> To: info-pdp11@village.org
> Subject: Re: UPS devices for PDP11
> From: dworkin@village.org
> Date: Tue, 23 Nov 2004 09:51:41 -0700
>
>
> Johnny Billquist wrote:
> : UPS? These old DEC machines have power supplies big enough to act as UPSes
> : themself. Ever looked at those capacitors? :-)
> : [...]
> : You have supplies sturdy enough to smooth out power glitches, and to save
> : themself if you remove power.
>
> True, but they don't take extended repeated brownouts all that well
> (five or six in a row, each lasting ~30 seconds). At least I've not
> had much luck along those lines.


The way I solved that problem when taking computers to sea on ships
was to build a simple relay circuit that connected to the "emergency
shutoff" on the DEC power controllers, and made any power failure
permanent until a manual reset was performed. So if it goes down,
it stays down until some higher intelligence decides that things
have stabilized again. Not directly suitable for unattended systems.

carl
--
carl lowenstein marine physical lab u.c. san diego
clowenst@ucsd.edu
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