Re: OLTC primary loss measurement

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "tesla by way of Terry Fritz <twftesla-at-qwest-dot-net>" <tesla-at-paradise-dot-net.nz>

Greetings Terry et al
Understand your comments
Clearly priority in performance terms is the big losses first and since it
is clear that IGBT losses do not dominate the idea is probably moot. But it
is actually an easy measurement to make.

Just one point, I do not agree with the notion of how long it takes to raise
the temperature being the appropriate method.
This is a brings in thermal mass, along with driving power and thermal
resistance heatsink to air. Its like trying to measure voltage given C and
time constant when the ohms law of thermal systems is more direct.
The driving electrical power is fully defined by the difference between
ambient and heatsink temperature at EQUILIBRIUM.

Delta Temp/Thermal Resistance (sink to air)=Watts
Good luck and we look forward to more installments of the OLTC story when
you have the time
Rgds
Ted L in NZ