Permanent Split Capacitor (PSC) Motor Modified for Speed Control?

Discussion in 'The Projects Forum' started by Dabu13, Jul 19, 2010.

  1. Dabu13

    Thread Starter New Member

    Jul 19, 2010
    I am trying to mod. a permanent split-capacitor motor so I can have variable speed control. my friend suggested that I could probably try using a junction box and PWM light-dimmer switch, but I don't really know how the motor would like that. This is a 3.5 Amp rated motor used in a squirrel cage type blower. I know that there are specialized Variable Frequency Drives used in HVAC, but don't want to spend that kind of money. Does anyone know of a way I can add a cheap (less than $30 USD) control system? If i could get two or even three speed settings I would be golden.
  2. Patman

    New Member

    Sep 16, 2010
    I'd love to find a solution to this problem, I'm restoring a 20-year old Bodine Electric PSC motor for use on a vibraphone, to which I don't have the controller circuit. I need to rebuild it, speed control and all. Huh boy...

    Please help us, anybody?
  3. Dyslexicbloke

    Active Member

    Sep 4, 2010
    With a PSC blower you can just drop the voltage, autotransformers and variacs are comonplace in older HVAC installations. You can still get the 3 speed autotransformer type new.

    Given that your current is so low a speed control board , 0-10V input typically, would not cost too much and would be doing the same jod as a high current dimmer board, which would probably be even cheaper.
    (I think velleman do a kit, but you'd have to check the specs.)
  4. marshallf3

    Well-Known Member

    Jul 26, 2010
    Whatever you use, if it's a light dimmer type circuit be sure it's rated for inductive loads such as fan motors.
  5. Dyslexicbloke

    Active Member

    Sep 4, 2010
    Good point ..... Sorry, I should have specified what specs.