GB672233A - Voltage and frequency regulating system for a motor-alternator - Google Patents

Abstract

672,233. Automatic voltage and frequency control systems. CLEVELAND, F. J. (Bendix Aviation Corporation). Dec. 24, 1947, No. 34266/47. [A Specification was laid open to inspection under Sect. 91 of the Acts, July 26, 1948.] Class 38 (iv). A system for automatically controlling the speed of a motor-alternator in response to alternator frequency is rendered effective by means responsive to motor input voltage. To maintain constant the frequency of a threephase alternator 2 driven by a D.C. motor 1, a rectifier 18, supplied in series with an ironcored inductance 37 from one phase 25, 26 of the alternator output, energizes the operating coil 15 of a carbon pile regulator 9 in series with the motor shunt field winding 7, while, to maintain the alternator voltage constant, a rectifier 49, supplied from the same phase of the alternator output, energizes the operating coil 46 of a carbon pile regulator 40 in series with the alternator field winding 24. The frequency control is naturally voltage responsive and a condenser 52 included in series with the supply to rectifier 49 makes the voltage control frequency responsive, the senses of these secondary effects being such as to produce stable voltage and frequency. To cut out frequency control during starting a relay 33 is insufficiently energized from the lowered voltage of a battery 6 supplying the motor so that relay contact 31 short circuits carbon pile 9 and disconnects the supply from rectifier 18, but, when the motor is up to speed, rise of battery voltage causes changeover of contact 31 to introduce frequency control. A thermal delay switch in place of electromagnetic relay 33 is referred to. Specification 608,508 is referred to.