GB568796A - Improvements in electric regulators and indicators - Google Patents

Abstract

568,796. Automatic control systems for heating systems &c. SAUTER AKT.- GES. FABRIK ELEKTR. APPARATE. F. April 20, 1943, No. 6337. Convention date, May 7. 1942. [Class 38 (iv)] [Also in Group XXXVIII] Temperature; variables in general.-To obtain a sensitive linear response of a regulator or indicator to a change in a variable quantity, a differential control device has two exciting coils in series respectively with the two parts of a resistance over which moves a contact operated in accordance with the condition of the variable quantity. The resistance of. the moving contacts or leads has therefore no effects. Fig. 2 shows a system in which a thermostat a, which may respond to room temperature, moves a contact 5 over a resistance 6. the two parts of which are respectively in series with coils 8, 9 differentially operative on a switch member 11 controlling a reversible motor 14 to adjust the opening of a valve 17 controlling heating fluid, The coils 8, 9 are also in series with. the respective parts of a second resistance 18 through a contact 20 adjusted by the motor to rebalance the excitation of coils 8, 9. A further resistance 36 in parallel with resistance 18 may have a contact 35 adjusted by a thermostat d subject to external temperature. The thermostat a being then responsive to the temperature of the heating fluid and the valve 17, preferably, a mixing valve. An adjustable resistance 40 may be provided to determine the sensitivity of the control. The rebalancing resistance 18 may be omitted or replaced by a resistance in series with one of the coils 8, 9. For remote indication of a variable quantity, the valve 17 is replaced by a pointer.