MAT-04 for expo & heater

[Tim Ressel]

To all,

This goes with the recent discussion on MAT-04s. This weekend I tried the AN-299
heater scheme using a MAT-04. It worked! That is, after some circuit tweeking.
For one, the tempco for the trannies is different than for a 3046. In addition,
the MAT-04 can only handle 30mA of collector current, so the clamp circuit on
the base of the heater tranny had to be tweeked. 

I am concerned about the lower collector current limiting the temperature range
of the heater, so this week I will be running some tests in the chamber. I will
publish the results Real Soon Now.

Tim Ressel--Compliance Engineer
Hewlett-Packard
Verifone Division
916-630-2541  
tim_r1 at verifone.com