Hello, the last time i had a few difficultys with this type of amps.
Repaired the outputs... On some amps, it was also neccesary to change the irs 21844s.. Checked everything, complete new batch of mosfets. All parts from mouser. Tested the gate-source with a cap, everything looks fine. Final check of the amps also ok.. Customer happy, everything works, even under full load for a longer time... After a few days, or a week, the amp goes in protect, with small load, or only on, with no music playing..
Found two output mosfest short, one highside, one low side from the same bank. Couldnt find anything wrong...
Is there something, what i dont see, maybe somebody can give me a hint, where or what to look...
Repaired the outputs... On some amps, it was also neccesary to change the irs 21844s.. Checked everything, complete new batch of mosfets. All parts from mouser. Tested the gate-source with a cap, everything looks fine. Final check of the amps also ok.. Customer happy, everything works, even under full load for a longer time... After a few days, or a week, the amp goes in protect, with small load, or only on, with no music playing..
Found two output mosfest short, one highside, one low side from the same bank. Couldnt find anything wrong...
Is there something, what i dont see, maybe somebody can give me a hint, where or what to look...
Are you sure that the mute/delay circuit is working?
It should prevent the amp from oscillating rail-rail until the rail voltage has reached full voltage as shown below.
http://www.bcae1.com/temp/ampstartup01.mkv
It should prevent the amp from oscillating rail-rail until the rail voltage has reached full voltage as shown below.
http://www.bcae1.com/temp/ampstartup01.mkv
No, iam not sure...But i think it was working, because the amp works for a few days. Only under small load, the fets short. I will check this out later. Thank you
But how, this would damage the amp? If the rail not comletely build, i think, the gate voltage is not fully build? Or some other reasons?
I'm not 100% sure that it's definitively responsible for amps to fail intermittently but it's happened enough times to make it worth checking.