Hello!
I need help...every time I replaced the power transistors with 60NF06, these transistors gets hot and after few hours or days these transistor become busted. The original transistors are 55N06 but due to inavailability, I replaced it with 60NF06.
I'm thinking that I have a problem driving these transistors. All 8 power transistors were directly drive by PWM ICSG3525 without any driver transistors this is the original design of this amp. Do you have any recommended transitors that can easily drive by PWM IC? any ideas? Pls see attach image of the amp...
Thank you
I need help...every time I replaced the power transistors with 60NF06, these transistors gets hot and after few hours or days these transistor become busted. The original transistors are 55N06 but due to inavailability, I replaced it with 60NF06.
I'm thinking that I have a problem driving these transistors. All 8 power transistors were directly drive by PWM ICSG3525 without any driver transistors this is the original design of this amp. Do you have any recommended transitors that can easily drive by PWM IC? any ideas? Pls see attach image of the amp...
Thank you
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Probably the original gate resistors were 39ohm that work correctly with the original ps FETS, maybe, with your substitute FETS, you need 47/68ohm gate resistor.
The originale FETS, are more difficult to drive, so were used 39ohm resistor, but the new, are more easily drive for sg3525, so with 39ohm, the FETS remain in conduction more time, heating UNTIL to destruction.
As already advised, check if sg3525 correctly generates the A and B signals (using an oscilloscope). Otherwise, replace sg3525 in addition to using a higher gate gate than the original.
If the problem persist, is likely a shorted primary/secondary transformer winding.
The originale FETS, are more difficult to drive, so were used 39ohm resistor, but the new, are more easily drive for sg3525, so with 39ohm, the FETS remain in conduction more time, heating UNTIL to destruction.
As already advised, check if sg3525 correctly generates the A and B signals (using an oscilloscope). Otherwise, replace sg3525 in addition to using a higher gate gate than the original.
If the problem persist, is likely a shorted primary/secondary transformer winding.
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