I am working on a magnetic variable voltage power supply. Motor-driven variac -> step-down isolation transformer -> rectifier. Output characteristics look like:
0-12 VDC, 125 A continuous.
0-24 VDC, 62.5 A continuous.
I would like it to be capable of 600 A for 5~10 seconds and 250 A for 2~5 minutes. (In low range.) The variac happens to be sized such that it will safely handle up to 900 A on the iso-TX secondary continuously. Iso-TX itself is encapsulated and ought to handle those numbers just fine.
This is to be a general-purpose power supply and needs to be robust enough to survive considerable abuse, namely consisting of inductive kick-back from contact-switched inductive loads and accidentally closing onto short-circuits/ground-faults.
I'm able to find a few N-channel MOSFETs whose ratings seem suited to this use, but I have no idea how to design them into a complete active full-wave rectifier.
Is this something that someone could explain to me like I'm five? Are there good drop-in schematics available for this sort of use? Or would I be better off wasting 400-1500 watts by way of Schottky diodes?
Not so much concerned with the wasted power as this is more of a 'bench' power supply than something for continuous use, but the voltage drop introduced by a set of diodes will end up being really annoying.
0-12 VDC, 125 A continuous.
0-24 VDC, 62.5 A continuous.
I would like it to be capable of 600 A for 5~10 seconds and 250 A for 2~5 minutes. (In low range.) The variac happens to be sized such that it will safely handle up to 900 A on the iso-TX secondary continuously. Iso-TX itself is encapsulated and ought to handle those numbers just fine.
This is to be a general-purpose power supply and needs to be robust enough to survive considerable abuse, namely consisting of inductive kick-back from contact-switched inductive loads and accidentally closing onto short-circuits/ground-faults.
I'm able to find a few N-channel MOSFETs whose ratings seem suited to this use, but I have no idea how to design them into a complete active full-wave rectifier.
Is this something that someone could explain to me like I'm five? Are there good drop-in schematics available for this sort of use? Or would I be better off wasting 400-1500 watts by way of Schottky diodes?
Not so much concerned with the wasted power as this is more of a 'bench' power supply than something for continuous use, but the voltage drop introduced by a set of diodes will end up being really annoying.
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