"Joerg" skrev i meddelelsen news:WFW2l.9412$ snipped-for-privacy@flpi146.ffdc.sbc.com...
Ohh - But this is quite common:
The typical wall-wart or 19,95 DVD player uses a transformer with so much leakage and resistance that it never blows anything; it just sit there and cook quietly until all the insulation is gone and it blows the fuse on the mains.
The fire brigade ;-)
I would consider having either a fuse in the secondary or a thermal fuse on the transformer.
Well, we are talking industrial grade power supplies here. Those that have to undergo real agency testing.
Then the client would have some questions ...
A thermofuse is mandatory in many markets but secondary fuses are usually frowned upon.
But you ae stuck with an off the shelf supply. You are going to have to do quite a bit of reverse engineering to ensure that the part of the path you were not responsible for won't be damaged. Worst case is that it appears to work but fails and takes the load with it after the tech has packed his tools back into the van.
Quiet as in you can't even tolerate the noise of an open SCR or zener at the load?
It already has an SCR across the output, like all good linears do. All I have to do is mod that as well (since it seems nobody has external modules big enough).
No, I was referring to "cheap supplies". Got to be ye olde LM723 as a controller, very nice noise performance.
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