I haven't looked at this in a long time, but I believe the H742 "bulk power supply" puts out a voltage to the regulators to convert to the required voltages. I don't remember what the voltage is.
Paul On Sun, Oct 22, 2023 at 3:27 AM Chris Zach via cctalk <cctalk@classiccmp.org> wrote: > > > https://vintagecomputer.net/digital/PDP11-40/PDP11-40_DC-pwr-supplies.jpg > > That brings up a question that's rattled around my mind: On a 745 it's > rated to supply -15 volts at 10a, but it has two of the lines designated > as "+15 in". Where did the +15 come from, the other supplies put out > +20, +5, and -5? > > Or does it put out +15 and -15 from the 20 volt AC input? > > C >
