Marco like you I had lost one of the dc dc converters. As I recall the 48 > 5V. I simply replaced it with another I had and the 3801 has been working for years. The board is a complicated board and I have not seen schematics for it. Though it would be quite reasonable to develop them. There is a small linear regulator as I recall also.
Why such a complicated arrangement is a good question. Though the first inverter is a very wide range 36v-60 V as I recall. Maybe the others could not handle it. But I do agree by todays standards the thing is a power pig and I am to lazy to change it. As they say if its working leave it alone. I did see a while ago that someone had replaced all of the supplies with a more traditional 110 V ac type multi-output supply. Thats should have improved the efficiency at a loss of the ability to run off of battery. I do not run on battery. So no real loss. But I will bet someone will answer you on this thread with far more detail. Regards Paul WB8TSL On Sat, Jul 9, 2011 at 9:43 AM, Marco IK1ODO <ik1...@spin-it.com> 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 -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/** > mailman/listinfo/time-nuts<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.