Hi everyone!
I have this darn amp blowing those IRS21844S (half bridge driver IC)..amp was used to drive subs ´break-in´ and blowed couple of ampFETs (IRFP360LC).
I changed all those 360LC:s and IRS21844S and their diodes from driver board but NO! Everytime I install new IRS the amp will keep up about 30sec and then go to protect and blowes those IRS:s. I don´t know what to do with it..everything seems fine but it´s not, and customer is calling all the time ´is it already, is it already´ 😀
Amp ´works´ fine with driver board NOT installed, RAIL voltages OK, +/-5/12/15 voltages OK.......gate and pulldown resistors OK....what else?
Please help me with this issue, I´m all lost with this one!
E: A little update: Last effort to change those IRS:s did end up blowing couple ampFET´s also - again. I´m getting a bit frustrated with this one, now I have to change all 360LC:s again and IRS and diodes and......a 100$ peace again. And still haven´t find a reason for all this.
I have a 15Amp fuse in 12V supply line...even that didn´t blow -> the protection circuit was faster but even though those IRS blew!
This kind of output driver board:
I have this darn amp blowing those IRS21844S (half bridge driver IC)..amp was used to drive subs ´break-in´ and blowed couple of ampFETs (IRFP360LC).
I changed all those 360LC:s and IRS21844S and their diodes from driver board but NO! Everytime I install new IRS the amp will keep up about 30sec and then go to protect and blowes those IRS:s. I don´t know what to do with it..everything seems fine but it´s not, and customer is calling all the time ´is it already, is it already´ 😀
Amp ´works´ fine with driver board NOT installed, RAIL voltages OK, +/-5/12/15 voltages OK.......gate and pulldown resistors OK....what else?
Please help me with this issue, I´m all lost with this one!
E: A little update: Last effort to change those IRS:s did end up blowing couple ampFET´s also - again. I´m getting a bit frustrated with this one, now I have to change all 360LC:s again and IRS and diodes and......a 100$ peace again. And still haven´t find a reason for all this.
I have a 15Amp fuse in 12V supply line...even that didn´t blow -> the protection circuit was faster but even though those IRS blew!
This kind of output driver board:
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Also please check the resistance between low and high side input gate gates if they have leakage. Between path tend to have leakage if some electrolytes of the capacitors leaks.
Thank you for your answers guys!
I´ll order new parts today, so this takes a couple days until I get to test it again. But this time I´ll change also every U and Q on that driver board 😀
Could you tell me if those U3/U4/U6 are just normal op-amps like TL072 for example? Never had to change those and they are sanded.
I´ll order new parts today, so this takes a couple days until I get to test it again. But this time I´ll change also every U and Q on that driver board 😀
Could you tell me if those U3/U4/U6 are just normal op-amps like TL072 for example? Never had to change those and they are sanded.
U3- TL072 is integrator, U4- LM211 is voltage comparator, U6-LM393 for protection.
You can check every input and output of this ICs with the corresponding function. thats is pretty straight forward.
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Yeah..thank you nonprof!
Just a bit scared that even with these replaces this damn thing won´t work....just a hunch 😀 But maybe I´ll manage, sometimes they just take a little more effort like one Carpower power 1/1000D - still having nightmares about that one 😀
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