| 摘要 |
PURPOSE:To easily judging serious damage such as short-circuit by arranging a sensor which irreversely changes by heat on the surface of a protecting element which is visible from the outside of a battery. CONSTITUTION:When a circuit is short-circuited by a malfunction, excess current flows through the circuit, and a PTC element 1 is heated by Joule heat and its temperature is increased. The resistance of the PTC element is sharply increased by the heat, and the color of a sensor 5 on the surface of the PTC element is changed. Increase in the resistance of the PTC element stops the excess current in the circuit to protect it. Since the color change of the sensor is irreversible, even if the PTC element 1 is recovered, the color change of the sensor is not recovered. |
