Dear members,
I have designed full bridge pure sine wave inverter using IR2101 with specs
Mosfets : irf740
mosfet driver : 2101
boostrap capacitor : 67 Uf
Gate to source res : 1 Kohm
main issue when i give about 125 DC to mosfet drain , pure sine wave produced
but when i give 300 V DC dirctly to make 220 V AC , sparking produced in MOSFETs ??? any idea how to overcome this issue ?? plz help
Thanks alot

 

I think you have to show us your layout and schematics (full not just some part if it)

 

it z simple diagram , just connect pin 1 to Vcc , 2 and 3 to high and low signalfrom microcontroller , 4 to ground and a capacitor between 1 and 4 pin of it2101 , pin 5 and 7 to gate of irf740 with low value resistor and a capacitpr between 6 and 8 pin of ir2101 of 68 uf . gate to source res of mosfet is about 1 k . plz help

 

That is not a drawing. It is also not a photo of how you connected the parts. We can not work with words because they do not show the mistake, only the intent.

 

Put 2 Zener's back to back between G and D.

 

It is also very important that you point out where the sparking occurred

 

I don't know why you have created another "Thread" on this?

However, this is taken from another forum, I don't know what your doing and why, that would be helpful for the Senior Members to help you.

I'm trying to learn these things myself, in my own project, different problems, and of course a different circuit not related to yours.

The relation of the gate voltage to the output current and resistance is not an exact specification. It varies between devices of the same part number and is affected by temperature. That means you could never design a circuit that takes an exact input voltage and passes a given current and it stays like that forever after. What you can do however is make sure your drive is beyond anything that could ever be needed, and that helps to ensure that you get the output you need.

 

Since your mosfet is only rated at 400V, that may be the problem. Mosfets should, as a rule of thumb, be rated at twice the input voltage and input amperage.