Armstrong, Westerman, Hattori, McLeland & Naughton
Charging apparatus with battery voltage monitoring circuitry
 The charging apparatus for charging a secondary battery by controlling the charging current on the basis of the change with time of the voltage of the secondary battery through sampling of the voltage. The voltage of the secondary battery is sampled by use of a voltage/frequency converter which converts the voltage of the secondary battery to pulses of a frequency corresponding to the voltage and a counter which counts the converted pulses for a predetermined time with a predetermined cycle. The counting time of the counter is set to be larger than half a cycle of a commercial alternating current source used as a charging power source. Short duration fluctuations in the battery voltage due to charging power source variations are compensated for because the average voltage during this time is converted to digital values, thus making it possible to sample the voltage of the secondary battery correctly without being influenced by the change of the voltage of the power source. 
Sanyo Electric Co., Ltd.
H
H02J
inventional
Masato Toru
Sano Morioka