[Moved] IRS2453 mosfet gate driver circuit with overolad protection needed

[rana_tdm]

I am a hobbiest. i am trying to design an DC to AC tranformerless inverter. i have connected 20 13.8v 7A dry batterise in series to get around 220 v DC. I found a circuit of IRS2453 Mosfet driver IC on a website.



I completed the circuit using four IRF840 and a 7815 regulator for 15 v supply to the IC. I connected the ground in common and connected 7815 positive input to the second battery in the series providing 24v to 7815. the positive 220v DC was connected to the drains of high side mosfets. the circuit started producing around 250vac. i connected some load around 500 watts. all was well for about 10 minutes. i continuosly wathed the mosftes but they were not exessivelt hot. and than a blow..... the Rt was 1M and Ct was 10n....please help me ...was it a test ciscuit only...i am unable to find another circuit on this IC IRS2453 with some kind of overload protection and safety....please someone give me some guidlines for this

 

[BradtheRad]

When your upper left mosfet turns on, it conducts and brings the left end of the load to 220V. Therefore your bias voltage to that mosfet needs to be higher than 220V, to keep the mosfet turned on.

Similarly with the upper right mosfet, during the other half of the cycle. Then it pulls the right end of the load up to 220V.

Not sure if this is the cause of your immediate problem.

 

[rana_tdm]

Thanks Brad for your help....but i am unable to understand what is the difference btw IRS2453 and other mosfet drivers like TL494...SG3525 etc...these ICs also work fine in this type of H-bridge circuits in some popular brands of UPS inverters. and another thing in which i need your guidance... IRS2453 pin 8 and 12...what is the function of these pins..TL494...KA7500..SG3525 work well without connecting upper mosfet source....Please let me know from where i can find the complete citcuit with overload protection... thanks again

 

[FvM]

IRS2453 pin 8 and 12...what is the function of these pins..TL494...KA7500..SG3525 work well without connecting upper mosfet source....Please let me know from where i can find the complete circuit with overload protection...

PWM controllers like SG3525 can't deive the high side of H-bridges at all. In so far the comparison is flawed.

IRS2453 is a self oscillating H-bridge driver. You can imagine it as a combination of a pwm controller (fixed duty cycle only) and two bootstrap drivers like IR2110. Like with other bootstrap drivers, a connection to the bridge center node is required to operate the bootstrap cicrcuit.

Like with simple bootstrap gate drivers, there's not overload protection implemented in IRS2453.