Sender: tomcat@gigapixel.com
Message-ID: <360DD319.DAA95C74@gigapixel.com>
Date: Sat, 26 Sep 1998 22:54:33 -0700
From: Tom McReynolds <tomcat@gigapixel.com>
Reply-To: tomcat@gigapixel.com
Organization: Gigapixel Inc.
To: "Ed Armstrong (by way of Marvin Kaye <marvkaye@olsusa.com>)" <ed@testelectronics.com>
CC: lancair.list@olsusa.com
Subject: Re: Solenoid flyback MOV vs diode
References: <3.0.3.32.19980926212655.0074e490@olsusa.com>
Mime-Version: 1.0

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Ed Armstrong (by way of Marvin Kaye ) wrote:

> In my opinion there is no need to use anything higher than the first one,
> the V18ZA05. For the best of both worlds, you could put the MOV in parallel
> with the solenoid, and then put the diode in series.

Will this work? Until the MOV conducts, the diode will be isolated from the
flyback current. It seems to me that the diode won't have the opportunity to
conduct
at a lower voltage; it will only increase the flyback threshold voltage by
adding a
.7V drop to the MOV-diode series circuit. I would expect this to increase noise

slightly.

I think you either have to put the diode in parallel with the MOV, and hope the

former doesn't fail (maybe the MOV will protect it somewhat from higher
voltages), or give up on having the MOV.

    -Tom