I have this amp for repair. Audio und ps damaged. Everything up again and working. Normally in the output stage must be irfp264n fets.
For testing I have only China fets irfp260n.
Nornaly this fets should be driven more easy. I have gate resistors with 33 ohm inside, now look at the oscilloscope.. It seems, the gate starts loading the gate capacity, then drop down and after that fully open. It heats up very fast.
What cause this?
For testing I have only China fets irfp260n.
Nornaly this fets should be driven more easy. I have gate resistors with 33 ohm inside, now look at the oscilloscope.. It seems, the gate starts loading the gate capacity, then drop down and after that fully open. It heats up very fast.
What cause this?
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What does the drive look like on the other side of the gate resistors?
What FETs are you going to use for the repair?
What FETs are you going to use for the repair?
It's only interesting for me, because the mosfets have lower rds on and lower gate capacitance according datasheet. But they are from China, so maybe fake.. Or do I sti have a problem here?
The RDSon is more likely to affect heating at high power.
By gate capacitance, do you mean Qg or Ciss? The datasheets I have show both are lower for the 264.
This is marginal and may be better with the 264. If you had to use the 260, I think I'd prefer to lower the gate resistors slightly.
What's the total rail to rail voltage?
By gate capacitance, do you mean Qg or Ciss? The datasheets I have show both are lower for the 264.
This is marginal and may be better with the 264. If you had to use the 260, I think I'd prefer to lower the gate resistors slightly.
What's the total rail to rail voltage?
The original part number may be OK. That's something that you'll have to confirm when you get them installed.
If the drive is only causing a slight heating problem of the 260s but working well, otherwise, I think it's likely OK.
If the drive is only causing a slight heating problem of the 260s but working well, otherwise, I think it's likely OK.