Author Topic: Before it's all over.....  (Read 1626 times)

BruceM

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Re: Before it's all over.....
« Reply #60 on: January 02, 2019, 03:20:41 PM »
Yep, after staring at a lot of datasheets, I'm switching to the Fairchild  FDA18N50 500v N-channel Mosfets in linear mode instead of NPN Darlingtons.  They have about 5x the linear current capability. At 100V drop across the transistor they can manage 2 amps until they cook.  My max current (16A) per transistor is only 2.2 amps at 0.55V drop.  They have relatively crappy on resistance (0.25 ohm) but that's fine for this application in linear mode with 7 in parallel.

I used Fairchild mosfets for my inverter project too- they have performance in slow, semi-linear transitions (not fully on or off) and good prices.

Things change pretty fast these days.