GB583728A - Improvements connected with direct current dynamo electric machines for use as electrical governors, and electrical governing systems - Google Patents

Abstract

583,728. Automatic control systems ; equalising load. WHEELER, H. D., and MOSSAY, P. A. H. Nov. 23, 1944, No. 23323. [Classes 35 and 38 (iv)]. A temperature compensated D.C. machine for use as an electrical governor has a pair of externally excited shunt windings in opposition, the positive winding incorporating a series connected ballast resistance of zero temperature coefficient. In one form, the machine G has shunt windings F1, F2 controlled by a regulator R, the resistance B giving temperature compensation. In a modified form, the field windings are connected in series through a ganged regulator, the ballast resistance shunting the negative winding. The machine may be used to maintain the speed of an engine or motor by virtue of the difference between its voltage and that of the supply energizing the field or armature of a pilot motor or contactor system P. Alternatively, by the use of further exciting windings in series with the motor any speed-torque characteristic can be obtained. In Diesel-generator sets the pilot motor can govern the generator field to load the engine so that it runs at constant speed and thus supplies constant power. Electronic amplification may be used. The ballast resistance may be of an alloy known as " Ferry " composed of 40 per cent nickel and 60 per cent copper.