GB525248A - Improvements in battery charging equipment - Google Patents

Abstract

525,248. Charging batteries. HINDS, R. S., MANDL, A., and, METROPOLITAN-VICKERS ELECTRICAL CO., Ltd. Feb. 22, 1939, No. 5903. [Class 38 (iv)] A battery 6 is charged from an A.C. source 1, 2, through a rectifier 4, and a choke coil 5 in the supply circuit to the rectifier is controlled in accordance with the changes in battery voltage as charging proceeds so that the charging current remains uniform over the charging period. The coil 5 has a saturating winding 5<SP>1</SP> connected across the battery opposing a second saturating coil 5<SP>11</SP> energized from an auxiliary rectifier 4<SP>1</SP> in accordance with the difference between the supply voltage and the voltage input to the rectifier. In this way compensation for supply voltage variations is also obtained. When the battery voltage attains a predetermined value a relay 11 operates to energize an electromagnetic switch 13 which changes a tap connection on the supply transformer 3 to reduce the charge to a gassing rate. A resistance 20 is inserted in the circuit of the coil 5' when the charge is made. A timing motor 10 energized by operation of the relay 11 terminates the charging after a predetermined time. A selector switch 17 may be positioned so that operation of the switch 13 changes from normal to conditional charge. In this case the motor 10 is rendered ineffective by a switch 26 coupled to the selector switch. A resistance 19 controlled by the switch 13 prevents " hunting " of the relay 11. In Fig. 2, not shown, the second coil 5" on the choke coil 5<SP>1</SP> is energized from an auxiliary rectifier connected across taps on the coil 5. In this arrangement the leakage of the tapped section increases with saturation.