A new design of battery charger supplying step-constant current employing complementary switches controlled by integration-feedback circuit

This paper introduces a kind of battery charger employing power MOS as complementary switches, which is controlled by integration-feedback circuit, and, the charging current changes in steps under control of micro-computer while keeps constant automatically within each step. It can charge a high-capacity battery-assembly in series connection of 18×12V. The device performances well under a wide range of AC voltage from 190V to 250V while the battery-assembly DC voltage varied from under 190V up to 250V. The performance of feedback and control circuits are discussed in detail, as well as the current's wave pattern in key elements.