Bs1 pot

Archiver

I'm trying to use the BS1 in a themostat for my heating system. It's
not entirely trivial because when the pump is turned on there is a
shock of cold water what would turn it off a standard thermostat.

So I worked out a circuit using a thermistor etc. Using the POT
command with the help of Alt-P and hot cup of coffee I managed to get
the a bread boarded version to work in the way that I wanted. In the
real life situation the thermistor is several meters (feet yards or
whatever) from the box of tricks. When I tried to attach the
thermistor via a long piece of wire things started to go wrong. The
scale paramter changed dramatically and even worse temperature
changes
had the opposite effect, that is rising temperature appeared to show
rising resitance.

Eventually I discovered that just attaching the wire between the
themistor and capacitor caused the same effect. I even changed to
using shielded wire with no improvement. Attaching the wire to Gnd
had
no ill effect.

What's happening - and more importantly - can I do anything about it?


Steve