AC motor speed control

[RubberDucky]

Hi,
I've searched around the web for a simple motor speed control circuit
and found a couple but all of them were 110v rated (i need 220v).

- is there a way to convert the circuit to work on 220v mains?
- anyone has a better circuit i can use?

i'm planing to use this circuit on my chinese dremel and build a veriable foot switch for it.

some of these schematics are dimmer circuits,
- can they be used as motor speed control? can they produce a steady output, even with a high load?

some of the links i found:

**broken link removed**
**broken link removed**
http://www.geocities.com/tomzi.geo/dimmer/dimmer.htm
http://www.techlib.com/electronics/power_control.htm

 

[stevez]

The speed of most AC motors cannot be reliably reduced with the simple motor speed controls that might otherwise work well to dim lights or reduce the speed of small fan motors. Lights (incadescant) and some small motors (universal AC) can operate with reduced voltage/power but the RPM of most AC motors is determined by the incoming frequency and number of poles - minus a little bit of slip. In order to change the RPM or speed the frequency of the incoming power must be changed.

 

[RubberDucky]

ok

ok, let's say i don't need that much speed control, will these circuits do?

 

[Russlk]

Any of those circuits will do, just double the voltage rating of the components. Your chinese dremel is no doubt a universal motor. It will run on AC or DC. If it has replacable Brushes, it is a universal motor. For a check, apply a low DC voltage and see if it turns.