GB400625A - Improvements in and relating to train lighting, heating and like electrical installations - Google Patents

Abstract

400,625. Charging batteries; automatic regulation. STONE & CO., Ltd., J., Deptford, and PRESTIGE, SIR J. T., 1A, Cockspur Street, both in London. April 27, 1932, No. 12120. [Class 38 (iv).] A train lighting &c. installation comprises a constant current dynamo and an automatic voltage regulator which functions only after the dynamo has charged the battery to a predetermined voltage and then maintains that voltage substantially constant while the battery charge is being completed. The regulator preferably comprises an electromagnet 1 operating upon a switch contact 4 normally shortcircuiting a carbon pile resistance 8 in the field circuit of the dynamo which pile is compressed by a spring 7 the tension of which is relieved by the electromagnet in response to dynamo or battery voltage. The regulator may be adjusted to operate at a desired voltage by means of a series calibrating resistance 1<1> or by the setting of a nut 10. The leverage of the solenoid on the pile may also be adjustable. The regulating resistance may be in series with a field winding 6<1> across the main dynamo brushes and with a field winding 6 supplied from the auxiliary brush or it may be only in series with windings fed from the auxiliary brush or only in series with a field-winding across the main brushes. The dynamo may have additional field windings, such as a series winding.