Apparatus for controlling a heating or cooling system of the type that includes an evaporator and a thermostatic expansion valve having a thermostatic bulb. The control apparatus comprises a thermoelectric heat pump device responsive to an electrical control signal for controlling transfer of thermal...http://www.google.com.au/patents/US4879879?utm_source=gb-gplus-sharePatent US4879879 - Apparatus for controlling a thermostatic expansion valve
