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PWM

The circuit diagram for your 250w to 5000w PWM DC/AC 220V Power Invertor is not very legible.Can you e-mail me a better copy?

Topic by AkhbarB    |  last reply


PWM fade

I am using micro controller in a project that has a set of functions (API) that can be used for a plethora of things.. (just up to you to program it that way) LOLIt has a PWM control... which i am trying to use to FADE in (and out eventually) a high powered LED (LUX III to be specific).. the problem I having is that at a certain point (say at 50-60%) of full brightness I see a VISUAL jump in brightness.. Im trying to get it to be smooth the whole way through to 100%more or less the code is like:PWM = PWM+2which I then wait 10 mSecs and loop it again...I have tried to put in some conditional checking to check to see if the current level of PWM is at a certain threshold..and then only loop it again after a longer delay (say 300mSecs) or something..I tried to search.. ut Im not sure on how to get a CONSISTANTLY smooth fade...ot smooth to say 50-60%..then a visual jump in brightness and then smooth to 100%..any ideas or links on the subject are appreciated.Thanks

Topic by xl97    |  last reply


PWM Not working? Answered

I have a circut with the following wiring and it works for what I have been doing, but I wan't to be able to dim the LED with PWM on the arduino.  Right now the light is running at about 50 for the length on the analogWrite.  There is really no difference between 50 and 255 in my opinion so I think something may be wrong.  When the length drops below 20 the light doesn't even come on.  This is for a bike light project and electronics aren't my strongest area.  I am guessing there is some period of time the MOSFET needs to switch on and off and the arduino's PWM is just too fast for this but I am not sure.  I have access to an oscilloscope so I can test to see if everything is working correctly as well.  I just get meaningless jitter with an inner oblong sine wave when I have attempted to use it, so where would be the best points to attach the scope to get some meaningful data.  (anywhere  I wrote PMW i meant PWM). I would like to point out that the LED is Rated for 13V and I am running it on  11.1 V, so no problems there. Aslo I got it working using a 10k resistor between the gate and ground, the arduino, on PWM mode doesn't sink the current very well. I have included the correct diagram.

Question by seedorfj    |  last reply


pwm arduino

I have a couple questions about driving motors from the arduino (I have a boarduino) - First off, these motors are from various walkmans and I think each one is rated for 1.7 volts. - If I need a transistor, can i use a 2n3904 (since these arn't giant motors) - How do I protect against the emf? The motors need to work going either way (clockwise or counter clockwise) - How would you program it so that the motor can go either forward or backwards?

Topic by guyfrom7up    |  last reply


Help with PWM dimmer?

Ello mates,so i biult a pwm dimmer acording to  https://www.instructables.com/id/PWM-dimmer-using-NE555-and-MOSFET-with-DIY-alumini/ but its kinda different,i used irf530n and ne555p ic, And when i connected all of the components with a 12v source it happens nothing except that little spark comes on gnd with adapter? Help please ? 

Question by JohnSmith-Workshop    |  last reply


Control Logic with PWM? Answered

I am currently working on a robotics project, and need a bit of help. I have this H bridge, and would need to control it via PWM. Speed control isn't necessarily what i need, though i wouldn't mind. (In4 i should have just bought an ESC) The whole bot is controlled by PWM (All servos) except for the two DC motors that i have on it -- One for forward and backward, and another for rotating an arm. How would i control the H Bridge with PWM? Which pins would i connect what to? 

Question by RocketPenguin    |  last reply


Controlling a motor with PWM

I'm building an ROV for the MATE ROV competition with a high school team this year.  For this year's competition, we've decided to control our bot via an Arduino Mega, and we're using PWM to potentiate the thrusters.  As the person designated to electrical, I fortuitously have no idea how to set up an intermediate step from the Arduino to our thrusters.  I've looked into H-Bridges with both Relays and Transistors, and defaulted to the transistor. How would I choose what transistor to use though? I've tried several (all BJTs) and they're giving me nothing but problems.  Should I switch to a FET? Should I use a P type and an N type, or only one?  What specs should I purchase them with?  Do I ask too many questions? Help!  (I'm trying to control a 12V 6A motor with a 5V Pwm signal. Thanks!)

Question by unununium    |  last reply


PWM to Digital Signal

I am trying to make an R/C sumo bot for a competition. What would be the easiest way to run regular DC gearhead motors from a servo controller? I'm thinking of somehow converting the pwm signal into a digital signal that would run the motors forward or backward.

Topic by Stingray    |  last reply


Pwm motor control

Please send the circuit of cintroller

Question by avoymaity63    |  last reply


PWM question for the experts here.. Answered

I am in need of some way to change a PWM signal coming from my Arduino. The firmware only allows for PWM settings from 0-255. What I want to accomplish is this: With the 0 as the lowest value and 255 the highest for the incoming PWM signal I want to change it to a "smaller bandwidth". Ok, your are confused according to my crystal ball... The connected device (here a powerful laser) starts to work at PWM values of 6. The hardware limit is at around 180 as otherwise the tube will overpower and could be damaged. But I would like to be able to convert the full input signal to a range equal to being 6 the lowest and let's say 16 the highest. So the original 0 should, after the conversion, equal to 5, just be sure the laser is off. And the original 255 should equal to 16. It seems to be a quite simple task but either my brain does not work today or my friend Google does not like me anymore. I tried to search through the Marlin firmware but could not find anything simple and obvious to make thes changes directly in the firmware. So I need something that I can implement into the firmware or something I can put on a little UNO or so that sits between the big Arduino and the laser.

Question by Downunder35m    |  last reply


555 pwm AND frequency controllable? Answered

Hello, I've been breaking my head on this for a while now, and still couldn't find a correct solution for this. I want to be able to adjust the duty cycle (pulse width) with one potentiometer, and the frequency with another potentiometer, using a 555 timer. Adjusting the frequency shouldn't change the duty cycle! (which is the problem in All of the circuits I find online). This is an example of a circuit I find online, many of the circuits look just like this one (see picture) Now, the problem is that when you increase the resistance of the potentiometer for adjusting the frequency, that makes sure you can never get 0% or 100% duty cycle anymore! or not even close to that. It's because increasing that resistance, also decreases the 'discharging current' of the capacitor, so it will also increase the discharging time when that's not wanted. Without R2 it works perfectly, from 0% to 100% duty-cycle; but with the frequency potentiometer it all gets messed up. It's a little difficult to explain, I'll try it with another example :) To get 0% duty-cycle (or something close to that, like 10%), you'll need to make sure the path for Discharging the capacitor goes near 0Ohm. Increasing the potentiometer for the frequency makes that impossible because it's in series with the capacitor's charging and discharging circuit. So that would also increase the discharging time while I don't want that. When the resistance of the frequency potentiometer increases, the duty-cycle gets variable between just something like 45% and 55% (example) so that's not good. Is there any way do do this? :/ Thanks in advance, Elecotrials

Question by DELETED_Electorials    |  last reply


Will a SSR work with a PWM signal?

Hey guys gotta quick question: I need to be able to cut a PWM signal from a motor for a project. I'm currently using mechanical relays but I'm curious, will a solid state relay work? I know there are easier ways to do this but for right now I'm on a clock and I just want to  know whether a SSR will work for cutting a PWM signal.  Thanks guys!

Topic by HavocRC    |  last reply


pwm o/p pic?

Dear sir,                how to get low frequency 30.....300c/s square wave from PIC MCU ,application required to simulate a tachometer.

Question by padmanabhan.k    |  last reply


PWM to MPPT solar Charge Controller

I have an Hybrid Solar Inverter with 50A PWM solar charge controller inbuilt into it. It works on 24V battery bank. I am having 800Watt of PV module installed in the system. As my inverter is having PWM charge controller, I am not able to harvest maximum of power from panels. I want to know that, is there any arrangement or device which can be put in between PV panel and my Inverter which can increase efficiency or can act as PWM to MPPT converter for my Inverter? My Solar Pannels generates often 39V but I couldnt utilize the surplus power as it stepped down to 24 Volt.

Topic by Shashi BhushanS    |  last reply


Arduino PWM and RGB LED strips

Hi.  So I bought an arduino uno, some IRL530NBPF, and 4,3m RGB LED strips. I want to control the strip with the arduino, but can anyone tell me how to hook it up?

Topic by sinding    |  last reply


Using arduino for Serial in/PWM control

Hello I am wondering if there is someone who can help out a super beginner.  I need to write a code that will allow me to type send a serial message to the micro (im using an arduino uno) to be able to set PWM port to a certain percentage thus changing the fade of an led. I would also like the program to echo back to me a text string indicating what has been done. Is there anyone who can help?

Topic by JonH23    |  last reply


*linear* PWM LED fade with arduino

Arduino comes with a simple program to make an LED fade on  or off, however, as far as I can tell, the apparent brightness of the LED does not change linearly with the wpm duty cycle. After some research I found that this is because humans percieve brightness logarithmicly, not linearly. (Also, LEDs don't change brightness linearly with current, but sisnce I'm using PWM, i don't think that comes in to effect.) I found a simple look-up table to correct for this on this page. 255, 180, 128, 90, 64, 45, 32, 23, 16, 12, 8, 6, 4, 3, 2, 1,0 This seems to work very well, but I don't know where this comes from. Does anyong know the ectual equation to get the % duty cycle from the %brightness? I like to abstractise things.

Topic by Vick Jr    |  last reply


Is it better to use a MOSFET with an Optocouple for PWM?

I want to control an LED strip from a microcontroller, ideally with parts I have on hand:- IRF740 MOSFET- PC123 Optocouple- ESP32 Microcontroller (Has 5V power regulator)- 12V LED strip (5m)A lot of the tutorials online seem to suggest that only a MOSFET are required (Except this one, which seems to me like a safer way of designing this, since I get to treat the 12V and 5V circuits as completely separate). I have a relatively limited knowledge of these things but it seems like sending the full current through the microcontroller on the ground side is a bad idea.Is it safe to run the LED strip's ground through the microcontroller? Are there any additional steps I should take to make sure I don't destroy my LEDs, MicroController, or anything else?

Question by jonrb  


Need help with PWM to Analogue conversion

I have a Futaba RC transmitter and receiver, and an electric wheelchair. I want to be able to control the wheelchair via RC (a-la battlebots), and I do not want to control the joystick via servo. I also want to leave the wheelchair's joystick controls intact and either solder another RC device in tandem with the joystick, or hijack the control by having an external switch that switches from either manual joystick, or RC Freq. I have some experience in electronics, but only in the troubleshooting arena. I can fix things if they are broken and can troubleshoot to the board level, but have no experience building bots and have no RC experience. The solution needs to be low cost please. I can solder build boards from directions. I just have no "vision" of how to put these 2 systems together. I think the words "pwm to analog" have been thrown around online, but I need to know more. Please point me to websites, or send me instructions and Ideas. The wheelchair will not be a wheelchair forever. R2-D2, Wall-E, and an RC Lawnmower are all in contention. Thanks in advance.?

Question by CementTruck    |  last reply


Lilypad RGB led pwm help

Hi everyone, I have started working with my new Lilypad Arduino and some RGB leds.  I have been loading code and testing 4 RGB leds (common anode) which I have set up in parallel across pins 11, 10, and 9.  While powering the lilypad by usb the leds cycle through all colours (which is what I programmed it to do).  Unfortunately, I have a problem when powering the lilypad by  this power supply. When powered by the power supply the only colour that lights up is red (pin 11).  Can anyone suggest anything? 

Topic by Br3ntg33k  


I need a simple way to generate a PWM signal?

Alright, so I took apart an old RC helicopter with a spy cam in it, and noticed it has 3 wires, just like a servo, so I modified an arduino script to keep a servo on all the time, and voila, the camera entered recording mode, now, I have an idea for something to do with this. I want to make a projectile for my air canon to fire the camera from, I think it might look pretty neat, however, I need a small simple circuit to make a PWM signal, and one that is constant enough to keep it recording constantly. I've seen some 555 timer ones but they fluctuate apparently, and I think that might turn the camera off then on.

Question by XOIIO    |  last reply


What is the advantage of PWM vs supplying variable voltage?

Friend and I are very new to electronics and we were dimming LEDs in completely different ways I think. We both defended the way we had learned to do it without really knowing why :) Any thoughts? Also, with a servo, can you do both methods as well? And is there a way to tell a servo to go to a specific "spot" on its turning radius, or is it all relative, like supply a low voltage and it will turn a little? Do you just sort of calibrate it, so you can figure out how much voltage at how much time goes a constant radial turn? Blah

Question by prismspecs    |  last reply


How to eliminate PWM noise at slow speeds when using a PC fan? Answered

My power supply has a cooling fan inside. I wanted to slow it down to reduce the fan noise. When i use this circuit in the picture the PWM works great except for the low speed buzzing. Turns the fan into a speaker. Is there some way to eliminate the buzzing?

Question by WWC    |  last reply


PPM vs PWM, why choose PPM over PWM and how does PPM work? Answered

I understand the basis of operation of PWM, however, PPM is what confuses me. What is it, and why would I choose to make a system for data transmission using it over PWM? What are the benefits? and also the drawbacks? I have a Skyfly 6 Ch radio Tx and Rx, it is even remotely possible to squeeze a slow serial data communication (9600 baud) down one of the channels reliably? I was wondering for simple non critical auxiliary mode control, I could have more than one thing controlled by a single channel on the radio, such as lights on or off, acro mode, GPS hold, and GPS return to home mode switch, and other auxiliary things by using a output of a microcontroller to multiplex all of those things with a serial data Tx. I do not want to make any major modifications, possibly use the S video port-like thing on the underside where another slave remote control can go.

Question by -max-    |  last reply


control the speed of the ac fan by pic with PWM

Hello I would like to know how to control the speed of the ac fan by pic with PWM I used optoisolator to protect the pic but the circuit does not work well is the optoisolator doing his duty ? is this circut working properly ? please help me  

Topic by MohamadK4  


PWM control and "off" for arduino IR remote?

I've built a simple IR remote to trigger a led bar using... https://www.instructables.com/id/Control-your-Arduino-with-a-remote/step5/Control-stuff/ As my template.  All the leds turn on a-okay but I'd like to be able to implement both an "off" function using the same button  ie. button1=High       leave on for desired period of time... button1=Low I'd like to be able to use a no delay fade in/out as well... ie. button7= All leds fade in/out until button7=low (using the method above^^) I've tried plugging in various other parts of code to no avail... Any help would be greatly appreciated!!! Thanks!

Question by vtrguy    |  last reply


LDR and/or PWM for energy efficient 'smart' dimmer?

Is there any way to combine a Light Dependent Resistor or other light sensor with a Pulse width modulator to (energy efficiently) dim indoor lighting in the presence of sufficient natural light?  Thanks!

Question by bbawco2    |  last reply


555 timer using PWM to throb an LED?

I'm trying extremely hard to figure out how to make an led throb with a 555 timer using PWM. What I have figured out how to do so far is how to make a 555 circuit with a potentiometer and manually throb it with the pot. But I don't want to just keep turning the pot to throb the led. Is there a I can put a potentiometer in the circuit to control the speed of the throb rather than dim the led? I need to use PWM for the throbbing. And the throbbing speed needs to be adjustable with a potentiometer. I'm really new to circuits, but I'm learning a lot. Can someone point me in the right direction? This is an extremely important project for me.

Question by SpiffyChee    |  last reply


Controlling the speed of a Delta fan via PWM? Answered

First off, i would like to state i am a beginner in this area of whatever this area may be considered to you (Not a complete beginner, i know one or two things...). With that being said, i may need things explained to me to a certain level of extent.  The way i learn is hands on, and having a goal. Since i want to learn the basics of Pulse Width Modulation, i started looking around for a project, and had found one after my brother, a person who works in the International part of Technology (IT Guy.) gave me a project to work on, The project being, to control a 12 volt,  4 amp, 48 watt delta fan and the speed it spins at. His reason being, "I have two delta fans that do a wonderful job at cooling my ridiculously overkill of a computer. My problem, is that the amount of noise they make is too loud, and i would like to be able to adjust the speed of them in order to reduce noise." Since his motherboard cannot control the speed of the fans, he is looking of a manual way of doing it, sticking some sort of device in between the ATX power supply, and the input for the fan(s). The fans have three cables: Red(Positive) Black(Negative) and Blue(With minimal research, i believe this is a censor for the CPU to know at what speed the fan is running at. I also heard it is used for speed control? Someone please clarify.) Looking into methods of reducing speed, adjusting the Pulse width looked like the best idea. Now, for my question. How would i make a device capable of controlling the PWM of such device listed above? I would like to adjust speed via a potentiometer. Thank you for your time and support, -RocketPenguin/Nicola Tesla/LinuxJunkie

Question by RocketPenguin    |  last reply


Reading the max voltage of a low duty cycle PWM?

How do I measure the maximum voltage reached by a very low duty cycle PWM signal without having to alter the signal. The multimeter shows no reading or gives a very brief wrong reading and falls back to zero. I don't have an oscilloscope. Are there any other alternative set-ups to measure just the voltage in this case. Please suggest.

Question by raftor    |  last reply



IS 12V SUPPLY FOR PWM CONTOL INVERTER IS FROM OUTSIDE SOURCE & WHERE TO CONNECT IT'S NEGATIVE(OF OUTSIDE SUPPLY )?

IS 12V SUPPLY FOR PWM CONTOL INVERTER COMING TO THE I.C 7808  ,APART FROM TRANSFORMER, IS FROM OUTSIDE SOURCE & WHERE TO CONNECT IT'S NEGATIVE(OF OUTSIDE SUPPLY )?

Question by ER. ARJUN SHARMA    |  last reply


How do I use an Arduino to write say 2.1 volts? Hobo dataloggers accept 0-2.5vdc inputs. Arduino outputs PWM.. thanks!? Answered

I'm working with a university and they love their Hobo's and I don't blame them... they're pretty straight forward to use...  I'd like to write to the Hobo... here's the hobo analog inputs: 0 to 2.5 Vdc; 0 to 5 Vdc; 0 to 10 Vdc; 4-20 mA Hobo stats: http://www.onsetcomp.com/products/data-loggers/u12-006 Analog channels: 0 to 2.5 Vdc; 0 to 5 Vdc; 0 to 10 Vdc; 4-20 mA Accuracy (logger only): ± 2 mV ± 2.5% of absolute reading; ± 2 mV ± 1% of reading for logger-powered sensors Resolution: 0.6 mV Sample Rate: 1 second to 18 hours, user selectable Time accuracy: ± 1 minute per month at 25°C (77°F), see Plot A Operating range: -20 to 70°C (-4° to 158°F) Operating temperature: Logging: -20° to 70°C (-4° to 158°F) Launch/readout: 0° to 50°C (32° to 122°F), per USB specification Humidity range: 0 to 95% RH, non-condensing

Question by hydronics    |  last reply


Can you take the arduino chip out of the arduino?

I have a pulse width modulation circuit set up on my arduino. Is there a way to take the chip out and connect it to leds? Can anyone explain this simple concept to me? I need to have a TINY PWM circuit

Question by SpiffyChee    |  last reply


How to use pc817 and tip122 to control rectified mains LED array?

I have 3sets of leds that conduct at 250v so I wanted to use my 100v TIP122 NPN(with TVS diodes to protect it from over voltage) and PC817 opto-isolator to PWM the LEDs which are common cathode, is there a way? Thank you all for all the superb suggestoins!

Question by yagoa    |  last reply


PWM with timer on a 12v constant voltage power supply? Answered

I have 5 - 12v LEDs running in parallel. Each lamp has it's own heat sink, fan and resistor,. Each one steadily uses about 850ma. I'm hoping to add a timer of sorts, something that adjusts the light level on a schedule. I've read about people using something like a 555 and/or the Arduino, but I'm kinda lost. Any pointers?

Question by lford4    |  last reply


Is it possible to use PWM to send data via a laser? Answered

I am looking into making a laser tag system with an arduino and was wondering how easy it would be to make a laser diode output PWM signals, instead of using an infrared LED. I'm sure this has been considered before, but I couldn't find it anywhere!! Obviously all players would be given protective glasses to wear :) (on a side note: I was also wondering that if it was possible, could it be used in an RGB laser, to make more than seven colours?) Thanks in advance :)

Question by 5225jackiechanman    |  last reply


Driving DC brushed motors with Pi/PWM/Arduino? Answered

I have a few motors (2) that i would need to be able to drive via a PWM input (Probably from pi/arduino). I have been looking at H bridges, and that seems to be my answer, however, I can't figure out which one i need... The motors are identical 9v ~2 amp stall current motors. I would need both directions for each, and would obviously be using an external power supply.  With that said, which H bridge would suite my needs, along with what type of setup? I only have abut 4-6 PWM pins left to use, if that helps.

Question by RocketPenguin    |  last reply


Can I limit the voltage to a motor using PWM?

Hi, I am trying to build a robot with a dual motors controlled by a l298 chip and PWM. I have some really nice 9.6V NiMh battery packs that I would like to use. The problem is that the motors need 3-5v. Could I just use PWM to control the voltage of the motors by working out what duty cycle would give me the correct voltage and then supplying that to the motors? Would I need a capacitor to smooth out the voltage and reduce noise? Thanks, David.

Question by David97    |  last reply


Could anyone help me with creating a PWM controller? Answered

Hello, I would like to create a PWM controller that has three pot's: - Duty-cycle pot - A pot for adjusting the frequency - a pot for adjusting the output voltage. I'd also like to create this one just with transistors (so no timer IC's). I have some MOSFET's that I can use for switching on and off the load. The PWM controller should output an AC voltage, but if that is too hard to make, an alternating DC voltage is also good. The frequency range should go from 30-50Hz up to 4-6kHz. (I don't really know if this is going to be possible to adjust with just one POT, but I can also use a Trim pot for this). You don't need to explain every little detail. I have basic electronics knowledge. I just don't know where to start. This is what I have until now. It's not working very well because when I change the duty-cycle the frequency also changes. The frequency POT is also not good because the frequency decreases when I go to higher resistance, and when I'm going to the highest resistance, the frequency increases again :(

Question by DELETED_Electorials    |  last reply


DIY Design PWM Contoller for 3 HP 36VDC Motor

A friend of mine and myself want to build a couple of small electric utility vehicles to use for chores around my farm and his cabin. We are thinking of something along the lines of the eMule.  http://www.solarevolution.com/eMule/  We just bought 2 new 3HP 36VDC motors for a really great price off of eBay.  See pics. I want to build some PWM controllers for these to help keep the price of the project down and because I like building things. I could use some help though on a few things. How many amps should the controller be rated for? 100 amps? Larger? Are there any designs out there for a DIYer like me? Thanks.

Topic by starguywisc  


What to do with a UC3842B (HIGH PERFORMANCE CURRENT MODE PWM CONTROLLER)

I have dismantled a CRT monitor and I was wondering what I should with a UC3842B (HIGH PERFORMANCE CURRENT MODE PWM CONTROLLER) that was on the mains power side of the PCB.Here's a link to the datasheet for it.Any suggestions on what I should use it for and how to wire it up?

Topic by thermoelectric    |  last reply


how do you set the duty cycles of the pwm to match the color?help please

How do you match the duty cycle of the pwm to the color of the rgb led? since there are 256 possible shades per Color in an RGB light, there would be 256*256*256 possible combinations, but how would you know which color is which.....

Question by pacificace    |  last reply


Arduino pwm output to control 12v led strip?

Hi, Im trying to figure out how to vary the brightness of an 12v rope light. i currently have the arduino to control the brightness of an 5v Led via the pwm output and would like to do the same but with an 12v rope light instead of the led. In theory i should be able to do this via an transistor but is it possible to Dim the 12v rope light using an transistor this way?

Question by lostangel556    |  last reply


How to drive a 10W RGB LED with 12v PWM? Answered

Hi all, I'd like to drive a 10W RGB LED, much like these ones found in the RGB LED floodlights. I want to strip all of the internal circuitry and control it with 12V PWM signals such as the ones that come from these controllers.  They all seem to provide around 4A/channel. My understanding is that each colour (Red, Green and Blue) needs around ~300ma, so I could use resistors, but as this is a fairly high power situation, there will be a large amount of power loss, and low efficiency. Is there another way ie with constant current drivers specifically for RGB chips that accept 12v RGB PWM input?  Thanks Joe 

Question by joearkay    |  last reply


I give up. Does anyone have a data sheet or manual for an electrocraft MAX-100 PWM drive? Answered

This is no longer supported by electrocraft.  I got it out of an old automated TIG welding positioner.  If anyone knows anything about this particular one I'd be eternally grateful if you would share it with me.

Question by AngryGuy70    |  last reply


Temperature and duty cycle controlling PWM help needed! Answered

Hello, I am working on a Hydrogen generation project. I am using a PWM (pulse width modulator) to control the Generator from going into thermal runaway. However, the current PWM's on the market dont offer temperature control. Only duty cycle control. So I need some help here. I need a way to control a potentiometer to increase or decrease resistance based upon a temperature range from 80 to 95 degrees. I dont want this to turn the unit off, only lower the duty cycle when the peak temp is reached. Then also, when the unit is cold on start up, it would release full amps into it until it reached it peak operating temp. The idea is to make a PWM control the generator via duty cycle (amperage draw) and temperature. Make it a "set it, and forget it" system. My thoughts are using two surface mount thermostatic switches. One for low limit the other for the high limit. Then a relay and another potentiaometer. Theory of operation: On initial start up, the generator is offered full amperage draw of 40 amps(100% duty cycle) until it reaches its operating temperature of 80 to 95 degrees. Once it reaches the peak of the operating temp the upper limit switch kicks open causing a relay to offer a differing resistance (80% duty cycle) that would effectively make the PWM still keep producing hydrogen, but cool down. When or if the lower limit of 80 degrees is reached the lower limit thermostat would close allowing again 100% duty cycle to the generator.  Thus, this system would keep the generator operating at an optimal temperature at all times regardless of outside temperature, and conditions. Current PWM's require the user to manually get them set. If the outside temps are colder the system will work less effectively. If the outside temps are hotter the temps may cause thermal runaway. All operating conditions require the user to be constantly fiddling with, and keeping an eye on the amp draw, temps, and voltage. This means eyes not on the road while driving. Bad ju-ju. I'd like to make this device super simple to operate, and build. With off the shelf items, not custom IC's. Any ideas?

Question by ydeardorff    |  last reply


Interfacing a parallel port and L293D motor drive( PWM)?

I have interfaced a L293D directly with the lpt port of my desktop. A java code in the cpu generates an output of either +5 or 0V. There is no other connection between the parallel port and the l293d. These voltages from the lpt are inputs directly to the motor drive, and the motor rotates when the code runs. My question is: Can you perform pulse width modulation, without using a micro controller? Is there a java code that can do this?

Question by gregarious1987    |  last reply


double multicopter flight controller? Answered

I wanted to know if there are any flight controllers that have separate sensors. I want to use 2 either quad, hex or octo flight controllers with one setup as + and one setup as X to make an octocopter, duodecacopter or hexadecacopter ( 8, 12 and 16 blades respectively ). I want to have a a 6 or 9 DOF IMU connected to 2 separate controllers for larger multicopters. Either that or would anyone know how one might go about designing an arduino controller using either a pwm shield or a TLC5940. Thanks in advance

Question by monty324    |  last reply


Controlling the speed of a 12/24V 100W DC motor? Answered

Hi all, I have been given a 24v DC 100W old scooter motor and one 12v battery (the other 12v battery died). I'd like to be able to control the speed of the motor and have been told I would need a PWM. I have found a PWM on ebay which says that it's a PWM HHO RC Controller, 12V 30A. Would this one be sufficient to slow the motor to say 10-20 RPM and back up to full speed? Thanks in advance.

Question by dchurch24    |  last reply