Guru
Joined: 02/02/2017
Location: AustraliaPosts: 1470
| Posted: 12:23am 30 Jan 2026 |
it is 1oz copper, if it shows promise I will make a v.2 with 2 oz copper, error fixes, unused footprints removed and space for 3rd main cap.
I have 3 similar inverters to compare.
this one, the first version of it that uses TIP41/42 transistors in the totem pole
type gate drive and Wiseguy's inverter with it's professional design.
All 3 require about 1330 W input to drive the same load. Maybe Wiseguy's inverter
used 1300 W but the load varies over time so it's hard to get it accurate.
The next thing to examine is gate drive signal shapes and look for shoot through
at idle and under load.
I want also to play with more or less capacitor powering the drive side
of the FOD3182 chips. At the moment it is only 1uf ceramic
with ESR of about 3 Ohms.
In the past I have used 10uf electro (ESR of 10 Ohms) with a 0.1uF ceramic parallel.
I varied gate drive voltage while running under load and changing from 12 to 15V
made no difference to input power.
Finally, I might need to put "some" resistance in the gate drive, at the moment
the FET gate is direct connected to FOD3182 output and I suspect there is
MHz oscillation. No doubt that is causing some shoot through.