Hi Phil,
If I recall correctly, the sensor is located adjacent center-bottom
of the lower roller. Unfortunately, the temperature of the sensor
and of that portion of roller the PCB contacts are probably
different. In a feedback control circuit, the sensor only has to
sense something proportional to the parameter being controlled. To
illustrate, the temperature at the sensor may only be one-tenth of
that of the place where you want the temperature controlled. The
control circuit must then provide gain to make up for the lack of
sensor sensitivity.
--- In Homebrew_PCBs@yahoogroups.com, "Phil" <phil1960us@y...> wrote:
>
> I was thinking that I would need to open it up, find the temperature
> sensor, put the thermistor there, close it up and run it until the
> light comes on. Then feed a piece of copper clad through and see
> what happens.