The over voltage warning could be due to AC ripple on the DC rail causing it to sense the AC peaks, either from the power supply board or the channel boards. I have seen something similar years ago on an HP power supply, AC ripple caused a voltage error.
Thanks Scott, yes that is indeed the direction i was also thinking, there is an AC pickup somewhere, it was also very sensitive during calibration, that failed when you just left an open wire in one of the outputs. it fail then also on OVP. after i received the AC filter i will also put some ferrite chokes around the output wires. i could have some HF going around in my shack too :)
Very nice looking power supply, Tony. Because it is a switch mode supply I would definitely try to find a replacement line filter. Your switch mod would still work with the original type and I agree that front panel power switches are a must. The display looks like it might have an ELP backlight, I've had some success replacing them with LEDs, it is a question of space (and how much it bothers you). Regards, David
Nice power supply Tony. It has great lab work potential with its high specification. I would image back in the day that PSU would have been very advanced and used for high end design work. I particularly like the way you were able to carry out controlled testing with the electronic load and especially the variable AC supply which is very smart indeed. I also thought the way you added the switch with the IEC connectors looked really smart and makes very a safe solution when compared to just hard wiring it in. Ian
Thanks Ian, yes i thought using the AC powers source with current limiter was sort of the lightbulb in series for nowadays :) to savely test it step by step... yes proper device, i was amazed how easy it calibrated too.
I agree with Defpom on replacing the caps, as maintenance. Also, to replace the battery, as maintenance. As you have it wired, the switch VAC wire is in the same compartment as the sense wire and, as you say, this may create the sensing problem. So, I wonder if you might find a way to put the new line filter on the incoming line of the switch... Instead of its original position, which would be after the switch path. This way, the switch line inside the sense compartment would be filtered. I imagine that in-line filters are manufactured and, if so, such might be easier to mount. Cheers.
The over voltage warning could be due to AC ripple on the DC rail causing it to sense the AC peaks, either from the power supply board or the channel boards. I have seen something similar years ago on an HP power supply, AC ripple caused a voltage error.
Thanks Scott, yes that is indeed the direction i was also thinking, there is an AC pickup somewhere, it was also very sensitive during calibration, that failed when you just left an open wire in one of the outputs. it fail then also on OVP.
after i received the AC filter i will also put some ferrite chokes around the output wires. i could have some HF going around in my shack too :)
@@TonyAlbus because of its age I would re cap it, even if they test ok.
Excellent power supply, very stable indeed. I had a bench multimeter with a similar Schaffner filter that had blown up.
Yes those filter will go, on my frequency counter PM6685 is also went.
Very nice looking power supply, Tony. Because it is a switch mode supply I would definitely try to find a replacement line filter. Your switch mod would still work with the original type and I agree that front panel power switches are a must. The display looks like it might have an ELP backlight, I've had some success replacing them with LEDs, it is a question of space (and how much it bothers you). Regards, David
Thank you David, yes the filter needs to be replaced, i agree. the backlight a maybe, depends if i am going to use it or sell it.
Nice power supply Tony. It has great lab work potential with its high specification. I would image back in the day that PSU would have been very advanced and used for high end design work. I particularly like the way you were able to carry out controlled testing with the electronic load and especially the variable AC supply which is very smart indeed. I also thought the way you added the switch with the IEC connectors looked really smart and makes very a safe solution when compared to just hard wiring it in. Ian
Thanks Ian, yes i thought using the AC powers source with current limiter was sort of the lightbulb in series for nowadays :) to savely test it step by step... yes proper device, i was amazed how easy it calibrated too.
I agree with Defpom on replacing the caps, as maintenance. Also, to replace the battery, as maintenance. As you have it wired, the switch VAC wire is in the same compartment as the sense wire and, as you say, this may create the sensing problem. So, I wonder if you might find a way to put the new line filter on the incoming line of the switch... Instead of its original position, which would be after the switch path. This way, the switch line inside the sense compartment would be filtered. I imagine that in-line filters are manufactured and, if so, such might be easier to mount. Cheers.
You might also do a visual inspection of the regulator boards...
Thanks, yes good points !
- A very large power supply, but only 120 watts of power...
- The technologies of those times probably did not allow us to do more..
Yes agree, but also on higher power you maybe do not need such high precision and still it does 10 Amps.
🙂👍👍👍👍👍👍👍👍
Thank you!