On 01/01/2014 06:28 AM, William Sommerwerck wrote:
"dave" wrote in message
m...

"Figure of Merit" in pulsed applications vs "efficiency"
in linear applications.

Any (???) device can produce more peak power in pulsed mode than
continuous, because it spends less time in the region where it
dissipates the most power.


RMS power is measured in heating ability versus DC.

There is no such thing (other than in a mathematical sense) as RMS
power. Voltage and current can have RMS (root-mean-square) values.
Squaring voltage and dividing by resistance, or squaring current and
multiplying by resistance produces the //average// power.



http://www.learningaboutelectronics....-explained.php

The audio duty cycle makes the device heat up more than pulsating full
on/full off does. That's the spec and the spec is based on a temperature
that will destroy the gate, source, drain, diode, etc. In audio service
an FET is always drawing some current, due to the high turn-on
threshold. The bias is just slightly above cutoff. Many amps use this
quiescent current to set the bias, either measured directly or by
measuring current draw at the mains.