The original power supply fets were STP11ON8F6
The gate resistors are 47 ohm
Drivers are C3228 and A1275
I have some IRF1018E’s laying around that I don’t use much and wooodnlole to use them up .
Wondering if I can use the 1018E’s in this amp ?
If so do I need to change the gate resistor value or should it be fine ?
The gate resistors are 47 ohm
Drivers are C3228 and A1275
I have some IRF1018E’s laying around that I don’t use much and wooodnlole to use them up .
Wondering if I can use the 1018E’s in this amp ?
If so do I need to change the gate resistor value or should it be fine ?
Here is what I get for drive on the power supply fets .
Scope is set up in differential mode and set to 5us 5 volts div the drivers are loaded with a 10 nf cap
Do these appear correct or do I have an issue ?
And the trace was so entered on the reference line
Scope is set up in differential mode and set to 5us 5 volts div the drivers are loaded with a 10 nf cap
Do these appear correct or do I have an issue ?
And the trace was so entered on the reference line
Attachments
You don't have to use differential mode for the power supply FETs of standard drive circuits (the kind almost universally used).
Try it with only one probe. Compare to the drive on the other bank.
Try it with only one probe. Compare to the drive on the other bank.
That's not right. It should look more like the first image. Are you sure that this is on the FET side of the gate resistor for the FET location that's loaded?
Do you happen to have a pic of the driver area for this amp ?
Maybe I put the drivers in backwards
If no picture so you know if it’s the base or emitter directly connected to the gate leg of the fets
Maybe I put the drivers in backwards
If no picture so you know if it’s the base or emitter directly connected to the gate leg of the fets
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I have the drivers in correctly .
I have a 1000pf cap loading the drive circuit .
Amp powers up and is idling fine producing grail and regulated voltages .
And yes I touched the gate pad for the fet when looking at the drive
I have a 1000pf cap loading the drive circuit .
Amp powers up and is idling fine producing grail and regulated voltages .
And yes I touched the gate pad for the fet when looking at the drive
Do you have another cap of higher value? Why did you go from 10,000pf to 1000pf?
The cap loading the drive in the first image looks nearly right. The second one isn't near right. It looks like it has no load or the gate resistors are a very low value.
Do you have a meter that reads frequency?
The cap loading the drive in the first image looks nearly right. The second one isn't near right. It looks like it has no load or the gate resistors are a very low value.
Do you have a meter that reads frequency?