17 Jun
2009
17 Jun
'09
3:47 p.m.
On Jun 17, 2009, at 6:26 PM, Eric Smith wrote:
I'm looking at the schematic for the H744, and I see an LM723 with
a big fat 2N5302 (Ic=30A) wrapped around it. Now, I'm aware that the
LM723 can be used in a switching regulator topology, but at first
glance that's not what it looks like to me.
I'm somewhat embarrassed to admit that, because I've repaired
probably a dozen H744/H7441 regulators, including one just a few
weeks ago in my newly-acquired PDP-11/50.
So...are you certain?
-Dave
--
Dave McGuire
Port Charlotte, FL
While I
agree with you here, I have to admit that, if my
PDP-11/70 had switching power supplies, I'd probably run it a lot
more often. I'd *never* make it an irreversible modification,
though.
Unless you've already replaced them with something else, your
PDP-11/70 *DOES* have switching power supplies!