DC motor control circuit using NE555

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Description.

A simple DC motor controller circuit using NE555 is shown here. Many DC motor speed control circuits have been published here but this is the first one using NE555 timer IC. In addition to controlling the motors speed its direction of rotation can be also changed using this circuit.

A PWM circuit based on timer NE555 is the heart of this circuit. NE555 is wired as an astable multivibrator whose duty cycle can be adjusted by varying the POT R1. The output of IC1 is coupled to the base of transistor Q1 which drives the motor according to the PWM signal available at its base. Higher the duty cycle the average voltage across motor will be high which results in higher motor speed and vice versa. Change of DC motor direction is attained using the DPDT switch S1 which on application just toggles the polarity applied to the motor.

Circuit diagram of DC motor controller.

Dc motor control circuit diagram
DC motor controller using NE555

Notes.

  • The circuit can be assembled on a Vero board or PCB.
  • Use 12V DC for powering the IC.
  • Vm is the power supply for motor and its value depends on the motors voltage rating. Any way maximum Vceo for BD139 is 80V and so Vm should not be exceeded 80 volts.
  • Maximum collector current BD139 can handle is 1.5A and so do not use a motor that consumes more than 1.5 amperes of current.
  • A heat sink is necessary for BD139.

Few other  DC motor speed control circuit you may be interested in:

1. Stepper motor controller

2. PWM Motor Speed Control Circuit

3. Speed control for PCB drill

Author

33 Comments

  1. kamlesh malviya

    i want to pcb board to operate camera head (3 dc motor controled) for panning , tilting, dutching (3 axis)

    • @kamlesh – we dont provide PCB for your requirement now. Sorry!

  2. I used a 33 ohm resistor for the base bias resistor as per the schematic, but it got extremely hot.

    I substituted a 470 ohm resistor and voila! it works perfectly. Thanks

  3. why ceramic capacitor is used in above circuit……. y not simple capacitor ?

  4. Hi there..!! when 12 volt is applied through battery to IC (in proteus schematic) it provides only 5v..?? why is it happening so..??

  5. Explain the principle of control of dc motor using microcomputer drive. Include diagrams

  6. i solder this speed controll cercuit using 555 but it is not working, please reply soon

    • ankitkumar herwade

      how speed can be measure for small motor

  7. Circuit diagram of DC motor controller. I think is better, but iwant to know this cercuit can drive brush motor. Give me a reply soon. Thank you.

  8. sorry can i use LM35 instead variable resistor….if yes …how can i connect it….plz ans me

  9. ANKUR PATEL

    CAN SOME ONE TELL ME. WHAT IS THE ROLE OF NE555 IN THIS CIRCUIT AND principal OF CIRCUIT IN SPEED CONTROL OF DC MOTOR.

    • Hi..!! actually in this circuit PWM (pulse width modulation) technique is used to rotate motor. This can be done in two ways :
      1) by controlling armature voltage (as done in this circuit)
      2) by controlling field current.

      So far as ne555 is concerned, it is used to provide pulse as PWM technique is used. With the help of var-resistor, the pulse width is adjusted to obtain required speed.

  10. Seetharaman

    Hi A brush less motor requires an AC signal through an electronic circuit to drive it. Hence the above circuit cannot drive a brush less motor directly.

  11. hello guyz , i wanna put a brushless motor in this circuit is that possible ??
    and could the voltage out drive that motor at its high speed (nearly 9000 RPM )
    quick help please

  12. hi, i have got a dc motor 240V 13A, if i substitute the BD139 with the BUW90 NPN 250V 20A transistor, the circuits work? thank for your time and excusme for my english, but i’m italian.
    Thanks

    • Seetharaman

      12volt DC 1amp motor is used. For higher rating Q1 can be replaced with power darlington like TIP142 etc

  13. sir!
    could tell me the path of the dc motor speed control by using 555 timer

  14. Ignore my previous question I just built it and it works perfectly on 11v dc and THANK YOU SO MUCH.

    • Do It means, jumper between +12V DC to Vm ? If its yes, then in the diagram its shown differently?

  15. Can i use the same power supply (12v 1000mA) for the ne555 and the motor, and can i just connect one ground to ground and two + to +12 dc and Vm?

  16. hi..can somebody help me to design the speed control and current control for DC motor drive in either PSCAD/EMTDC or Matlab-simulink

  17. Satyasheel Pandey

    Good explanation of circuit and concept.
    Please explain the working of induction billet heater of large capacity like more than 1000 Kw.

  18. Hi..I want to make a motorised tray that can work on 12 V DC…I want the tray to operate with a single button…I.e…I want the motor to work back and fro with a single button..please somebody help me…..thanks

  19. cool whip

    i tried it on circuit wizard and the 33ohm resistor explode..can you pls specify the ratings of the materials used in this project?..ty..

  20. how can i control a brushless dc motor to rotate clockwise and counter clockwise. thanks

  21. lemorlenny

    I’m looking for a simple DC motor controller where i can change the direction of rotation very quickly to simulate a galvanometer. This schematic would be good for this but i don’t now how replace the DPDT with electronics components.
    Anybody can help me?

    Regards.

  22. eng : ahmad hamedi

    thank yoooooooooooooooooooouuuuuuuuuuuuuuu verrrrrrrrrrrrrry much & if you may please send to me or face some circuit about smps detail repairing with discription . oh my god & thank you againnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn