VAX 11/750 Restoration Project

From: Eric Smith <eric_at_brouhaha.com>
Date: Fri Nov 8 14:53:16 2002

> They are not like the PDP-11 PSU blocks. Those can
> operate without any load as they are series regulators.
> The PSU's of the VAX 11/750 *must* have a certain minimum
> load for correct operation because they are switched-mode.
> I do not remember if those SMPSU's can be damaged by
> running them without a minimum load, but I know SMPSU's
> that will die without a load.

Actually many PDP-11 power supplies are switchers as well, even
in some of the fairly early models. For instance, the H744 and H745
power supplies of the 11/40, 11/45, 11/55, and 11/70, and the OEM
versions of those, 11/35 and 11/50. The small-box version of the
11/35 (10.5-inch tall chassis) might use something else, I don't have
docs on it.
Received on Fri Nov 08 2002 - 14:53:16 GMT