John, I did try to observe any anomalies using the disconnect button to open the load relay. Nothing, just a straight line drop to zero volts as expected. There may very well be odd stuff happening upstream of the relay, but I did not open the PS up to check. Bottom line; the relay is doing its job and protecting the load from any strange spikes or weird stuff. And it's protecting against starting the PS up under load. So I am happy with it.
Stan, I have not actually tested a power interruption event, or momentary power blip, to see if the relay drops out fast enough to protect the load . May have to check that out. Originally I was thinking of adding a 100-220uf or so cap across the relay coil connections, but I did not want to slow down relay opening at all in the event of power loss.
Another thing, I added right across the output terminals a 36V TVS, just like those used on the layout. The manual mentions the importance of disconnecting an inductive load before turning the PS off, likely to mitigate any back EMF kick that might damage the PS electronics. So I figured a TVS should take care of that sort of an event regardless.
Another interesting item in these PS's is shown below:
The circled iron ring encircles the main + and gnd wires from the main board to the output terminals on the front of the PS. I note in John's pics that his has the same item installed. I figured this might be some kind of choke to perhaps kill output spikes on startup or shutdown. What do you guys think?
Rod
