Mark Kinsler wrote:

> I'm wondering if those old 110V DC motors care if they're run on a
> pulsating DC with an average voltage of 110 volts, or if they really
> prefer to be run on Thomas Alva Edison's original pure, no-ripple
> 120-volts accept-no-substitutes direct current.  It probably doesn't
> matter a bit.  Some of the old solenoids might care, however.

To Mark, and others:  This is true of pipe organ magnets, and might
also be true of solenoids in general.  Pure DC often causes the
armatures to 'lock' or 'seize' making them slow to release.

I used to service a large theatre pipe organ built by the Smith
company, which was particularly susceptible to cyphers caused by
sticking magnets.  When the old 'pure DC' generator was replaced with
a solid-state rectifier, the problems vanished.  Sometimes, the ripple
is a good thing!
";-)

Regards,
Bob Loesch
http://home.jps.net/~rrloesch/index.htm