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 :

 

1234_cr3

 

 

Eagle 6.1 design.

1234_cr4

 

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:

      Hello,

      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.
      Success.

      • 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
        Paul.

  3. Henri says:

    Hy
    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:

      hi,

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

      • Henri says:

        Hy
        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:

      Hello,

      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.

      Iulian

  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
    http://imageshack.us/photo/my-images/7/img0087kt.jpg/

  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.

    Regards

  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:

    Hi,
    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.
    Ben

  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:

    hello,
    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.

    Thanks!

  23. Drew says:

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

    Drew

  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.
    Cheers

  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 ?
    Thanks

  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,
    Rafael.

  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.
    regards
    padmanabhan.k

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

  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
    Theo

  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!
    Joe.

    • 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
      danke

  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:

      Hello,

      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:

    hi,
    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 ?

    Thanks.

  39. Piotr says:

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

  40. Elvin says:

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    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.
    regards
    padmanabhan.k

  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

    tanks

  43. WALID says:

    salut
    s’il vous plait j’ai un moteur 90V 5A EST CE QUE JE PEUT UTILISER CETTE SHEMA
    ET LORSQUE JE REDUIRE LA TENSION ENTRE 15 ET 3OV CA VA MARCHER
    EST CE QUE JE PEUT CHANGER LE TRANSISTOR BUZ11 AVEC EQUIVALENT
    MERCI

  44. WALID says:

    hi
    please I have a 90V motor 5A IS WHAT I CAN USE THIS SHEMA
    AND WHEN I REDUCE THE TENSION BETWEEN 15 AND IT WILL WALK 3OV
    IS WHAT I CAN CHANGE THE TRANSISTOR WITH EQUIVALENT BUZ11
    THANK YOU

  45. Piotrek says:

    Hi

    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.
    felicidades

  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.

    regards
    padmanabhan.k

  49. Uday says:

    Sir
    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
    Candrashekar

  53. Nicos says:

    Hello
    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:

    Hi.
    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,
    Salvador

  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

  66. victor says:

    hola me podrias ayudar?
    hice el circuito pwm con lm339 en una bicicleta electrica usa 24v, 2 baterias de 12v en serie,yo alimente el pwm con una bateria de 12v y deje la salida de potencia de los mosfet a 24v.
    sin carga funciona perfecto, pero con carga no tiene casi fuerza solo trabaja en lo plano en subidas pierde fuerza.
    tengo 2 preguntas
    1 como aumento la potencia fuerza torque ?
    2 puedo alimentar el pwm directamente con 24v sin el regulador de 12v ?
    ya inverti mucho y no logro solucion, tambien te comento que en las compuetas de los mosfet puse resistencias de 4.7 ohms.
    te dejo mi correo y gracias byktor_tj@msn.com

    • victor says:

      Hello could you help me
      I made the pwm circuit with lm339 on an electric bicycle using 24v, 2 12v batteries in series, I power the pwm with a 12v battery and let the power output of the mosfet to 24v.
      No load works perfect, but with load it does not have almost strength only works in the flat in rises loses strength.
      I have 2 questions
      1 how to increase power torque strength?
      2 Can I feed the pwm directly with 24v without the 12v controller?
      I already inverted a lot and I did not get a solution, I also said that in the compuetas of the mosfet I put resistors of 4.7 ohms.
      I leave you my mail and thank you byktor_tj@msn.com

  67. thigiru says:

    Hi Lulian, what is the best mosfet to run on a 144v 400 A dc car drive?

  68. victor says:

    In the physical circuit of the go kart using a large blue capacitor
    Which value or number corresponds in the circuit?
    Thank you, but it seems that this issue is no longer addressed

  69. Joshua says:

    Your both circuits do not work. I think all hobbyists should be aware of such so called electronics gurus who looks like info scammers!

  70. victor says:

    If the go-kart circuit works, but the diagram is not the same as the physical circuit that prevails. The big blue capacitor is not in the diagram, just like the parallel mosfet bridge. It is important to note that it is what keeps the torque.
    I did the gokart project on a bike engine and if it works but it does not have torque, what is it? Nolo se, possibly I miss more mosfet in parallel, although I have no heating, or possibly my motor 400w is boy, greetings

  71. gelifatsy says:

    Thank you, this is so helpful.
    i am building my own EV bike using 1.2k BLDC motor and am looking for simple speed controller. is there any suggestion you can give me to start with?
    Thank you again, you effort means a lot.

  72. To all, I’ve built serveral versions of the DC controller of Iulian, all driven to several mosfets, both N as P as well, and all worked fine. It needs a little tweaking for each version mosfet, and viewing with an oscilloscoop to get it right, and paralleling multiple mosfets when draining current, but the main piece of electronics is working ok.
    The only thing I really changed was the oscillation frequency, I lowered it by a somehow factor 10, leaving out R13 and 14 and increasing value of R12. That really made the difference.
    At last I added a hall sensor electric motorbike handle, directly to the non inverting input of the first opamp.

  73. victor says:

    Hello
    You can give me the values of the resistors you modified
    Or diagram link, picture please
    I can not get good torque by varying frequency or duty cycle
    The original working frequency causes a lot of noise.
    I have a small motor 250w 24v with a output of 6 mosfet in parallel of 90a you connect resistor to the output pwm of 4.7 ohms and one of 4.7ohms to each gate of mosfet …. I am left with doubt that big capacitor to be Look at the physical circuit, what is it?
    My only problem is that I do not have torque strength, it only works well on flat terrain, not hills uphill.
    Help me please my email is: byktor_tj@msn.com

    greetings thank you

    yo hablo español disculpa la traduccion ingles

    • victor says:

      I speak Spanish, excuse the English translation

      • Do you have enough torque when not using a pwm controller, just directly motor attached to 24V?

        • victor says:

          Do you have enough torque when not using a pwm controller, just directly motor attached to 24V?

          Yes, this motor is used on a bicycle.
          The original circuit burned the mosfet to take a mountain slope

          I use the go-kart pwm circuit, and it works well only on flat ground
          In terrain with rise loses force torque.

          There is no heating of anything in the circuit.

          regards

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  75. gelifatsy says:

    Thank you for sharing this.
    I am working on EV motor speed controller, I have 2K BLDC motor, my input from solar panel is 48V, can you please suggest me something to start with?
    Best regards

  76. Charles Knouse says:

    Outstanding work! I really like the way you approached this and made very intelligent use of lower tech, less expensive components through great design.
    I would like to take a look at converting this circuit in order to control the speed of a 1 Hp DC brushed motor with rpm feedback – perhaps an optical sensor on the motor drive gear or shaft.
    I am working on using very cost effective brushed DC motors to convert a lathe over from a 3 phase AC motor to the DC motor with very precise and stable rpm control – operator variable, but automatic feedback rpm circuitry to keep the rpm rock steady and the torque constant at whatever lathe speed the operator chooses.
    Are you interested in taking a look at how to do that? I’m sure your approach would be much smarter than mine, LOL.

  77. M says:

    Hi, thanks for the good job, i want to use it for brushless motor 220v, is it possible’
    thank you

  78. Charles Knouse says:

    Dear Julian207, thank you very much for your outstanding work and your willingness to share. I take back my request; I can see you are buried under a mountain of requests from people who don’t understand electronics at all. I am going to integrate your design with an H-bridge controller, and when I do I will send the design to you for you to use as you wish.
    I am also designing for a 220 KW motor, a huge thing, and I will forward to you my design for that as well – of course, as you know, it’s about mosfets that can handle well over a thousand amps in surge current, with Rds(on) of less than a milliohm – or paralleling mosfets in order to achieve well below a milliohm of resistance. And, of course, heavy heatsinking and fast current limiting, both of which I think most of your responders know nothing about.
    Very Best Regards, in Christ’s Love, Charles

  79. Sînt din România,am un motor D.C. 12-24V/20A(este cu diferențial+ electro frînă150 ohmi). SCHEMA DE MAI SUS(LM339) merge la motorul meu? Vă mulțumesc,aștelt răspuns ce pași trebuie urmați? O zi bun multă sănătate,spor și izvor n” toate.

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  81. HyunChul says:

    Hello. nice to meet you.
    I am Korean.
    I am interested in this.
    I want to make this.
    But there is one question.
    In the first circuit
    I want to change the 7812 to 7805 or 7809.
    If I change it, should I change the resistance values?
    Can you tell me the resistance value?
    Or can you tell me how to calculate the resistance value?
    Please teach me.
    Thank you.

  82. kkren says:

    Hi, Thanks for the tutorial, I was wondering if this circuit will work for a DC motor 48 volts, 98 Amps.
    the powers is 2000 – 4000 Watts,
    Torque 9 N.m
    Speed 2150 – 4250 rpm
    If it does not work, can you suggest what kind of changes can I make? I will appreciate if you can help me with the circuit schematic.

    Thanks