Quote:
Originally Posted by GriffinRU
Very nice post, Five-oh-joe 
More fet's bigger foot print more surface area to dissipate heat, more overall losses...
Fet's driver need to be very nice or need to be on each FET's board, but try to sync them...possible.
Let's do quick theoretical calc, if you can drive fet's as fast as fet can switch (non-real) then 300 fet's you meant total, so 50 fet's per leg/100 fet's per phase. Dynamic losses would be ~10W on fet and ~10W on diode, check attached image. With 3 phases your loss would be ~60W just for switching at 15kHz PWM, that would cook ESC pretty fast without proper heatsinking, by the way can be a nice heater :)
It would be nice to keep dynamic losses matched to pcb heat dissipation capacity.
I am pretty sure, Patrick can add/correct my post if required. |
Thanks Artur!
Lutach- sounds like you got some serious stuff planned. I haven't read through all of your posts yet, so I'm a bit behind. It's nice to have consumer ideas thrown into the mix though!
So what's the difference between the SO8 FETs and the DPAKs? I'm guessing DPAKs have a metal type housing whereas SO8s are still that resin/plastic?