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Please let me know if my very-high-power load has a fatal flaw

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Davidwasalreadytaken:
Attached is the schematic.  I have started building this but before I get too far down the road I would like some input from the community.  It works in LTSpice but I haven't run it yet IRL. I am using some DIP-specific perfboard for the small signal bits and I know there may be some concern with oscillation but that will have to be discovered when I actually get her all put together and under test.  There will obviously be some heat coming off this especially at high voltages, but I have about 17lbs. of heatsink for that and I can easily go bigger.  I usually won't be putting high power through for very long, and it will be fan-cooled so I *may* be ok with heatsinking.

R33 is for current sensing, pulled from a defunct Agilent power supply. To be used with a digital panel meter for live indication of current input

There will be a bipolar +/-15V supply for the opamps, and I intend to take my reference from that.  R34 eats most of the voltage, R35 and R36 are coarse and fine current adjustment potentiometers. 

The current goal for current is about 8 amps per FET, limited by the 3 Watt 0.05 ohms sense resistors between each 47N60C3 and ground.  I think that should be enough current for most of my needs (!) but the FETs can go quite a lot higher.

Opamps I think will work are LT1007 https://www.analog.com/media/en/technical-documentation/data-sheets/LT1007-LT1037.pdf
Nice low offset for use at the very low voltages required for control at low current

The MOSFETs are 8 pieces of 47N60C3 https://pdf1.alldatasheet.com/datasheet-pdf/view/428753/INFINEON/47N60C3.html
TO-247 650V, 30A @ Tc 100ºC, 415W

The polarity protection diode is 300UR60A http://www.vishay.com/docs/93508/vs-300urseries.pdf
Giant stud mount, 600V 300A
I ran 80 amps through this and it got warm but not hot, maybe 55ish C on the case, so I may not heat sink this.

Gyro:

--- Quote ---I am using some DIP-specific perfboard for the small signal bits and I know there may be some concern with oscillation but that will have to be discovered when I actually get her all put together and under test.
--- End quote ---

You will probably want to put the 150R resistors directly on the Mosfet gate pins - or better still, split them into two resistors, one at the opamp output, one at the Mosfet, to prevent the opamps seeing too much capacitive load too.

You haven't said what the source voltage is going to be (although you have mentioned plenty of high voltage parts). You need to keep a close eye on the 47N60C3 SOA graph to make sure they don't suffer breakdown when operating in linear mode (they look like to be optimised as fast switching fets).

Yansi:
You better put a cap from the inverting input to the OPAmp's output, rather then splitting the gate resistor in two, which I'd say is very likely not necessary.

Vovk_Z:
47N60C3 have to be ok for linear mode. And yes - a 2.2nF..4.7nF cap have to be from output to inv. input.
And consider much more powerful FDL100N50 (but not too expencive) - it may need less transistor cases than with 47N60. It costs only a little more then 47n60 but can withstand up to 1000W per case.

With lt1007/1037 don't forget to use Vos trim circuits for every opamp to adjust its input offset (or some transistors will be partially open with zero control voltage).

schmitt trigger:
Your basic circuit looks ok.

My only comment would be that your control voltage to be derived from a proper reference IC.
Even the inexpensive and ubiquitous TL431 will provide a significant set-point improvement.

And start thinking about the protection circuits. Fuses, voltage clamps, thermal shutdowns.

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