JPS588373Y2 - Exciter for ultrasonic nebulizer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an exciter for an ultrasonic nebulizer, and more particularly to an exciter for an ultrasonic nebulizer, which has a simple circuit and structure, and produces less unnecessary radiation and noise interference.

First, the configuration of an ultrasonic atomizer used as a humidifier and the like, and the conventional exciter used therein will be described.

FIG. 1 is a block diagram showing the structure of an ultrasonic atomizer.

In the figure, reference numeral 2 denotes an ultrasonic vibrator attached to the bottom of the water tank 1, which is generally disk-shaped and uses thickness vibration.

When a voltage is applied to the vibrator 2 by the high frequency power source 3, the vibrator 2 vibrates at a frequency near its resonance frequency and imparts vibrational energy to the spray liquid 4 placed in the water tank 1.

The vibration propagates toward the liquid surface, but if the diameter of the vibrator 2 is made sufficiently larger than the wavelength of the vibration and it is placed at an appropriate depth,
Vibration energy concentrates near the liquid surface and generates a fountain flow/spray 5.

In order to obtain such a fountain flow/spray 5, it is practically necessary to use several W.
Since high-frequency excitation power of about 20 W is required, power transistors are mainly used as semiconductor output elements for excitation.

FIG. 2 is a circuit diagram showing a prior art exciter circuit used in an ultrasonic atomizer.

FIG. 2 is a circuit diagram of a so-called self-exciting type exciter in which a vibrator 2 is connected between the collector and base of a transistor 6 and used as an inductor of an oscillation circuit.

The oscillation circuit includes a capacitor 11 between the collector and emitter.
, a feedback capacitor 12, a choke coil 13, and a bypass capacitor 14 are used.

Power to supply the exciter is applied to the power supply terminal 15.

This circuit is an Emmink grounded circuit, and the transistor 6 has its envelope fixed to the base substrate 7 via an insulator.

Therefore, the vibrator 2 and the base substrate 7 are connected via the insulating plate capacitor 17, as shown by the broken line in the figure.

This is undesirable because it increases the number of man-hours required to attach the transistor 6 to the base substrate 7 and also increases the heat dissipation resistance of the transistor 6 due to the insulating plate.

In addition, in this conventional exciter, the base board 7, the circuit earth 9, and the electrodes of the vibrator 2 are not directly connected, so the spatial radiation of the excitation power and the leakage from the power supply line are large. However, when the excitation power is large, harmonics tend to cause noise interference to radio receivers, television receivers, etc.

The purpose of the present invention is to provide an exciter for an ultrasonic atomizer that eliminates the problems of the prior art described above, has a simple circuit and structure, can reduce man-hours and cost, and has less radiation and leakage of excitation power. It is in.

In order to achieve this purpose, the present invention adopts a circuit system that fixes the transistor envelope (collector) and the base substrate without intervening an insulating layer, and also uses a spray liquid and
One of the electrodes of the vibrator is configured to have the same potential as the base substrate, thereby simplifying the circuit and structure, and at the same time achieving the effect of suppressing radiation and leakage of excitation power. A nebulizer exciter is provided.

Next, one embodiment of the exciter for an ultrasonic atomizer according to the present invention will be described with reference to FIGS. 3 and 4. FIG.

FIG. 3 is a circuit diagram of this embodiment, and this circuit is a so-called self-excited exciter circuit in which the resonator 2 is connected between the collector and base of the transistor 6 and used as an inductor of an oscillation circuit. .

In this embodiment, unlike conventional products, a collector grounding type is adopted, so that the collector, that is, the envelope of the transistor 6 is directly connected to the base substrate 7 without using an insulator, as shown in FIG. Can be fixed.

Therefore, the number of assembly steps can be reduced compared to the case where the transistor 6 is attached to the base substrate via an insulator as in conventional products, and at the same time, the thermal resistance between the transistor 6 and the base substrate 7 can be reduced. This is effective in terms of heat dissipation.

Furthermore, by connecting the ground 9 of the circuit board 8 to the collector, the circuit section, the base board 7, the spray liquid 4 in the water tank 1, and the electrode 10 on the side of the vibrator 2 that is in contact with the spray liquid 4 can be connected to each other. Since all can be kept at the same potential, the effect of reducing leakage of high frequency power can be obtained.

Oscillation in the circuit of this embodiment is caused by the capacitor 11 between the collector and emitter of the transistor 6, and the emitter
This can be obtained by selecting the capacitance of each of the capacitors 12 between the bases and setting the operating frequency slightly higher than the series resonance frequency of the vibrator 2.

In the figure, 13 is a choke coil, 14 is a high frequency bypass capacitor, 15 is a power supply terminal for supplying power to the circuit, and 16 is a DC blocking capacitor.

In the above embodiment, NPN is used as the semiconductor output element.
type transistor is used, but instead of this, PNP type transistor is used.
Even when a type transistor is used, the same structure and effect as in the previous embodiment can be obtained by simply changing the polarity of the circuit.

Further, the transistor used in the present invention is not limited to a bipolar transistor, and it goes without saying that the same effect can be obtained even if a field effect transistor is used, for example.

Furthermore, in the above embodiment, a so-called self-excited type exciter is described, but a so-called separately-excited type exciter that has a separate oscillator and drives an output transistor can also be described.
Similar effects can be obtained by implementing the present invention.

In addition, in the description of the prior art and the embodiment of the present invention described above, the case where water is atomized using a humidifier is described, but the present invention can also be implemented in the case of atomizing liquid other than a water body. For example, it can be used for ultrasonic atomization of kerosene burners.

As described above, according to the present invention, in the exciter for an ultrasonic sprayer, the base substrate and the outer peripheral device of the excitation output element are directly connected, and the spray liquid and the electrode on the side of the vibrator in contact with the spray liquid are connected. By maintaining the same potential, it is possible to simplify the structure and reduce costs, and also to reduce radiation and leakage of excitation power to the outside, thereby reducing noise interference to other equipment.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the configuration of an ultrasonic atomizer, Fig. 2 is a circuit diagram of a conventional exciter for an ultrasonic atomizer, and Fig. 3 is a circuit diagram of an embodiment of an exciter for an ultrasonic atomizer according to the present invention. , FIG. 4 is a partial cross-sectional view showing the structure of this embodiment. Explanation of symbols: 1... Water tank, 2... Vibrator, 3... High frequency power supply, 4... Spray liquid, 5... Fountain flow/spray, 6...Transistor, 7...Base board, 8...Circuit board, 9...Earth, 10... Electrode, 11... Capacitor, 12... Capacitor, 13... Choke coil, 14...
... Bypass capacitor, 15 ... Power supply terminal, 16 ... DC blocking capacitor, 17 ...
...Insulating plate capacity.

Claims (1)

[Scope of utility model registration request] In an exciter for an ultrasonic atomizer, which is composed of a vibrator, a base board that holds the vibrator and is cooled by contacting the spray liquid, a circuit board on which excitation circuit components are mounted, and an excitation output element, The envelope of the output element is fixed to the base substrate without intervening an insulating layer, and the spray liquid and one of the electrodes of the vibrator are configured to have the same potential as the base substrate. Exciter for ultrasonic atomizer.