JP4496329B2 - Ultrasonic oscillation circuit - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to an ultrasonic oscillation circuit that does not deviate from an optimum frequency due to load, water level, or temperature change.
[0002]
[Prior art]
Normally, an ultrasonic cleaning device uses a separately excited oscillation device because of its relatively simple configuration, and an oscillation device of an automatic tracking system because oscillation is stable against changes in load and temperature. Is used.
[0003]
[Problems to be solved by the invention]
However, the separately-excited oscillator has a problem that the frequency of the ultrasonic vibrator deviates from the optimum frequency due to a change in load or the like, and the vibration of the ultrasonic vibrator is reduced to significantly reduce the cleaning effect. Since a stable feedback voltage is required in the oscillation device of the system, a stable voltage must be applied to the oscillation device, and the oscillation output must also be stable. There is a problem that a voltage must be generated, and the circuit is complicated and expensive.
[0004]
[Means to solve the problem]
The present invention relates to an AC power source, a rectifier that half-wave rectifies the voltage from the AC power source, and a ripple voltage generator that generates a ripple voltage adjusted to have a resonance frequency with respect to a standard temperature and a standard load at the output of the rectifier. A circuit, an oscillation circuit whose frequency is changed by the ripple voltage by applying the ripple voltage, an output whose frequency is changed from the oscillation circuit, and a half-wave voltage from the rectifier, and a half-wave voltage And an output circuit that applies an output on which the pulse output is superimposed to the ultrasonic transducer, and the ripple voltage generation circuit includes a first capacitor charged with a voltage from the half-wave rectifier, A transistor that conducts when the charge of the capacitor reaches a predetermined charge voltage, and a second capacitor that is charged by the output of the transistor It made, in which the frequency of the output of the oscillation part by the charge voltage of the second capacitor is to be varied.
[0005]
Embodiment
In the present invention, since the voltage from the oscillation circuit is intentionally supplied with a ripple voltage without intentionally stabilizing the voltage, the frequency of the output from the oscillation circuit changes with the ripple voltage. Even if there is a change in water, temperature, temperature, etc., the frequency sweeps, so there is no significant difference in output change (cleaning effect), and the configuration is simple. Become cheaper.
[0006]
【Example】
FIG. 1 is a circuit diagram of an ultrasonic oscillation circuit according to an embodiment of the present invention. An anode of a rectifier 2 is connected to one end of an AC power source 1, and a cathode of the rectifier 2 is connected to a resistor 4 of a ripple voltage generation circuit 3 and a first one. Is connected to the other end of the AC power source 1 via the capacitor 5, the cathode of the Zener diode 6, the resistor 7 and the collector of the NPN transistor 8 are connected to the connection point of the resistor 4 and the first capacitor 5. 7 is connected to the base of the transistor 8 and one end of the resistor 9, the anode of the Zener diode 6 and the other end of the resistor 9 are connected to the AC power source 1, and the emitter of the NPN transistor 8 is a second capacitor. 10 is connected to the power supply terminal of the oscillator 12 of the oscillation circuit 11, and is connected to the input terminal of the oscillator 12 via the third capacitor 13 to the other end of the AC power supply 1. Variable resistor 14 and the resistor 15 is connected between the input terminal and the output terminal of the vessel 12, the ground terminal of the oscillator 12 is connected to the other end of the AC power supply 1.
[0007]
The output of the oscillator 12 of the oscillation circuit 11 is connected to the base of the NPN transistor 18 via the resistor 17 of the output circuit 16, and is connected to one end of the AC power supply 1 via the resistor 19, The collector of the transistor 18 is connected to the collector of the NPN transistor 8 through the resistor 20, and is connected to the gates of the NPN transistor 21 and the PNP transistor 22, and the emitter of the NPN transistor 21 and the emitter of the PNP transistor 22 are connected to each other. The collector of the NPN transistor 21 is connected to the collector of the NPN transistor 8, the emitter of the NPN transistor 18, the collector of the PNP transistor 22, and the source of the MOS field effect transistor 23. The transformer is connected to the other end of the AC power source 1, and the primary winding of the transformer 24 is connected between the cathode of the rectifier 2 and the drain of the MOS field effect transistor 23. An ultrasonic transducer 25 is connected.
[0008]
In the ultrasonic oscillation circuit of the present embodiment configured as described above, the output waveform at the point A of the rectifier 2 becomes a half-wave rectified voltage waveform as shown in FIG. 2, and the emitter of the NPN transistor 8 of the ripple voltage generation circuit 3. The output waveform at point B is a ripple voltage waveform as shown in FIG. 3 depending on the charge voltage of the first capacitor 5 and the second capacitor 10, and this ripple voltage is input to the power supply terminal of the oscillator 12 of the oscillation circuit 11. Is done.
[0009]
Further, a negative half-wave voltage is applied to the oscillator 12 of the oscillation circuit 11 from the AC power supply 1 through the third capacitor 12, the oscillation frequency of the output is adjusted by the variable resistor 14, and the output of the oscillation circuit 11 is The ripple voltage from the ripple voltage generation circuit 3 and the negative half-wave voltage from the AC power source 1 generate pulse voltages having different frequencies, and these voltages are output from the NPN transistors 18 and 21, the PNP transistor 22 and the output circuit 16. The output voltage waveform as shown in FIG. 4 is obtained by superimposing the positive half-wave voltage from the AC power source 1 and the amplified pulse voltage from the oscillation circuit 11 on the transformer 24. Voltage is output.
[0010]
As described above, in the ultrasonic oscillation circuit according to the embodiment of the present invention, the output from the oscillation circuit 11 has a frequency in a predetermined range from the standard temperature of the ultrasonic transducer 25 and the resonance frequency at the time of standard load. By adjusting the output voltage from the ripple voltage generator circuit 3 so that the output voltage from the ripple voltage generator circuit 3 always varies even if the ultrasonic transducer 25 fluctuates with respect to the standard temperature and the standard load. As a result, the ultrasonic transducer 25 is driven without causing a large difference in output change (cleaning effect) by a short shift in resonance from the resonance for a long time operation. be able to.
[0011]
【The invention's effect】
As described above, in the ultrasonic oscillation circuit of the present invention, since the voltage is intentionally supplied to the oscillation circuit and a rippled voltage is supplied, the frequency of the output from the oscillation circuit changes with the ripple voltage. Even if there is a change in the resonance frequency of the ultrasonic vibrator, such as load (washed material in the cleaning liquid), water level, temperature, etc., the frequency sweeps, so there is a large difference in output change (cleaning effect). In addition, there is an advantage that the configuration is simple and inexpensive.
[Brief description of the drawings]
FIG. 1 is a circuit diagram of an ultrasonic oscillation circuit according to an embodiment of the present invention.
FIG. 2 is an output waveform diagram at point A of the circuit of FIG. 1;
FIG. 3 is an output waveform diagram at point B of the circuit of FIG. 1;
4 is an output waveform diagram of a transformer of the circuit of FIG. 1. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 AC power supply 2 Rectifier 3 Ripple voltage generation circuit 4, 7, 9 Resistance 5 1st capacitor 6 Zener diode 8 NPN transistor 10 2nd capacitor 11 Oscillation circuit 12 Oscillator 13 3rd capacitor 14 Variable resistance 15, 17 Resistance 16 output circuit 18, 21 NPN transistor 19, 20 resistor 22 PNP transistor 23 MOS field effect transistor 24 transformer 25 ultrasonic transducer

Claims (2)

An AC power supply, a rectifier that half-wave rectifies the voltage from the AC power supply, a ripple voltage generation circuit that generates a ripple voltage adjusted to a resonance frequency with respect to a standard temperature and a standard load at the output of the rectifier, By applying a ripple voltage, an oscillation circuit whose frequency is changed by the ripple voltage, an output whose frequency is changed from the oscillation circuit, and a half-wave voltage from the rectifier are input, and a pulse output is generated in the half-wave voltage. An ultrasonic oscillation circuit comprising: an output circuit for applying the superimposed output to an ultrasonic transducer. The ripple voltage generation circuit includes a first capacitor charged with a voltage from the rectifier, a transistor that is turned on when the charge of the capacitor reaches a predetermined charge voltage, and a second capacitor charged with an output of the transistor. 2. The ultrasonic oscillation circuit according to claim 1, comprising a capacitor, wherein the frequency of the output of the oscillation circuit is varied by the charge voltage of the second capacitor.

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