Query about this PWM DC motor controller schematic

Discussion in 'The Projects Forum' started by tioJim, Nov 12, 2014.

  1. tioJim

    Thread Starter New Member

    Nov 12, 2014
    7
    0
    Hello

    Referring to the attached schematic for a PWM DC motor controller does the +V motor label (top right) imply that the motor itself is powered by it's own supply separate from the +3-18V supply labeled above the 555 (which powers the IC).

    If so, could the motor be powered by the same power supply anyway and if it were would the circuit need changing or would it indeed be redundant. I know one use of transistors is to isolate supplies from one another - put crudely I'm sure, limited knowledge, forgive me!

    I simply want to vary the speed of a DC motor. From Googling I gather just using a pot to control voltage isn't the best way to do things. I'm making a zoetrope and I don't yet know the optimum speed for the motor not least of all because the drive mechanism is yet to be finalised.

    Thanks
    Jim

    Schematic credit: http://www.dprg.org/tutorials/2005-11a/index.html
    Motor details: http://proto-pic.co.uk/micro-metal-gearmotor-100-1/
     
  2. alfacliff

    Well-Known Member

    Dec 13, 2013
    2,449
    428
    they could be tied to the same supply as long as the voltage ratings for the 555 and motor were not exceded, and the supply could handle the current.
     
  3. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,548
    2,373
    They run around $5.00 on ebay.
    ebay 251539147533.
    Max.
     
  4. tioJim

    Thread Starter New Member

    Nov 12, 2014
    7
    0
    thanks to you both
     
Loading...