GB996469A - An electric regulator for controlling variables such as temperature - Google Patents

Abstract

996,469. Automatic temperature control systems for furnaces. PYROMETRIE INDUSTRIELLE. Dec. 12,1962 [May 16 1962], No. 46951/62. Heading G3R. An automatic temperature control system for a furnace or an enclosed space having a relay 6 controlling the heating device and provided with a thermo-couple T sensitive to the temperature of the furnace or space so as to control a galvanometric instrument G such that a vane 16 on the instrument pointer moves between the coils 1, 2 of an oscillator 4 when the temperature of the furnace or space increases to terminate the operation of the oscillator 4 and hence the "flip-flop" device 7, 8 thereby causing the relay 6 to remove the supply from the furnace or space heating device is characterised by the provision of two further auxiliary coils 18,19 which are connected in series with the main coils 1, 2 of the oscillator, the coupling of the two coils 18,19 being varied to cause the oscillator to control the relay 6 in advance of the datum positions thereby reducing the "overshoot" of the system. The coils 18, 19 are carried on bimetallic members 20, 22, the member 22 providing ambient temperature compensation whilst the member 20 is provided with a heating coil 21 which is switched ON and OFF by the relay 6 together with the furnace or space heating device. In a second embodiment the coucoupling of the coils 18,19 may be controlled by a ferrite core movable in accordance with the operation of the relay 6. The vane 16 may be arranged to co-operate with the coils 18,19 when in its extreme position to prevent damage to the system should the thermo-couple T become unserviceable. Specification 779,193 is referred to.