GB738081A - Improvements relating to electric battery charging circuits - Google Patents

Abstract

738,081. Charging and discharging batteries. METROPOLITAN-VICKERS ELECTRICAL CO., Ltd. April 2, 1953 [May 22, 1952], No. 13017/52. Class 38 (4). [Also in Group XXXVII] An electric battery charging circuit, e.g. as used in a vehicle lighting system, having contactor contacts CIC/1 for connecting the battery 1 to a charging generator 2 whose output voltage varies during operation, has for controlling said contacts means responsive to the generator voltage but incapable by itself of closing the contacts within the generators working range acting in conjunction with means responsive to current flow in the charging direction through a circuit shunting said contacts to close said contacts when and only when the generator voltage exceeds the battery voltage ; also provided are means to open the contacts CIC/1 in response to reverse current flow therethrough, and means in said. shunt circuit to prevent reverse current flow therethrough. As shown, on attaining a given generator voltage which generally is below the minimum expected of the battery, a reverse current relay voltage coil RCR/V closes its normally open contacts RCR/1 and RCR/2 to energize a polarised coil CIR of a cut-in relay which then closes its normally open contacts CIR/1 to permit energization of the main contactor coil CIC which closes its contacts CIC/1 to-commence charging. Closure of the latter contacts effectively short-circuits the coil CIR so that the cut-in relay drops out but the contactor remains energized through its maintaining contact CIC/2. When the generator voltage falls below that of the battery reverse current through the coil RCR/C de-energizes the reverse current relay which drops out the main contactor. In another embodiment, not shown, a further current coil on the reverse current relay replaces the cut-in relay. The reverse current flow in shunting circuit may be prevented by a rectifier, a permanent magnet, or by additional relay contacts.