Modulate a transmitter with a signal generator? Answered

Hi I'm doing some experiments with an fm transmitter. Now, instead of transmitting and modulating audio, I wanna try to feed the base of transistor using a ramp generated by a NE555. I ended up with this schematic http://s30.postimg.org/pbe0oyu4x/base_sawtooth_modulation.png , would be ok to pass the signal on the base using a 220 ohm resistor and a 10nF capacitor? I suspect that I have to increase the value of the resistor R5. kind regards.

Question by akopelumenuscu   |  last reply


Firmware for RAMPS without diode? Answered

HI. I have already lost an Arduino. So I want to remove the D1 diode in my RAMPS 1.4 to protect the Arduino Mega from over voltage.Can  I run the printer powering the arduino from my laptop's usb? Also do I need to change anything in the firmware for this? I am using the sprinter firmware. 

Question by SowmenD   |  last reply


how can I connect my ramps 1.4 and arduino mega to my Laptop?

Hello guys. I need to ask you on how to connect my ramps 1.4 &arduino mega to my laptop, because in the first time I fried my arduino and my ramps 1.4. can I plug the power to my arduino from my laptop and my ramps to the power supply  simultaneously?

Question by joee1   |  last reply


Help with some engineering issues on a folding tail gate ramp?

I'm building a folding ramp to replace my tailgate on my truck. It's going to be used to load/unload a ztr lawn mower. (It's been built primarily from discarded bed frames, with the addition of some expanded steel grating.) Because these mowers are back heavy, and low to the ground, a longer ramp is needed than you need to load a conventional mower. My solution is a spring loaded 8' ramp that is comprised of two 4' sections that fold down and out. It functions, it fits, the mower goes up and down it ok. The problem is that it is so heavy, that after it comes down about 2/3 of the travel, it is very difficult to control. When it comes down hard, it puts tremendous stress on the center - where the two sections of ramp meet. It can be hard enough to break it. I know my welding isn't the best, but that's really not the issue here. This is a design problem. I'm going to post a few pictures, to better illustrate my situation, and to show some of the things I've tried to soften the blow. The picture of the partially folded ramp was taken at the point where it begins to get difficult to lower without losing control. So, to clarify, I need a way to lower and raise the ramp with more control, and or soften the blow towards the middle.  The springs I'm using are 140lb garage door extension springs, the largest springs available at any big box home center. I need to get this finished yesterday, so I'm going to try some things while I'm waiting for a response, like move the springs back further in the bed to put more tension on the whole thing. I'll also post this to the welding web forum, but I started here because I've got a lot of faith in the ingenuity of the instructables community. If we get the bugs out of this thing and anyone wants it in instructable form, I'll do my best. Thanks for reading the War and Peace of ramp questions. -Amir

Question by Amir   |  last reply


slow voltage current builder: how to increase voltage,current in ramp manner upto the desired value?

Let us assume a system requires 230V ac, 6 amp. When we switch it on, the voltage and current instantly shoots up from zero to 230V,6amp. I want the system to receive the voltage,current slowly ,i.e, when it is  switched on, the voltage,current should increase from zero in a ramp manner ,and when it reaches 230V,6amp, it should remain there till  the system is switched off.

Question by iamnimisha   |  last reply


Can I use an arduino mega and a R.A.M.P.S. board to run a CNC machine? Answered

Right now, I`m planning to use an arduino duemilanove, and 3 EasyDriver Stepper Motor Drivers. RAMPS board: http://ultimachine.com/ramps EasyDriver Board: http://www.sparkfun.com/products/10267

Question by Stuffses   |  last reply



did I destroy my arduino mega and ramps 1.4?

I was using an arduino mega and ramps 1.4 motor controller for my 3d printer.During the time of testing ,i switched the power polarities in the ramps 1.4 , then I put 12V in the arduino then the mega chip got hot. This is the state now,when i plug the mega on to my computer : 1)The red ON led lights up and the L lights up. 2)device not detected. 3)Reset button does not make any change. 4)RX-TX  lighting up. when i plug the 12 in the ramps: 1) the red ON led lights up, the green doesn't I want to know if this arduino and the ramps 1.4 can ever be used again. please help!! thanks in advance!!

Question by joee1   |  last reply



how to connect my 6 wire stepper to ramps 1.4 shield, and which stepper driver should i use ?? Answered

Stepper is nema 17 4.5kg torque  and the current rating is 1.3 A , please give me the link for the stepper driver ...... :) Thanks in Advance

Question by _Boltz_   |  last reply


"Super-magnet ramp" is world's best visual illusion

The video below was awarded Best Illusion of the Year at this year's Vision Sciences Society meeting.  I originally saw this posted in Nature News: In a packed concert hall, Kokichi Sugihara wields a pickaxe and mimes a blow to the stage. "I am a miner, and I have a secret," Sugihara says, adjusting his hard hat and headlamp. "I have discovered a new super-magnet." A screen behind Sugihara begins playing a video. A cardboard structure appears, consisting of four ramps ascending to a raised platform. A hand places a wooden ball at the base of a ramp, and it rolls uphill, before stopping on the 'super-magnetized' platform. As the same trick is repeated for the other three ramps, the crowd lets out an "ooh". Thanks to Kiteman, here's the author's own Web site: http://home.mims.meiji.ac.jp/~sugihara/hobby/hobbye.html Image and video from Koichi Sugihara, Meiji University.

Topic by kelseymh   |  last reply


Cnc using ramps 1.4 ,repatier host,nema 17. Help with the software?

Hey guys I am almost ready with my CNC which I was building during my summer vacations. Well I have nema 17motors ,ramps1.4 and polulu motor controller. Well I can't get the firmware that is to be uploaded onto the arduino to work properly. I tried repatier/marlin firmware,but have no clue what to tweak and what not.

Question by chrissunny94   |  last reply


Why will my Arduino not power up when I use an external power supply for my Ramps 1.4?

I am working on my 3D printer and I am using the Arduino Mega 2560 with the Ramps 1.4 board. when I power the ramps board the Arduino will not power up and operate. I have tried moving the header pin across VCC and the other connecter but there is not effect. I have to power the Arduino separately Via USB. is there something I am hooking up wrong or is there damage that I have to fix on the board itself.

Question by Dietrick K.   |  last reply


Arduino mega fried/not working?

Hey guys I was using ramps 1.4 for a CNC project of mine.When I was trying to upload a code for repatier when the ramps 1.4 was already connected to a 12v source, this forced my laptop to shutdown as well as forcing the mega to get heated up bad. Now I think the laptop ram is fried cause the display is not working and mega (even though the lights are blinking),the code cannot be uploaded

Question by chrissunny94   |  last reply


I need a circuit that can convert sine waves to square waves.

I need a circuit that can convert sine waves to square waves that works with a wide range of frequencies and doesn't change the frequency, for a project i am working on. I also need a circuit that can convert square waves to ramp waves that also works with a wide range of frequencies and doesn't change the frequency. Thank you in advance.

Question by Super_Nerd   |  last reply


What sensor should be used, or what can i make to precisely align a vehicle up to a ramp?

Sorry i couldnt decide how to word my question but here is my situation and i would be gratefull for any input because i am not sure what would be the best or easiest way to go about it.  My car is lowered and therefore i can not park in my driveway without having a ramp(plank of wood) infront of each tire at the sloped base of my driveway. This does not bug me as much as the fact that every time i go to back out of or pull up to my driveway i have to align my tires as best as i can guess up to the ramps, take car out of gear, put on parking brake, get out, check one tire, then the other, and occasionaly move the ramps left or right before i can get back in my car and procede up into the driveway. Ok so its not only my laziness that fuels this project... my mustang isnt the quiestest and when its late I feel bad leaving it idleing (making noise) while i get out to make sure i'm lined up to the ramps. I would love to make some kind of proximity sensor or something that lets me know when each tire is propperly lined up.   I have thought about a few different things like a camera under the front bumper that feeds to a monitor on the dash, (similar to a backup cam) also i was trying to think of a way to use an old cell phone and its camera for this.  IR proximity sensors in the bumper attached to LED lights on the dash that tell me im lined up if the propper LED's are lit. I dont know much about them but maybe some sort of magnetic sensor or metal detector.  One issue is that the placement of the ramps can be detected in different ways depending on the sensors used. whatever the factor is, that is being sensed (reflective surface, metal, tiny magnets) needs to be durable and able to be ran over on a daily basis. Also I want something that can be fairly accurate, although an err either left or right of an inch would be alright. Sorry for being longwinded but i look forward to some ideas! Thanks!

Question by colie1904   |  last reply


Simulated dawn & dusk LED aquarium light?

Instead of using a timer to turn the light on and off I would love to simulate dawn and dusk by having the light slowly ramp up to full power and then slowly ramp down to off at the end of the cycle.I do have some limited electronics experience but over the years have done less and less so I'm not as sharp as I used to be.If anyone has some ideas how I can do this I would love to hear them.Thanks to all.

Question by gjm   |  last reply



I need LOTS of help with a 3d printer

So, I am trying to build a wolfstrap 3d printer, and I am having a lot of problems with the electronics.  I have a RAMPS 1.4 and 5 stepper motors. -RAMPS 1.4 Test Code       -Y and Z motors work fine.       -There is no power to E0 and X motors.       -E1 motor locks up -Marlin Firmware + Pronterface       -I can connect, but none of the motors move when I print or do manual control. -Sprinter Firmware + Pronterface       -I can connect, but motors just vibrate when moved Thank you for all of your help.

Question by pianoman99a 


how do i get a persons name from craigslist R&R??? Answered

Theres a moron on craigslist R&R that keeps harassing me & outher people. or if i find it will i get in trouble from craigslist???

Question by bigmark   |  last reply


Is there a specific waveform that needs to be produced by the driver electronics in a solid state tesla coil?

Is there a specific waveform (for example sine, square, sawtooth, ramp, etc) that the driver electronics (an oscillator i think?) in a solid state tesla coil in order to properly drive the coil?

Question by UbuntuNinja   |  last reply


What is the most efficient way to transfer motion? Answered

What is the most efficient way to transfer lateral movement to vertical movement via a ramp. The following curve is equal on both sides of the apex, if that is the correct term.  Is this the best way to transfer the movement to strait vertical or should something else such as a long start to the incline and then a sudden shoot up.

Question by jj.inc   |  last reply


I fried the arduino mega?

Ok i was using an arduino mega and ramps 1.4 motor controller for my home build cnc.During the time of testing ,there was ahuge back current and probably the mega is fried. This is the state now,when i plug the mega on to my computer : 1)The Green ON led lights up 2)device detected ,but not recognized.( tried  re installing the drivers ,but no use ) 3)Reset button does not make the L light blink. 4)RX-TX not lighting up. I want to know if this arduino can ever be used again. And for the safe use of the cnc,what micro-controller/micro-controller precautions/PLC   should be used. Can i fix this MEGA by replacing some components , i really dont want to spend more on the cnc(i have already spend around 400$ till date)

Question by chrissunny94   |  last reply


How to know if Arduino is working?

I bought the RAMPS and Arduino Mega 2560 and 5 stepper drivers. I plugged in everything to the pc and everything was working perfectly. I installed all my arduino drivers easily. Then at my friends place when I plugged the psu to the mains and turned everything on, 1 of the stepper drivers started smoking from the chip attached to it and got fried. I think it was  due to too much voltage. After a while removing the burnt driver when I connected my Arduino to the pc, the pc does not find its hardware. Only this 1 light stays on and nothing happens. I don't see that there is any physical damage to the board.. but there might be .. I am not sure what to do now.. I want to know if I can check wether the board is still working and how can I connect it to the pc?

Question by SowmenD   |  last reply


3d printer not homing correctly

Hello, I uploaded marlin firmware to my arduino mega that uses ramps 1.4, and my printer will not home correctly. When I hit home in repetier host, the axis moves a centimeter. have to press the button repeatedly till it hits the endstop, where it bounces back as it should. Where do I fix this in the firmware? 

Question by jbaker22   |  last reply


3d printer won't move Answered

Hello, I have recently hoked up the motors and sensors of my xyz printer to a ramps v 1.4 running marlin  firmware. I can't make anything but the z axis to move. I put every motor in the z axis and found the can make the motors work. So, why wont they move when they are in their correct plug for their axis? I am using pronterface to make the axis move by the way.

Question by jbaker22   |  last reply


How do I create a 5 second soft-start with an LM334Z current regulator?

Hey all, A bit of a newbie to creating circuits I have a 12V battery regulated to 2mA with an LM334Z current regulator. Here are the docs for the current regulator: http://www.ti.com/lit/ds/symlink/lm134.pdf I would like to create a soft start, so that when I turn the device on there is not a rush of current.  I’d like it to ramp up over 5 seconds. I’ve breadboarded a few schematics I found online but I can’t get them working. Even if the battery power is slowly ramped up, the LM334 rams the voltage to get the current at exactly 2mA. (my Rset w/ a 33ohm resistor) Here’s a couple I’ve tried unsuccessfully. http://dl.dropbox.com/u/5822/softstart1.gif (might be b/c the 317 is different?) I even tried this schematic to no avail: http://dl.dropbox.com/u/5822/Screen%20Shot%202012-04-29%20at%209.16.57%20AM.png But I was using different transistors, didn’t think that mattered- let me know if it does Can anyone help me figure this out? I’ve been stumped for days. Starting to pull my hair out :) Thanks Nick

Question by tontoa4   |  last reply


Micro High Voltage

I'm going to attempt to make a super micro tesla coil that is 100% contained (unless it runs off of like 12 volts dc, then I'll use a wallwart). Of course, one of the i biggest problem is the power supply. So this is what I'm asking, what's the best way of ramping up the voltage? A tiny toroid transformer? An inductor that gets pulsed? Voltage Multiplier? Something with static electricity? Some type of Inverter? Using Greinacher Cascades? A marx generator hybrid? Other stuff I havn't heard of?

Topic by guyfrom7up   |  last reply


Need Help writing a Star Trek themed Arduino code

Hey Folks. I really need help  writing an arduino code to control a star trek model i'm working on. I don't really understand programming but I'd really like if anyone can help out. The code is supposed to use 2 momentary switches. When the main switch is pushed it will activate some leds in sequence, the last 2 will fade on one after the other in the same manner, this will be called the 'startup mode'. Then when the second momentary switch is pushed (while the main is on) it will 'switch modes' and the 2 leds that faded on one after the other initially will now fade off or ramp down at the exact same time then 2 more leds will fade on or 'ramp up' in their place at the exact same time. Finally, when the button is pushed again it will simply switch back. A video demo shows what im talking about with some very small differences. Any help would be appreciated! This video below shows what Im trying to do. Please see from time frame 0:35 to 0:54 which shows the 'start up sequence' described above. And one more showing the actual model i'll be working on and the startup sequence with the movie timing.

Question by jamesstills 


Electronics for a diy 3d printer Answered

Hello, I would like to know if these parts will be suitable for building a 3d printer without modifying the code made for 3d printer. Yes, I see modifying the code as inevitable for making the 3d printer accurate. If there are any other parts beside a powers supply, a the hot end parts I would appreciate that.. Can I use this microcontroller?  http://www.ebay.com/itm/Microcontroller-Board-ATmega2560-16AU-USB-Cable-For-Arduino-Module-R3-MEGA2560-/181531871863?pt=LH_DefaultDomain_2&hash;=item2a44248a77 And these step sticks?  http://www.ebay.com/itm/RepRap-StepStick-Pololu-A4988-stepper-driver-for-Sanguinololu-Arduino-Mega-RAMPS-/281182048802?pt=LH_DefaultDomain_0&hash;=item4177c19222 Thanks for any help.

Question by jbaker22   |  last reply


Auto bed levelling probe problems on marlin.

When i try to set the probe routine (g29) the servo dose not deploy the probe. Also if i try it with the probe down (m401) it will try to probe but the motors don't move so it ends up probing the same spot 3 times. (on the lcd it thinks the motors have moved but they haven't) 3- point probe mode Marlin 1.0.3 dev These problems are when i try on pronterface. My config file: http://forums.reprap.org/file.php?4,file=58699,filename=Configuration.h

Question by bonze77 


Simple on/off delay switch circuit

Here's what I am trying to do. I am already controling 4 LEDs with a 9 volt zener regulator. I now want to control the source of the regulator (ie voltage from the battery on board my motorcycle) with an electronic switch. Not a big deal, but I also want the voltage to the LEDs to ramp up slowly so that when they initially turn on, they are dim, but get brighter and brighter until they reach their 9 volt regulated source. Then when I turn the motorcycle off, they fade slowly until all the way off. So I guess is what I want is a delay switch. Should I be switching the 9 volts regulated to the LEDs or should I switch the source to the regulator? What is the cheapest and easiest way to do this? Any help would be appreciated. Thanks.

Question by Motoman9   |  last reply


Led color control w rotary switch?

I am working on a project to rewire an old industry hair dryer into a funky floor lamp. It has a cool panel on the back that would fit some kind of a rotary switch.  I would like to use an existing product or products to emit blue light and yellow light from the bell of the dryer. The rotary switch would allow me to ramp it from the blue leds to the yellow leds with some cross over in the middle. my challenge is that, while I understand basic electrical circuits, I know very little when it gets into the more technical circuits and arduino stuff. I want to learn but this isn't the project for it. does anyone know of an easy way to set this up?  My  thought was a set of blue strips, a set of yellow strips and a rotary controller. But, I don't know what to search for online. thanks!

Question by mckeephoto   |  last reply


using a thermoelectric cooler for High powered LEDs

Has anyone tried using a thermoelectric cooler, like this one http://www.allelectronics.com/cgi-bin/category.cgi?item=PJT-7to cool down a high powered LED star. I am considering mounting one on the back of a new Luxeon RebelI plan on ramping the current up to max (1 amp) on the led, and run the Thermoelectric cooler (TEC) as high as possible off a lead-acid battery. Strap a giant heat sink on it (maybe a fan too) plus thermal and silicone over the whole thing. It wouldn't be pretty, but it would be a neat experiment on how many lumens you could crank out of one of these things. Any inputs, suggestions, Ideas? Feel free to make an instructale on this if you want, I can't guarantee I will do it anytime soon.

Topic by John Culbertson   |  last reply


Idea: Smart LED front door light with PIR detector and light sensor

Hello to all. I searched the forums for the project I plan to do, but found no real answer. Here is the idea: I want to have a front door light using CREE high power LEDs that would: - stay off during the day - turn on at 10% current level when night falls - ramp up the current gradually to 100% current when a movement is detected, stay at 100% for a preselected amount of time, then return back to 10%. This would make a very efficient front door light. I have some experience making headlamps using buckpucks and power LEDs (thanks to dan from this site), but I have no idea on how to make the "gradually changing" current driver for that project. I guess it would involve a microcontroller of some sort. Has anyone some insights on this ? Thanks for reading, Mike, Switzerland

Question by 4fontaines   |  last reply


How to make a 2-row Sequential LED flashing circuit? Answered

I want to make a circuit that lights up two LED's then turn them off then lights up the next two LED's and so on. I want it so it looks like the light is scrolling across the LED's. I know how to do this with one row but how do I do it with two rows so that the two row are in sync? *Update: August 8, 2013* I have a ramp for my R/C car with 2 rows of 6 LED's. I want the bottom two to light up, then turn off. Then the next two above them to light up, then turn off and so on. As if the light was travel from the first two LED's, to the second one, to the third, to the fourth and so on. Then have the light come back to the start. I'm also really new to electronics so, if possible, try to keep it as simple as possible. 

Question by jeffrey_stjean   |  last reply


Quadcopter build help? multiwii is causing motors to twitch when throttle is applied

I have been working on a large X525 quadcopter kit/ w/ multiwii SE v2.5 from amazon, and have had success with configuring the multiwii for the quadX configuration, however, when I arm it and try to take off, all 4 motors ramp up to speed but then cut out and continue ramping up, particularly one motor, whichever is the lowest. Balancing the quad on 2 legs, the quad seems to want to stabilize, but keeps tetering violently since the motors keep randomly cutting out. I have tried to calibrate the ESCs by connecting them individually directly to the CH3 (throttle) receiver, powering up the Tx with the throttle high,plugging in the LiPo battery, and after hearing the jingle, lowering the throttle back down to the lowest position and waiting for the first few beeps before I unplug the LiPo battery and moving on the the next ESC. I was looking at the multiwii outputs through the software and they were in fact jumping around like crazy but after taking the props off the amount of twitching did go down a little, but still about 10-20% deviation in the bars of the software readouts. I've also tried dismounting the multiwii from the quad to eliminate the possibility of vibration from the motors from causing the multiwii to attempt corrections to the motor. though it seems to have the same for as long as I could tell because by the time I tested this, the multiwii board touched the power distribution board causing magical smoke to be released. Oops! Now the multiwii is completely dead all but the green power light which is directly connected to power Vin. The board and all the chips appear completely fine with no damage, and there is voltage to the main ATmega328, I don't know if I should try desoldering the ATmega and buying a replacement, or suck it up and buy a new $30 board. For all I can tell, I do not see how other sensors could have failed since the the exposed through-hole headers that likely touched the distribution board are directly connected to the multiwii's analog/digital input/output pins, I suspect that is all that went bad is the ATmega chip, even though if shows no sign of burning and does not overheat with power applied. Anyway while I wait, I thought I will ask about this problem to see if it is something simple like sensors calibration. (w/o motors operating, the output appears as it should!!!)

Question by -max-   |  last reply


Why do prints on Repetier Host not start, when manual heating and motor controls work?

I am running a RAMPS board Prusa i3 on the newest version of Repetier Host, and everything worked fine on the last computer I had. I set Repetier up on a new computer, and everything functions as it should except that when I try to start a print, it says a print is in progress, but it's not printing. The stop/pause buttons are there as if a print is in progress, the bottom right corner forever says its printing layer 0, and the manual control window does not show a print in progress. Testing has indicated that the motors and heaters respond correctly when using manual controls, so the problem isn't the connection, baud rate, etc. Nothing was changed in terms of the hardware or firmware of the printer itself. The print runs fine using the virtual printer simulation. I also tried deselecting the box for "check extruder and bed temperature". Does anyone know what would cause the print to fail to start?

Question by AmpOwl   |  last reply


Digital Scope Specs: wfms/s vs. GSa/s vs. Mpts/s vs. bandwidth?

Question say's it all. I understand the concept of analog bandwidth, being that the signal amplitude will be attenuated about 70% at the rated frequency, or something along those lines. I also think I understand the concept of sampling rate, being that the ADC inside the digital scope samples the input voltage level periodically (possibly billions of times per second), and then this gets stored in memory, and displayed. However, then what does the "Mpts/s" figure mean? Is this telling me how many points of the signal can be stored in the memory to be plotted on the screen? how much of this is 'good' and 'good enough'? Also, what about Waveform Capture Rate (wfms/s) I really have no idea for what might be, How it 'waveform' defined? a single period of a repetitive signal, like a ramp wave or triangular wave? Perhaps also a arbitrary wave? What would this tell me? Again, how much of this is 'good' and 'good enough'?

Question by -max-   |  last reply


what motor should i get PLEASE HELP?

For science fair, i need to make a car for a 'king of the hill' type thing I need 2 motors (one for each back wheel) that can get me up the hill relatively quickly. The maximum power source i'm allowed is two nine volt batteries at one time (i can switch out dead ones in between runs) The hill is 40 inches in height and the ramp leading to the top of the hill is eight feet long The motors need to have a driveshaft sticking out about 1-2 inches for the wheels to fit on I'm not allowed to use remote control but i've devised a way so that the car will stop, regardless of what the motor is. I have plenty links to websites, i just dont know which one to get, if someone could point one or a few out for me that'd be great (please below $15 per motor) Help would be GREATLY appreciated I'm told by multiple friends that solarbotics.com is a GREAT resource edit: my car will weigh about 1 -1.5 pounds

Question by ishmal1103   |  last reply


Hi Guy's Im looking to build a Led controller that can operate a12v 600 leds in 4 channels 200wh 100red 100blue?

Each channel has two on times and two off times in a 24hr period.Each event ie; morning, can have 4 ramp times ie:red led channel comes on and rises red channel starting0% led power up to say 85% over a one hour period meanwhile the white channel comes on say 20 mins in to event and rises led up 0% to 100% over the hour and red led will fade out.This giving the effect of sunrise. There will be different light for different times of day.For the night the blue channel will fade in simulating the moon.There can be up to 256 stages of color.So a need a system controller that can control Both the time that a channel is turned on/off and the level of power that is put to that particular led channel. This project is for my aquarium.The idea is to be able to simulate daylight for the the fish that doesn't have a florescent light flashing on make fish jump. Sorry for the long explanation.I,m a electronic dunce sorry guys.Any help or advise would be very much appreciated Regards Jon

Question by    |  last reply


FIXED: Power Mac G4 1.25 Duel Mac OS X 10.5.8 Freezing after 6 Minutes!

A couple of days ago I ran across the problem that my mac would have a high CPU usage and kernel panic or freeze after about 6 minutes.  First I plan the put the hard drive in my PC and back up all of the data, as I have important stuff on it.  The high CPU usage was caused by a process call mds, and mdworker.  Both for the PowerPC Architecture, because it is a G4 PowerPC Processor.  The computer is maxed out at 2 GB. of RAM.  The fans sound like a jet engine on boot up, but then ramp down one the desktop is loaded.  Please help! System Specs: Duel 1.25 GHZ PowerPC G4 2 GB DDR RAM Mac OS 10.5.8 200 GB Seagate hard drive (from when Seagate hard drives were good) DVD Combo Drive PCI FW 800/400 USB 2.0 Card USB 4Ex 1In USB 2.0 crad 128 MB Graphics I have attached a video so that you can see exactly what happens:  

Topic by iApple guy   |  last reply


What motor should I get? PLEASE HELP?

For science fair,  i need to make a car for a 'king of the hill' type thing I need 2 motors (one for each back wheel) that can get me up the hill relatively quickly. The maximum power source i'm allowed is two nine volt batteries at one time (i can switch out dead ones in between runs) The hill is 40 inches in height and the ramp leading to the top of the hill is eight feet long The motors need to have a driveshaft sticking out about 1-2 inches I'm not allowed to use remote control but i've devised a way so that the car will stop, regardless of what the motor is. A link to a website where i can buy the motors or where i could get them would suffice (please below $15 per motor) Help would be GREATLY appreciated edit: my car will weigh about 1 -1.5 pounds edit: i dont know a whole lot about which motor to get so if someone could (not to sound helpless) pick one for my situation that'd be great

Question by ishmal1103   |  last reply


Why does my printer add defects to my prints (nothing to do with slicer)? Answered

So I have a FDM 3D printer which I designed and built, it is very sturdy so I am sure that none of this is caused by flexing/resonances of the printer. My set up makes use of Repetier host and firmware, with cura being my preferred slicer. I have noticed that it has started to add strange details to my prints, both on corners and on rounded sides (see photos). These do not show up on the  slicer preview, and when i switch between slicers (cura and slic3r) they still remain. This has led me to believe that it may be a issue on the printer side. I have watched the printer as it prints and they are definitely being added on purpose by the machine (as in no flexing/resonance/lack of tension in the belts). this made me think it might be a firmware issue. It also does not go away if I slow down the printer. This has only happened recently, but  I can find no settings on the firmware that I have changed in this time period that would indicate something like this should happen. Just to be clear, in the photos, the near circular print should be perfectly circular, and the other print should have a perfectly square cross section. It also happens on both the models and the rafts/brims that I use. Any thoughts or ideas will be much appreciated.

Question by JamieApps   |  last reply


Wall of PC Case Fans?

Hello guys, sorry if this is the wrong section but, I was thinking of making a DIY fan out of PC case fans to keep myself cool in the summer. I've tried a number of fans in the past, but they don't seems to be very good. I usually put them right next to an open window to draw cold air in. I was thinking of making some kind of rig like in the video below, only without the bitcoin mining computer. I got the idea from this video and from when I was messing around with the fans in my own PC. I was chancing the speed of the fan for the PCI cards and noticed that it could get really cold if ramped up a bit. ) I was thinking of using 9 identical 120mm or 140mm fans, preferably ones that can be used with a fan controller. Here is a few of the things I need help with. How will I power the whole thing? What kind of cabled will I need? Could I use a fan controller to power all 9 fans? Can I even hook up 9 fans to a fan controller? Maybe I could use 2 fan controllers or something? What brand of fans should I use? How will I attach the fans together? Cable ties like in the video? Maybe I could make a makeshift wooden stand to hold them upright.

Topic by BionicSammich   |  last reply


SMPS failure, the Gates of the MOSFETs exploded?????? Answered

I've just build an SMPS using a TL494 chip using the power circuit from this circuit from uzzors2k, it's just a standard half bridge in my case using IRFP460's. The MOSFETs are driven through a small transformer that itself is driven with a H-bridge.  Yesterday I was trying it's first mains power test slowly ramping up the voltage with a variac when at about 180VAC i could hear some fizzling from the circuit and at 200V the GATE's of the MOSFET's exploded violently, at close inspection there was no shorts or flashovers and the gates were the only thing that was damaged at all. One thing i noticed later was the output waveform of the power transformer, unlike the signal waveform it didnt exhibit the same 96% duty cycle but a 100% with a lot of ringing on the rising peaks of the square wave, i know this can probably be fixed by reducing the duty cycle but i cant see how it could've blew up the gates. I've included some pictures so you can see what i mean by explode, as you can see on the left Fet the gate pin has completely blown off and the copper has melted slightly and the right image the same happened but i cracked the Fet open with a hammer to see if there were any clues inside. I really dont have a clue why this happened and would appreciate some help, thanks in advance.

Question by The MadScientist   |  last reply


DEPLOYABLE FIRE ESCAPES for TOWERING BUILDINGS

The “9/11” World Trade Center disaster horrified Americans as they witnessed people leaping out of 100 story windows to their death. There was simply no available escape system to facilitate a safe yet quick evacuation to the ground floor. Elevators weren’t working and internal staircases were blocked by sporadic debris, black smoke and fires. The situation was virtually hopeless to the point where many chose to jump rather than be burned alive. So here we are, with technology capable of constructing 100+ story buildings but without the means for external fire-escapes. Unfortunately, the public isn’t aware that at our current level of technology we can finally address this problem with our architects. We are talking about a means to rapidly deploy a flexible escape tube-chute from 100+ stories that hangs along a guy-wire which is pre-attached to our escape floor and anchored to the ground (Fig-1). This tube-chute escape system will deliver a person from 100-stories down to ground level and safely outside the building in under 10-minutes. Prior to deployment, the entire system is housed inside a container that is either attached to the outside of the building or built into a structured wall, opening to the outside at various floor levels. When in deployment, the inlet of the flexible escape tube will be anchored to the outside wall of a designated escape window and contain an inner diameter sufficiently sized to accommodate an individual. The tube’s exit end is tethered to a rope-wire that runs down our permanently located guy-wire, through a series of guy-wire slip-rings, and quickly pulls the tube's exit end to ground. The rope-wire is permanently attached to a winch-motor located on the ground. During deployment, the winch pulls the tube’s rope-wire down to ground level by slipping along the guy-wire rings. As the tube-chute deploys downward, it automatically forms a spiral about the guy-wire, creating a very long escape slide that gets anchored to the ground. A fully deployed tube-chute exhibits three basic attachments for stability: 1) a set of flexible slip-rings and tethers attached between the permanent guy-wire and tube to form its downward spiral, 2) a tube-chute inlet anchored to the outside of the building at various floor levels, and 3) a tube-chute exit anchored to the ground and providing a fully deployed and reliable escape system ready for use. As each person enters the tube-chute, they are only aware of the outside winds which buffet the tube plus the internally hanging cloth fingers used to slow their descent as they slide down to safety. They are not aware of any height and feel relatively secure due to their complete envelopment by both the tube and its touching fingers.  A 100-story descent would take about 6-to-10-minutes to reach the outside safety of ground while travelling at a speed of roughly 5-fps (3.5 MPH) as regulated by the spiral-ramp and internal cloth-fingers retarding gravity.   Technical  Details: The tube-chute is reinforced by a sewn-in spiral wire that gives it strength and flexibility. Its tube is made of heavy duty nylon, much like the large yet light air-hoses used on many high stress applications today. The tube cork-screws its way down and around a permanently deployed guy-wire that stretches from the designated floor of the building to the ground. The tube is sized for a person to enter and slide down the spiraling pathway until he reaches ground level. Gravity will act to propel the sliding individual down the tube. To counter gravity, we rely on the tube’s spiraling design to produce a gradually declining ramp that slows and checks an individual’s descent speed. The number of spirals and ramp-angle necessary to reach the ground will be sized to limit the gravity-induced speed so as not to endanger an individual’s sliding descent. That and the internally hanging cloth fingers guard against excessive speeds and will prevent skin-burns from the sliding friction. The tube’s nylon material is impregnated with anti-flammable chemistry and its exterior is aluminized to prevent radiative heatloads from causing a fire due to either direct flames or the radiant heat from indirect flames. A final note on the overall weight for this flexible tube-chute structure. Clearly, since we are designing a deployable fire-escape system, its weight must be kept to a minimum for deployment safety and reliability. Items such as the cloth materials, tube-wire reinforcements, and spiraling tube tether attachments must be carefully chosen for weight, strength and durability. While issues of weathering may not be that important, as it will be housed and protected from the elements, the shelf life of the various materials chosen is of paramount importance.

Topic by RT-101   |  last reply


how to make a microcontroller potentiometer control a servo and motors on my rc lorry for rear wheel steer?

Hi Guys, Im a keen modeller and build rc 1:14 scale trucks, I'm trying to build a trailer as many have done that uses a potentiometer which is turned when the lorry turns and the trailer follows through the tow pin, this then turns a servo that makes the rear wheels of the trailer steer creating rear wheel steering. the servo doesn't start turning till the pin is turned about 5 degrees either way, allowing the lorry to reverse easier as the rear steering won't work if not turning past the 5 degrees. On the trailer it has a detachable neck that is driven by a motor. Another servo or small motor to lower and raise the loading ramps Another motor that raises and lowers the legs to support the trailer when disconnected from the lorry. All of this I would like to be able to control separate from the lorry, so i can press a button and the legs will lower and lorry can drive away without wires going from one to the other. Ive attached some videos to give you some idea of what I'm trying to achieve This video has a circuit board that they refer to as E.T.S. Module (electronic trailer steering) This has been made by a fellow member but wants big money for them, it controls the rear wheel steer and neck detach motor, sorry its a long video. https://www.youtube.com/watch?v=ioOHjobQPho&spfreload;=10 This next video you can see the movement pause, roughly 5 degrees each way. https://www.youtube.com/watch?v=Z0MvFHVAa1w Im trying to achieve one board that can control the items above and be somehow wireless or link in with my rc gear, Hope you guys can help. Many thanks

Question by brummy2002   |  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


Problem driving a stepper motor using the A4988 reprap driver board and an Arduino? Answered

Hi guys I am having a problem driving a stepper motor using the A4988 reprap driver board and an Arduino I have set up the wiring using an example I found online (Diagram attached: A4988 wiring) https://www.youtube.com/watch?v=5CmjB4WF5XA.. However the motor does not seem to turn. The motor I am using is from an old Hitachi printer which I took apart a while back. Printed on it is 0.9A/ph. It has six wires however I am using it as a bipolar stepper by just leaving the center tap of each winding unconnected. I have adjusted the VREF on the A4988 board to insure that the current is limited bellow the 0.9A. To do this I used the data sheet of the A4988. As I wanted to run the motor at full step mode, the A4988 data sheet specifies that the winding current could only reach 70 percent of the current limit. consequently: Current limit = 0.9 * 0.7 = 0.63A Current limit = Vref * 2, Therefor Vref = 0.63/2 = 0.315V or 315mV I have therefor set the current limit using the potentiometer on the A4988 to aprox 315mV Once the wiring was set up, I applied power and measured the Vref to confirm it is still the same and it was. Next I disconnected the Power to both the Arduino and the driver and connected in the stepper motor. I then connected the power and uploaded the following code: // defines pins numbers const int stepPin = 3; const int dirPin = 4; void setup() { // Sets the two pins as Outputs pinMode(stepPin,OUTPUT); pinMode(dirPin,OUTPUT); } void loop() { digitalWrite(dirPin,HIGH); // Enables the motor to move in a particular direction // Makes 200 pulses for making one full cycle rotation for(int x = 0; x < 200; x++) { digitalWrite(stepPin,HIGH); delayMicroseconds(500); digitalWrite(stepPin,LOW); delayMicroseconds(500); } delay(5000); // five second delay digitalWrite(dirPin,LOW); //Changes the rotations direction // Makes 400 pulses for making two full cycle rotation for(int x = 0; x < 400; x++) { digitalWrite(stepPin,HIGH); delayMicroseconds(500); digitalWrite(stepPin,LOW); delayMicroseconds(500); } delay(5000); } Nothing happened... started off with 5 volts on the power supply and ramped it up to aprox 12vs however still nothing happened. I can feel the heat sink heating up on the A4988 which means power was reaching it. I measured the voltages from the Arduino to the A4988 and the power supply to the driver and the voltages matched the input. I started shaking about the power connections to and suddenly the motor made one step, but that was it. So i thought it was a problem with the breadboard. I checked the connections on the breadboard and all where connected. To be safe i decided to use another breadbord. Again nothing happened. I checked the Aarduino using the 28byj48 and UNL203 driver and stepper that came with it and they worked fine. I confirmed the wiring sequences and layout multiple times and they all matched the tutorial I followed. My inital thinking was that the stepper motor was broken, so i disconnected it and tried running it using the power supple (5V) by connecting and disconnecting each coil in manually one by one, and it turned one step at a time, which meant that the stepper was working. Finally i decided to see if current was reaching the stepper, I therefore connected the Altimeter in series with one of the coils and it did not read any current, which meant that current was not reaching the coils. Now I am unsure what to do, or what has gone wrong. The vref still reads aprox 310 - 320 mV, this makes me assume that driver is not fried. I do have another A4988 driver however I started working on that one and now the Vref does not go above 62mV so I'm guessing that it is burnt, however the second one reads fine. I have tried using the enable button with the following code (Attached; A4988 wiring 2) however it still didnt' make in difference. The following code is what i used for when I set the enabled to low (Note that the pin numbers have been changed) int Index; void setup() { pinMode(4, OUTPUT); //Enable pinMode(2, OUTPUT); //Step pinMode(3, OUTPUT); //Direction digitalWrite(4,LOW); } void loop() { digitalWrite(3,HIGH); for(Index = 0; Index < 2000; Index++) { digitalWrite(2,HIGH); delayMicroseconds(500); digitalWrite(2,LOW); delayMicroseconds(500); } delay(1000); digitalWrite(3,LOW); for(Index = 0; Index < 2000; Index++) { digitalWrite(2,HIGH); delayMicroseconds(500); digitalWrite(2,LOW); delayMicroseconds(500); } delay(1000); } Why did the motors initially step (only one step upon each shake) when I shook the power supply leads? I am afraid to try that again as I think this is what damaged the first driver I was using. And why is there no current reaching the coils? I would really appreciate an opinion on this issue as I have no idea what to do Many thanks for you time. Adnan

Question by k1228438   |  last reply