Expo conv. heater (tomg et al.)

[Steve Varner]

I haven't built a discrete VCO yet (just CEM chips in a kit VCO). I want
to build a 3046/thermostat circuit, but I have a few questions.

1. Do you really need a separate power source for the heater part?
That's a real pain in the rear. You mentioned regulators and I've seen
separate supplies mentioned on the web... so that's why I want to know.

2. Barry Klein suggested putting the 3046 under a styrofoam cover to
isolate the chip from heat loss or gain - sort of a chip calorimeter.
Has anyone done this?

3. How do you know where to set the temperature trim on the thermostat?
I mean, how do you know where to set the temperature and how do you
measure a silicon chip's temperature accurately anyway? Not having the
temp too high or low was discussed, so this is important.

PS, if you folks lived in San Diego instead of 2 degrees from the Arctic
Circle you might not worry so much about temperature   ;-)

SV