Originally posted by machinealive
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you need to consider reality:
- We need FETs rated for high voltage in order to stand those voltage spikes. We are not alowed to kill them.
- At standard FET technology HV property comes along high RDSon up to 0.5...1Ohm. (worst case derating factor 2 to be considered) Therefore I choose Infineon coolmos. Their technology offers 0.041 Ohm at high voltage (temp and current derating => 0.08Ohm per FET). Thus you get @ 100A 100% duty a dissipation of about 200...400W with coolmos instead of 1 KW - that is the good news. The bad one is you need to drain up to 400W anyway. For future units we will use superiour SiC technology from CREE. (57$ for one piece just now - but they will come down soon!)
- Please prepare to attatch two good heat sinks with fan to those two FETs and mount heatsinks stableon to PCB. You'll find heat sinks in scrap PC PSUs. Maybe you can reuse case, fan, bunch of cables and heatsinks and mount your driver into the case.
- Please do not go for rheostat! If inevitable use bunch of H4 bulbs. Calculate them to not light at current expected. They will light if overcurrent.
Preferrable is to first reduce voltage to 12V, get FET driving stable and then go for 24V. Repeat procedure. for 36, 48 V ........
JS


. The 3 driver setup per gate is gonna be for safety/ruggedness,later.
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, They each work fine seperately, but for the life of me, I can not figure out how to get three to get 3 drivers to switch at once. tried 18v controll pulse. 15v, 5ampn psu across drivers, but no, JS, I hope you or someone can shed light. It's simple but I am blind. I want to switch 4 sets of three drivers, one for each gate. Or is this arduino's job, still learning that one.
You will not have 100% duty on your drivers! Do you own a Tesla EV and want to rework it?
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