at 50 or 100kHz the transformer design and construction are quite critical...
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I spent alot of time researching the transformer to make sure was designed correctly, selecting the correct core, considering skin effect etc.
Im pretty sure its fine for 100Khz and 200W
p.s. for 100kHz on the control chip the osc needs to run at 200kHz, 50kHz power circuit a better idea...
The peak input power of a sine inverter is double the average power, this suggests to make the bus capacitor large enough to smooth the DC bus current and make the DC/DC converter run at almost constant power with respectively higher efficiency (several 100 µF to 1000 µF) . If L1 still makes sense is up to a calculation. I guess it can be omitted without much negative impact.
The primary drain overvoltage can be best clamped with a RCD snubber, as used in flyback converters. Of course a topology with energy recovery would be preferred, but it's not possible for simple transformer push-pull.
As a minor point, R11 resistance seems an order of magnitude too low, power disspation is very high with intended 340 V bus voltage.
A fuse will be never fast enough to protect against shoot-trough.
Agree, its a very unfortunate choice of circuit.I wonder what's the purpose of L1 at all?
Agree, its a very unfortunate choice of circuit.
It looks to me like a very poor attempt at building a classic current driven inverter, which would work, but requires two very strict operating conditions.
There must always a load on the output, and the drive to the output bridge must be overlapping, such that there is no dead time. The bridge must directly short out top to bottom during each switching cycle to maintain the current flow through L1.
Any overlap or momentary zero conduction condition will be instant death due to extreme flyback voltage, as there is no voltage clamping anywhere.
Current driven inverters are very good for some highly specialised applications such driving motors and highly capacitive loads. But are totally useless as a general purpose inverter, as the inverter must always be run loaded.
The whole thing is a dog's breakfast, and a very unfortunate choice.
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