| 摘要 |
<P>PROBLEM TO BE SOLVED: To count the number of times of heating without using a battery. <P>SOLUTION: The thermal history detection switch 40 is provided with first and second permanent magnets 42a and 42b, a temperature sensitive ferrite 43, first and second soft magnetic bodies 44a and 44b, a switch body 45, and first and second electrodes 47a and 47b. The first and second permanent magnets 42a and 42b clamp the temperature sensitive ferrite 43. The first and second soft magnetic bodies 44a and 44b face the first and second permanent magnets 42a and 42b, and the free ends of the first and second soft magnetic bodies 44a and 44b face the temperature sensitive ferrite 43. The switch body 45 is supported freely movably along a first direction. At a temperature lower than the Curie point, the first and second soft magnetic bodies 44a and 44b pull the switch body 45 in the first direction. When it is higher than the Curie point, a spring 46 moves the switch body 45 in a second direction. When the switch body 45 is moved in the second direction, it is brought into contact with the first and second electrodes 47a and 47b. <P>COPYRIGHT: (C)2009,JPO&INPIT |
