| 摘要 |
PURPOSE:To make it possible to issue warnings at a low temperature and a high temperature, by setting detecting temperatures at a low temperature and a high temperature, and providing an electronic circuit, which can issue the precaution warning at the low preset temperature and can issue the maximum warning at the high preset temperature. CONSTITUTION:With the increase in ambient temperature, the resistance value of a thermistor TH is decreased. When the output voltage VA of a voltage detecting circuit 1 becomes lower than a reference voltage VB of a first voltage comparing circuit 2, a PTU4 is conducted. When the ambient temperature is further increased and the output voltage VA of the voltage detecting circuit 1 becomes lower than a reference voltage VC of a second voltage comparing circuit 3, a PUT5 is conducted. When the PUT4 is conducted, a part between a precaution warning terminal L1 and a common terminal C is shorted and maintained. When the PUT5 is conducted, a part between a maximum warning terminal L2 and the common terminal C is shorted and maintained. Thus the warning can be issued at the low temperature and high temperature, respectively. |
