Hello guys I’m repairing the power supply on this amp, it had blown all the fets from the original installment which was irf48, I’ve installed rfp50n06 and it played for 10mins on one double coil 4ohms (2ohms) after I added another Speaker making the total ohms 1ohms it played about 2minutes.
I’m rebuilding the power supply again but I’m using the o-scope and I’m not getting a solid square wave on the gate of the mosfets.
Should I also change the gate drivers and the KA3525 (even tho the fets aren’t overheating?).
I’ve attached the waveform I’m getting see if I’m wrong.
I’m rebuilding the power supply again but I’m using the o-scope and I’m not getting a solid square wave on the gate of the mosfets.
Should I also change the gate drivers and the KA3525 (even tho the fets aren’t overheating?).
I’ve attached the waveform I’m getting see if I’m wrong.
Attachments
I’m not on a variable power supply but what I’ve noticed is when I put audio thru the amp and increase the gain it will slide into the desired square wave then I will feel the fets beginning to warm, I didn’t play it beyond a minute as I didn’t assemble it in the heat sink chassis (it’s on a 4ohm speaker).
Is there another fault?
Is there another fault?
Well I'm not seeing anything other than to think I would get a solid square wave at idle, and the fact that it failed the second repair of fets on a load of two double 4ohms coil kicker (1ohm total).
My question Mr Babin, is this amp a true 1ohm stable? As the customer says he played it for almost a year on one kicker double 4ohms and only had issues recently when the second speaker is been added.
My question Mr Babin, is this amp a true 1ohm stable? As the customer says he played it for almost a year on one kicker double 4ohms and only had issues recently when the second speaker is been added.
I don't know how reliable it is at 1 ohm but I'd expect it to last for more than 2 minutes.
There are 4 drive circuits that all need to be checked. Are you sure that all 4 drive circuits are OK? Check at the gate of every FET.
This amp appears to have a regulated power supply so it will reduce the duty cycle of the drive when the target rail voltage is reached.
There are 4 drive circuits that all need to be checked. Are you sure that all 4 drive circuits are OK? Check at the gate of every FET.
This amp appears to have a regulated power supply so it will reduce the duty cycle of the drive when the target rail voltage is reached.
I didn’t find any additional problems and the amp is up and performing as expected on one Speaker (dual VC at 2ohms each) hard hitting. But I don’t think that amp is 1ohm stable in my opinion. I don’t think he has a faulty speaker either as it played either one at any given time but when it’s parallel that’s where the initial problem started. Thanks again on this one.
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