LeIand C. Scot wrote:
Tacking the diodes on to the case of the transistor works better than
attaching them to the heat sink due to the relatively slow thermal response,
the heat sink changes temperature slower than the cap on the transistor.

That's simply not true... while the heat sinks response might be a bit
slower... it's a much better indicator of the temp of the transistor
die. The ceramic cap on those transistors will overshoot the die temp
in both directions because of it's poor thermal contact with the die.

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