JPS599721Y2 - Ultrasonic atomizer - Google Patents

Description

[Detailed description of the invention] This invention relates to an ultrasonic atomizer that atomizes liquid by vibrating a piezoelectric vibrator using an oscillation circuit.More specifically, the invention relates to an ultrasonic atomization device that atomizes liquid by vibrating a piezoelectric vibrator using an oscillation circuit. The purpose is to prevent circuit elements such as piezoelectric vibrators and transistors from being destroyed.

Conventionally, this type of ultrasonic atomization device has a structure as shown in FIG.

In FIG. 1, D1 to D4 are diodes constituting a bridge rectifier circuit, X is a piezoelectric vibrator, Tr1 is a transistor, C1 to C4 are capacitors, R1 to R3 are resistors, and L is a coil. C1
~C4, resistors R~R3, coil L, and piezoelectric vibrator X constitute an ultrasonic oscillation circuit.

That is, in this conventional ultrasonic atomization device, piezoelectric? The piezoelectric vibrator X is vibrated ultrasonically by an oscillation circuit using the vibrator X as an oscillator, thereby emitting ultrasonic waves into the liquid and atomizing the liquid.

However, in such a conventional ultrasonic atomizer, the collector voltage of the transistor Tr varies from v1 to V2 as shown in FIG. When the collector voltage of the transistor Tr1 increases as the piezoelectric vibrator X comes out of the liquid, i.e., the voltage applied to the piezoelectric vibrator X increases, the piezoelectric vibrator X and other Circuit elements may be destroyed.

The present invention solves these conventional problems, and the ultrasonic atomization device of the present invention will be explained below with reference to FIGS. 3 and 4.

Note that the same parts as the circuit shown in FIG. 1 are given the same numbers.

FIG. 3 shows a block circuit of an ultrasonic atomizer according to an embodiment of the present invention. In FIG. 1, A is a conversion circuit that detects the collector voltage of the transistor Tr1 and converts it into a DC voltage, and B is a conversion circuit for detecting the collector voltage of the transistor Tr1 and converting it into a DC voltage. A first switching circuit that switches according to the magnitude of the DC voltage obtained by conversion circuit A, and C a second switching circuit that operates based on the output of this first switching circuit B and turns the oscillation circuit ON and OFF. These circuits constitute the control section.

FIG. 4 shows its specific circuit structure, in which the conversion circuit A is composed of a transistor Tr2, resistors R4 to R6, and R10zR.
11. Capacitors C5 to C7 and diodes D5 to
The first switching circuit B is composed of a thyristor SCR and resistors R7 and R8, and the second switching circuit C is composed of a transistor Tr3, a resistor R9, and a capacitor C8.

That is, in the circuit shown in FIG. 4, the transistor T
The collector voltage of r1 is divided by resistors R4 and Rs, and is then applied to transistor Tr2, capacitor C5, and resistors R6 and R.
The output of the emitter follower is voltage-doubled and rectified by diodes D6, D, and then input to the gate of the thyristor SCR.

When the piezoelectric vibrator X is in the liquid, the collector voltage of the transistor Tr1 is small as shown in FIG. .

Furthermore, when the piezoelectric vibrator X is outside the liquid, the collector voltage of the transistor Tr increases as shown in FIG. do.

When the thyristor SCR is OFF, the anode voltage of the thyristor SCR is high and this voltage is applied to the base of the transistor Tr3.
r3 is OFF, and the oscillation circuit that drives the piezoelectric vibrator
In the case of N, the anode voltage of the thyristor SCR becomes the ground potential, so the transistor Tr3 turns ONj, thereby the bias voltage of the oscillation circuit becomes zero, and the oscillation circuit stops oscillating.

That is, according to the ultrasonic atomization device of the present invention, when the piezoelectric vibrator X comes out of the liquid, the oscillation circuit that drives the piezoelectric vibrator X can be automatically stopped.

As described above, according to the ultrasonic atomization device of the present invention, when the piezoelectric vibrator comes out of the liquid, the oscillation of the oscillation circuit can be automatically stopped, thereby causing the piezoelectric vibrator and the circuit element to stop. It is possible to obtain an effect of extremely high practical value in that it is possible to prevent destruction.

[Brief explanation of the drawing]

Figure 1 is an electrical circuit diagram of a conventional ultrasonic atomizer, Figure 2a
, l) is a voltage waveform diagram showing the collector voltage of the transistor in the oscillation circuit when the piezoelectric vibrator is in the liquid and when it is not in the liquid, and Fig. 3 is an ultrasonic atomization device according to an embodiment of the present invention. FIG. 4 is an electrical circuit diagram showing the specific circuit configuration of the device. A: conversion circuit, B: first switching circuit, C: second switching circuit,
X...Piezoelectric vibrator, Tr1...Transistor.

Claims (1)

[Scope of utility model registration request] In an ultrasonic atomization device that atomizes a liquid by vibrating a piezoelectric vibrator with an oscillation circuit, a collector voltage of a transistor that drives the piezoelectric vibrator of the oscillation circuit is detected to control ON/OFF of the oscillation circuit. An ultrasonic atomization device comprising: a control section; the control section stops the operation of the oscillation circuit when the piezoelectric vibrator comes out of the liquid.