Subject: Re: US vs European PS requirements.
To: Brian D Chase <bdc@world.std.com>
From: Jacob Suter <jsuter@intrastar.net>
List: port-vax
Date: 05/31/1998 02:57:56
> I have the PS of a VS3100/M38 "extracted" from the case here in front of
> me and I don't see any explicit way to switch it over to accepting
> different input voltages.  Would the PS need to be replaced, or is the
> thing just smart about how it handles the different input voltages?

Two possabilities - 

A> It'll just accept it (This *IS* DEC we're talking about, so probably
not...)

B> You'll have to change the coil tap on the primary step down
transformer in the power supply, if there even is one.

C> Get a 220 to 110 step down transformer.  I know some people that use
these on medical equipment and they work fine except for cases when line
frequency is an issue (most of the world uses 50 hz, we (Being
US/Canada/Japan (Mexico?) use 60 hz.  In the case of computer switching
power supplies I have never heard this to be a problem, its mostly a
problem with old standard motorized alarm clocks, and other AC motors
that depend on the line clocking to regulate their RPM.

I really do think my 3100M30 has a 220/110 switch on it, but its been a
few weeks since I looked at one so I'm probably wrong.

JS