| 摘要 |
PURPOSE:To ensure the assured working of a power supply device of a PTC thermistor for a liquid level detector, by using the heat-sensitive ferrite at least at a part of the core of a power supply coil. CONSTITUTION:A power supply coil 2 of a magnet type generator 1 is connected in parallel to a PTC thermistor 3 and an alarm device 4. The coil 2 functions as a heating power supply of the thermistor 3. The thermistor 3 is set so as to be exposed into the air when the flow rate to be detected is reduced. When the liquid level is lowered to expose the thermistor 3 into the air, the thermistor 3 exceeds the Curie point to increase its resistance. As a result, the device 4 is actuated to inform the reduction of the liquid level. |
