Patent ID: 8860373

Claim:
A protective circuit comprising: a smoothing circuit that is configured to (i) receive a pulse-like charging output permitting signal in a normal charging state and output a smoothed first signal having a first magnitude and (ii) not receive the pulse-like charging output permitting signal in an abnormal charging state and output a second signal having a second magnitude, the second magnitude being less than the first magnitude; and a charging output control element that is controlled so as to permit or stop a charging output with respect to an electric storage device, permits the charging output conditioned on receiving the smoothed first signal in which the charging output permitting signal is smoothened by the smoothing circuit, and stops the charging output when an abnormal charging state is detected, wherein the smoothing circuit includes: a first input terminal and a second input terminal to which the pulse-like charging output permitting signal is input; a first output terminal and a second output terminal that output a control signal to the charging output control element; a series circuit that includes a first condenser and a first diode in forward direction which are inserted between the first input terminal and the first output terminal; a second diode in which an anode is connected to a power supply line which connects the second input terminal and the second output terminal and a cathode is connected between the first condenser and an anode of the first diode; and a second condenser that is inserted between the power supply line and a cathode of the first diode.