If you measure all of the gate resistors, do you get a majority of common values?
What about R10A and R11A?
Are those gate drive pull-down to ground resistors?
What about R10A and R11A?
Are those gate drive pull-down to ground resistors?
R20 = 68.1ohm
R21 = 71.4ohm
R22 = 69.9ohm
R17 = 13.16k
R18 = 6.30k
R19 = 1.92k
Both R11A, R10A are pull-down to ground and test the same 465.5ohm
This is done in circuit. I will pull one leg and do another measurement.
R21 = 71.4ohm
R22 = 69.9ohm
R17 = 13.16k
R18 = 6.30k
R19 = 1.92k
Both R11A, R10A are pull-down to ground and test the same 465.5ohm
This is done in circuit. I will pull one leg and do another measurement.
The gate resistor could be 68 ohms, even though that seems a bit high unless the PS has added deadtime programmed in.
The pulldown resistors are likely 470 ohms.
The pulldown resistors are likely 470 ohms.
I don't know what or how to check deadtime is?
Plus on another note: I read that you like when people put testing equipment on their sig but I can't find where my sig is. I'm so tied I didn't sleep all night and I bet it's looking right at me.
Plus on another note: I read that you like when people put testing equipment on their sig but I can't find where my sig is. I'm so tied I didn't sleep all night and I bet it's looking right at me.
What PS driver IC are they using?
It's no longer possible unless you pay for the privilege of having a sig line.
It's no longer possible unless you pay for the privilege of having a sig line.
The resistor between pins 5 and 7 will determine deadtime. The deadtime can be measured or calculated (from formula on datasheet).
The resistor between pins 5 and 7 is 22ohms. I can't see any formula on the datasheet. the only mention of deadtime is in this photo.
Well... I can't find it either. 22 ohms won't give much deadtime.
The IRF3205 is very similar and works with 47 ohm gate resistors.
I don't know if this supply is regulated but if it's NOT, you can replace the FETs and gate resistors. Power it up at idle and check the temperature of the PS FETs. If the run cool, the gate resistors are OK. If they run hot, the value will have to be reduced.
The IRF3205 is very similar and works with 47 ohm gate resistors.
I don't know if this supply is regulated but if it's NOT, you can replace the FETs and gate resistors. Power it up at idle and check the temperature of the PS FETs. If the run cool, the gate resistors are OK. If they run hot, the value will have to be reduced.
Those work great. Heat didn't get above 92 at idle and then I pumped a little music and the IRF3205 stayed around 100 with no heat sink. Do you know if IRFB31N20D be swapped with IRF640N? What do you look for when to see if you can change mosfets?
I'm just having a hard time finding them plus Digikey says it was discontinued without a replacement.
Yes. You need to replace all 6. I don't have a confirmed drop-in replacement but I've been told that the IRFB38N20D worked. What you'll need to do if they run hot is to adjust the CCS on the driver board. It's covered on the Generic Class D - Type 2 page of the tutorial if you have it.