JP3491015B2 - Ultrasonic output circuit - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic output circuit for driving a piezoelectric vibrator by a half-wave voltage of an AC power supply. 2. Description of the Related Art Generally, in an ultrasonic generator, the output of an oscillation circuit using a direct current (a power source obtained by rectifying and smoothing an AC power source) as a power source is boosted by a transformer and input to a piezoelectric vibrator. It was configured to generate ultrasonic waves. However, in such an ultrasonic generator, the output transformer and the smoothing capacitor are large and heavy, and the power supply voltage must be changed to adjust the output. was there. According to the present invention, there is provided a half-wave rectifier having an anode connected to one terminal of an AC power supply, and a half-wave rectifier having one end connected to a cathode through a first resistor. A current detecting circuit including a piezoelectric vibrator connected to a terminal, a resistor and a capacitor connected to the other terminal of the piezoelectric vibrator and the other terminal of the AC power supply, and a first terminal connected to a cathode of the half-wave rectifier. An FET is connected to the piezoelectric vibrator and the current detection circuit in a parallel circuit through a resistor of the first type, and a collector of a first transistor is connected to a cathode of the half-wave rectifier through a second resistor and a third resistor. The first transistor has an emitter and an emitter connected to the other terminal of the AC power supply, and a gate of the FET connected between the third resistor and a collector of the first transistor. Transi An output circuit connected to the other terminal of the AC power supply via a fourth resistor, and one terminal of a capacitor connected to the cathode of the half-wave rectifier via the second resistor. A gate of the second transistor is connected through a transistor collector and a fifth resistor, the gate is connected through a Zener diode to the other terminal of the AC power supply, and a collector of the second transistor is connected to a capacitor. A power supply circuit of an oscillation circuit connected to the other terminal of the AC power supply via the first terminal of the output circuit;
The input terminals of the first, second, and third inverters are sequentially connected to the gate of the transistor via a sixth resistor, and a capacitor, a seventh resistor, and a third transistor are connected to the input terminals of the third inverter. The other terminal of the AC power supply is connected to the input terminal of the first inverter via a collector and an emitter, and a variable resistor, an eighth resistor, a ninth resistor,
A fourth inverter is connected via a capacitor, and the other input terminal of the AC power supply is connected to an input terminal of the fourth inverter via a tenth resistor and an emitter of a second transistor of the power supply circuit via an eleventh resistor. And an oscillation circuit connected to a connection between the current detection circuit and the piezoelectric vibrator through a capacitor, and a gate of a third transistor of the oscillation circuit through a twelfth resistor. The output terminal of the fifth inverter is connected to the emitter of the second transistor of the power supply circuit via a capacitor, and the input terminal of the inverter has a variable resistor and a first resistor.
A piezoelectric vibrator connected to the cathode of the half-wave rectifier via a third resistor and connected to the other terminal of the AC power supply via a fourteenth resistor, and connected to the oscillation circuit; It outputs more ultrasonic vibration. According to the present invention, a part of the half-wave rectified power supply of the commercial AC power supply opens the gate transistor of the ultrasonic oscillation circuit to oscillate the ultrasonic oscillation circuit and supply the same to the piezoelectric vibrator. The ultrasonic output can be obtained, and the range of the supply voltage for operating the ultrasonic oscillation circuit can be easily moved, so that the output can be easily changed. FIG. 1 is a block diagram of an ultrasonic output circuit according to one embodiment of the present invention. An anode of a half-wave rectifier 2 is connected to one terminal of an AC power supply 1, and this half-wave rectifier 2 One terminal of a piezoelectric vibrator 4 is connected to the cathode of the piezoelectric vibrator 4 via a resistor 3, and the other terminal of the piezoelectric vibrator 4 is connected to a The other terminal is connected. Further, an FET 8 is connected to the resistor 3 in parallel with the piezoelectric vibrator 4 and the current detecting circuit 7, and a collector of the transistor 11 is connected to the cathode of the half-wave rectifier 2 via the resistors 9 and 10. Emitter is AC power supply 1
Of the FET 8 is connected to the resistor 12
And the gate of the transistor 11 is connected to the other terminal of the AC power supply 1 via the resistor 13. The FET 8 and the transistor 11 constitute an output circuit 14 of an oscillation circuit. Have been. [0008] One terminal of a capacitor 15 and a resistor 16 and the collector of a transistor 17 are connected to the resistor 9, the other terminal of the capacitor 15 is connected to the other terminal of the AC power supply 1, and the other terminal of the resistor 16 is a transistor. 17 is connected to the cathode of the Zener diode 18, the emitter of the transistor 17 is connected to the other terminal of the AC power supply 1 via the capacitor 19, and the anode of the Zener diode 18 is also connected to the other terminal of the AC power supply 1. The capacitors 15 and 19, the transistor 17, the resistor 16, and the Zener diode 18 form a power circuit 20 of an oscillation circuit. The emitter of the transistor 17 is connected to the gate of a gate transistor 22 via a resistor 21, the collector of the gate transistor 22 is connected to the input side of an inverter 24 via a resistor 23, and the output side inverters 25 and 26 of the inverter 24. Are connected in series, the gate of the transistor 11 of the output circuit 14 is connected to the output side of the inverter 26 via the resistor 27, and the resistors 28 and 29 are connected in series to the emitter of the transistor 17 of the power supply 20. The other terminal of 29 is connected to the AC power supply 1,
The input side of the inverter 30 is connected to the connection point of the resistors 28 and 29, the output side of the inverter 30 is connected to the input side of the inverter 24 via a capacitor 31 and a resistor 32, and also via a resistor 33 and a variable resistor 34. Inverter 2
6, the other terminal of the AC power supply 1 is connected to the input side of the inverter 24 via the capacitor 35, and the input side of the inverter 30 is connected to the piezoelectric vibrator 4 and the current detection circuit via the capacitor 36. 7, the transistor 22, the inverters 24, 25, 26,
The oscillation circuit 37 is constituted by 30 and the like. Furthermore, a resistor 3 is connected to the cathode of the half-wave rectifier 2.
8. The input side of the inverter 40 is connected via the variable resistor 39, the output side of the inverter 40 is connected to the gate of the transistor 22 of the oscillation circuit 37 via the capacitor 41, and the input side of the inverter 40 is connected to the resistor 42. The other terminal of the AC power supply 1 is connected via the AC power supply 1 to form an input circuit 43. The operation of the thus constructed ultrasonic output circuit of the present embodiment will be described. First, the voltage (E in FIG. 2) rectified by the half-wave rectifier 2 is passed through the resistor 9 to the control circuit 43.
And a smoothing capacitor 1 in the power supply circuit 20 to the oscillation circuit 37.
5 and 19 are connected as a DC power supply. Since the power of the oscillation circuit 37 and the control circuit 43 is sufficiently smaller than the power required in the output circuit 14, the voltage supplied to the output circuit 14 is a half-wave rectified voltage. The half-wave rectified voltage waveform (A in FIG. 2) is supplied to a control circuit 43 through a resistor 38, and a pulse width (B in FIG. 2) determined by a differential multiplier of the resistor 21 and the capacitor 41.
Only the gate transistor 22 of the oscillation circuit 37 is turned off, the oscillation circuit 37 oscillates (C in FIG. 2), and the output circuit 14
Is operated (D in FIG. 2) to output ultrasonic waves from the piezoelectric vibrator 4. When this output circuit 14 is operated, FIG.
As shown by D, the ultrasonic wave is output from the piezoelectric vibrator 4 by oscillating only for the time when the oscillation circuit 37 of the output E of the rectifier 2 operates, and the other is simply applied as a DC voltage. As described above, in the circuit of this embodiment, the resistance 3
9, the operation position with the half-wave power supply can be changed, and the operation time width can be changed by the size of the resistor 21 (capacitor 41) of the input circuit 43. As is apparent from the above description, in the ultrasonic output circuit of the present invention, the ultrasonic oscillation output is performed by controlling the phase and time for opening the gate transistor of the ultrasonic oscillation circuit. In addition, by using a part of the half-wave voltage, the output of the ultrasonic wave can be controlled, and there is an advantage that a smoothing capacitor is not required in the power supply circuit, and the device is downsized.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of an ultrasonic output circuit according to one embodiment of the present invention. FIG. 2 is a voltage waveform of each part of the output circuit of FIG. [Description of Signs] 1 power supply 7 current detection circuit 14 output circuit 20 power supply circuit 37 oscillation circuit 43 input circuit

Claims (1)

(57) [Claim 1] A half-wave rectifier having an anode connected to one terminal of an AC power supply, and a cathode connected to the half-wave rectifier connected to one terminal via a first resistor. A current detecting circuit including a piezoelectric vibrator, a resistor and a capacitor connected to the other terminal of the piezoelectric vibrator and the other terminal of the AC power supply, and a first resistor connected to a cathode of the half-wave rectifier. An FET is connected to the piezoelectric vibrator and the current detection circuit through a parallel circuit, and a cathode of the half-wave rectifier is connected to a collector of a first transistor through a second resistor and a third resistor. And an emitter of the first transistor is connected to the other terminal of the AC power supply; a gate of the FET is connected between the third resistor and a collector of the first transistor; Is the fourth An output circuit connected to the other terminal of the AC power supply via a resistor; one terminal of a capacitor, a second transistor collector and a fifth resistor connected to the cathode of the half-wave rectifier via the second resistor; Is connected to the other terminal of the AC power supply via a Zener diode, and the second transistor is connected to the other terminal of the AC power supply via a Zener diode.
The collector of the transistor is connected to a power supply circuit of an oscillation circuit connected to the other terminal of the AC power supply through a capacitor, and the first and second transistors are connected to the gate of the first transistor of the output circuit through a sixth resistor. 2. The input terminals of the third inverter are sequentially connected, and the other terminal of the AC power supply is connected to the input terminal of the third inverter via a capacitor, a seventh resistor, and a collector and an emitter of a third transistor. And a fourth resistor connected to an input terminal of the first inverter via a variable resistor, an eighth resistor, a ninth resistor, and a capacitor.
Connected to the input terminal of the fourth inverter via a tenth resistor and the emitter of the second transistor of the power supply circuit and the other terminal of the AC power supply via an eleventh resistor. An oscillation circuit connected to a connection portion between the current detection circuit and the piezoelectric vibrator via a capacitor, and a second power supply circuit connected to a gate of a third transistor of the oscillation circuit via a twelfth resistor. The output terminal of the fifth inverter is connected to the emitter of the transistor via a capacitor, and the input terminal of the inverter is connected to the cathode of the half-wave rectifier via a variable resistor and a thirteenth resistor. And an input circuit connected to the other terminal of the AC power supply via a fourteenth resistor, and outputs ultrasonic vibration from a piezoelectric vibrator connected to the oscillation circuit. Ultrasonic output circuit, characterized in that.