that,
its
pulse
the
target at
hoping to be just able to wait ~5 time constants or so. I must admit I thought it might be fun to watch the heat leak out of the transistor.
to
the
down to do either ther resistor or transistor as heater. (measure the voltage and current.) I guess there is some beta current error.. I've ordered a bunch of pnp medium power transistors. Beta's in the ~200 range but that drops at low temperature. But the SOT89 packs look great...
I find resistors a lot easier to drive to get a readily traceable heat pulse. Controlling both current and voltage separately is a more difficult proposition. Transistors do like to switch.