...From a safety point of view the circuit is not isolated. Via the diodes there is connection to mains. Thus it is be dangerous to touch the circuit .. even the NE555 part...
...no diode values. Maybe the used ones are not suitable...
RFN30TS6D FastRecovery 30A 600v
IDW30E65D1FKSA1 DIODE GEN PURP 650V 60A TO247-3
...Wire is marked with "20m". I assume this means 20 mOhms. This maybe is just the DC resistance. Don´t know if impedance matters.
Maybe the wiring impedance causes voltage peaks that may harm the IGBTs...
IGW75N65H5XKSA1 IGBT TRENCH 650V 120A TO247-3
With the inductance the wire has. Also depends on how fast the IGBTs switch and the current it switches. I doubt there will be a problem to the IGBT's big output capacitance.You assumed correct they are 20mΩ but how can it harm the 650v rated IGBTs?
With the inductance the wire has. Also depends on how fast the IGBTs switch and the current it switches. I doubt there will be a problem to the IGBT's big output capacitance.
Mains has already earth connection, usually neutral is earthed. Shorting a node of the rectifier circuit to ground is not possible, otherwise you get destroyed rectifier and tripped mains fuse.The only way I can think of that would fix this is using earth ground
The only way I can think of that would fix this is using earth ground
~3uH inductance. Characteristic impedance's order of magnitude is somehow large. Simulate it please with the IGBT's model.Its a 16awg @ 1.8meter extension cord cabling,
...Your internal circuit ground carries mains voltage like all other circuit nodes, it must be isolated against earth ground and never being touched...
...placing D5 next IGBT and 4.7mF capacitor...
...Simulate it...
Yes it does, once you download the model.Unfortunately the simulator hasn't built in IGBT support
Probably, but expect voltage spikes to be much less with IGBT model. Simulate it please and see by yourself. Your idealistic switch model has no capacitance modeled.I presume the IGBTs capacitance would have not saved it from catastrophic failure at the voltages the simulator showed.
Why guessing?I presume the IGBTs capacitance would have not saved it from catastrophic failure at the voltages the simulator showed.
It's unclear what you are actually doing and where you are expecting problems.I still dont understand the issue since its inconsequential if 1. the chassis is double insulated (non metalic chassis) and 2. I do not touch the circuit whilst its energised.
...As for D5/D6: D6 is the right place for the diode to protect the IGBT against flyback overvoltage...
It's unclear what you are actually doing and where you are expecting problems
In post #3, you started to discuss possible earth connection...
From a safety point of view the circuit is not isolated. Via the diodes there is connection to mains....
...Simulate it...
...like D6...
...If you want to see more than what is already known before, you'll use real IGBT and diode models.
The IGBT incurs a ~4kv dampened ring per turn on with the 4nF capacitance it has ofcourse this was only obtained by attaching a parallel 4nF capacitor to the idealized switch.
I have tried IGBT models of Infineon but they do not work in LTSpice. Gives the error "QTOT1() function" not implemented but the function is there...Would it sim if I place a BJT symbol and use the IGBT model?
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