Electrical heating system including convectors with thermostats - has control circuit error compensated and including photosensor associated with transistor and potentiometer

摘要

The electrical heating system has convector units each having an individual electronic thermostat and a potentiometer(P1) setting the overall chosen temperature. A differential amplifier(A1) allows the local light level to automatically lower the overall heating requirement. It allows setting errors due to the inclusion of the temperature lowering circuit(D) to be compensated for by connecting this circuit in parallel with the temperature sensor(Th) or with the potentiometer. A second potentiometer(P2) can also be included, controlling night temperature and the former, day temperature. Potentiometer selection(R1) is then governed by the ambient light sensor(L). The light sensing element is connected in the emitter-collector loop of an NPN transistor(T) which controls the setting of the selector switch via a relay.