Guru
Joined: 09/08/2007
Location: AustraliaPosts: 4406
| Posted: 12:00pm 08 May 2021 |
While we are kicking around a few ideas for hardware layout, this is the very last PWM inverter I built, just over three years ago.
Its now become a pretty dated design, in that it uses an old EGS board, but this was just a design exercise to try out a few different mechanical and thermal construction ideas.
It also uses four ten amp gate driver chips mounted up fairly close to each pair of mosfets. Each chip has short direct gate connections to each pair of mosfets in an attempt to get cleaner more direct gate drive signals as discussed in this thread.
It also bears a slight resemblance to Nicks laminated busbar idea. Not quite so neat, but it uses busbars bolted to the circuit board to carry the heavy current.
This is the dc side with +ve and -ve busbars and the single low esr electrolytic.
The ac side busbars cross over.
Its only a one ounce board, but source and drain connections are reinforced with solder lugs, so that if it ever blows up the pcb tracks are just about indestructible
Installed in a metal enclosure with still only half the mosfets installed. The mosfets are inside, but the heatsink is outside the enclosure.
A large piece of 6mm thick L section conducts the heat to the outside heatsink. That seemed to work quite well.
I don't know if any of this is of any interest to anyone, or even relevant, but I thought it might spur a few ideas.