" wrote:

I remember that Thermostat . The A and B screws act as a heat
anticipator does ; the more you back out the A screw with the B
screw turned all the way in....the greater the differential will be
and the greater the room temperature swing will be.

Your explanation indicates that the amount of turns of the screw is
somehow sensed by the thermostat's circuitry.

This assumption is incorrect.

On this thermostat, the screw is not functioning as the core of an
inductor or coil (as per your explanation). The only function the screw
has is to bridge the wire contacts on the upper surface of a machined
plastic block. The wires connect to the PC board.

If variable operating was desired, then Honeywell would have used a
potentiometer instead of a significantly more complicated reactance
circuit.

All the printed manuals for these thermostats indicate that the screw
has basically only 2 settings: Fully turned in (tightened down) or
unscrewed (turned out) by one turn. The one turn is sufficient to raise
the underside of the screw head enough so that it is not contacting
(bridging) the wires.