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From: winans@sirius.mcs.anl.gov (John Winans)
Newsgroups: sci.electronics
Subject: Re: solid state relays
Message-ID: <1991May16.162454.12133@mcs.anl.gov>
Date: 16 May 91 16:24:54 GMT
References: <12500@qisoff.phx.mcd.mot.com> <1991May14.135524.25014@wsrcc.com> <1991May15.132910.1396@specialix.co.uk>
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In article <1991May15.132910.1396@specialix.co.uk> stevem@specialix.co.uk (Steven Murray) writes:

[stuff deleted]

>especially anything more than 'one motor, one relay' can be painful.  You
>can tend to get problems with inductive spikes and back EMF - zero crossing
>switch-on is fine, but that doesn't control the switch off.  Snubbers are
>great, VDR's aren't such a bad idea either.  Aim to protect the SSR's with
>VDR's rather than stop interference from the load.

Excuse my ignorance please... but... uhmmm.....  what is a VDR?

--
! John Winans                     Advanced Computing Research Facility  !
! winans@mcs.anl.gov              Argonne National Laboratory, Illinois !
!                                                                       !
!"The large print giveth, and the small print taketh away"-- Tom Waits  !