| 摘要 |
PROBLEM TO BE SOLVED: To cut off a current instantaneously at a temperature before a resistor is carbonized or short-circuited by detecting the leakage current generated when soft resins fused by an abnormal temperature are kept in contact with the resistor. SOLUTION: When a power supply J is turned on, a current flows in a resistor 1, and a nonflammable heating element and a double-faced control body are heated. If the resistor 1 is locally overheated in this state, soft resins 2 fused at 80-115 deg.C are fused at 115 deg.C and are short-circuited to nonflammable paper good conductor faces, metal foil good conductor faces, or good conductor raw material good conductor faces 3, and a current flows from the connecting terminal of a single or double-faced good conductor to a lead wire connected to a good conductor terminal. The current flowing in a resistor R is amplified and detected by the built-in transistor of a photo-coupler P, and a relay coil L is operated based on a detection signal to open switches S, thereby the feed of the current to the resistor 1 is stopped to prevent overheating of the nonflammable double-faced control body.
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