On Wed, 17 Dec 2008 18:51:17 -0500, Brian Lawson
wrote:




Hey guys,

Any I've seen used a 20 Amp DPDT Center Off non-shorting
spring-loaded-one-side, with a full wave bridge and an in-line cap.
Switch markings as ON-OFF-RELEASE, with the RELEASE being the
spring-loaded side of the DPDT. Not sure why they would require 20
Amp, other than to be physically more robust and therefore a bit
longer lasting.

20A may have been the AC rating. Or a physically larger switch may
have been necessary to get enough separation in the contacts to
control arcing. With AC you get 120 chances per second to quench any
arcing that occurs on opening the switch. Not so with DC. Switching DC
that's supplying a large inductive load is very hard duty for a
switch.

--
Ned Simmons