| 摘要 |
<p>A secondary battery protection circuit has: a first switch that permits or inhibits charging of a secondary battery by switching a charge conductor between a conducting and a non-conducting state; a voltage detection portion that monitors the voltage of the secondary battery to output an error signal when the voltage is an overvoltage; and a first current path that has one end connected to the positive-side conductor and the other end connected to the negative-side conductor, and through which a current corresponding to the supplied electric power passes. The first current path, other than during charging of the secondary battery, is kept in a non-conducting state and, when the error signal is outputted while the first current path is in a conducting state, is irreversibly brought into a non-conducting state by a current of a predetermined amount or more passing therethrough. The first switch, when the first current path is in a conducting state, permits charging and, when the first current path is in a non-conducting state, inhibits charging. Thus, other than during charging, electric power consumption associated with overcharge protection is reduced, and once an overcharged state occurs, charging never again takes place.</p> |
