Patent ID: 8890483
Filing Date: 2014-11-18
Classification: H01M,H02H,H02J,Y02E

Abstract:
1. A protection circuit, comprising: a connecting terminal for receiving a voltage for charging a rechargeable battery; a switching element interposed between the connecting terminal and the rechargeable battery; a temperature fuse for blocking a conductive path between the connecting terminal and the switching element; a heater for melting the temperature fuse; a voltage detection unit for detecting a voltage relating to the conductive path; a first abnormality detection unit for detecting occurrence of a first abnormality that is pre-set as a recoverable abnormality; a second abnormality detection unit for detecting occurrence of a second abnormality that is pre-set as an abnormality on the basis of which the temperature fuse should be melted; a protection control unit for turning OFF the switching element when the first abnormality is detected by the first abnormality detection unit; a heater control unit for executing a temperature fuse melting process of applying the voltage of the conductive path to the heater when the second abnormality is detected by the second abnormality detection unit and the voltage detected by the voltage detection unit is not less than a predetermined threshold voltage; a temperature detection unit for detecting a temperature relating to the temperature fuse; and a threshold voltage setting unit for lowering the threshold voltage as the temperature detected by the temperature detection unit rises, wherein the voltage detection unit is a terminal voltage detection unit for detecting a voltage of the connecting terminal.