Expo conv. heater (tomg et al.)

[Martin Czech]

> I'm a physics / chemistry person and so I'm not sure on the definitions of
> some of the electronic terms you guys used. I don't want an entire
> electronics coarse...just some clarification. I'm sure some of the other
> folks out there are as lost as I am.
> What do you mean by:
> regulation loop
> temperature loop and overshoot
> SOA
> migration and junction degradation
> second breakdown
> 

Quick and dirty:

regulation loop: chip heater, sensor, and controll cicuitry form a regulation loop

temperature loop: same

overshoot: all closed loops tend to have a step response with overshoot

SOA: Safe Operation Area (safe area in the current and voltage plane)

migration: atom or molecule motion in direction of electron movement
           too much current stresses the wiring inside chips->open

junction degradation: all kind of effects destroy ideal diode behaviour,
                      leakage, hfe changes
second breakdown: thermal runaway of Si and/or bipolar Ut lead to
                  "hot spot", all current flows in one spot,
                  too much heat, filamentation, melting, exitus

m.c.