| 摘要 |
PROBLEM TO BE SOLVED: To provide a gas detector hard to cause an error in the supply quantity of power to a heater even if the output voltage of a power supply is varied after the start of the supply of a current to the heater and capable of suppressing the lowering of gas detecting precision. SOLUTION: The gas detector 150 is constituted so that battery voltage VB is detected over a plurality of times in the current supply time band (voltage application executing time Ton) to the heater in one cycle of PWM control and the power quantityΣWi supplied to the heater 4 is operated on the basis of the detected battery voltage VB. That is, this gas detector 150 can judge the quantity of the power actually supplied to the heater 4 even if the battery voltage VB is varied after the supply of a current to the heater 4 is started and the supply quantity of the power to the heater 4 can be allowed to precisely approach the target quantity of power. In this gas detector 150, the temperature control of a gas sensor element due to the heater 4 becomes well and the change in the activated state of the gas sensor element caused by the variation of temperature can be suppressed and the lowering of gas detecting precision can be suppressed. COPYRIGHT: (C)2008,JPO&INPIT
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