GB478783A - Improvements connected with boosters - Google Patents

Abstract

478,783. Electricity supply; automatic control systems. ECLAIRAGtE DES VEHICULES SUR RAIL. March 18, 1937, No. 7963. Convention date, March 25, 1936. [Class 38 (iv)] Boosting by dynamo-electric machines ; controlling electromotive force.-In a system in which a load is supplied either from a constant voltage dynamo or from a battery through a booster group consisting of an electromotor coupled to a dynamo, the booster dynamo' is provided with two field magnets opposite in action only one of which is operative during charging of the battery by the dynamo. When switch 3 is closed, a constant voltage dynamo supplies a load 5 through leads 2 and also charges the battery 4 through the booster dynamo 8 which is driven from the motor 6. The two oppositely acting fields 10, 11 of the dynamo 8 are connected across the battery and either may be short-circuited by the armature 14 which is acted upon by a spring 16 in opposition to a winding 13 across the leads 2. When the dynamo is connected, the full voltage acts upon winding 13 which attracts armature 14 and short-circuits field 11. When switch 3 is opened, armature 14 short-circuits field 10 and the voltage of the current supplied to the mains by battery 4 is boosted by dynamo 8 until armature 14 leaves contact 17 and acts as a vibrating controller of voltage. The field 7 of the motor 6 may be connected permanently across the battery 4, or may be so connected only when switch 3 is opened by the additional blade 19 moving with switch 3. The armature 14 will then not vibrate, but will short-circuit one or the other of the fields 10, 11. A resistance 22 may be inserted in the circuit of the motor field 7 to reduce the speed of the motor at the commencement of the period of discharge of the battery.