computer. Or, the second alternative would be that the box lid would only open if a certain signal was received via the USB cable. I can do the software programming to either send or interpret the signal, it's the mechanical part I can't figure out. I would happily pay someone to build this for me. Any suggestions? Thanks! Lee

Topic by Indecisiveo   |  last reply


Help connecting a Led strip to laptop power source.

Hi all, I want to illuminate my laptop keyboard and since the name of the device is LAPTOP meaning it is a mobile device, the tutorials on Youtube were not that promising ... and trust me I searched a lot. I work at a lighting company, we have tons of led stips ... the lowest is a 12V 7W LED strip and that's 7W per meter ... the closest CUT-HERE mark on the strip involves 6 SMD LEDs which is enough for me, this strip doesn't overheat, I put my finger on it.  The question is it possible to solder these 6 LEDS to the 12V DC power jack of the laptop or the USB power (+ / -) port ( on the mainboard ) .... as for the strip itself, I can install it on the Laptop Chassis, not necessary inside te Chassis in a very neat way. can it be done? is there any risk on the laptop ? .... will the USB still be usable ? ( again I don't want to plug a USB cable to power the LEDs I want to solder on the USB port on mainboard) Thank you

Topic by ElGringo82   |  last reply


Rescue a defunct phone charger

I have an old cell phone charger that is very handy for charging my Kindle Touch and a set of Bluetooth earbuds. It quit working one day after someone used it to charge a high demand device. I read that the capacitors in these often fail. I got two electrolytic capacitors at a surplus store for less than a dollar total. I had to use a fine saw to open the plastic case. The new capacitors were the same electrical size, but not the same physical size. Closing the plastic case was not an option. I covered all exposed electrical contacts with hot glue, which is an excellent insulator. It looks ugly, but I have a good versatile charger again. (The high voltage connections are buried deep down where my fingers can not reach. As best I can tell, the terminals covered with hot glue for insulation are all low voltage.)

Topic by Phil B   |  last reply


Tin Can Turbine Engine

Hello!               Let me give you some insight into this project (Tin Can Turbine). I'm going to school to get an Airframe and Power Plant Cert. (Aircraft Mechanic). I stumbled across this idea on YouTube one day in class and it really got my gears turning. It's purely for fun, and I'm not even sure if I have the technical skills to get it to work.             First of all the way a turbine engine works in layman's terms is Suck, Squeeze, Bang, Blow. The fan section sucks air in from the atmosphere, Where it is moved to a compressor section which squeezes the air into a tighter pocket of air; which makes the air hotter and more explosive. When the compressed air is pushed into the combustion chamber, it is more volatile than normal air due to the compression. When you add a fuel (jet fuel, gasoline, propane, kerosene etc...) it will ignite with the compressed air (given that there is a spark to get the fuel vapors to ignite). When the fuel/air mixture is lit the fire will continue to burn without an ignition source due to the explosive nature of the compressed air. And the gas (burnt fuel/air) is pushed out the exhaust. There are blades in the rear of the engine called turbine blades, which are connected to the front of the fan/compressor section, in some cases there are two or three turbine blades, which drive the fan, compressor sections independently. Due to the turbine blades being pushed by the exiting gasses, the engine becomes self sustaining. And through black magic, you have a jet engine!!!              I'm going to attempt to construct a jet engine (not a motor!) out of a "tin can". I'm really not going to use a tin can, I'm actually going to use .032" thick 3" wide, and about 6" long exhaust piping made out galvanized steel. It's a lot thicker than a typical soup can, thus willing to stand up to more heat. My proposed fuel source will be propane, because it's cheap, and the I'm sure that I'm capable of controling the amount of fuel going into the engine. I'm not sure yet how many fan blades vs. turbine blades that I'm going to use. Right now I'm in the experiment phase. My blades are going to be made out steel can tops, because there is very little cutting involved, beside the actual cutting and angling the blades. and they fit perfectly into the pipe. As for the fuel delivery i'm going to use a copper pipe that is approx .042 thick and hallow. I'm going to cap the end, and wrap it around the inside of can. There will be eight holes drilled into the copper, which should give it plenty of fuel at equal pressure all the way around the can, equals same heat all around.         As for the drive shaft, I'm not exactly sure of what to use for that. I may want to go with something hardened already, so the heat surrounding it won't melt it. (that's the hope anyways) . I'm also not sure of what sort of bearings I will use. I was thinking skate board bearing with the plastic crap around the middle taken out (so it doesn't melt and seize the bearings) and extreme high temp. white lithium grease for lube.          This is an experiment and I guarantee myself absolutely no success. But I think it will be fun to try. Questions or comments are more than welcome. Please, if you see any problems with the design, let me KNOW!!!

Topic by shawnpc   |  last reply


Does anyone do Automated Car Wash System by using Arduino with LDR?

I wish to know how am i able to write a program which i could control the water spraying, brushing and drying by using arduino.  My project is to use a laser pointer which will send the signal to the LDR and it will trigger the water to spray, brush and dry the toy car on the conveyor belt. Can anyone help me?? I'm a diploma student, and my supervisor is a mad man which who asked me to do such project which he doesn't know either.  The first image is how i think my circuit looks like The second image shows what i had done

Topic by ahchuan.ycc   |  last reply


PC Power Supply To Power CB Radio?

I have a cb radio my uncle gave me 12v 2-4 amps.. I have an old computer with a power supply with lines for 12v 6amps and 12v 8amps. is there anyway I can get this to power my cb radio without blowing the thing? EDIT I forgot to mention, this is a mobile cb radio, I'm trying to run it in the house, which is why I wan't to use a pc power supply to run it....

Topic by acer5050   |  last reply


How to use these salvaged cell phone parts?

I found a busted up LG Chocolate the other day (it still turned on but it had no network or anything so I took it) and decided to take it apart and use what I could find. What I got was: -A camera -A microphone -A nice speaker (the loud one that the ringtone plays through) -A little silver circle (what is it!?) -And all of the IC's. I really want to know how I can use the camera, can anyone point me in the right direction? Also, the phone has GPS, but I doubt I'll be able to remove the module without destroying it (especially since I don't know which one it is..) And where is the vibrating motor?!

Topic by Login258   |  last reply


Transformers connected in reverse

Hi can a transformer connected in reverse. if 230v to 12v transformer is connected in reverse,. will it generate around 230v Just some silly doubt. Actually i was trying to find a step up transformer.. which converts 6v to 24v. what exactly its called.

Topic by nominds   |  last reply


how to combine 2 Arduino codes together ?

Hello, I have a question. I need to combine my code for my Arduino project. I'm using a Arduino micro board .  The 2 codes are maxsonar and another is a flying drones coding. I'm lost and don't know how to combine the both of them as the maxsonar code will overwrite the flying drones code causing it unable to fly. Maxsonar code const int anPin1 = 0; const int anPin2 = 1; int triggerPin1 = 13; long distance1, distance2, cm1 ,cm2; void setup() {   Serial.begin(9600);  // sets the serial port to 9600   pinMode(triggerPin1, OUTPUT);   pinMode(A5, OUTPUT);   pinMode(A11, OUTPUT); } void start_sensor(){   digitalWrite(triggerPin1,HIGH);   delay(1);   digitalWrite(triggerPin1,LOW); } void Fading()//led1 { if (distance1 == 9) {    analogWrite(A5,25.5);     delay(10); } else if (distance1 == 8) {    analogWrite(A5,76.5);     delay(10); } else if( distance1 == 7) {    analogWrite(A5,153);     delay(10); } else if(distance1 == 6) {    analogWrite(A5,255);     delay(10); }   }   void Fading2()//led1 {   if (distance2 == 9) {    analogWrite(A11,25.5);     delay(10); } else if (distance2 == 8) {    analogWrite(A11,76.5);     delay(10); } else if( distance2 == 7) {    analogWrite(A11,153);     delay(10); } else if(distance2 == 6 ) {    analogWrite(A11,255);     delay(10); }   }   void read_sensors(){   /*   Scale factor is (Vcc/512) per inch. A 5V supply yields ~9.8mV/in   Arduino analog pin goes from 0 to 1024, so the value has to be divided by 2 to get the actual inches   */   distance1 = analogRead(anPin1)/2;   distance2 = analogRead(anPin2)/2; } void count_in_cm() {   cm1 = distance1 * 2.54;   cm2 = distance2 * 2.54; } void print_all() {     if( distance1 <10 && distance2 >=10 )   {   Fading();   analogWrite(A11,0);   Serial.print("Sensor1: Warning");   Serial.print(" ");   Serial.print(" ");   Serial.print("S2");   Serial.print(" ");   Serial.print(distance2);                                                                                                                                                                                                                                                                                                              Serial.print("in");   Serial.print(" ");   Serial.print(" ");   Serial.print(cm2);   Serial.print("cm");   Serial.println();   delay(700);     }   else if(distance1 >= 10 && distance2 < 10)   {   Fading2();   analogWrite(A5,0);   Serial.print("S1");   Serial.print(" ");   Serial.print(distance1);   Serial.print("in");   Serial.print(" ");   Serial.print(" ");   Serial.print(cm1);   Serial.print("cm");   Serial.print(" ");   Serial.print(" ");   Serial.print("Sensor2: Warning");   Serial.println();   delay(700);   }   else if (distance1 < 10 && distance2 < 10)   {     Fading();     Fading2();     Serial.print("Sensor1: Warning");     Serial.print("  ");     Serial.print("Sensor2: Warning");     Serial.println();     delay(700);      }   else   {   analogWrite(A11,0);   analogWrite(A5,0);   Serial.print("S1");   Serial.print(" ");   Serial.print(distance1);   Serial.print("in");   Serial.print(" ");   Serial.print(" ");   Serial.print(cm1);   Serial.print("cm");   Serial.print(" ");   Serial.print(" ");    Serial.print("S2");   Serial.print(" ");   Serial.print(distance2);   Serial.print("in");   Serial.print(" ");   Serial.print(" ");   Serial.print(cm2);   Serial.print("cm");   Serial.println();   delay(700);   } } void loop() {   start_sensor();   read_sensors();   count_in_cm();   print_all();   delay(200); //This is the equivant of the amount of sensors times 50.  If you changed this to 5 sensors the delay would be 250. } flying drone code #include #include // channel declaration Servo channel1; // throttle Servo channel2; // yaw Servo channel3; // pitch Servo channel4; // roll Servo channel5; // ball drop servo // PWM freq setting, should it be 62.33Hz? const int PWMConst = 20022;//50HZ // global variables byte incomingByte, incomingByteUSB; byte rcBuffer[32], usbBuffer[12]; int i = 0, j = 0, STATE = 1; int Flag = 0, usbFlag = 0; unsigned int thr_16int = 0, yaw_16int = 0, pit_16int = 0, rol_16int = 0, gear_16int = 0; unsigned int thr_16int_usb = 0, yaw_16int_usb = 0, pit_16int_usb = 0, rol_16int_usb = 0; float throttle = 1000, roll = 1500, pitch = 1500, yaw = 1500; int gear = 1500; float currT, prevT = 0, _flagHover, throFlag; // functions declaration void extract_RC_cmd(void); void extract_USB_cmd(void); void translate_RC_cmd(void); void translate_USB_cmd(void); void RC_Neutral(void); void reset_usb(void); void reset_rc(void); void hover(void); void sonar(void); void setup() {   // setting registers   TCCR1A = _BV(COM1A1) | _BV(COM1B1);   TCCR1B = _BV(WGM13) | _BV(CS11);   ICR1 = PWMConst;   // set PWM I/O ports   channel1.attach(6);    // throttle   channel2.attach(9);    // yaw   channel3.attach(5);    // pitch   channel4.attach(10);    // roll   channel5.attach(11);   // fail safe-attit   //init usb buffer   usbBuffer[0] = 0x03;   usbBuffer[1] = 0xE8;   usbBuffer[2] = 0x0D;   usbBuffer[3] = 0xAC;   usbBuffer[4] = 0x15;   usbBuffer[5] = 0x7C;   usbBuffer[6] = 0x1D;   usbBuffer[7] = 0x4C;   reset_rc();   reset_usb();   Serial1.begin(115200);   // rc Rx data in   Serial.begin(115200);     // USB } void loop() {   // accept serial data from computer   if (Serial.available() > 0)   {     incomingByteUSB = Serial.read();     if (incomingByteUSB >= 0x03 && incomingByteUSB <= 0x07)     {       usbFlag = 1;     }     if (usbFlag == 1)     {       usbBuffer[j] = incomingByteUSB;       j++;       if (j == 12)       {         usbFlag = 0;         j = 0;         extract_USB_cmd();       }     }   }   // accepte serial data from RC   if (Serial1.available() > 0)   {     incomingByte = Serial1.read();     if (incomingByte >= 0x80 && incomingByte <= 0x87)     {       Flag = 1;     }     if (Flag == 1)     {       rcBuffer[i] = incomingByte;       i++;       if (i == 32)       {         Flag = 0;         i = 0;         extract_RC_cmd();       }     }     // Serial.print(rcBuffer[i]);   }   // STATE MACHINE   switch (STATE)   {     case 1:       translate_USB_cmd();       reset_rc();       //Serial.print();       break;     case 2:       translate_RC_cmd();       reset_usb();       //Serial.print('R');       break;     case 3:       landing();       break;     default:       RC_Neutral();       break;   }     // output PWM   channel1.write(throttle);   channel2.write(yaw);   channel3.write(pitch);   channel4.write(roll);   channel5.write(gear); } // local functions void extract_RC_cmd() {   if (rcBuffer[0] >= 0x80 && rcBuffer[0] <= 0x87) // double check throttle range   {     thr_16int = rcBuffer[0] << 8 | rcBuffer[1]; // 16 bit throttle     // Serial.print(thr_16int);   }   if (rcBuffer[4] >= 0x19 && rcBuffer[4] <= 0x1E) // double check yaw range   {     yaw_16int = rcBuffer[4] << 8 | rcBuffer[5]; // 16 bit yaw     //Serial.print(yaw_16int);   }   if (rcBuffer[16] >= 0x09 && rcBuffer[16] <= 0x0E) // double check yaw range   {     rol_16int = rcBuffer[16] << 8 | rcBuffer[17]; // 16 bit yaw     //Serial.print(rol_16int);   }   if (rcBuffer[20] >= 0x11 && rcBuffer[20] <= 0x16) // double check yaw range   {     pit_16int = rcBuffer[20] << 8 | rcBuffer[21]; // 16 bit yaw     //Serial.print(pit_16int);   }   if (rcBuffer[22] >= 0x21 && rcBuffer[22] <= 0x26) // double check gear range   {     gear_16int = rcBuffer[22] << 8 | rcBuffer[23]; // 16 bit pitch     //Serial.print(pit_16int);   }   // state   if (rcBuffer[24] == 0x37 && rcBuffer[25] == 0xE0)    // Fmode SW state 1: Auto   {     STATE = 1;   }   else if (rcBuffer[24] == 0x34 && rcBuffer[25] == 0x00) // Fmode SW state 2: Manual   {     STATE = 2;   }   else if (rcBuffer[24] == 0x31 && rcBuffer[25] == 0xB4) // Fmode SW state 3: Emergency landing   {     STATE = 3;   } } void extract_USB_cmd(void) {   if (usbBuffer[0] >= 0x03 && usbBuffer[0] <= 0x07) // double check throttle range   {     thr_16int_usb = usbBuffer[0] << 8 | usbBuffer[1]; // 16 bit throttle   }   if (usbBuffer[2] >= 0x0B && usbBuffer[2] <= 0x0F) // double check yaw range   {     yaw_16int_usb = usbBuffer[2] << 8 | usbBuffer[3]; // 16 bit yaw   }   if (usbBuffer[4] >= 0x13 && usbBuffer[4] <= 0x17) // double check pit range   {     pit_16int_usb = usbBuffer[4] << 8 | usbBuffer[5]; // 16 bit pitch   }   if (usbBuffer[6] >= 0x1B && usbBuffer[6] <= 0x1F) // double check rol range   {     rol_16int_usb = usbBuffer[6] << 8 | usbBuffer[7]; // 16 bit role   }   // state   if (usbBuffer[10] == 0x2A && usbBuffer[11] == 0xF8)   {     //state = 1; // auto   }   else if (usbBuffer[10] == 0x2C && usbBuffer[11] == 0xEC)   {     STATE = 3; // emergency landing   }   else if (usbBuffer[10] == 0x2E && usbBuffer[11] == 0xE0)   {     STATE = 0; // default rc neutral   } } void translate_RC_cmd(void) {   throttle = (thr_16int - 30752 ) / 2.016;   yaw   = (9243 - yaw_16int) / 1.382;   pitch = (pit_16int - 3047) / 1.378;   roll  = (5129 - rol_16int) / 1.373;   gear  = (gear_16int - 7506) / 1.165;   throttle = min(2000, max(1000, throttle));   yaw      = min(2000, max(1000, yaw));   pitch    = min(2000, max(1000, pitch));   roll     = min(2000, max(1000, roll));   gear     = min(2000, max(1000, gear)); } void translate_USB_cmd(void) {   throttle = thr_16int_usb;   yaw = yaw_16int_usb - 2000;   pitch = pit_16int_usb - 4000;   roll =  rol_16int_usb - 6000;   //Serial.print(thr_16int_usb);   throttle = min(2000, max(1000, throttle));   yaw      = min(2000, max(1000, yaw));   pitch    = min(2000, max(1000, pitch));   roll     = min(2000, max(1000, roll)); } void RC_Neutral(void) {   throttle = 1000;   yaw = 1500;   pitch = 1500;   roll = 1500; } void landing(void) {   throttle = throttle - 1;   if (throttle <= 1000) throttle = 1000;   yaw = 1500;   pitch = 1500;   roll = 1500; } void reset_usb(void) {   thr_16int_usb = 1000;   yaw_16int_usb = 3500;   pit_16int_usb = 5500;   rol_16int_usb = 7500; } void reset_rc(void) {   thr_16int = 0x8000;   yaw_16int = 0x1C03;   pit_16int = 0x13FD;   rol_16int = 0x0C07; }

Topic by singno123   |  last reply


How to convert analog MQ4 sensor output to ppm

Hi everyone,  My final year engineering involves a rover that can sense methane gas. Initially the idea was to just detect the gas as digital input but now i wanna do a bit more. I've searched all over the internet on how to convert the analog values to ppm, but couldn't understand any of it. I'd be really great-full if someone could give me the formula or the code to do this.  I don't intend on calibrating the sensor to find precise answers, just a rough picture of the ppm values is enough to begin with. Thanks a lot in advance. 

Topic by ZeeshanA27   |  last reply


How to install an LED on/off Indicator to Monitor 24v AC line?

I want an LED indicator that will lite when an AC circuit is on. The line/output is 24vAC at .5A. This is an irrigation controller, which sends 24vAC to activate a water/sprinkler controller valve.   I need a basic cicuit design and/or instructions. Googling led me to the 3 pages below, but I am not sure what to do. Any advice appreciated.  Thank you. http://www.boat-project.com/electro/panellight.htm http://www.discovercircuits.com/DJ-Circuits/aclinepilotled1.htm http://www.electro-tech-online.com/datasheets-manuals-parts/41821-1n4004.html

Topic by 222fbj   |  last reply


alternative ignition of thermite

Allright im looking for information on a number of different ways to ignite thermite. sure we've all heard of magnesium and yes it's usually third or fourth time is the charm also potassium permanganate which is pretty cool too and the ever popular sparkler of course lots of companies have taken out the magnesium chlorates and perchlorates from these sparklers and are now selling crappy ones without hazmat fees for them so they don't work worth a crap. i read an article from a guy stating he used simple visco fuse to light it even though ive heard it won't work but perhaps it depends on the mesh as in much finer. i use the dark german aluminum about 625 mesh and it will coat any and everything it touches. really though guys let's come up with some ways to lite thermite outside of tradition and share these methods of doing so along with how to obtain materialsin conventional and unorthodox ways because without frst time reliable ignition it's just no fun. also the first fire mix, much like the thermite ignition mix at united nuclear what exactly is it made of and how are some ways the monetarily cahllenged can obtain it and of course the not so challenged.

Topic by pyracantha   |  last reply


Real Tone Cable (Rocksmith) 1/4" to USB adapter

I'm doing a project. Attempting to replicate the rocksmith real tone cable. Yeah it's not going to be easy... I need to; amplify the signal coming from the guitar, then find an Analog to digital Converter, then figure out how to conect via USB, then I want to write a program on the computer... but thats a looooonnnng way off. I figure the voltage coming from the guitar output is about 500mv but im not sure because it's too small to read with my meter. What kind of transistor or op-amp can I use to get the voltage to around 10v where an ADC can read it? If you have any advice on what kind of ADC to use please let me know. I think 10v is around the min for ADC's input range. Would it be a better idea to amplify the signal further so i can use a different ADC? If anyone has a real tone cable they feal like opening up... let me know whats inside eh? Thanks for any help

Topic by amplifihip   |  last reply


WTV020M01 sound module need help

Hi I recently bought a cheap WTV020M01 (WTV020SD) sound module from china. i know you get what you pay for but i cant really afford to spend big on that kind of electronics or else i would have. Any ways my problems is i have wired up the component as instructed, loaded up the audio files as per instruction on the micro SD card and connected it to power and hit the play pin. And NOTHING happened. i then tested to see if it was getting power and yes the power was fine. After being frustrated i tried moving around the power connector and discovered that if i placed the power in the reset pin the module lit up as if it was working and all the buttons worked but still no sound. i am not sure that as its a cheap component its a dud or have i just wired it up up wrong, or an i missing something like an amp. any help would be good thanks. here is some links to the component specs http://www.datasheetq.com/view.jsp?pn=WTV020M01&fac;=ETC&lang;=en

Topic by solarsun   |  last reply


The file may be corrupted, located on a server that is not responding, or read only.

Hello, I have Win 7 and Excel 2007. When I try to open my .xls files I always get the same error message: The file may be corrupted, located on a server that is not responding, or read only. I`m sure that all my files are on the C disk and they are not read only…just week ago I was able to open it. My friend adviced me to make a scan disk and check my computer for viruses, but it didn`t help in the issue. Can you give me some tips how could I solve this problem?

Topic by AddyMaddy   |  last reply


ATX power supply to run a raspberry pi

Has anyone used a ATX power supply to run a raspberry pi with peripherals such as hdd's and dvd drives. If you have what considerations should I take into account, I found this howto here https://www.instructables.com/id/ATX--%3E-Lab-Bench-Power-Supply-Conversion/ but it's for making a lab power supply so not exactly what I need. Thanks

Topic by donestuff   |  last reply


Technology Makes Cheap Drinking Water from Air

INTRODUCTION:   How can we best apply basic technology to help the underprivileged and/or disaster-hit countries like Haiti? Daily hygiene and nourishment are among the top needs for disaster ridden regions!  Simply put, no water means no hygiene. The Romans understood that over two millennia ago and created their complexly beautiful aqueduct networks for handling both fresh and wastewater! Other ingenious water systems like “air wells” have been found in the city of Theodosia (cf: discovered in 1900 by Zibold, see Zibold’s Collectors/Dehumidifiers) dating back to Greco-Roman times during the Byzantine Empire. These were strictly passive systems that naturally dehumidified air, collecting its potable water in underground basins. All air, even in relatively dry desert regions, will precipitate or release its natural water content (initially in the form of vapor) through condensation when it hits its dew-point temperature and below. That means you “chill” it to an appropriate level that is anywhere from 5F to 50F below its current air temperature, depending upon how much water content (relative humidity) it has locally absorbed. The condensation of the water vapor releases its internal latent heat (reheating the cooled air) which must be constantly dissipated (absorbed by something) in order for water formation to steadily continue. So how do we dissipate this resultant vapor-heat and chill our air without any infrastructure or electricity, in an underprivileged or disaster-ridden region? We simply bury a long cast-iron or any metallic drain-pipe sufficiently underground where the temperature of the earth is naturally held to a constant at around 45F to 55F. That’s our “free” chiller gift from nature. One end of the pipe, Figure-1,  sticks out of the ground to suck-in local outside hot air, and the other end dumps cooled dry air and water into an underground cistern where it gets collected and is piped to the surface to both exhaust the cooled dry air and connect to a water pump. We need a hand operated water pump to lift up the water above ground, and we need an electric fan to constantly pump air through the ground-chilled piping system. We can even force the cooled piped air to exhaust into a tent-like structure where it provides air conditioning as an added bonus, but this adds the penalty of both power and the increased fan size necessary to drive our required airflow further into an enclosure! While this concept is not “passive” (requiring electricity to work) like those clever Byzantine air-wells, it will produce much more potable water and within a smaller volume than those elegantly passive historic devices. The electricity for our fan power requirements can be produced by any one of four ways using either “active” or “passive” techniques: 1) An active playground or bike-pedaling-person or oxen-driven mechanism-generator, 2) A passive windmill generator, 3) A passive solar energy collection system that directly generates electricity, or 4) A passive thermo-electric system that directly generates electricity using the Peltier effect, operating solely on temperature differences between the cell’s top and bottom surface (we jury-rig the cool pipe and hot ambient air to contact separate sides of the cell). Depending upon how much water is needed, the required air volume plus pipe length and diameter, together with the fan will be sized accordingly. We can also configure groups of parallel fan-driven air pipes that are radially fed into the cistern. The sizing of this underground network depends upon the ambient air’s local average temperature and relative humidity (how much water gets absorbed into the air) plus buried pipe depth and effective underground temperatures achieved. The basic concept is one where we “wring” water from air at some given humidity content. The higher its relative humidity the more water is recovered from the air. The air-wringing process simply chills the air as it scrubs along the cooled internal pipe surface until it starts to rain inside the pipe from condensation onto its surface. The condensation is like the dew that forms on car windows, grass or any cooled surface in the early morning, before the sun comes out and evaporates the dew back into the heating air. A further bonus is that our dew-formed water is naturally distilled and very clean. It is potable water ready to drink without the need for additional sterilizing agents. Of course, we must make sure that the interior piping and cistern network is biologically cleansed before burying it underground. The hand pump with its 10 to 15 foot extended piping to reach the underground cistern must also be cleansed. The beauty of this constantly replenishable water supply is its convenient underground installation anywhere! After the in-ground installation, we have a virtual, partially passive, no moving parts, non-breakdown system containing above ground total access to all moving parts that could breakdown, namely the water pump and electric fan. Also, it is easily maintained, with few moving parts (water hand-pump and electric fan) and basically lacking any technical complexity which makes it ideal for technologically backward regions. The example below uses a relatively small industrial fan moving air at 1500 CFM (Cubic Feet per Minute) with a DC motor rated at 1kW. This fan together with our underground piping system will conservatively generate 12 GPH (Gallons Per Hour) of potable drinking water without need for any purification chemistry. Based on an average electrical cost of 14-cents per kWh (kilo-Watt hour), the typical commercial distillation of one gallon of drinking water costs roughly 35-cents as compared to our cost of only 1.2-cents. Furthermore, if we decide to go green and use solar energy for generating our water, it would effectively cost us nothing beyond the initial installation! USING A PSYCHROMETRIC CHART TO SIZE OUR WATER SUPPLY: The following gets a little technical and is only provided for those die-hards who are truly interested in how the science works. Those non-technically schooled may skip this part and not miss the basic concept. Figure-2 shows a Psychrometric Chart for air. This chart summarizes some of the basic thermodynamic properties of air throughout its typical range of operating temperature. The chart uses six basic air properties that defines the physical chemistry of water evaporation into air:  (1) the enthalpy or total energy contained within a unit of air which is a combination of its internal and external energy, expressed as the amount of BTU-energy per unit mass of reference dry-air, (2) the specific volume or the ratio of a unit volume of local air to its mass of reference dry-air, (3) the humidity ratio or the amount (mass) of moisture in a local unit of air divided by its reference mass of dry-air, (4) the percent relative humidity per unit of local air, or the mass ratio (expressed in percentage form) of the partial pressure of water vapor in the air-water mixture to the saturated vapor pressure of water at those conditions (the relative humidity depends not only on air temperature but also on the pressure of the system of interest),  (5) the dry-bulb temperature or the locally measured air temperature, and (6) the wet-bulb temperature or saturation temperature which is the local air temperature experienced during constant water evaporation (a wet-bulb thermometer is typically used:   a thermometer that measures resultant temperature while wrapped in a water wet-gauze and spun to generate local air movement and max-evaporation)  1.0   The Process and A Sample Calculation Our Psychrometric Chart uses six thermodynamic properties that help to determine the amount of water available for extraction from the local ambient air as a function of its temperature, pressure and relative humidity.  Let’s assume the following local ambient conditions for the region we plan to construct our water system at:  (1) Typical daily air temperature Td = 106F and one atmosphere pressure assumed at sea-level, (2) Relative Humidity, RH = 55%, and (3) Typical underground temperature down at six feet is measured at Tu=55F (at 12ft. it drops to ~45F). This yields the following calculated results for obtaining a steady-state supply (changes at night) of water to fill the cistern:      1)      In our example, the “local” air (dry-bulb) temperature is Td=106F, at a relative humidity of RH= 55%.  Fig-2 indicates that the resultant Humidity Ratio is HR= 0.0253 Lbs-water/Lb-Dry-Air (intersection of Td=106F line and RH=55% line, then horizontal to HR value).  We then determine the “gulp” of air volume containing the HR Lbs-water which corresponds to the point of intersection of Td and RH. Interpolating on specific volume “mv” yields mv=14.7 ft3/Lb-Dry-Air (this value sets the optimum unit airflow for our given ambient conditions, and creates a ballpark pipe length to diameter ratio needed later). It represents the basic unit of air volume that will enter our underground pipe per given time, and ultimately defines the size of our fan and piping network. For increased water creation, multiples of this unit volume will scale up the additional amounts of water that can be collected. 2)      As the inlet air cools down to a temperature of Tu=55F, from contact with the relatively cold underground pipe, we follow the constant enthalpy line (red upward left-diagonal) from the intersection of Td and RH to its saturated air temperature condition of Ts= ~88F, which is its dew-point temperature where the corresponding local RH=100%.  At this temperature or under, the air precipitates and releases its moisture content, resulting in water condensation onto the pipe walls.  Since our air will chill to a final pipe temperature of Tu=~55F, we follow the RH=100% saturated curve (green) down to yield an HR=~0.009 Lbs-water/Lb-Dry-Air. This is how much water is left in the air when it gets to 55F.  Therefore for every pound of local outside air that enters the pipe, mw=0.0253 – 0.009 = 0.0163 pounds of absolute pure, distilled potable water precipitates onto the inside pipe wall (per pound of dry air that is cooled and dehydrated) to gravity-flow out the pipe exit and into the cistern. 3)      We now convert pounds of air per unit time into a unitized volumetric airflow that yields gallons of hygienically pure potable water production per unit time. For every Va=100 ft3 of local volumetric air movement per minute (CFM) through the pipe, which translates into ma=Va/mv= 100/14.7 = 6.8 lbs. of dry air per minute or 6.8 * 60 = 408 lbs. per hour (PPH), to yield a water-flow of mwf=ma * mw = 408 * 0.0163 = 6.65 PPH or 6.65/8.345 = 0.8 GPH of water.  An industrial fan rated at 1kW DC will typically move 1500 CFM at a pressure of 8-iwc, to continuously produce 15 * 0.8 = 12 GPH of pristine potable water. 4)      Not shown here are the design details of sizing our pipe, fan and solar collection system for electric power requirements using heat transfer principles coupled with a thermodynamic heat balance, and aerodynamic fan performance assessment. These details help to size the electric power generation requirements plus margin used to properly size a solar collector containing further margins for overcast days. The engineering involved here is straight forward but beyond the scope of the current project.

Topic by RT-101   |  last reply


Can I wire RGB LED flex ribbon with cat5?

I made 4 custom light boxes using rgb led flex ribbon, can I power and wire these using cat5 cable or is that too thin for 6 amp 12v power supply these things are going to? the longest run from one box to the powersupply will be 20 feet

Topic by Negativecreep0   |  last reply


Awesome stuff you can do with high-speed internet?

So I recently thought up the idea that I can get free high speed internet at the computers at the public library in town (I can only get dial-up at my house). I have to ride my bike a few kilometers to get into town but I can get like 100 KB/s!! Gah, I wish I'd thought of this a long time ago. When I went in yesterday I just downloaded a bunch of crap. I got 60 MB of stuff, mostly podcasts, in about ten minutes. That would've taken me over five hours to get on my dial-up. But is there any thing else that I should try, other than just downloading a buttload of stuff? I've never had broadband, so I'm kinda just dumbfounded by the possibilities.

Topic by Aeshir   |  last reply


Arduino MCP2515 connecting to Volkswagen

Hello, I'd like to connect an arduino with mcp2515 with my Volkswagen Golf 6, in order to look whats going on in the CAN Bus network  :) This is the MCP2515 breakout is used (chinese clone): [attachment 1] Therefore I used this script:[ https://github.com/coryjfowler/MCP_CAN_lib/blob/master/examples/CAN_receive/CAN_receive.ino I did the wiring like this one [attachment 2] After uploading the source code to my arduino nano, I got the following message: [quote]Entering Configuration Mode Successful! Setting Baudrate Successful! MCP2515 Initialized Successfully! MCP2515 Library Receive Example... [/quote] I think everything should be fine. But I didn't see any canbus message there. Which steps do I have to take, to see any message on the CAN Bus. Whats the setting for can bus communication (baud rate, oscillator mhz...)? Thanks in advance BR, Julian

Topic by julianpe   |  last reply


Does nobody modify vacuum cleaners?

Lately I've been looking for vacuum cleaner mods. I've done several Google searches and Instructables searches, and found only this one bag-to-bagless conversion. I expected there to be at least a handful of pages on vacuum cleaner modification on the Web. Does anybody have any suggestions on where to look?

Topic by PointyOintment   |  last reply


arduino

Hi,    iam using the arduino uno in my project.The project is to display the temperature and humidity in lcd and ethernet and stored in the sd card in every 1 minute ,using the dht 22 sensor.But the lcd display is not working simultaneously with the sd .Hereby i am attaching the code.pls hlp me to trobleshoot the problem.

Topic by sruthys   |  last reply


Arduino bluetooth HC-05 game controller to control Android games

I got a new project to make a pretty unconventional (fitness) game controller using Arduino to control Android games. The ideea is the following: using the Android VR technology (Cardboard or Dive) it was pretty simple to create a basic game (3d world to walk around) using Unity3D and Dive SDK. If you put on the Google Cardboard, the VR experience begins. But still so few devices are on the market, which give you back the control over your smartphone, which now is fixed in front of your eyes. I want to use this and make a fitness app which will be controlled by running on a treadmill (or using a workout bike). Something like the old Nintendo Wii and the running game from Sports. Or a game like Temple Run, in which running the treadmill faster, gets you faster in the game. For this I would like to create a game controller which records the leg movements, direction, body position, etc. which would then influence the actions in the game. A lot of details I still need to work out. So the question is, does anybody know of a guide or tutorial on how to create a game controller like this, using an Arduino a bluetooth module like HC-05. The controller should not be bound to a specific game or 3rd party app, should work like a usual game controller for android (connecting to some bluetooth android game profile?). There are many android game controllers out there which dont need a special android driver/3rd app to control any game. So this has to work somehow. So how can I programm an Arduino to send (once paired) the same events a bluetooth gamecontroller (or bt keyboard or mouse) sends, which doesn't need any 3'rd party Android app to be able to send basic key pressed events to a random game. Best regards, F

Topic by fcfelix   |  last reply


Stupid Question: (soldering iron) = (woodburning iron)

I have a woodburner and I was wondering if I could use it as a soldering iron? Is it just getting hot enough to melt the solder that I have to worry about or is there some kind of load problem with using a woodburner for this purpose? need help!! (obviously)

Topic by bardon08   |  last reply


Fixing broken power supply?

Have been using my FolgerTech Prusa i3 printer for a few weeks now, and was doing some cable management when, "Pop!" goes the power supply. I had the mains power unplugged from the power supply, and didn't connect or disconnect any other wires. I was working on hiding some endstop cables (That i will probably just go ahead and shorten later) and when i was satisfied with the job, i went ahead and plugged the printer back in. Pop! Immediately unplugged the printer to prevent further harm. Sounded as if a .22 went off in my room. No burning or acidic smell, just a pop. From the sound of it, i assumed it had to be the power supply. So i examined everything, the ramps boards, the arduino, etc. Nothing. Everything looks fine. I remove the power supply from the printer, and plug it back in. LED light stays off, no more sounds. Using my multimeter, i checked the output voltage, and sure enough, it's dead. So i go ahead and crack the power supply open, and begin examining the components. Nothing. Absolutely nothing. All the caps look fine, no charred marks, no scorches or burns. No component looks any different than its functional counterpart. Beyond the cheap chinese soldering job, the board looks fine. So i take the board off of the metal plate to examine the backside. Solder splatter everywhere, but no shorts or anything (It worked for about 3 weeks.). I do, however, notice that there is a nice dry joint on one of the large capacitors. Thinking that might be the problem, i go ahead and fix the joint by reflowing the solder. Put it back in its case, plug it in, nothing. Anyone have any idea what may have happened? I am a student who currently doesn't have 30$ to fork out for another power supply, but do have an arsenal of spare electronic components. (Will eventually buy another power supply, but currently don't have money to set aside for it.) What should i look for? What blew up? Why does it not work anymore? If any more info is needed, let me know!

Topic by RocketPenguin   |  last reply


Battery pack rebuild

I read the instructable on rebuilding the 14.4v cordless tool battery pack and I've done it before with a decent Milwaukee battery. Now I have one that the thermistor is shot. It said 6k8j on it. It was a disc like an advil pill with two leads. Where would I find a replacement? I've looked on digikey.com but can't make heads or tails of it. I imagine you would want it to stop charging at 70 degrees c like a lot of r/c packs do.

Topic by jdubs   |  last reply


How to earn a quick Buck!?!?!?!?!?!?

I having money trouble and i need to know how i can earn a quick buck?!?!?!?

Topic by killer7   |  last reply


wiring a dpdt switch like a dpst switch

I need a DPST rotary switch so that i can turn on two circuits at once but the closest i've been able to find with appropriate ratings is a DPDT switch, is it possible to wire it up to my circuits in such a way that it works like a DPST switch? I've attached an example diagram i found of a DPDT switch, if i was to disconnect the lamp from pin 1 and the buzzer from pin 2 would the first position of the switch become Off and the second position become On powering the LED and speaker? also assuming that the LED and speaker only connected back to their respective batteries and not to each other, could i attach a low voltage battery to pin 3 for the LED and a higher voltage battery to pin 4 for the speaker without causing damage?

Topic by ambientvoid   |  last reply


Post your Computer Setup

I'm surprised nobody's done this yet. Post your desktop/computer/workstation setup. Pics of mine below:

Topic by Firebert010   |  last reply


Help Identifying unknown Transformer

Hello I got this transformer from an old ups, there are four wires on the primary side black, blue, green , yellow and two on the secondary red and blue. This transformer used to charge 12v 7.5ah battery also converts it back to 220V in backup mode. Tried testing its output and got this (Mains 220V) Black to ground Blue to mains-> 7.9v on secondary Green->5.5v Yellow->6.5v Connecting Blue and Green to mains and it was a shot circuit and blown my fuse. I want to use this for making a decent power supply 12v+ output, is this possible? I also saw this video https://www.youtube.com/watch?v=mc4GZM-kFUY&hd;=1 The guy is using his ups transformer for generating hv to power cfl using tip122, i am not sure how to do this using my transformer. I need to make use of this transformer somehow, otherwise its just eating dust at my home.

Topic by Clarkdale44   |  last reply


jeep

Jeep skipping problems

Topic by larry3deer   |  last reply


Gaining free game credits with Jackpot Credit Device?!? (Hack or Smokin Crack?)

I was surfing the web and came across these cheating 'devices.' The claim is that somehow these black boxes manipulate the system into giving additional free credits as you're feeding the machine and/or causing the machine to more likely pay out. I am 99.5% sure this is total BS. Still the chance to play TimeCrisis 3 for hours and hours at a deep discount sounds awesome. ;-)Here is the descriptions on the website: Third and Fourth Items downThis device was developed through years of research on machines and by beta testers. It has potential to jackpot or give credits in gambling machines and fruit machines. When put in a small box and powered by 1 or 2 (9VDC) batteries, it will fit in your pocket or up your sleeve. This unit can be used as a contact induction device (soundless arc system) or EMP induction device via magnetic induction pulses which are also soundless. This device uses in excess of 1000volts so use caution. There are two ways to use this device in either mode: as you are inserting coins, adding credits or adding money to the machine you activate the device and it will cause the credits to jump higher. The other way to use the device is to use it while you are playing and you have great odds of hitting a jackpot or winning. Kit includes all parts to build a complete unit to operate in either mode.The completed kit can be used in two modes: vacuum arc induction or magnetic induction coil mode. The device is so small you will need to coat it with epoxy and electrical tape, as a box would take up too much space. It is powered by one 9v battery, it will fit in your pocket, up your sleeve or in the palm of your hand. This unit is a contact induction device (soundless arc system) or can be converted into an EMP induction device via magnetic induction pulses which are also soundless and generated by connecting a small pinwheel coil to the output probes. This device generates around 500volts so use caution. There are two ways to use this device: as you are inserting coins, adding credits or adding money to the machine, you activate the device and it will cause the credits to jump. The other way to use the device is to activate it while you are playing and you have great odds of hitting a jackpot or winning. Kit includes all parts to build one complete unit, epoxy and tape not included.

Topic by GrumpySteelMan   |  last reply


Is it possible to modify a soft-power button?

I'm not sure if this is the correct place to post this (apologies if its not).... I have a small stereo receiver (Lepai S-60) that I use to power speakers in my kitchen and it works well, but the stereo requires that I press the power button on it or the remote every time I want to turn it on.  I was hoping to hook it up to a WeMo switch so that I could turn it on/off via Google Home, but the fact that its a soft power button means that even if the switch turns on or off, the radio doesn't remember what state it was in last. Is there a way to modify the circuit board so that the receiver is always on and thus, I could control it via the WeMo switch? Thanks in advance, Tim

Topic by tbelcher98   |  last reply


Dremel just stopped

Hi I was using my Dremel with a saw attachment cutting wood half way in the Dremel just stopped. The spindle rotates cleanly I have checked the fuse etc which is fine   There were noises at all love my Dremel helps me a lot in my hobby repairing and repanting Model buses cash a little shirt so I can’t just go out and buy a new one 

Topic by Gefcon   |  last reply


Raspberry Pi Zero W

I received a Raspberry Pi Zero W kit (from Adafruit) over the holidays, but it didn't come with any doco. And I haven't found much by Googling. Does anyone know of information that could help me get started? I haven't worked with any Raspberry Pi product.

Topic by arshag 


I need to make an electromagnet that continues to turn on and off (on 20 seconds off 45 seconds)

Hello, I am trying to make an electromagnet that turns on and off on an interval. On for 20 seconds off for 45 second. It would continue to turn on and off until the power is turned off. Any and all suggestions as to how to make (or buy) this would be great! I am making this for an art piece.. I am a glass artist so I am not well versed in any of this electrical engineering Thanks! Maia

Topic by MaiaS5   |  last reply