Quote:
Originally Posted by Diabolical Artificer
... Is the gate of fets their Achilles heel, would a BJT be less prone to faults? Also should i be looking for a fet with a low gate capacitance or would using a beefier device help, something like a TO247 package? ...
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I confess I'm starting to get out of my depth now. I have seen some fairly huge FETs blown up in kit which comes in, so I suspect it is the fragile gate insulator which is the weak point. The fact that this is still a problem despite large numbers of people having tried to solve it for 30+ years rather suggests that there isn't an easy solution.
Buried deep in nearly 30 pages (yup !) of posts on a DIYAudio thread on the subject was the advice (I'm remembering what I can) that:
Protecting against limited overcurrent can be quite straightforward. But that's very different from protecting against an instantaneous hard short with a large reservoir capacitor behind the FET. If you want to build a genuinely bomb-proof lab-grade supply then study the circuits developed by HP and incorporate the tricks that they built in.
At that point I found room for a 6080.
Cheers,
GJ