AN INNOVATIVE AND VERSATILE BATTERY CHARGER CONTROLLER DESIGN EMPLOYING STATE OF THE ART DETECTION CONCEPTS FOR APPLICATIONS IN CHARGING BATTERIES

摘要

PURPOSE: To obtain a battery charging circuit applicable to both an NICD battery and an NIMH battery by ending the charge sequence upon generation of any one of a signal for detecting the cell voltage drop with regard to the time or a signal for detecting the cell voltage for some constant interval with regard to the time. CONSTITUTION: Upon detecting a cell voltage drop with regard to the time, a voltage drop detection circuit M9 generates a first detection signal. Upon detecting a cell voltage for some constant interval with regard to the time, a voltage detection circuit M10 generates a second detection signal. When first or second detection signal is generated, charge sequence is ended. Since both detectors M9, M10 operate simultaneously, end of charge sequence is indicated by detecting any one of a voltage drop or a flat gradient. Consequently, the battery charging circuit is applicable to both an NICD (nickel cadmium) battery and an NIMH (nickel metal hydride battery).