Newsgroups: comp.robotics
Path: cantaloupe.srv.cs.cmu.edu!das-news2.harvard.edu!news2.near.net!news.mathworks.com!uunet!in1.uu.net!hearst.acc.Virginia.EDU!pen.k12.va.us!wdeal
From: wdeal@pen.k12.va.us (Walter F. Deal)
Subject: Re: Solenoids
Message-ID: <D6L30z.1CBF@pen.k12.va.us>
Date: Wed, 5 Apr 1995 22:41:23 GMT
References: <3lq87d$1h29@violin.aix.calpoly.edu>
Organization: Virginia's Public Education Network
Lines: 26

RE: 20 Volts @ 4.5 amps ---> 400 Volts @ 50 amps.....

I don't think that its possible to do this with a continuous
output at this level.  That's 90 watts input and 20,000 watts
output.  However, this could be possible on a pulsed output.
A technique commoly used is a voltage inverter to step-up the
output voltage (potential) and charge a capacitor, then
discharge the capacitor via an SCR.  Think if you will, about
electronic flash units for photography or CD ignition
(capacitive discharge) units.  These units can provide some
really high V-A discharges for very short duration.

Kind of reminds me of an incident that I experienced as a kid
experiementing with my 40/80 meter transmitter power supply.
The power supply was rated at 1200 volts @ 250 ma with 8mf
oil-filled capacitors in a pi setion filter.  I was always told
to "discharge" capacitors when working on equipment.  I did,
with a small screw driver. It burned the end off of the screw
driver!  That really opened my eyes!

The point.... a small current charging a capacitor will yield
large currents for a short period.

Thanks... my $0.02

Walt Deal
