GB191501435A - Improvements in and relating to Dynamo Electric Machines and Electrical Systems connected therewith. - Google Patents

Abstract

1435. Stone & Co., J., and Darker, A. H. Jan. 28. Lighting systems; systems of charging and discharging galvanic batteries.-In the installation shown in Fig. 3 for train-lighting &c., the dynamo a is of the self-regulating supplementary-brush type with intermediate regulating poles c, the windings l of which are connected across a resistance in the lamp circuit ; the poles c serve to raise the output in accordance with increased demand in the lamp circuit, in the manner described in Specification 7589/14. The battery o is protected against overcharge by an electro-magnetic switch 5, which, at a predetermined voltage of the battery, throws a resistance z across the battery ; the switch 5, acting in conjunction with the cut-in switch s, also serves to change the values of resistances used in connexion with the regulating - pole windings l. The overcharge switch 5 comprises a voltage winding 6 which is placed in circuit after the closing of the cut-in switch by means of an extra contact 7<a> and brush s<1> ; the switch 5 also has an assisting series winding 13. By the employment of a resistance 9<a> and an additional contact 12 on the lighting switch q, the overcharge switch requires a greater voltage to cause it to operate when the lamps are switched off as compared with when they are switched on. An adjustable resistance r is used in connexion with the windings l to regulate the strength of the current charging the battery o, more particularly when the lamps are not in use. When the dynamo is stationary or is running but has not cut in, a low resistance 24 is shunted across the resistance in the lamp circuit ; as soon as the switch s cuts in the dynamo, a switch y is lifted by the core v and opens the circuit of the resistance 24. Further movement of the core v opens the switch y<1> and breaks a short-circuit about the resistance r. A further resistance 27 may be provided for preventing an undue increase in the battery-charging current when a heavy lamp load is turned on. The overcharge switch 5 may insert resistance in the circuit of the field - magnet winding h to reduce the output, or it may open the circuit of the winding h. Specifications 7470/10 and 4073/12 are referred to. Starting prime-movers, dynamo-electric machines with control circuits for. - In an installation in which the dynamo is driven by an internalcombustion engine, the dynamo may be run as a motor from the battery to start the engine by moving the switches 31, 32, Fig. 4, from the full-line positions to the dotted-line positions, the switch s being open. The switches 31, 32 may be operated by an electro-magnet, the circuit of which can be closed only when the switch s is open.