| 摘要 |
PURPOSE:To enable a simple and less-expensive sensing of a flame to be carried out by a method wherein a reference voltage for a thermovoltage amplifier is used as a reference voltage for supervising a cell voltage, and then the reference voltage and the cell voltage are compared to each other. CONSTITUTION:Since a forward voltage of a diode 3D3 is not related with a cell voltage, an electric current I flowing in a transistor 5 becomes constant without having any relation with a cell voltage and a voltage at a resistor 18 also becomes constant. This voltage is a reference voltage of a thermovoltage amplifier 9 and also a reference voltage of a cell voltage supervising circuit 10. If the values of a variable resistor 11 and a resistor 12 are specified, a voltage VR12 of a resistor 12 having a relation of E<E' with E being a cell voltage becomes lower than Vs and thus an output of a comparator 13 is inverted from L to H. As a result, a transistor 14 is ON, an output of the thermovoltage amplifier 9 is reduced to a ground level and a flame sensor terminates its operation. |
