Air filtering apparatus
In an air filtering apparatus in which power is supplied from a power supply to electrodes in an electrolytic bath to electrolyze water in the electrolytic bath and thus generate electrolytic water and the generated electrolytic water and air are supplied to a gas-liquid contact member to filter the air, a voltage varying unit varies the voltage applied between the electrodes, and includes a voltage switching unit for switching a power supply voltage, a voltage adjusting unit for adjusting the power supply voltage switched by the voltage switching unit and applying the adjusted voltage between the electrodes and a controller for controlling the voltage switching unit so that the power supply voltage is adjusted to a voltage nearest to the adjusted power supply voltage by the voltage adjusting unit.
1. An air filtering apparatus in which power is supplied from a power supply to electrodes in an electrolytic bath to electrolyze water in the electrolytic bath and thus generate electrolytic water and the generated electrolytic water and air are supplied to a gas-liquid contact member to filter the air, comprising:
a voltage varying unit that varies the voltage applied between the electrodes and includes a voltage switching unit for switching a power supply voltage, a voltage adjusting unit for adjusting the power supply voltage switched by the voltage switching unit and applying the adjusted voltage between the electrodes and a controller for controlling the voltage switching unit so that the power supply voltage is adjusted to a voltage nearest to the adjusted power supply voltage by the voltage adjusting unit.
2. The air filtering apparatus according to claim 1 , wherein the voltage switching unit switches a resistor connected to the power supply, and outputs the voltage based on the switched resistor, thereby switching the power supply voltage. According to this construction, the power supply voltage is switched by switching the resistor, so that the construction of the voltage switching unit can be simplified.
3. The air filtering apparatus according to claim 2 , wherein the voltage switching unit comprises plural resistance elements, and a switching unit for selectively connecting the plural resistance elements to the power supply under the control of the controller.
4. The air filtering apparatus according to claim 1 , wherein the voltage adjusting unit adjusts the power supply voltage switched by the voltage switching unit through pulse width modulation.
5. The air filtering apparatus according to claim 1 , wherein the controller has a detector for detecting the electrical conductivity or resistance value of water in the electrolytic bath, sets target current to flow between the electrodes on the basis of the detection result of the detector, and controls the voltage switching unit and the voltage adjusting unit so that current flowing between the electrodes is converged within a predetermined range based on the target current.
6. The air filtering apparatus according to claim 5 , wherein the controller controls the voltage switching unit and the voltage adjusting unit so that the voltage applied between the electrodes is gradually varied when the current flowing between the electrodes is out of the predetermined range based on the target current and then kept to the voltage at the time point when the current flowing between the electrodes enters the predetermined range.
7. The air filtering apparatus according to claim 5 , wherein the controller controls the voltage switching unit and the voltage adjusting unit so that the voltage applied between the electrodes is equal to the lowest voltage under a condition that the current flowing between the electrodes exceeds the target current and the difference between the current and the target current is equal to a predetermined value or more, and executes alarm processing insofar as the condition concerned is satisfied even after the control.