| 摘要 |
PURPOSE:To obtain a simple structure and to reduce the unevenness of temperature by connecting a temperature sensor with a positive temperature coefficient property and a flat type heating body in series, and covering at least the common one side with a uniform heating member. CONSTITUTION:When an adiabatic substance is provided to a part or to the whole body of a flat type heating body 1, the temperature of the heating body 1 at the part covered therewith is raised. This abnormal temperature rise is transmitted rapidly to a temperature sensor 4 nearby through a uniform heating member 7, and the temperature of the sensor 4 is raised. Since the sensor 4 and the heating body 1 are connected in series to a power source A, the current flowing through a circuit is reduced by the increased resistance of the sensor 4 by its positive temperature coefficient property, and the heating amount of the heating body 1 is also reduced to stop the temperature rise. And since the sensor 4 is provided in parallel to the heating body 1 and along the whole length, an abnormal temperature rise of the whole body can be detected by only one sensor 4. In such a way, the dispersion of the temperature is reduced in a simple structure. |
