View single post by David Allen
 Posted: Thu Dec 7th, 2017 05:40 pm
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David Allen

 

Joined: Mon Mar 6th, 2017
Location: Northport, USA
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Steve Stephens wrote: The best way to control speed of a fan is by using a Variac.  Good old ones from the 1960s-80s and US made can be had for under $100, often for $25, more or less, at radio swap meets, etc.   I run fans from 120 volts down to less than 6 volt battery DC fans using my variac and, when needed for DC, a bridge rectifier, about $5 or less and readily available and tiny.
Yes this is true; however I was thinking he wanted something small which could be installed permanently on a fan. But yes the variac is the way to go, with its undistorted AC waveform and full variability.