Well I certainly fit this section. Just a little background. My hobby is acquiring and playing with high power military and non-military searchlights. I had a WWII General Electric 60" Carbon Arc "grand Opening" light. I have a few 1KW and 2.2KW Army tank and helicopter searchlights. I also have smaller 100 to 600 Watt Short Arc lights I use a variable regulated power supply to run. All of these ballasted lights are from 12V to 28VDC input. I am NOT an electronics expert, probably not even a novice for that matter but I am fairly knowledgeable in general electrical. I can read schematics and identify many electronic components. I can replace components on a board.
OK, now my issue. In the last three years I've fried a couple of Mastech 30V, 50A regulated variable DC bench supplies. The first one when I was making some ballast input connections by just touching wires together and probably caused a spike? I was powering a flashlight ballast. On the advice of a member at a different forum, on the second Mastec, I installed a Schottky diode in the + output cable. I was recently testing a defective 15 Watt ballast which flickered heavily and before I could disconnect it, poof went my PS. In both cases the displays died and in the latest case, it still produces Voltage that is variable but won't sustain a load.
I've been told by some that a switch mode DC PS (which I'm told my Mastecs are) is not really the best PS to use for running HID ballasts - which is my primary use. I don't remember what they're called but it was suggested that something like an "SDR"? the older, bigger, heavier supply would be better. I don't think "Linear" was the word they used but I'm not sure. I want something in the neighborhood of 30V & 70 Amps, which, I know will require 240V input which is not an issue and will be relatively expensive. The Mastecs were about $450 each. I would like to be able to power two of my helicopter lights at one time (started separately) which requires 28V and 32A (total) while running but as much as 2 to 3 times the current when igniting and during boost phase. It doesn't matter if its somewhat big and heavy. I found some Sorensen 40-75's and a Lambda 40-60 but I'm gun-shy to get another one and end up frying it, too. I don't specifically need a variable but I want one. Who knows what I might need different voltages for in the future.
Lastly, I was told that there needs to be two "diodes" used to protect against reverse power flow and "something else" (again, I was not fast enough to absorb everything said). I heard the term "blocking diode" but it looks like something that is used in solar power systems?
So I'm seeking advice on:
1. What type (and brand, if important) of Variable Regulated PS to buy for running ballasted loads
2. How to protect it.
This is the diode I was advised to use in the mastec.