View single post by Mark Olson
 Posted: Thu Sep 17th, 2020 09:46 am
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Mark Olson


Joined: Thu Nov 22nd, 2018
Location: Baton Rouge, Louisiana USA
I may be off base here, but I believe that the speed control coil for that switch would be wound with resistance wire. The reason that I say this is because the switch base is non metallic. A choke would be wound on a magnetically saturable core, or steel lamination stack. This causes the current to be shifted out of phase with the voltage in an alternating current circuit. Unfortunately, I have no idea what resistance values you should shoot for, but I think it would be reasonable to experiment with resistors to come up with speeds that seem appropriate. Use relatively large resistors, say 75 watts, and values less than 100 ohms, say 25 ohms, 50 ohms, 75 ohms and test the fan speeds. Then wind the coil to reflect the chosen resistors. Alternatively, wind a length of resistance wire on a non metallic form, say a porcelain tube, and tap the winding manually to determine what resistances seem appropriate. Be careful, good luck, and keep us posted.