My educated guess is that they expected to sell these to telcos, who traditionally run everything in a central office on -48v and running off of ac was an afterthought.
On Jul 9, 2011, at 9:43, Marco IK1ODO <[email protected]> wrote: > Hello group, > > after many years (about 12, I think) of faithful continuous operation, my > Z3801 failed. > I opened it, and found that there was no supply to the main PCB. The power > supply board in the Z3801 (and Z3805, 58503A, possibly all the series) is > marked 58503-60003. It is a very strange board. It seems to have a first > DC-DC converter taking 48V input, powering two other DC-DCs that work on 48V > (!), one supplying +5/+15/-15V to the main board, the other supplying 5V 4A > to a fourth DC-DC that drives the outer oven with up to 18V. > Well, it is the first DC-DC that failed. I bypassed it, powering directly the > no. 2 and 3 from 48V, and all works again. The questions are: does a > schematic for that board exist? Anyone knows why such a complex power supply > architecture was adopted? It is not very energy-efficient, all those DC-DC > run hot. > > 73 - Marco IK1ODO / AI4YF > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
