Document Type and Number:
Japanese Patent JPS4740048
Kind Code:
A
Abstract:
1384584 Battery charging systems GATES RUBBER CO 17 April 1972 [19 April 1971] 17594/72 Heading H2H A battery charging system comprises a power source and a controlled rectifier S.C.R. series connectible to a battery B to be charged, a potential divider R1, 30 being connected across the power source and the rectifier being allowed to heat up during initial charging of the battery to lower the potential across the gate-cathode junction at which the rectifier conducts and thereby increasing the initial charging rate. The power source includes a transformer T connected to a mains A.C. supply and the device 30 may be a thermistor, strain gauge, pressure transducer, resistor or photodiode but is preferably a Zener diode (ZD 2 ), Fig. 2 (not shown), connected in parallel with a potentiometer (R2) the tapping point of which is connected via a diode D1 to the gate electrode 28 of the rectifier. During initial charging the rectifier heats up since it is not provided with a heat sink, and due to the fact that the gate-cathode potential at which the rectifier conducts is inversely proportional to the temperature, the rectifier is fired early in each half cycle to supply a high charging current to the battery. As the battery approaches the end of charge the current through the rectifier decreases and the resultant cooling of the rectifier S.C.R. delays its firing point until the rectifier is eventually switched off. Thus overcharging of the battery is prevented. The power source may include a full wave rectifier.
Application Number:
JP3952272A
Publication Date:
December 09, 1972
Filing Date:
April 20, 1972
Export Citation:
International Classes:
H02J7/00