| 摘要 |
<p>Provided is a cheap long-term use cutoff device capable of reliably preventing fires starting from wires. A CPU (63) repeatedly calculates a temperature difference between the ambient temperature surrounding a wire (4) and the temperature of the wire (4) over time. If the temperature acquired by adding the temperature difference calculated by the CPU (63) to the ambient temperature is equal to or greater than a prescribed temperature, a control circuit (53) cuts off the current flowing in the wire (4) by turning off an FET (51). The CPU (63) sets the initial temperature difference, which is a positive value, on the basis of the ambient temperature. The CPU (63) uses the set initial temperature difference to calculate a first temperature difference, and uses the last calculated temperature difference to calculate the temperature difference thereafter.</p> |
