GB229827A - Improvements in electric lighting and like systems having a constant voltage load and a variable voltage source of supply current - Google Patents

Abstract

229,827. Ferguson, T., Johnstone, J. R., and Metropolitan-Vickers Electrical Co., Ltd. Jan. 19, 1924. Regulation, automatic; systems of charging batteries.-A variable speed generator 1, Fig. 1, such as used for railway lighting systems, supplies a constant, voltage load 5 through a rheostat 6, which is automatically adjusted according to the voltage across the generator as determined by a voltage solenoid 8. The voltage of the dynamo is also regulated by the automatic operation of a field rheostat 7 actuated independently by the solenoid 8 and by another solenoid 9 subjected to the charging current of a battery 4. Energization of the solenoid 8 lifts a core 16, Fig. 3, attached to a lever 18, the ends 23, 25 of which are constrained in guides 21, 22. At first, the end 23 lifts operating the rheostat 6, and the end 25 slides horizontally without any action on the rheostat 7. After the full value of the rheostat 6 has been reached, the end 23 slides horizontally and the end 23 begins to lift, swinging another lever 19 about its slotted end 24, and lifting a slotted member 26, which operates the rheostat 7. Energization of the solenoid 9 lifts a core 17 and swings the lever 19 about its end 25 thereby operating the member 26 and rheostat 7 independently of the solenoid 8. One terminal of the generator instead of being connected to the conductor that leads direct to the lamps 5, may be connected to an intermediate point of the solenoid 9 so that this solenoid is energized in accordance with the difference between the load and battery currents. A switch 13, which is closed when the lamps are switched on, connects part of a resistance 10, which is in series with the solenoid 8, in parallel with the rheostat 6. The rheostats 6, 7 may be of the type described in Specification 26646/13.