Hello everyone.
i have a PWM pulse generator. I need to fire the mosfets of a 3 phase bridge inverter with these pulses. I know usually a mosfet or IGBT are used for inverters. But here is a new circuit i found in the net. Iam not getting what it is?

PWM pulses are given to an opto isolator (MCT2E). As far as my knowledge concerned, the output of the isolator can be given to a mosfet.

Can anyone explain this circuit.

 

Hello everyone.
i have a PWM pulse generator. I need to fire the mosfets of a 3 phase bridge inverter with these pulses. I know usually a mosfet or IGBT are used for inverters. But here is a new circuit i found in the net. Iam not getting what it is?

PWM pulses are given to an opto isolator (MCT2E). As far as my knowledge concerned, the output of the isolator can be given to a mosfet.

Can anyone explain this circuit.

That's an old fashioned "totem pole" circuit. (There are some OMITTED connections in the diagram, since they're redundant). It's not as efficient as thyrastors or IGBT's but pretty forgiving.

eric

 

PVI Opto-isolators are often drawn similar, and are very interesting/useful devices.

Internally, they consist of an LED and several tiny solar cells. When energized, they create 5V @ < 10uA, enough to boost the voltage when switching a high side MOSFET, or a low side MOSFET unassisted.