[TowerTalk] Rotator problem solved

Leeson leeson@ix.netcom.com
Mon, 03 Nov 1997 09:01:22 -0800


Hi, Chris, you need a non-polarized cap to handle ac without 
deteriorating (the juice will evaporate on the reverse cycle in a 
polarized standard electrolytic).  However, there's an easy fix:

Use two back-to-back electrolytics in the 100-150 microfarad range, 
each with a diode across it so it won't experience back voltage.  
Connect the negative sides of the electrolytics together, and connect 
the diodes so that the "bar" is at the positive end of each cap (I 
always have to think about which way it goes, but you want no current 
to flow through the diode when the voltage at the positive end of the 
cap is positive).

Also, motor caps are special nonpolarized units, but you can get them 
at a motor supply outfit for a lot less.  They gradually wear out as 
the juice inside dries up, so they are a standard replacement item.

Cheers de Dave, W6NL

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