UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post

trobbins · 14th May 2019, 1:10 pm

This thread could focus on why some amp modules have blown up - as per post #5. If they hadn't blown up, then this thread may not exist.

Post #5 indicates a concern about poor thermal transfer between fet and heatsink. That raises alarm bells for me, as those fets use a very common package, with what should be very standard heat transfer design. I reckon the flatness of the base etc are red herrings.

I don't see any information about fet current and voltage waveforms, and designed junction and case temperatures - all very basic design and faultfinding aspects.

14th May 2019, 1:10 pm	#48
trobbins Heptode Join Date: Oct 2009 Location: Melbourne Australia Posts: 901	Re: Power MOSFETs This thread could focus on why some amp modules have blown up - as per post #5. If they hadn't blown up, then this thread may not exist. Post #5 indicates a concern about poor thermal transfer between fet and heatsink. That raises alarm bells for me, as those fets use a very common package, with what should be very standard heat transfer design. I reckon the flatness of the base etc are red herrings. I don't see any information about fet current and voltage waveforms, and designed junction and case temperatures - all very basic design and faultfinding aspects.