| 摘要 |
PURPOSE:To appropriately control an air-purifier, by comparing two reference values obtained by dividing a battery voltage, with an intermediate level detected voltage to detect a variation in the battery voltage, and by controlling the air-purifier in accordance with the result of the detection. CONSTITUTION:A battery voltage setting means 21 divides a battery voltage, by means of resistors R1-R4 to set two reference voltages, and an intermediate level detected voltage between the reference voltages. Further, an amplifier 2 amplifies the detected voltage, and a variation detecting means 23 compares thus amplified detected voltage with the reference values to detect a variation in the battery voltage. Further, a smoothing section 24 smoothens the detected voltage from the means 23, and a comparator 25 compares thus smoothened detected voltage with the reference voltages set by the variable resistors. Further, a drive circuit 26 drives an air purifier 17 in accordance with an operational signal from the comparator 25. With this arrangement, even if the battery voltage lowers, the detection of a battery voltage may be stably made, thereby it is possible to control the air-purifier 17 always appropriately. |
