GB430835A - Improvements in electrical switching apparatus for battery charging - Google Patents

Abstract

430,835. Charging batteries. ACCUMULATOREN - FABRIK AKT.-GES., 3, Askanischer Platz, Berlin. Jan. 25, 1934, No. 2617. Convention date, Jan 25, 1933. [Class 38 (iv)] [See also Group XXXVII] In an electromagnetic cut-out for use in battery-charging circuits the effect of separate differentially-acting series and shunt windings is obtained by a single winding and a network of resistances, a part of the charging current being arranged to flow through this winding and a series resistance which shunt a resistance in the charging circuit, a further resistance being arranged in series with the relay winding across the charging circuit. As shown in the Figure the effect of separate differentially-acting shunt and series coils is obtained by a single coil r and a network of resistances rl, r2 and w. These are connected in such a manner that a part il of the charging current i is shunted from a resistance w in the charging circuit over the whole or a part of the relay winding r and a variable resistance r2. A resistance r1 is connected in series with the relay winding r across the charging circuit. This resistance may however form part of the winding itself. The relay coil is thus energized in a manner, as described theoretically in the Specification, which is equivalent to that produced by differentially acting series and shunt relay windings and the resistances may be so chosen and adjusted that when a constant-voltage charging circuit is utilized and the charging current is at first relatively large the current through the relay coil is at first relatively small, but as charging progresses the latter current rises until the cut-off switch s is operated. The cut-out is particularly adapted to control an initial rapid charging operation and, if required, an additional slow charge may be given controlled by a timing device associated with the relay or by an ampere-hour meter.