# Help with fan speed control



## Schizems (Jul 12, 2008)

I have a 120v Vacuum cleaner motor, I want to be able to control the speed on it but i can't remember the name for the little things i used on my 12v dc motor. Can someone help?


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## Basementgeek (Feb 7, 2005)

Rheostat

BG


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## Schizems (Jul 12, 2008)

so i need a 120v rheostat to control my vacuum cleaner motor


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## Basementgeek (Feb 7, 2005)

This should work with AC/DC motor ( meaning it has brushes inside the motor)

http://www.harborfreight.com/router-speed-control-43060.html

What are you trying to do?

BG


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## Schizems (Jul 12, 2008)

kool thnx, im pretty sure it's a brushed motor. Im planing on making a air hockey table and would like to be able to adjust the air speed thru the motor


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## Done_Fishin (Oct 10, 2006)

you might want to consider using thyristor control using pulse width modulation. A rheostat will just reduce the amount of Voltage going through to the motor. Whilst effective and simple it means energy loss. Using a circuit to control the amount of time that voltage is applied across your motor will "help" to keep your electricity bill at a low level.

Make sure that you get a circuit designed for inductive loads.


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