Simplest PWM Motor Control Circuit Using Op Amp


5,380

32

8

Hello People!

This instructable is about how to build the simplest(probably) PWM circuit to control DC Motor speed, LED Strip Brightness, etc.

Specs:

Input Voltage : 5-30v

Current Handling : Depends on the MOSFET(Around 10A for IRFZ44)

Please comment if you tried building it!

Teacher Notes

Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.

Be the First to Share

    Recommendations

    • Made with Math Contest

      Made with Math Contest
    • Multi-Discipline Contest

      Multi-Discipline Contest
    • Robotics Contest

      Robotics Contest

    8 Discussions

    0
    None
    morton6689

    7 months ago

    i could be wrong but shouldn't there be a diode hooked across that motor to protect the MOSFET from back EMF? I realize this is a old post that i came across and doubt ill get a reply but if anyone new to electronics is going to build this i am 98% sure (i am not an expert on this) that you need to hook up a diode across the dc motor. look up snubber diode. when current is stopped the windings in in the motor have built up energy that becomes a voltage spike going backwards through the circuit which can damage (in this case) the MOSFET.

    1 reply
    0
    None
    Usairum Mirzamorton6689

    Reply 5 months ago

    it depends upon which load you are using e.g if your load acts like a inductor (stores energy) then yes you need to have a protecting diode

    0
    None
    megapix

    3 years ago

    Clever circuit. I also like the use of the bottle cap as a control knob.

    0
    None
    BeachsideHank

    3 years ago

    What advantages does this circuit posses over the more popular 555 PWM designs?

    2 replies
    0
    None
    Stuff BuilderBeachsideHank

    Reply 3 years ago

    Here are two

    One advantage might be higher operating voltage and other might be that two individual controllers can be designed using a single IC