[AMRadio] Dow Key


K4XM, Mike Dorworth k4xm at arczip.com
Sat Sep 16 18:59:45 EDT 2006


> Okay... maybe I missed something the day they taught magnetism.  I have
> a Dow Key that sometimes stays energized with the source completely
> removed.  Not every time but sometimes.  It has a 115 vac coil and
> nothing else.  No capacitor across it, no nothing.  It's as if the coil
> is acting as a capacitor and retaining enough of the 115 vac to keep the
> armature of the relay engaged.


It's name is " residual magnetism" High quality relays have a tiny brass
screw in the center of the armature with an adjusting nut so that the
armature can never quite touch or get too close to the pole piece. You might
try a piece of scotch tape over the pole piece to keep it from getting too
close.. Mike

----- Original Message ----- 
From: "Rick Brashear" <rickbras at airmail.net>
To: <AMRadio at mailman.qth.net>
Sent: Saturday, September 16, 2006 5:57 PM
Subject: [AMRadio] Dow Key





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