GB1462916A - Battery charging and discharging system - Google Patents

Abstract

1462916 Systems for charging and discharging batteries TADIRAN ISRAEL ELECTRONICS INDUSTRIES Ltd 22 July 1974 [3 Aug 1973] 32408/74 Heading H2H A system for charging and discharging a battery B comprises a circuit for charging the battery from a mains supply, a switching circuit responsive to failure of the mains supply to discharge the battery through a lighting load L1 and a control circuit which stops the discharge of the battery when the battery voltage falls to a predetermined level. When the mains supply is present, a relay RL1 is energized so that its contacts RL1-C engage contacts 10, 12 thereby enabling the energization of a relay RL2 via movable contact PC1 and fixed contact 62 of a three position switch PSW which is set in its "automatic" position and a series resistor R3. The contact RL2-C of the relay RL2 engages a contact 24 so that the battery B is charged by a bridge rectifier BR. On failure of the mains supply the relay RL1 is de-energized so that the contacts RL1-C engage contacts 14, 16 but the relay RL2 remains energized by the battery. The load is therefore energized by the battery until the battery voltage falls to a level which is insufficient to maintain the contact RL2-C in its actuated position. This contact therefore engages a contact 22 to disconnect the battery from the load. In another position of the switch PSW in which contacts PC1, PC2 engage contacts 50, 60 respectively, "non-automatic" operation of the system occurs such that on failure the battery is not automatically connected to the load until the switch has been momentarily actuated to a third unstable position from which it returns to the "automatic" position.