| 摘要 |
PURPOSE:To protect a transistor and a motor by fixedly providing a heat sensing body in between a radiating fin for a transistor and an electric conductor, as a part of the circuit of a motor current, and enabling said circuit to be shut off due to the fusion of said heat sensing body. CONSTITUTION:A heat sensing body is formed with a lead-bismuth alloy, while being formed so as to be fused when the temp. of a fin 6 becomes above its allowable temp. In this structure, if a blower is stopped and the temp. of the fin 6 rises above a defined value due to a locked motor, etc. the heat sensing body 5 is fused and separated from between the fin 6 and an electric conductor 4, shutting off the circuit between the fin 6 and the electric conductor 4. Accordingly, even if a short circuit condition takes place due to the overheating of a transistor T1, and the like, a short circuited current will not flow. Thereby, the burning of a motor and a transistor can be prevented. |
