Abstract: A digital input circuit includes a pair of input terminals that an input signal of a digital voltage signal is inputted; a photocoupler for transmitting the input signal from the input terminals to an input port of a microcomputer and having one light emitting diode and one phototransistor, wherein the light emitting diode of the photocoupler is connected between the input terminals, a collector of the phototransistor is connected to a positive side of a power supply, and an emitter of the phototransistor is connected to ground via a first resistor; and a bipolar transistor provided between the ground and a second resistor, wherein a collector thereof is connected to the second resistor for pulling up the input port of the microcomputer, an emitter thereof is connected to the ground, and a base thereof is connected to a connection node between the emitter of the phototransistor and the first resistor.

Abstract: An atomizer includes a piezoelectric element 50 with comb-type electrodes having one electrode and the other electrode formed alternately at one side, a mesh member 40 having many small holes arranged in the proximity of a no-electrode formation plane of piezoelectric element 50, a liquid reagent bottle 20 storing a liquid L, and a solenoid 26 supplying the liquid L of liquid reagent bottle 20 between piezoelectric element 50 and mesh member 40. The vibratory wave of piezoelectric element 50 by an oscillation circuit is a bulk wave that travels within the piezoelectric element, not the surface wave propagating at the surface of the piezoelectric element defined by the comb-type electrode pitch. As a result, an atomizer can be provided improved in atomization efficiency and stabilized in atomization.