12v speed control help

Discussion in 'The Projects Forum' started by AggieTX, Sep 29, 2010.

  1. AggieTX

    Thread Starter New Member

    Sep 29, 2010
    Hopefully, you guys can help me.

    I'm using a car battery charger to power a windshield wiper motor. The motor is spinning a bicycle gear which is spinning a rotisserie.

    My problem is that under load, it spins too fast. Would a speed controller work? I can build circuits, but I'm not any good at designing them.

    Thanks for any help that can be provided.
  2. Pich

    Senior Member

    Mar 11, 2008
    search PWM circuit using a 556 timer lots around or motor speed control using PWM.
  3. marshallf3

    Well-Known Member

    Jul 26, 2010
    Actually just hooking a 12V lamp in series with the motor might work but we'd need to know how much current the motor draws.
  4. windoze killa

    AAC Fanatic!

    Feb 23, 2006
    You could also try using different sized cogs on the motor.
  5. Bernard

    AAC Fanatic!

    Aug 7, 2008
    Some possible bulbs, automotive types: 1129,1130, 6.4V,2.6A== 2.4Ω; 1133,1134, 6.2V, 3.91A =1.6Ω; 1143, 1144, 12.5V, 2A =6.25Ω;1156, 12.8V, 2.1A = 6.Ω
    If wider range of control is desired, try a darlington power transistor like D1326, NTE2336, TIP261. TIP263, configured as emitter follower, with 1k to 5k pot for control, heat sink needed.