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


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


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


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


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


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


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


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


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


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


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


I need to know where to put the POT in the treadmill motor controller?

 I need to know where to put the POT in the treadmill motor controller? Because I have a digital controller from model MC2100 (proform 400X) Thanks

Question by dulo   |  last reply


Capacitor charger? Answered

Ok so im planning on building a portable coil/rail gun. But one issue is I cant quite find a circuit that would work best to drive a custom transformer. The charger I have now is a flyback driver that I used a wall adapter to power. I just need some advice and maybe schematics. Thanks, bud

Question by budhaztm   |  last reply


Electronics Help

Hi ppl,I am currently making a variation on this circuit:http://www.edn.com/article/CA257052.htmlhttp://www.edn.com/contents/images/257052f1.pdfI understand how it all works but do not understand the principle of the inductor capacitor used (bottom left), if anyone could give a brief explanation of this (links are good too) and also some formulae i would b e very greatful!!thanks

Topic by drummer ian   |  last reply


Is the led driver malfunctioning? or am I?

The led driver  http://www.parts-express.com/pedocs/manuals/073-048-parts-express-manual-7169.pdf Im using an arduino to fade LEDs through PWM. The code works on normal rgb LEDs, but i need it to be much brighter. I bought 3, 3 watt, HPLEDs. they are very very nice and bright. but only work with all colors full brightness... i have attached the arduino pins that controlled the normal rgb LEDs to the driver. but this does nothing different then if the pins were disconnected. also if i dont power up the driver and just plug in the arduino it will change the colors of the leds. but it will be just as bright as the normal ones because its only getting 5 volts instead of 13.5. also the color fade cycle acts really weird. not sure what thats all about or why it even does anything just with the arduino plugged in. Does anyone know where to get a decent LED driver? i have looked around for days and could not find what im looking for. this looked like my best option but its not working... thanks for your help. -Rex 

Question by RexHex   |  last reply


Using a hall effect sensor with TL494 pulse width modulator.

I have an electric billy cart with a dead controller board. I constructed the kit circuit below to replace the dead board and it works well enough for the job except for one small problem. The throttle on the billy cart utilizes a hall effect device and not a pot. The billy cart also has a handbrake with a switch that closes when applied. I use this with a resistor to discharge C2 and pull pin 4 (inhibit) high. This ensures a gentle start (as the capacitor slowly charges through the 100k resistor) if the brake is released with the throttle advanced. The output range of the throttle is 950 mV to 4.1 V if VREF (5V) is used as the supply. (I'm dropping it in in place of the pot.) 4.1 V is sufficient to achieve the maximum 90% duty cycle of the chip, but 950 mV leaves me with a minimum duty cycle of about 21%, and of course a motor that won't stop. Will changing the divider ratios 20k/2k2 & 47k/47k be sufficient to get me zero speed or am I going to have to do something more exotic? Thanks in advance.

Topic by Rasputin182   |  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


*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 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


Is it possible to use PWM on Arduino to control the voltage of an external power source? Answered

Let's say I want to vary the speed of the motor that operates at 12V. Since PWM on Arduino only provides the maximum current of 5V it can't power the motor sufficiently. So my question is how can I use PWM on Arduino to increase or decrease the input voltage of the external source? I will appreciate your answers.

Question by Shizen   |  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


Does anyone know any good PWM tutorials for the AtMega32 and AtMega168 chips. These are not arduinos. Answered

Does anyone know any good PWM tutorials for the AtMega32 and AtMega168 chips. These are not arduinos. I am looking specifically for servo and DC Motor control but any tutorial on PWM should give me the base I need to move forward.

Question by TheTrustedOne   |  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


If I use 12v, the motor burns, 8v it takes longer to burn and 5v is not enough, will PWM save me? Answered

Here's the deal: I'm working on a project that uses 2 motors (PS2 controller vibrating motor, without the counterweight), I assume these are 5v dc motors, right? Both rotate the same axis (1 is not enough due to the pressure that is being put on it, a spring mechanism stuff) With 12v it runs like a dream, till they burn! and from what I observed, always 1 motor hits higher temperature than the other, is there a problem with that? Then I dropped it to 5v with diodes and the motors didnt have the strenght to start spinning, so I raised to 8v and they spin, not very smoothly (is that spell right?), but you know, they work, but still they're overheating! If I used PWM to control both of the motors, would it work and not burn'em? Thanks and sorry for the long and confusing text.

Question by Kokkan   |  last reply


Motor controlers?

I have a 24 volt motor from an old mobility scooter and I want to control it with my arduino but I have no idea what motor controller to use. I presume that I will need to use PWM to control it but what hardware to use I have no idea. Any help I would really appreciate. Thanks

Question by cheesemarathon   |  last reply


Is feedback compulsory for a pmdc motor controller?

I am designing a controller circuit(pwm based) to control a 36V,12A pmdc motor to be used in an electric cycle.  As i won't have any load changing situation, is it essential to have a tachogenerator feedback or is it fine to just have a current limiting algorithm?  Please help me out , am stuck with this for a long time..

Question by elec_freak   |  last reply


rc project

I decided to go for the rc car. I'm using the 1/5 scale  maxstone trying to combine it with the raspberry pi. I'm also using adafruit's pwm. I know this might be old to others but it is new to me. I am a beginner and I am very excited about it!    I am open to any suggestions, comments, feedback, links, anything would be great!

Topic by SMILEY4242   |  last reply


AVR sense/PWMing Help!

Hi again! I'm intent on finishing up a few loose end projects of mine, but before I do so, need the following information. How can I sense some resistance or voltage with my uC? I know I can do an a/d conversion, but that only triggers when Vin > some 1 preset value. I'm looking to make an adjustable knob to turn the intensity of an LED up and down. Also, how can I PWM some LEDs with my AVR uC - I can use the tiny2313 or mega8 or tiny 13, but I have no preference. I just need 3 different PWM channels. Any ideas? I already googled, but apparently I'm terrible at finding good tutorials. (oh, and I'm coding in C) The LEDs will be inserted into this nice, custom built (by myself) welded devil duckie. Horns and tail will turn to control RGB. Thanks a whole lot, -Muffin

Topic by T3h_Muffinator   |  last reply


Speed controller for brushless electric bike motor? Answered

I have obtained a 400W 24V 2800RPM Monophase BLDC motor with related power supply and a 24V 40A-rated pulse width modulator unit, however from what i understand the PWM won't give me full control (if any at all) of the actual speed of a BLDC motor. I want my motor's torque to remain relatively intact and for it to cover a range of about 50-300 RPM, with no need for exact control. Are my only choices to build a pulley mechanism or to buy a mechanical gearbox? I'd like to control my motor electronically.

Question by Khalim   |  last reply


Noise in Amp from LED Strip & servo

Hi, I am working on a project in which TL072 is amplifying an audio signal which is going to speakers & arduino analog input. Amp is powered by a wall wart with 12V 2A output. The same 12V is also regulated to 5V and used to power an AVR. The AVR is being used to PWM, using a power transistor(TIP120), an LED strip taking 1A from the same 12V supply. There  1) Now the rapid switching of current for LED strip is messing up the amplifier output. It's working fine with LED Strip off but when using PWM, there is a high frequency noise in the amplifier output. I have a 0.1uF and 10uF caps near power inputs for both AVR and amplifier. This is probably due to insufficient decoupling. Can someone please help me make it better? 2) There is another independent source of noise I'm finding which I'm unable to explain. The audio is going into Arduino which is controlling a servo as well. As soon as the servo is connected, there is a constant loud noise in amplifier output. This remains even after powering the arduino and servo using seperate USB supply(only ground connected). I placed audio setup and servo data wire far apart since they may be interfering due to PWM used for servo, but it wasn't of any use. Since in both cases, amplifier is producing noise, I think my amplifier diagram might be at fault. If I remove the amplifier, the audio stream reaches arduino without any noise . Anybody got any ideas how to remove these 2 noises? Attached images: amplifier schematic, graph of audio input in Arduino analog pin. -Antzy

Topic by Antzy Carmasaic   |  last reply


Connect DC motor to Servo Output? Answered

I am currently working on a robot of sorts, and have a quick question i would like to ask. I am using a Raspberry Pi as my "Brain", and am using ServoBlaster as my software. I am currently working on driving 6 servos and two motors with said software. My question is, how would i attach the motors to the board? I would like to control the motors with the same software (ServoBlaster) and thus would like to have them run off of PWM. The software allows me to change the min and max range of width, along with a whole bunch of other things, but that is for a later date.  So, my question is, how would i wire a motor up to a PWM output? I would like the motor to be continuous rotation (I am using a Mindstorms motor for the task, which will move the robot). I guess i could use an ESC, but i would like to do it without one (Though, if you linked one that would work in this situation, I wouldn't kill you :P Here is a link to the motor if you need more info on it: http://www.amazon.com/LEGO-Mindstorms-Interactive-Servo-Motor/dp/B003BCCYSK )  Preferably a method that doesn't require purchasing something i don't have would be best. If this isn't possible, please keep it on the lower end of price tags, as my funding is running dry. Thanks!

Question by RocketPenguin   |  last reply


Solar panel short reads 28v? yet charge controller reads 14v? Batteries?

I have a solar panel that I picked up on internet for free due to damaged glass(no biggie).  Placing a voltmeter across the output leads has 28.6volts.  I connected this to a PWM charge controller recycled from a junk yard.  I set the CC parameters to 24v and hooked up two 12v car batteries(13.2v good) in series to make my 24v circuit.  Now the CC digital panel reads 14v.  Checked all the connections and retested the panel, two batteries and CC. It checks out ok. But why does the CC readout at 14v in full sunlight? yet the panel reads 28.6v? The only thing is the two batteries are different in AH ratings. One is 96 Ah and the other 115Ah.

Question by JuG2   |  last reply


Rotating a simple DC motor really slowly (1 rotation per 2 hours)?

This is to rotate a bike chain on a small cog. After doing some research, I came across a component called a Pulse Width Modulator. Would this be suitable for turning a simple DC motor at 1 rotation per 12 hours(EDIT: I meant 1 rotation per 2 hours, not 1 every 12 hours)? Or, would it only get me to a certain point before I need to use gear ratios to achieve my ideal revs? This really is a budget project so nothing too fancy.  Thanks

Question by Nenagh   |  last reply


Does anybody know a tiny MCU for PWM and USB Connection?

I need a microcontroller with 3 PWM pins, for an RGB LED. I also need to connect it to a computer using USB. I`ve seen the attiny2313 has enough PWM pins for this, but is quite big. As I understand, the attiny 25 has just 2 PWM channels. Does the attiny24(or 44 or 84) have enough pins for USB Serial comunication and 3 PWM pins?

Question by flixer   |  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


What is the easiest way to fade in and out/pulse leds?

Consists of 21 blue leds connected in parallel taken from one of those cheap toy lightsabers. Before disassembly, the leds were powered by an on/off switch and 3 AA batteries. All options considered - 555 PWM, PIC, or even descrete components. Finally, circuit to be powered from 5V-9V.

Question by clint2880   |  last reply


DC motor speed controling Answered

HI! I'm trying to mod my Tascam cassette recorder. I want to be able control speed of the motor. So I bought on ebay PWM controller and after installation thing don't run so smooth as I wish. the problem is ... when pot is all the way down at 7 clock motor is off, when I turn it to 8 a clock motor starts spinning and reaches its full speed at 9 a clock. and from 9 a clock to 4 there is no effect on speed. Please help me! .... my electronic skills are too weak to understand this. p.s it is 12v dc motor and there is link for the pwm I use. http://www.ebay.co.uk/itm/111817741979?_trksid=p2057872.m2749.l2648&ssPageName;=STRK%3AMEBIDX%3AIT Thanks

Question by AndrisT1   |  last reply


DC motor speed controling

HI!  I'm trying to mod my Tascam cassette recorder. I want to be able control speed of the motor. So I bought on ebay PWM controller and after installation thing don't run so smooth as I wish. the problem is ... when pot is all the way down at 7 clock motor is off, when I turn it to 8 a clock motor starts spinning and reaches its full speed at 9 a clock. and from 9 a clock to 4 there is no effect on speed. Please help me! .... my electronic skills are too weak to understand this. p.s  it is 12v dc motor and there is link for the pwm I use.  http://www.ebay.co.uk/itm/111817741979?_trksid=p2057872.m2749.l2648&ssPageName;=STRK%3AMEBIDX%3AIT Thanks    

Topic by AndrisT1   |  last reply