Joined: 08/02/2015 Location: New ZealandPosts: 1138
Posted: 10:37pm 29 Mar 2017
I guess it saves having to solder in 20 resistors, there is no reason why their method isnt valid, its hardly likely to go open circuit and allow the gates to float. I dont know how fast those TIP41\42 buffers can switch, need someone to build it and look at the waveform with a storage scope.
HY4008's are beefy, 80v rating though, there must be a way to run the inverter on a lower voltage temporarily so any voltage ringing spikes across the mosfets can be looked at with a scope, to ascertain whether the RC snubbers are correct. In fact as any ringing is dependant on the torroidal core, lead lengths etc, I would remove the snubbers, run it at a lower voltage and measure the frequency of any ringing, then calculate snubber values accordingly, this would give optimal results at 50v supply.