A sonic wave control circuit for a megasonic cleaning device

Abstract

The invention discloses an automatic sound wave control circuit for a megasonic cleaning device, comprising a feedback unit, an oscillation unit, a detection unit and a control unit. The control unit is connected with the feedback unit and the detection unit, and the feedback unit is connected with the oscillation unit. The oscillation unit is used to generate and feed back an oscillation signal. The feedback unit is used to adjust and feed back a reference signal required by the control unit and to control a feedback channel for the oscillation unit to obtain a frequency modulation signal. The detection unit is used to detect a resonance point of a piezoelectric ceramic piece when the oscillation unit feeds back an oscillation signal and to feed back a confirmation signal when the piezoelectric ceramic piece is at the resonance point. The control unit is used to enable the oscillation unit to feed back an oscillation signal with a frequency that continuously changes within a frequency range to the piezoelectric ceramic piece during matching, so that the detection unit can detect the resonance point of the piezoelectric ceramic piece, and automatically adjust the working frequency after matching is completed.

Description

Technical Field

[0001] The invention relates to the technical field of megasonic wave control, and in particular to a sound wave control circuit of a megasonic wave cleaning device. Background Art

[0002] Megasonic cleaning converts oscillating electrical signals into mechanical vibrations through the piezoelectric effect. The high-energy sound waves generated by the resonance effect of the piezoelectric material propagate in the liquid, triggering acoustic flow and cavitation effects, thereby effectively removing pollutants on the surface of the object. However, when the piezoelectric ceramic is working, it will be affected by various factors such as external load and temperature, resulting in a decrease in its resonant frequency. When the frequency of the oscillation signal differs too much from the resonant frequency of the piezoelectric ceramic, it will affect the energy conversion effect and even fail to work normally. Therefore, when performing megasonic cleaning, it is necessary to manually adjust it appropriately to keep it at the optimal working frequency as much as possible. However, the influence of external load and temperature on the piezoelectric ceramic is not fixed, and it is difficult to keep it at the optimal working frequency by manual adjustment. Therefore, an automatic sound wave control circuit of a megasonic cleaning device is proposed, which can automatically match the resonance point of the oscillation signal and the piezoelectric ceramic. After the matching is completed, the working frequency is automatically adjusted and feedback is performed based on the user's selection to ensure that the piezoelectric ceramic can work at the optimal frequency every time the cleaning is performed. Summary of the invention

[0003] In view of the above technical problems, the purpose of the present invention is to provide an automatic sound wave control circuit for a megasonic cleaning device, including a feedback unit, an oscillation unit, a detection unit, and a control unit. The control unit is connected to the feedback unit and the detection unit, and the feedback unit is connected to the oscillation unit. The oscillation unit is used to generate and feed back an oscillation signal. The feedback unit is used to adjust and feed back a reference signal required by the control unit and to control the feedback channel of the oscillation unit to obtain a frequency-modulated signal. The detection unit is used to detect the resonance point of the piezoelectric ceramic piece when the oscillation unit feeds back an oscillation signal and to feed back a confirmation signal when the piezoelectric ceramic piece is at the resonance point. The control unit is used to enable the oscillation unit to feed back an oscillation signal with a frequency that continuously changes within a frequency range to the piezoelectric ceramic piece during matching, so that the detection unit can detect the resonance point of the piezoelectric ceramic piece, and automatically adjust the working frequency after the matching is completed.

[0004] Furthermore, it also includes a third trigger U3, a first field effect transistor Q1, a first diode D1, a second diode D2, a first capacitor C1, a third capacitor C3, a first connector P1, a second connector P2, a sixth resistor R6, an eighth resistor R8, a ninth resistor R9, and a tenth resistor R10;

[0005] The first pin of the third trigger U3 and the fourth pin of the third trigger U3 are connected to the power supply, the second pin of the third trigger U3 and the sixth pin of the third trigger U3 and the drain of the first field effect tube Q1 are connected, the third pin of the third trigger U3 is connected to the cathode of the first diode D1 and the cathode of the second diode D2, the fifth pin of the third trigger U3 is connected to one end of the ninth resistor R9, the source of the first field effect tube Q1 is connected to one end of the eighth resistor R8, the gate of the first field effect tube Q1 is connected to the end of the first connector P1, the anode of the first diode D1 is connected to the first capacitor C1, The fifth and sixth pins of the third trigger U3 are signal output terminals, the third pin is a clock input terminal, the second pin is a data input terminal, the first pin is a direct reset terminal, and the fourth pin is a direct set terminal.

[0006] Furthermore, it also includes a fourth operational amplifier U4, a second field effect transistor Q2, a third diode D3, a second capacitor C2, a first switch S1, a third connector P3, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, and an eighteenth resistor R18;

[0007] The in-phase end of the fourth operational amplifier U4 is connected to the cathode of the third diode D3, one end of the thirteenth resistor R13, one end of the fifteenth resistor R15, and the end of the third connector P3. The inverting end of the fourth operational amplifier U4 is connected to one end of the twelfth resistor R12 and one end of the fourteenth resistor R14. The output end of the fourth operational amplifier U4 is connected to the anode of the third diode D3 and the gate of the second field effect transistor Q2. The source of the second field effect transistor Q2 is connected to one end of the eighteenth resistor R18. The drain of the second field effect transistor Q2 is connected to the positive electrode of the first switch S1 and one end of the eleventh resistor R11. One end of the first switch S1 is connected to the end of the second connector P2. The other end of the first switch S1 is connected to one end of the second capacitor C2. The other end of the thirteenth resistor R13, the other end of the fourteenth resistor R14, and the other end of the eighteenth resistor R18 are connected to the power supply. The negative electrode of the first switch S1, the other end of the second capacitor C2, the other end of the eleventh resistor R11, the other end of the twelfth resistor R12, and the other end of the fifteenth resistor R15 are connected to the ground.

[0008] Furthermore, it also includes a first operational amplifier U1, a second operational amplifier U2, a sixth operational amplifier U6, a third field effect transistor Q3, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a seventh resistor R7, a nineteenth resistor R19, a twentieth resistor R20, a twenty-first resistor R21, a fourth connector P4, a fifth connector P5, and a sixth connector P6;

[0009] The first operational amplifier U1 is connected to the same phase end with one end of the first resistor R1 and one end of the twenty-first resistor R21, the first operational amplifier U1 is connected to the inverting end with one end of the second resistor R2 and one end of the third resistor R3, the output end of the first operational amplifier U1 is connected to the other end of the third resistor R3 and the end of the sixth connector P6, the second operational amplifier U2 is connected to the same phase end with one end of the fourth resistor R4 and one end of the nineteenth resistor R19, the second operational amplifier U2 is connected to the inverting end with the other end of the second resistor R2 and the output end of the second operational amplifier U2, the same phase end of the sixth operational amplifier U6 is connected to the second capacitor C2 is connected to one end, the inverting end of the sixth operational amplifier U6 is connected to the other end of the first resistor R1, the other end of the nineteenth resistor R19, and the end of the fifth connector P5, the output end of the sixth operational amplifier U6 is connected to the drain of the third field effect transistor Q3 and one end of the seventh resistor R7, the gate of the third field effect transistor Q3 is connected to the gate of the second field effect transistor Q2, the source of the third field effect transistor Q3 is connected to one end of the twentieth resistor R20 and the end of the fourth connector P4, the other end of the fourth resistor R4, the other end of the seventh resistor R7, the other end of the twentieth resistor R20, the other end of the twenty-first resistor R21 and the ground are connected.

[0010] Furthermore, it also includes a fifth operational amplifier U5, a fourth diode D4, a sixteenth resistor R16, and a seventeenth resistor R17;

[0011] The in-phase end of the fifth operational amplifier U5 is connected to one end of the sixteenth resistor R16 and one end of the seventeenth resistor R17, the inverting end of the fifth operational amplifier U5 is connected to the end of the first connector P1, the output end of the fifth operational amplifier U5 is connected to the anode of the fourth diode D4, the other end of the sixteenth resistor R16 is connected to the power supply, the cathode of the fourth diode D4 is connected to one end of the twelfth resistor R12, and the other end of the seventeenth resistor R17 is connected to the ground end.

[0012] Furthermore, it also includes a fifth resistor R5;

[0013] One end of the fifth resistor R5 is connected to the gate of the first field effect transistor Q1, and the other end of the fifth resistor R5 is connected to the ground.

[0014] Furthermore, the fourth resistor R4 is an adjustable resistor.

[0015] The beneficial effects of the present invention compared with the prior art are:

[0016] The present invention can automatically match the oscillation signal with the resonance point of the piezoelectric ceramic piece, and after the matching is completed, automatically adjust and feedback the working frequency based on the user's selection, ensuring that the piezoelectric ceramic piece can work at the optimal frequency every time it is cleaned. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the prior art and the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 The present invention provides an overall structural diagram.

[0019] Figure 2 This is a schematic diagram of the structure of a control unit provided by the present invention. DETAILED DESCRIPTION

[0020] In order to make the objects and advantages of the present invention more clearly understood, the present invention is specifically described below in conjunction with embodiments. It should be understood that the following text is only used to describe one or several specific implementations of the present invention, and does not strictly limit the scope of protection specifically requested by the present invention.

[0021] The invention discloses an automatic sound wave control circuit of a megasonic cleaning device, comprising a feedback unit, an oscillation unit, a detection unit and a control unit. The control unit is connected with the feedback unit and the detection unit, and the feedback unit is connected with the oscillation unit. The oscillation unit is used to generate and feed back an oscillation signal. The feedback unit is used to adjust and feed back a reference signal required by the control unit and to control a feedback channel for the oscillation unit to obtain a frequency modulation signal. The detection unit is used to detect a resonance point of a piezoelectric ceramic piece when the oscillation unit feeds back an oscillation signal and to feed back a confirmation signal when the piezoelectric ceramic piece is at the resonance point. The control unit is used to enable the oscillation unit to feed back an oscillation signal with a frequency that continuously changes within a frequency range to the piezoelectric ceramic piece during matching, so that the detection unit can detect the resonance point of the piezoelectric ceramic piece, and automatically adjust the working frequency after matching is completed.

[0022] like Figure 2 As shown, specifically, it also includes a third trigger U3, a first field effect transistor Q1, a first diode D1, a second diode D2, a first capacitor C1, a third capacitor C3, a first connector P1, a second connector P2, a sixth resistor R6, an eighth resistor R8, a ninth resistor R9, and a tenth resistor R10;

[0023] The first pin of the third trigger U3 and the fourth pin of the third trigger U3 are connected to the power supply, the second pin of the third trigger U3 and the sixth pin of the third trigger U3 and the drain of the first field effect tube Q1 are connected, the third pin of the third trigger U3 is connected to the cathode of the first diode D1 and the cathode of the second diode D2, the fifth pin of the third trigger U3 is connected to one end of the ninth resistor R9, the source of the first field effect tube Q1 is connected to one end of the eighth resistor R8, the gate of the first field effect tube Q1 is connected to the end of the first connector P1, the anode of the first diode D1 is connected to the first capacitor C1, The fifth and sixth pins of the third trigger U3 are signal output terminals, the third pin is a clock input terminal, the second pin is a data input terminal, the first pin is a direct reset terminal, and the fourth pin is a direct set terminal.

[0024] like Figure 2 As shown, specifically, it also includes a fourth operational amplifier U4, a second field effect transistor Q2, a third diode D3, a second capacitor C2, a first switch S1, a third connector P3, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, and an eighteenth resistor R18;

[0025] The in-phase end of the fourth operational amplifier U4 is connected to the cathode of the third diode D3, one end of the thirteenth resistor R13, one end of the fifteenth resistor R15, and the end of the third connector P3. The inverting end of the fourth operational amplifier U4 is connected to one end of the twelfth resistor R12 and one end of the fourteenth resistor R14. The output end of the fourth operational amplifier U4 is connected to the anode of the third diode D3 and the gate of the second field effect transistor Q2. The source of the second field effect transistor Q2 is connected to one end of the eighteenth resistor R18. The drain of the second field effect transistor Q2 is connected to the positive electrode of the first switch S1 and one end of the eleventh resistor R11. One end of the first switch S1 is connected to the end of the second connector P2. The other end of the first switch S1 is connected to one end of the second capacitor C2. The other end of the thirteenth resistor R13, the other end of the fourteenth resistor R14, and the other end of the eighteenth resistor R18 are connected to the power supply. The negative electrode of the first switch S1, the other end of the second capacitor C2, the other end of the eleventh resistor R11, the other end of the twelfth resistor R12, and the other end of the fifteenth resistor R15 are connected to the ground.

[0026] like Figure 2As shown, specifically, it also includes a first operational amplifier U1, a second operational amplifier U2, a sixth operational amplifier U6, a third field effect transistor Q3, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a seventh resistor R7, a nineteenth resistor R19, a twentieth resistor R20, a twenty-first resistor R21, a fourth connector P4, a fifth connector P5, and a sixth connector P6;

[0027] The first operational amplifier U1 is connected to the same phase end with one end of the first resistor R1 and one end of the twenty-first resistor R21, the first operational amplifier U1 is connected to the inverting end with one end of the second resistor R2 and one end of the third resistor R3, the output end of the first operational amplifier U1 is connected to the other end of the third resistor R3 and the end of the sixth connector P6, the second operational amplifier U2 is connected to the same phase end with one end of the fourth resistor R4 and one end of the nineteenth resistor R19, the second operational amplifier U2 is connected to the inverting end with the other end of the second resistor R2 and the output end of the second operational amplifier U2, the same phase end of the sixth operational amplifier U6 is connected to the second capacitor C2 is connected to one end, the inverting end of the sixth operational amplifier U6 is connected to the other end of the first resistor R1, the other end of the nineteenth resistor R19, and the end of the fifth connector P5, the output end of the sixth operational amplifier U6 is connected to the drain of the third field effect transistor Q3 and one end of the seventh resistor R7, the gate of the third field effect transistor Q3 is connected to the gate of the second field effect transistor Q2, the source of the third field effect transistor Q3 is connected to one end of the twentieth resistor R20 and the end of the fourth connector P4, the other end of the fourth resistor R4, the other end of the seventh resistor R7, the other end of the twentieth resistor R20, the other end of the twenty-first resistor R21 and the ground are connected.

[0028] like Figure 2 As shown, specifically, it also includes a fifth operational amplifier U5, a fourth diode D4, a sixteenth resistor R16, and a seventeenth resistor R17;

[0029] The in-phase end of the fifth operational amplifier U5 is connected to one end of the sixteenth resistor R16 and one end of the seventeenth resistor R17, the inverting end of the fifth operational amplifier U5 is connected to the end of the first connector P1, the output end of the fifth operational amplifier U5 is connected to the anode of the fourth diode D4, the other end of the sixteenth resistor R16 is connected to the power supply, the cathode of the fourth diode D4 is connected to one end of the twelfth resistor R12, and the other end of the seventeenth resistor R17 is connected to the ground end.

[0030] like Figure 2 As shown, specifically, a fifth resistor R5 is also included;

[0031] One end of the fifth resistor R5 is connected to the gate of the first field effect transistor Q1, and the other end of the fifth resistor R5 is connected to the ground.

[0032] like Figure 2 As shown, specifically, the fourth resistor R4 is an adjustable resistor.

[0033] See also Figure 1 , Figure 2 A feedback unit, an oscillation unit and a detection unit are arranged in the control circuit. The oscillation unit is used to feed back an oscillation signal to the piezoelectric ceramic piece. The feedback unit is used to adjust the reference signal required by the feedback control unit and control the feedback channel of the oscillation unit to obtain the frequency modulation signal. The detection unit is used to detect the resonance point of the piezoelectric ceramic piece when the oscillation unit feeds back the oscillation signal and to feed back a confirmation signal when the piezoelectric ceramic piece is at the resonance point. Pins 5 and 6 of the third trigger U3 are signal output terminals, pin 3 is a clock input terminal, pin 2 is a data input terminal, pin 1 is a direct reset terminal, and pin 4 is a direct set terminal. In the initial state, pin 6 of the third trigger U3 is a high level, and pin 2 is a high level. , 3 pins, and 5 pins are low level, the signal at the first connector P1 end is fed back to the gate of the first field effect tube Q1, the fifth resistor R5 is used to discharge the parasitic capacitance of the gate of the first field effect tube Q1, the matching signal is fed back by the terminal or manually, and the matching signal is fed back to the feedback unit. When the feedback unit obtains a matching signal feedback, the feedback unit continuously feeds back the working signal to the first connector P1. When the first connector P1 end obtains the signal feedback, the voltage difference between the gate of the first field effect tube Q1 and the source of the first field effect tube Q1 is higher than the conduction threshold, the first field effect tube Q1 is turned on, and the 6-pin signal of the third trigger U3 is fed back through the drain of the first field effect tube Q1 and the first field effect tube Q1 The source, the eighth resistor R8, and the sixth resistor R6 are connected to the ground terminal. At the same time, the signal potential of the first capacitor C1 terminal rises. The signal of the first capacitor C1 terminal is fed back to the 3rd pin of the third trigger U3 through the first diode D1. When the potential of the first capacitor C1 terminal reaches the working voltage of the third trigger U3 pin, the levels of the 6th pin and the 5th pin of the third trigger U3 are replaced. The 6th pin of the third trigger U3 is at a low level and the 5th pin is at a high level. The potential of the first capacitor C1 decreases. The signal of the 5th pin of the third trigger U3 is connected to the ground terminal through the ninth resistor R9 and the tenth resistor R10. At the same time, the signal potential of the third capacitor C3 terminal rises. The signal of the third capacitor C3 terminal is fed back to the 3rd pin of the third trigger U3 through the second diode D2. , and feedback is given to pin 3 of the third trigger U3. When the potential of the third capacitor C3 reaches the working voltage of the third trigger U3 pin, the levels of pins 6 and 5 of the third trigger U3 are replaced again. The signal at the sixth resistor R6 is fed back to the oscillation unit via the second connector P2 and the feedback unit. The oscillation unit adjusts the oscillation frequency based on the amplitude of the signal at the sixth resistor R6. The higher the amplitude of the signal at the sixth resistor R6, the higher the frequency of the oscillation signal fed back by the oscillation unit, and vice versa. In this way, when matching, the oscillation unit can feed back an oscillation signal with a frequency continuously changing within the frequency range to the piezoelectric ceramic piece, so that the detection unit can detect the resonance point of the piezoelectric ceramic piece.

[0034] When the piezoelectric ceramic piece is at the resonance point, the working current of the piezoelectric ceramic piece reaches the maximum value. The detection unit feeds back a confirmation signal at the resonance point of the piezoelectric ceramic piece based on the detection of its working current. The third connector P3 end is used to receive the confirmation signal. The power signal passes through the thirteenth resistor R13 and the fifteenth resistor R15 to the ground end. The power signal passes through the fourteenth resistor R14 and the twelfth resistor R12 to the ground end. The signal at the fifteenth resistor R15 end is fed back to the in-phase end of the fourth operational amplifier U4. The signal at the twelfth resistor R12 end is fed back to the inverting end of the fourth operational amplifier U4. The signal amplitude at the twelfth resistor R12 end is set to be higher than the signal amplitude at the fifteenth resistor R15 end so that the fourth operational amplifier U4 is in a cut-off state when the first connector P1 end obtains the signal. The signal at the output end of the fourth operational amplifier U4 is fed back to the gate of the second field effect transistor Q2. The power signal passes through the eighteenth resistor R18, the source of the second field effect transistor Q2, the drain of the second field effect transistor Q2, and the eleventh resistor R11 to the ground. The signal at the eleventh resistor R11 is fed back to the power input terminal of the first switch S1, the first switch S1 is in a closed state, the potential at the second capacitor C2 follows the potential at the first capacitor C1, and when the third connector P3 obtains a signal, the fourth operational amplifier U4 outputs, and the signal at the output terminal of the fourth operational amplifier U4 passes through the third diode D3 and the fifteenth resistor R15 to the ground terminal. The signal amplitude at the fifteenth resistor R15 is clamped at the signal amplitude at the output terminal of the fourth operational amplifier U4 after the voltage drop of the third diode D3, so as to prevent the fourth operational amplifier U4 from being cut off when the confirmation signal stops being fed back. At the same time, the voltage difference between the gate of the second field effect transistor Q2 and the source of the second field effect transistor Q2 is higher than the conduction threshold, the second field effect transistor Q2 is cut off, and the potential at the second capacitor C2 stops following the signal of the first capacitor C1. At this time, the signal amplitude at the second capacitor C2 is the frequency signal amplitude corresponding to the resonance point of the piezoelectric ceramic piece, thereby completing the matching of the frequency of the oscillation signal with the resonance point of the piezoelectric ceramic piece.

[0035] Considering that when the piezoelectric ceramic piece works at the resonant frequency point, the amplitude is much higher than the non-resonant point, and the energy conversion efficiency is also the highest, however, working at the resonant frequency for a long time will accelerate the fatigue and aging of the piezoelectric ceramic piece. Therefore, when the frequency of the oscillation signal is matched with the resonant point of the piezoelectric ceramic piece, it is necessary to allow users to make independent choices based on their needs. The fifth connector P5 end is used to receive the reference signal fed back by the feedback unit. In the initial state, when the feedback unit does not obtain the adjustment signal, there is no signal feedback at the fifth connector P5 end, and the signal at the second capacitor C2 end is fed back to the in-phase end of the sixth operational amplifier U6, and the sixth operational amplifier U6 outputs. The signal at the output end of the sixth operational amplifier U6 is connected to the ground end through the seventh resistor R7. The signal at the seventh resistor R7 end It is the adjustment signal required by the feedback unit. When the detection unit feeds back a confirmation signal, the fourth operational amplifier U4 outputs, and the signal at the output end of the fourth operational amplifier U4 is synchronously fed back to the gate of the third field effect tube Q3. The voltage difference between the gate of the third field effect tube Q3 and the source of the third field effect tube Q3 is higher than the conduction threshold, and the third field effect tube Q3 is turned on. The adjustment signal passes through the drain of the third field effect tube Q3, the source of the third field effect tube Q3, and the twentieth resistor R20 to the ground terminal. The signal at the end of the twentieth resistor R20 is fed back to the feedback unit through the fourth connector P4. When the feedback unit obtains the signal feedback, it increases the signal amplitude at the end of the fifth connector P5. The signal at the end of the fifth connector P5 is fed back to the inverting end of the sixth operational amplifier U6. When the signal at the end of the fifth connector P5 is When the amplitude of the signal is consistent with that at the second capacitor C2 end, the sixth operational amplifier U6 is cut off, the feedback unit loses the adjustment signal feedback, and the feedback unit stops signal adjustment. When the feedback unit stops signal adjustment, the feedback unit cuts off the feedback channel of the second connector P2 end to the oscillation unit, and at the same time opens the feedback channel of the sixth connector P6 end to the oscillation unit and disconnects the signal feedback of the first connector P1 end. The signal at the fifth connector P5 end passes through the first resistor R1 and the twenty-first resistor R21 to the ground end, and the signal at the twenty-first resistor R21 end is fed back to the in-phase end of the first operational amplifier U1. At the same time, the signal at the fifth connector P5 end passes through the nineteenth resistor R19 and the fourth resistor R4 to the ground end, and the signal at the fourth resistor R4 end is the lower frequency of the operating frequency after the matching is completed. The resistance value of the fourth resistor R4 is adjusted as needed. If the matched operating frequency does not need to be lowered, the resistance value of the fourth resistor R4 can be set to 0. The user can choose between sacrificing part of the energy conversion efficiency to extend the service life of the piezoelectric ceramic sheet, and ensuring the energy conversion efficiency to reduce the service life of the piezoelectric ceramic sheet. The resistance value of the fourth resistor R4 can be adjusted as needed. The signal at the fourth resistor R4 end is fed back to the in-phase end of the second operational amplifier U2, and the output end of the second operational amplifier U2 is negatively feedback connected to the inverting end of the second operational amplifier U2. The second operational amplifier U2 follows and outputs the signal at the fourth resistor R4 end. The output end of the first operational amplifier U1 is negatively feedback connected to the inverting end of the first operational amplifier U1 through the third resistor R3.At the same time, the output signal of the second operational amplifier U2 is fed back to the inverting terminal of the first operational amplifier U1, and the first operational amplifier U1 outputs the difference signal between the signal at the fifth connector P5 and the signal at the fourth resistor R4. At this time, the output signal of the first operational amplifier U1 is a frequency signal corresponding to the optimal operating frequency of the piezoelectric ceramic selected by the user. The signal is fed back to the oscillation unit via the sixth connector P6 and the feedback unit. The oscillation unit adjusts the oscillation frequency based on the amplitude of the output signal of the first operational amplifier U1.

[0036] The power supply signal reaches the ground terminal through the sixteenth resistor R16 and the seventeenth resistor R17, and the signal at the end of the seventeenth resistor R17 is fed back to the in-phase terminal of the fifth operational amplifier U5. The signal at the end of the first connector P1 is synchronously fed back to the inverting terminal of the fifth operational amplifier U5. When there is no signal feedback at the end of the first connector P1, the fifth operational amplifier U5 outputs, otherwise it is cut off. When the fifth operational amplifier U5 outputs, the signal at the output end of the fifth operational amplifier U5 reaches the ground terminal through the fourth diode D4 and the twelfth resistor R12, and the fourth operational amplifier U4 is cut off, so as to obtain the frequency signal corresponding to the optimal operating frequency of the piezoelectric ceramic piece in the oscillation unit, so that the partial circuit that enters operation during the matching process is restored to the initial state to reduce the power consumption of the entire control circuit.

[0037] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and scope of the equivalent elements of the claims be included in the invention. Any marking in a claim should not be considered as limiting the claim to which it relates.

Claims

1. An automatic sonic control circuit for a megasonic cleaning device, characterized in that: It includes a feedback unit, an oscillation unit, a detection unit, and a control unit. The control unit is connected to the feedback unit and the detection unit. The feedback unit is connected to the oscillation unit. The oscillation unit is used to generate and feed back an oscillation signal. The feedback unit is used to adjust and feed back a reference signal required by the control unit and to control the feedback channel of the oscillation unit to obtain a frequency modulation signal. The detection unit is used to detect the resonance point of the piezoelectric ceramic piece when the oscillation unit feeds back an oscillation signal and to feed back a confirmation signal when the piezoelectric ceramic piece is at the resonance point. The control unit is used to enable the oscillation unit to feed back an oscillation signal with a frequency that continuously changes within a frequency range to the piezoelectric ceramic piece during matching, so that the detection unit can detect the resonance point of the piezoelectric ceramic piece, and automatically adjust the working frequency after matching is completed. It also includes a third trigger, a first field effect transistor, a first diode, a second diode, a first capacitor, a third capacitor, a first connector, a second connector, a sixth resistor, an eighth resistor, a ninth resistor, and a tenth resistor; The first pin of the third trigger and the fourth pin of the third trigger are connected to the power supply, the second pin of the third trigger and the sixth pin of the third trigger and the drain of the first field effect transistor are connected, the third pin of the third trigger is connected to the cathode of the first diode and the cathode of the second diode, the fifth pin of the third trigger is connected to one end of the ninth resistor, the source of the first field effect transistor is connected to one end of the eighth resistor, the gate of the first field effect transistor is connected to the first connector end, the anode of the first diode is connected to one end of the first capacitor, one end of the sixth resistor, the other end of the eighth resistor, and the second connector end, the anode of the second diode is connected to one end of the third capacitor, the other end of the ninth resistor, and one end of the tenth resistor, the other end of the first capacitor, the other end of the third capacitor, the other end of the sixth resistor, the other end of the ninth resistor and the ground end, the fifth and sixth pins of the third trigger are signal output ends, the third pin is a clock input end, the second pin is a data input end, the first pin is a direct reset end, and the fourth pin is a direct set end.

2. The automatic acoustic wave control circuit of the megasonic cleaning device according to claim 1, characterized in that: It also includes a fourth operational amplifier, a second field effect transistor, a third diode, a second capacitor, a first switch, a third connector, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, and an eighteenth resistor; The in-phase end of the fourth operational amplifier is connected to the cathode of the third diode, one end of the thirteenth resistor, one end of the fifteenth resistor, and the third connector end; the inverting end of the fourth operational amplifier is connected to one end of the twelfth resistor and one end of the fourteenth resistor; the output end of the fourth operational amplifier is connected to the anode of the third diode and the gate of the second field effect transistor; the source of the second field effect transistor is connected to one end of the eighteenth resistor; the drain of the second field effect transistor is connected to the positive electrode of the first switch and one end of the eleventh resistor; one end of the first switch is connected to the second connector end; the other end of the first switch is connected to one end of the second capacitor; the other end of the thirteenth resistor, the other end of the fourteenth resistor, and the other end of the eighteenth resistor are connected to the power supply; the negative electrode of the first switch, the other end of the second capacitor, the other end of the eleventh resistor, the other end of the twelfth resistor, and the other end of the fifteenth resistor are connected to the ground end.

3. The automatic acoustic wave control circuit of the megasonic cleaning device according to claim 2, characterized in that: It also includes a first operational amplifier, a second operational amplifier, a sixth operational amplifier, a third field effect transistor, a first resistor, a second resistor, a third resistor, a fourth resistor, a seventh resistor, a nineteenth resistor, a twentieth resistor, a twenty-first resistor, a fourth connector, a fifth connector, and a sixth connector; The non-inverting end of the first operational amplifier is connected to one end of the first resistor and one end of the twenty-first resistor, the inverting end of the first operational amplifier is connected to one end of the second resistor and one end of the third resistor, the output end of the first operational amplifier is connected to the other end of the third resistor and the sixth connector end, the non-inverting end of the second operational amplifier is connected to one end of the fourth resistor and one end of the nineteenth resistor, the inverting end of the second operational amplifier is connected to the other end of the second resistor and the output end of the second operational amplifier, the non-inverting end of the sixth operational amplifier is connected to one end of the second capacitor, the inverting end of the sixth operational amplifier is connected to the other end of the first resistor, the other end of the nineteenth resistor and the fifth connector end, the output end of the sixth operational amplifier is connected to the drain of the third field effect transistor and one end of the seventh resistor, the gate of the third field effect transistor is connected to the gate of the second field effect transistor, the source of the third field effect transistor is connected to one end of the twentieth resistor and the fourth connector end, and the other end of the fourth resistor, the other end of the seventh resistor, the other end of the twentieth resistor, the other end of the twenty-first resistor and the ground end are connected.

4. The automatic sonic control circuit of the megasonic cleaning device according to claim 2, characterized in that: Also includes a fifth operational amplifier, a fourth diode, a sixteenth resistor, and a seventeenth resistor; The non-inverting end of the fifth operational amplifier is connected to one end of the sixteenth resistor and one end of the seventeenth resistor, the inverting end of the fifth operational amplifier is connected to the first connector end, the output end of the fifth operational amplifier is connected to the anode of the fourth diode, the other end of the sixteenth resistor is connected to the power supply, the cathode of the fourth diode is connected to one end of the twelfth resistor, and the other end of the seventeenth resistor is connected to the ground end.

5. The automatic sonic control circuit of the megasonic cleaning device according to claim 1, characterized in that: Also including a fifth resistor; One end of the fifth resistor is connected to the gate of the first field effect transistor, and the other end of the fifth resistor is connected to the ground.

6. The automatic acoustic wave control circuit of the megasonic wave cleaning device according to claim 3, characterized in that: The fourth resistor is an adjustable resistor.

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