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Hi Duncan, sorry, I wasn't getting notifications about new posts. The "diode" is actually 2 diodes in parallel, with a common cathode, which is the middle leg. So, there's anode #1 which is leg #1, and anode #2 which is leg #3, and then common cathode (and back of the TO-247 package) is leg #2. So, the middle leg has to carry 2 times the current of the other 2 legs. But it's not the problem you might think. The back acts like a big heat sink, so it's actually much harder to vaporize the middle leg from high current than it is to vaporize leg 1 or 3. It's the same way with the mosfets. The drain leg is usually still intact after a failure, since it's connected to the back.
Sure, you could drill in the power board. You could use those little plastic flange things to isolate the bolt. I have no idea what they are called though. Man, I just bought some the other day... It seems like "bearing" is one of the words. Flange bearing?
Hi Johannes! The puny torque just comes from the fact that it's limiting the current to 500 motor amps. Even at a lower frequency it would still limit the motor amps to 500 amps. You just need more motor amps, and this poor little controller will start to blow up above 600amp. There is an option in the code, however, to run the pwm frequency at 8kHz rather than the standard 15.6kHz.
I submitted the stupid paperwork for the retirement money and now they are doddling, probably waiting until the market tanks so they don't have to give me as much. haha.
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