| 摘要 |
PURPOSE:To provide a ventilator by which the drive control of an exhaust fan can be interlocked with the detection signal of a gas sensor. CONSTITUTION:A ventilator is provided with resistances R1, R2 which can divide a drive power supply+B into a reference voltage VRef1, a gas sensor 10 which can detect the gas density in a space which is a detection object and can generate a detection signal S1 in compliance with the gas density, an amplifier 11 which can amplify the detection signal S1 to a prescribed level and can output the detection signal S2, and a comparator 12 which can generate the detection signal D1 when the detection signal S2 is below the reference voltage VRef1 after comparing the reference voltage VRef1 with the detection signal S2 further, a switching transistor Tr3 which can be turned on by the receipt of the detection signal D1 and a relay L1 whose contact point is turned on when the switching transistor Tr3 is turned on. Therefore, when the gas sensor 10 detects oxygen shortage, the relay L1 is turned on and the drive power supply+B is supplied to an exhaust fan 21. |
