This is the best cheapest DC motor speed controller circuit that you can find on internet.

In the past i tried wit NE555 and other circuits but the results were every time in shorted mosfet`s 😀 and not stoppable GO KART (not very good thing when you do not have a big red kill switch).

In in the following i will  present my DC Motor speed controller capable of adjusting speed (PWM)  form 0 – 100% and the frequency form  ~ 400Hz to 3kHz, based on LM339 comparator.

The power supply is from 14-30volts,  expandable to practical any value with little modification.

From R15 VR 10k you can adjust the speed from 0 -100%

From R14 VR 100k you can adjust the frequency.

If the jumper JP1 is shorted you can adjust the PWM frequency from 400Hz  to 3kHz. If jumper is open Freq is fixed at 100Hz.

The circuit is designed in Eagle cad 6.2



You can use almost any Channel N mosfet`s you want. The fets will be mounted on a radiator if the current is  higher than 2-5 amp.

It is possible to increase the voltage supply to any value if you separate the power to the logic circuit from power to the load and mosfet`s

This is my second prototype of dc motor controller


Depending on Rds ON value of the mosfet`s you will need a smaller or bigger radiator.

The wires will be at least 12 AWG for a 30 -35  amp load.

For any questions you can  ask me any time via my e-mail found on about menu.

Success with the circuit.

This is the real life testing of the circuit.




High quality improved PWM controller based on MC33035 IC.

Schematic :





Eagle 6.1 design.



I used as mosfet driver the TC4452 IC with is capable of 12Amp output.

I used this schematic in conjunction with power stage formed by 10 mosfets in parralel with all gate connected via 10pcs  20 ohm resistor to the output of the IC driver.

For current sense circuit i used allegro sensor ACS758

50-200A current sensor IC

The Allegro CA and CB package current sensor ICs are fully integrated current sensor solutions. They contain the primary conductor, concentrating ferromagnetic core and the analog output Hall-effect linear in a single IC package. The conductor resistance is a typical of 100 µΩ for ultra low power loss when sensing current up to 200 A. These sensors are automotive grade devices that can take the heat and deliver highly accurate open loop current sensing in the most harsh applications environments.

The Allegro medium current devices are much smaller than bulky current transformers and have the added advantage of sensing both AC and DC currents. The package design also provides galvanic isolation to 3000 VRMS and can be used in many line side applications.

  1. Stefano says:

    very nice project!! I hope you will manage to finish it soon!

    post more videos and details about your equipment and your improvements =)
    i’d like to build something similar if it will work…

    good luck!!

  2. Hello, excellent design, I intend to use it with a dc motor 100v electric treadmill, I want to use IGBT, FET in place, so I’m going to separate the power of the logic on the part of power, you recommend for me, any more change circuit?

    good luck.

    Mauro de Amorim

    • iulian207 says:


      Thank you for interest,
      You only need IGBT if the voltage is above 200v, so in this case is better to put Mosfets.
      There is no absolutely need to separate the power source. You need a switching power supply working on 100v dc input and 15 volts output.(not very easy to find)
      So it`s up to you what is better.
      In this circuit you do not have under voltage protection, to achieve that you need a mosfet driver like. IR2103.

      If you have further questions please do not hesitate to ask.

      • Frank says:

        first of all i would like to Salyut because of you are shearing your knowledge with the other peope to help to cove them targets. and i very thank full to you. i need to use this for ran the treadmill machine. there working voltage is 30v – 160v. so how can i use this circuit or if you have another circuit for more than suitable for ran treadmill. please advice me. in treadmill the motor must need to ran very smoothly and linearity, so please kindly help me.

        thank you.

      • Pauly says:

        Dear Iulian,

        I saw your video on youtube for the motor driver. Awesome. What are you currently working on?

        Would it be possible to vary the pwm frequency to higher levels?

        I am trying to implement a wire edm power supply. I need a (arduino) logic driven mosfet circuit that can deliver: 50 – 150 VDC at a few amps with a varying pwm frequency of between 1kHz-200khz. Any help or advice would be much appreciated. Happy to donate ofcourse. Kind regards

  3. Henri says:

    I am planing to do a Pwm-Controller based on a Arduino for my elecrtic car.
    I first tried with a Simple Pwm based on a NE555 but I drove half a meter and the Print got overvoltage trough the Mosfet.
    Do I need more protection than a flying diode and the RC compensator?

    Thanks dude for the good Description!

    • iulian207 says:


      You need to put a mosfet driver like im my schematic with 2 bc transistors.
      Where do you read overvoltage?

      • Henri says:

        Ok but wich use does the secound Mosfet has? Is just to divide the Current?
        No the Motor produced overvoltage, and destroid the mosfet and so the ne555.

        Thanks for the Help!

  4. nabiel says:

    nice, can i have that circuit board layout and component list and send to my email thanks before goodluck and brovo

    • iulian207 says:


      for the moment i discovered a bug in the schematic and want to modify.I need to add CD4049 to invert the high side and the low side.
      After i can give you the brd file and sch in eagle.


  5. muy bueno tu circuito el de dc gracias

  6. armandd says:

    What’s the expected efficiency of this controller, sir?

    • iulian207 says:

      The efficiency is given by multiple things.
      1. Position of hall sensors ( timing)
      2. Internal resistance of the mosfets in conduction state.
      3. Commutation losses in the mosfets.

      • armandd says:

        Thanks for the answer! =). One last question, you said that this controller can use supply from 14-30V. Can I use 12V supply? Thanks again.

  7. armandd says:

    Hi iulian. You mentioned that you’ve discovered a bug in the schematic and wanted to modify it. Can you post it here pls? Thanks a bunch!

  8. armandd says:

    pls iulian, need your help here!

  9. ady says:

    salut!am un motor brushless si vrea sa incerc sa-i fac un controler.problema este ca nu stiu unde sa-i pun senzorii magnetici.poate ma ajuti tu,trimit o poza cu motorul

  10. handoko says:

    please give me the circuit. and give me tutorial how to make BLDC motor fully

  11. FJ says:

    Hi there,

    I’m going to do a speed controller for green power motor that is supplied by 24 DC volt. The running current will be 10A but the starting current will be around 100A. Do you think it will work safely if I designed a circuit with voltage regulator, NE555 and transistors. Also, could you please tell me more about NE555 problem that you had before.


  12. Kaan says:

    Circuit looks simple and applicable, congrats for your work my friend. However, your switch frequency might be higher for a better performance. Last week I built a circuit for my 200watt prototype car and set frequency as 100khz. This is a bit high but when I checked oscilloscope data the oscilloscope could not see any ripple. This might increase your efficiency of your motor, and if you write your specs of your motor we can check a better frequency if you want.

  13. Radu DOMIDE says:

    Buna ziua.
    V-am gasit prin Internet, cautind module electronice de comanda pentru motoare de curent continuu fara perii. Sint pe cale sa construiesc un vehicule de tip Segway, cu partea electronica pilotata cu un microcontroler Arduino. Partea mecanica nu-mi pune nici o problema, insa pentru electronica as avea nevoie de o minte stralucita de roman. Daca vreti sa ma ajutati, trimiteti-mi, va rog, prin email un numar de telefon fix. este mai simplu de comunicat decit prin email. Cam peste o luna voi veni la Bucuresti si mi-ar fi facut placere sa va cunosc. Ar putea fi o ocazie sa va expun in detaliu proiectul meu. Cine stie daca nu va va da noi idei pentru proiecte viitoare.
    Cu stima, Radu DOMIDE.

  14. mingtje says:

    dear iulian,can you sed me e-mail for 3kw pwm schematic,i need to repair my sonsh go kart with two motors,i prefer if you have the layout of pcb,thank you
    sorry my native language is indonesia

  15. Oleg says:

    Study to write himself, the post from one more source

  16. Ben says:

    I’m going to try and build this. it will be a first for me. I’m gathering parts and having a little difficulty. do you have a BOM? One in particular is the 7812tv. there seem to be plenty of 7812’s and many variations but not “tv” at least that i can find. thank you for all your help. really amazing what you’re capable of creating.

  17. mendi says:

    Hi, how many mosfets did you used? at the schematic i can see 2 mosfets but at the videos i can see 4 or 5 mosfets? and and how many mosfets can put to get maximum power?

  18. Luis Fregenal says:

    Hello. . I want to build some similar. . I not understand the Big Capacitor. . I want to use H-Bridge. ¿Where put the Big capacitor?

  19. hamdy says:

    i made your circuit as a controller for an H-bridge circuit… to control the speed of the motor, I used MOSFETs IRF1010N to can withstand the 30 amp of the motor …. after all that it doesn’t control the H-bridge circuit … i also feed the controller circuit with 24VDC..
    i don’t know what is the wrong with what i done.. thanks & i appreciate your help

    • iulian207 says:

      First you need to see if you have any fault conditions. Fault Led turn on. Led need to be off in order to work.

  20. Интересная статья по этому поводу…

  21. ryan says:

    How many diodes did you use for the 24 mosfets? 1 per bank of 6? How does that work for back emf? That diode seems way too small! Why isn’t it blowing up from the back emf especially when the controller is at a high frequency and low speed?

    • iulian207 says:

      In do not need any diode. The mosfets have a diode inside. How you can say that diode seems way to small when there is no diode?
      Please document more about the 3 phase brushless controllers, and after came with some mentions.
      The controller is working perfectly even at 100Amp. So why is nothing blowing up?
      At dc controllers you need a big fat diode for back emf like RURG8060.

  22. Drew says:

    Will the design work for a 12V brushed motor?

    Can you provide a bill of material? I would like to build this to speed control a go kart for my 12 year old son.


  23. Drew says:

    Just for clarification, I was interested in the high quality improved PWM controller based on MC33035 IC.


  24. Jimmy says:

    Can you provide me the schematics or details to be used in 48v DCmotor , thank you

  25. José Gonçalves says:

    Hi. Can you sent me your schematics i will try to reproduce your project.

  26. nesa says:

    can you give me a scheme to tying MOSFET in parallel?

  27. Richie says:

    I need you to make 3 PCBs of your project and send them to me. I also need you to get all the components needed, 3 DC motors, and 3 compatible vehicles, and send those as well. Oh, and a female model must be in each vehicle. I’m joking of course – it’s just funny what some of these people ask you for (actually demand), and I had to make fun of them a little. Nice circuit though! I’ve been working on a 100v 100a DC motor (10hp) drive circuit and it’s been a nightmare – even when things are rated for 10000 watts, they still burn up (even with a soft start). Maybe it’s because I can only afford cheap components from China that are over-rated. 🙁

  28. Andy says:

    Hi iullian, there’s some great information here.
    I am struggling to understand the MOSFET arrangement. I see in the schematic there are clearly 2 FETs but on an image and in a previous post to a question you state there are 24. Could you please specify this arrangement in more detail?

    Thanks. Andy.

  29. hamdy says:

    Firstly, good job & bravo
    my question is can i use the driver part of this circuit to drive an H-bridge just to control the direction of motor & Kart too ?

  30. Hello Julian! Great projects you have here!

    I build your circuit and I am facing this problem that when I put any load near 15a the circuit shuts down… then I suspend the load and it turn on again after about 5 seconds.

    It seems like the energy from the logic circuit is sucked out by the load.
    Maybe one capacitor or a diode somewere could solve it but I dont know :S

    If you have any Idea of how to solve it would be very much apreciated.

    My regards,

  31. Dear sir,
    iwant to build a Dc motor control working on 24v Dc and current of 30A in both direction, can i adopt the circuit of yours using mc 33035 and pl let me know if there is any updated version.

  32. Dear sir,
    waiting for your reply, kindly reply at the earliest.

  33. Theo says:

    Hello Iulian

    I like the go kart you built. I bought a similar DC motor and i also did the chasis so i was wondering if you can send me your circuit diagram so i can power it up!

    Great Job!!! All the best

  34. Joe Mosbacher says:

    Hi Iulian!
    I just wanted to thank you for the DC controller schematic. I built it and it works perfectly.
    The benefits of old school analog PWM generation with comparators have been forgotten a bit since microcontrollers are everywhere these days. I had a very hard time finding anything as simple and robust as this. Thank you again, the internet is a beautiful place because of people like you.
    Keep up the good work!

    • iulian207 says:

      I glad that you made it. Success with other projects.

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    • slavko josipovic says:

      kannst du mir auch das DC-Controller-Schema schicken

  35. sel says:

    hi i need to full bridge dc motor driver 50amp

    if you have good shematic please help me
    i made hip4081 and irf1405 but the mosfet much warm haw can use good snubber

    • iulian207 says:


      For 50A if you use 4 mosfets in parallel should be no problem, you can use 4110 is much better. because the internal ON resistance is 3.5mohmi cand can sustain 120A continuous at (least in the datasheet).

  36. hanie333 says:

    i want to build a pwm dc motor controller using pic16f877a. the motor is rated 120Vdc, 1/4 hp, 2.8A, 1800rpm. i have already finshed programming the pic to generate the PWM signals but i dont know how to design the schematic for the controller. i have read a lot about h-bridge for controlling smaller voltage motors but still i am confused on how should i apply and modify it accordingly to 120V DC motor. Any help would be appreciated. Thank you.

  37. John says:

    Hi Julian

    Thank you for the circuit as I have been looking for something to control 12v DC golf cart motors. Your circuit looks to be designed for 24 volt but I am wondering if I change the voltage regulator for a 7810 regulator instead and apply a 12 to 14 volt supply instead if the circuit will continue to work as is.
    Unsure if fet control voltages would be effected to the point of damage?
    Be grateful for any advice.

    Will build and try this but you may be able to save me a lot of time.

    Cheers John

  38. Vijay Sahasrabudhe says:

    Dear sir,

    I am planning to make DC controller for 24 V 1500 W (PMM) motor.
    What should be the Suitable MOSFET number and also what should be snubber combination. I have burnt 555 and multiple IRFZ540 (10 in parallel) any driver needed ?


  39. Piotr says:

    I have one question. What if the motor have 25amps current?

  40. Elvin says:

    This article will assist the intesrnet viewers for setting up new
    weblog or even a blog from start to end.

  41. Hello sir,
    i had posted 2 requests during 9th FEB 2014, iam yet to get any reply from your end.

  42. doki says:

    hi, i want bidirectional speed control circuit for control dc motor 20 horse (150v-240v)
    i want circuit diagram and layout pcb and program if circuit contain pic


  43. WALID says:

    s’il vous plait j’ai un moteur 90V 5A EST CE QUE JE PEUT UTILISER CETTE SHEMA

  44. WALID says:

    please I have a 90V motor 5A IS WHAT I CAN USE THIS SHEMA

  45. Piotrek says:


    I have a problem with controller based on mc3335. I have FAULT(LED light). I have the same board, pin 9 csensin is unconnected and the power on pin 17,18 is 12VDC. I don’t know what I’m doing wrong… Could you help me?

  46. Epifanío says:

    Hola Julian esto es barbaro muy sorprendente sobre todo la potencia que maneja.

  47. Epifanío says:

    voy a implementarlo para ver los resultados en México

  48. Hellow sir,
    i had posted 3 requests, and till date i have not received any response from your end. kindly reply when free.


  49. Uday says:

    In DC Motor Speed Controller PWM 0-100% ,

    How to connect hall effect sensor (49e) instead of 10k pot.

    Thank you in advance.

  50. Arnold says:

    Dear sir ,

    can I use the above circuit to control the speed of a car starter motor.

    Thank you.

  51. Hi,
    Rigged up your circuit to control 12V Dc car wiper motor.Not able to control speed from min to max.Motor starts to rotate only from speed and up ,Kindly advice on my mail Id

  52. Hi.

    Rigged up this circuit for 12v Dc car viper motor.

    It starts to rotate only after certain amount of ratatoin of potential meter please advice to over come this problem dose not start at minspeed. Please advice

    Thank you

  53. Nicos says:

    I am going to use the first circuit using an LM393 ic since you used only two of the four comparators of the LM339. Is that ok?
    Then I will use four RU4099R MOSFETs in parallel which are 200A continues current, RDs 2.8m each. How much will be the max current of the controller depending on my MOSFETs?
    Also according of the 2.8m RDs should I make any changes?

  54. ketan says:

    im looking 12v dc 25amp 3000 rpm seep controller can u help me in that pl.

  55. Roji says:

    r these electric drives ? which u have used here…..

  56. Nandasiri says:

    Dear Sir.I need to control 100V / 6A motor from 230 mains voltage.How can I modify this circuit to that specifications.Thanks

  57. Noman Javed says:

    Dear,your work is excellent,i am undergrade Mechatronics Engineer,i want to know somethings from you
    1)what is the reason behind shorted Drain to source Mosfet,i wasted lots of money on mosfets and getting same problem all the time,also mention the cure
    2)why you have used lm339,are these for constant current source?are these recommeneded?
    3)why not simply produce diffrent pulses with any microcontroller rather then fabricatting all that circuit?

  58. Mihael says:

    Do you perhaps have a scheme for controler power 5 or 6 kw 24

  59. Berca,

    I built the first DC-motor controller and it worked fine.
    the first opamp is a oscillator, the second to compare with a voltage between 2.1V and 9.9V, fed by a potentiometer of 10k.
    Now I want to add a electric scooter throttle, and it seems to be a hall-sensor, fed by 5V, and giving values between 0.8 V and 4 V.
    Can I drop the power of 12v to 6V so I can feed the positive input of the second opamp directly with this range, if I lift up the ground of the hall sensor with 1 V?
    The hall sensor then will operate on 5V, giving ranges of aproximately 1.2 V to 5V measured from ground. The opamps should operate on 6V fine as well.
    Or do I have to change the resistor values of the setting of the two transistors to the Mosfets?

  60. Second thought:
    If I replace the 7812 with a 7805, the Hall sensor output should match exactly the needed input for the comparator…
    The mosfets should open on 5v as well if I’m not mistaken.
    I’ll try this weekend and take a look at my scope. Hope my go-kart will go soon now

  61. Matejbrbrbr says:

    I really need a good pwm circuit for various uses as well as for lower currents as your circuit seems very stable and as you mentioned, very good to mosfets as I also blew a few more expensive mosfets as I was testing to the point I had no more.
    I was just wondering, is there a way to change frequency on your improved pwm controller or what is the stock frequency range.
    And that pwm output connects to the gate of mosfet(s) and a recovery / flyback diode like a schottky would be good. Correct me if I am wrong about connecting to the mosfets part.
    Good stuff man 🙂

  62. Salvador Jiménez Martínez says:

    Hi, I´m from Mexico, I want to buy the controller and the accelerator for my conversion proyect: vw bug to ev. I need a cheap price because I´m unemployed, and the future ev is for to work. The motor that I have is used (forklift), Raymond dc brushed series motor FD1-4001 36-48vdc, high torque, and 18 KW aprox., may be 200 amp or more continuos.
    Please say me the price of controller and the accelerator complete for vw bug model 92.
    you say me too the pay conditions from México and I pay shipping from US to México.
    Please is very urgent.
    Best regards,

  63. PRIYABRATA says:

    sir, would you plz give me a circuit diagram to speed and direction control a 12
    volt 250 watt bldc motor used for quadcopter….
    plz sir…..
    thank you….

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  65. Hey, I am a mechanical engineer I’m working on a project similar to your go kart and i have some questions related to final RPM and speed, if you have a chance to contact me by email i will appreciate any help i can get.

    Roberto Mojica