摘要 |
A circuit for detecting the completion of the charging of a battery from a source of direct current employs two reference voltages, one of which is established by charging a capacitor when the charging of the battery begins, the other reference voltage is maintained by a thermistor connected across the direct current supply and in heat-exchange relationship to the battery. The first voltage is maintained by a diode which isolates the capacitor from discharging, but the other voltage drops when the fully charged battery lowers the resistance of the thermistor. The reference voltages are fed to the inputs of a difference amplifier whose output controls a switch circuit to disconnect the battery from the power source.
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