Ultrasonic device

Abstract

The present application provides an ultrasonic device, which includes: a resonant network unit, which is composed of an inductor module with adjustable inductance value and an ultrasonic transducer connected in series; a resonant voltage detection unit, which is electrically connected to the ultrasonic transducer and used to detect the resonant voltage of the ultrasonic transducer; a resonant current detection unit, which is electrically connected to the ultrasonic transducer and used to detect the resonant current of the ultrasonic transducer; a signal modulation unit, which has an input end and an output end, the input end of the signal modulation unit is electrically connected to the resonant voltage detection unit and the resonant current detection unit respectively, and the duty cycle and frequency of the output PWM signal are adjusted according to the resonant voltage and the resonant current; a boost unit, which has an input end and an output end, the input end of the boost unit is electrically connected to the output end of the signal modulation unit, and the output end of the boost unit is electrically connected to the resonant network unit. The resonant frequency of the ultrasonic transducer can be accurately determined.

Description

Technical Field

[0001] The present application relates to the field of ultrasound, and in particular, to an ultrasound device. Background Art

[0002] Ultrasonic cleaning is a cleaning method with high cleaning efficiency. No matter how complex the shape of the object to be cleaned is, as long as it is placed in the cleaning liquid, the ultrasonic wave can play a cleaning role as long as the liquid can touch it. However, different cleaning objects need to be matched with appropriate ultrasonic frequencies and powers to ensure the cleaning effect without damaging the cleaning objects. The working frequency of ultrasonic cleaning machines is roughly divided into three frequency bands according to the cleaning object: low-frequency ultrasonic cleaning (20kHz-100kHz), medium-frequency ultrasonic cleaning (100kHz-500kHz) and high-frequency ultrasonic cleaning (500kHz-1000kHz). Among them, low-frequency ultrasonic cleaning is suitable for the surface of large parts or occasions where the bonding strength between dirt and the surface of the cleaning parts is high; medium-frequency ultrasonic cleaning is suitable for the fine cleaning of computers and microelectronic components; high-frequency ultrasonic cleaning is suitable for the cleaning of integrated circuit chips, silicon wafers and thin films. Different ultrasonic transducers have different inherent resonant frequencies and need to be impedance matched with the power supply module to work in the best state.

[0003] Different cleaning objects require different ultrasonic transducers and appropriate ultrasonic power output. Different ultrasonic transducers require different resonant networks for impedance matching to make them work in the best state.

[0004] The prior art is unable to automatically match appropriate resonance network parameters according to different replaced ultrasonic transducers and accurately lock their inherent resonance frequencies. Summary of the invention

[0005] The main purpose of the present application is to provide an ultrasonic device that is unable to automatically match appropriate resonant network parameters and accurately lock its inherent resonant frequency according to different replaced ultrasonic transducers in the prior art.

[0006] In order to achieve the above-mentioned purpose, according to one aspect of the present application, an ultrasonic device is provided, including: a resonant network unit, which is composed of an inductor module with adjustable inductance value and an ultrasonic transducer connected in series; a resonant voltage detection unit, which is electrically connected to the ultrasonic transducer and is used to detect the resonant voltage of the ultrasonic transducer; a resonant current detection unit, which is electrically connected to the ultrasonic transducer and is used to detect the resonant current of the ultrasonic transducer; a signal modulation unit, which has an input end and an output end, and the input end of the signal modulation unit is electrically connected to the resonant voltage detection unit and the resonant current detection unit respectively, and is used to adjust the duty cycle and frequency of the output PWM signal according to the resonant voltage and the resonant current; a boost unit, which has an input end and an output end, and the input end of the boost unit is electrically connected to the output end of the signal modulation unit, and the output end of the boost unit is electrically connected to the resonant network unit.

[0007] Furthermore, the inductor module includes N switches and N inductors, the N inductors are connected in series, the first ends of the N switches are electrically connected to the boost units respectively, the second end of the Mth switch is electrically connected to the first end of the Mth inductor, and the second end of the Nth inductor is electrically connected to the ultrasonic transducer, wherein 1≤M≤N, N≥2.

[0008] Further, the boost unit includes: an H-bridge driving unit having an input end and an output end, the input end of the H-bridge driving unit being electrically connected to the output end of the signal modulation unit; an H-bridge having an input end and an output end, the input end of the H-bridge being electrically connected to the output end of the H-bridge driving unit; a transformer having a primary coil and a secondary coil, the primary coil of the transformer being electrically connected to the H-bridge, and the secondary coil of the transformer being electrically connected to the resonant network unit.

[0009] Further, the H-bridge includes a first MOS tube, a second MOS tube, a third MOS tube and a fourth MOS tube, the gate of the first MOS tube is electrically connected to the first output end of the H-bridge driving unit, the gate of the second MOS tube is electrically connected to the second output end of the H-bridge driving unit, the gate of the third MOS tube is electrically connected to the third output end of the H-bridge driving unit, the gate of the fourth MOS tube is electrically connected to the fourth output end of the H-bridge driving unit, the drain of the first MOS tube and the drain of the fourth MOS tube are electrically connected to the power supply end respectively, the source of the first MOS tube is electrically connected to the drain of the second MOS tube, the source of the fourth MOS tube is electrically connected to the drain of the third MOS tube, the source of the second MOS tube and the source of the third MOS tube are grounded, the same-name end of the primary coil of the transformer is electrically connected to the drain of the third MOS tube, and is electrically connected to the first upper bridge arm reference floating end of the H-bridge driving unit; the opposite-name end of the primary coil of the transformer is electrically connected to the drain of the second MOS tube, and is electrically connected to the second upper bridge arm reference floating end of the H-bridge driving unit.

[0010] Further, the resonant voltage detection unit includes a first resistance module, a second resistance module, a third resistance module, a first diode, a first electrolytic capacitor module and a first capacitor module, the first end of the first resistance module is electrically connected to the first end of the ultrasonic transducer, the second end of the first resistance module is electrically connected to the first end of the second resistance module and the positive electrode of the first diode, the second end of the second resistance module is grounded, the negative electrode of the first diode is electrically connected to the first end of the third resistance module, the first end of the first electrolytic capacitor module and the first end of the first capacitor module are electrically connected to the second end of the third resistance module, and the second end of the first electrolytic capacitor module and the second end of the first capacitor module are grounded.

[0011] Further, the resonant current detection unit includes a fourth resistor module, a fifth resistor module, a second diode, a second electrolytic capacitor module and a second capacitor module, the first end of the fourth resistor module is grounded, the second end of the fourth resistor module is electrically connected to the second end of the ultrasonic transducer and the positive electrode of the second diode, respectively, the negative electrode of the second diode is electrically connected to the first end of the fifth resistor module, the second end of the fifth resistor module is electrically connected to the first end of the second electrolytic capacitor module and the first end of the second capacitor module, respectively, and the second end of the second electrolytic capacitor module and the second end of the second capacitor module are grounded.

[0012] Further, N=3, the three switches are respectively a first switch, a second switch and a third switch, the three inductors are respectively a first inductor, a second inductor and a third inductor, and the frequency of the output PWM signal is adjusted according to the resonant voltage and the resonant current, including: controlling the first switch to be closed, the second switch and the third switch to be disconnected, and outputting a PWM signal in a first frequency range, and controlling the frequency of the PWM signal to increase with a first step length, and obtaining a first resonant voltage and a first resonant current of the ultrasonic transducer in real time; when a first condition is met, determining that the resonant frequency of the ultrasonic transducer is within a first sub-frequency range, the first sub-frequency range is expressed as Q+A×P~Q+(A+1)×P, wherein Q represents the minimum value of the first frequency range, A is a positive integer, P represents the first step length, and the first condition is that the first resonant voltage is greater than a first voltage threshold, and the first resonant current is greater than a first current threshold; when the first condition is not met, controlling the second switch to be closed, the first switch and the third switch to be disconnected, and adjusting the frequency of the PWM signal.

[0013] Further, when the first condition is not met, the second switch is controlled to be closed, the first switch and the third switch are disconnected, and the frequency of the PWM signal is adjusted, including: outputting a PWM signal in a second frequency range, and controlling the frequency of the PWM signal to increase with a second step size, and acquiring a second resonant voltage and a second resonant current of the ultrasonic transducer in real time, wherein the minimum value of the second frequency range is greater than the maximum value of the first frequency range; when the second condition is met, determining that the resonant frequency of the ultrasonic transducer is within a second sub-frequency range, and the second sub-frequency range is expressed as R+B×S~R+(B+1)×S, wherein R represents the minimum value of the second frequency range, M is a positive integer, S represents the second step size, and the second condition is that the second resonant voltage is greater than a second voltage threshold, and the second resonant current is greater than a second current threshold; when the second condition is not met, the third switch is controlled to be closed, the first switch and the second switch are disconnected, and the frequency of the PWM signal is adjusted again.

[0014] Further, when the second condition is not met, the third switch is controlled to be closed, the first switch and the second switch are disconnected, and the frequency of the PWM signal is adjusted again, including: outputting the frequency of the PWM signal in a third frequency range, and controlling the frequency of the PWM signal to increase with a third step size, and detecting the third resonant voltage and the third resonant current of the ultrasonic transducer in real time, wherein the minimum value of the third frequency range is greater than the maximum value of the second frequency range; when the third condition is met, determining that the resonant frequency of the ultrasonic transducer is within a third sub-frequency range, and the third sub-frequency range is expressed as U+W×V~U+(W+1)×V, wherein U represents the minimum value of the third frequency range, W is a positive integer, V represents the third step size, and the third condition is that the third resonant voltage is greater than the third voltage threshold, and the third resonant current is greater than the third current threshold; when the third condition is not met, issuing an alarm prompt message.

[0015] Furthermore, the signal modulation unit is also used to perform the following steps: after determining that the resonant frequency of the ultrasonic transducer is within the first sub-frequency range, controlling the frequency of the PWM signal to increase with a fourth step size, and acquiring a fourth resonant current of the ultrasonic transducer in real time, wherein the fourth step size is smaller than the first step size; comparing three fourth resonant currents acquired consecutively; and when the fourth resonant current acquired for the second time is greater than both the fourth resonant current acquired for the first time and the fourth resonant current acquired for the third time, determining that the frequency of the PWM signal corresponding to the fourth resonant current acquired for the second time is the resonant frequency of the ultrasonic transducer.

[0016] Furthermore, the signal modulation unit is further configured to perform the following steps: determining whether the fourth resonant current acquired for the second time is greater than a predetermined current; and if so, reducing the duty cycle of the PWM signal.

[0017] By applying the technical solution of the present application, an ultrasonic device consisting of a resonant network unit, a resonant voltage detection unit, a resonant current detection unit, a signal modulation unit and a boost unit is adopted. The duty cycle and frequency of the output PWM signal are adjusted according to the above-mentioned resonant voltage and the above-mentioned resonant current. Since the inductance value of the inductance module in the resonant network unit is adjustable, different inductance values ​​can be adapted for different ultrasonic transducers, that is, suitable resonant network parameters can be adapted for different ultrasonic transducers, and the duty cycle and frequency of the output PWM signal are adjusted according to the resonant voltage and the above-mentioned resonant current, thereby realizing accurate determination of the resonant frequency of the ultrasonic transducer. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings constituting part of the present application are used to provide a further understanding of the present application. The exemplary embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0019] Figure 1 A schematic diagram of an ultrasonic device according to an embodiment of the present application is shown;

[0020] Figure 2 A partial structural schematic diagram of an ultrasonic device according to an embodiment of the present application is shown;

[0021] Figure 3 A flow chart of a rough scanning mode according to an embodiment of the present application is shown;

[0022] Figure 4 A flow chart of the fine scanning mode according to an embodiment of the present application is shown.

[0023] The above drawings include the following reference numerals:

[0024] 10. Resonant network unit; 20. Resonant voltage detection unit; 30. Resonant current detection unit; 40. Signal modulation unit; 50. Boost unit; 51. H-bridge driving unit; 52. H-bridge; 53. Transformer. DETAILED DESCRIPTION

[0025] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0026] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0027] It should be understood that when an element (such as a layer, film, region, or substrate) is described as being "on" another element, the element may be directly on the other element, or there may be intermediate elements. Moreover, in the specification and claims, when an element is described as being "connected" to another element, the element may be "directly connected" to the other element, or "connected" to the other element through a third element.

[0028] As introduced in the background technology, the prior art cannot accurately determine the natural resonant frequency of the ultrasonic transducer. In order to solve the problem that the natural resonant frequency of the ultrasonic transducer cannot be accurately determined, an embodiment of the present application provides an ultrasonic device.

[0029] A typical embodiment of the present application provides an ultrasonic device. Figure 1 As shown, including:

[0030] The resonant network unit 10 is composed of an inductor module with adjustable inductance value and an ultrasonic transducer connected in series;

[0031] Specifically, since the inductance value of the inductance module is adjustable, different impedances can be adapted for ultrasonic transducers with different natural frequencies, so that the ultrasonic transducers work in an optimal state.

[0032] A resonance voltage detection unit 20, electrically connected to the ultrasonic transducer, and used to detect the resonance voltage of the ultrasonic transducer;

[0033] A resonant current detection unit 30, electrically connected to the ultrasonic transducer, and used to detect the resonant current of the ultrasonic transducer;

[0034] A signal modulation unit 40 having an input end and an output end, wherein the input end of the signal modulation unit 40 is electrically connected to the resonant voltage detection unit 20 and the resonant current detection unit 30, respectively, and is used to adjust the duty cycle and frequency of the output PWM signal according to the resonant voltage and the resonant current;

[0035] Specifically, since the duty cycle of the PWM signal output by the signal modulation unit is controllable, the output power of the ultrasonic transducer is controllable.

[0036] The boost unit 50 has an input end and an output end. The input end of the boost unit 50 is electrically connected to the output end of the signal modulation unit 40 , and the output end of the boost unit 50 is electrically connected to the resonant network unit 10 .

[0037] In the above scheme, an ultrasonic device consisting of a resonant network unit, a resonant voltage detection unit, a resonant current detection unit, a signal modulation unit and a boost unit is used. The duty cycle and frequency of the output PWM signal are adjusted according to the above resonant voltage and the above resonant current. Since the inductance value of the inductance module in the resonant network unit is adjustable, different inductance values ​​can be adapted for different ultrasonic transducers, that is, suitable resonant network parameters are adapted for different ultrasonic transducers, and the duty cycle and frequency of the output PWM signal are adjusted according to the resonant voltage and the above resonant current, thereby realizing accurate determination of the resonant frequency of the ultrasonic transducer.

[0038] In one embodiment of the present application, the inductor module includes N switches and N inductors, the N inductors are connected in series, the first ends of the N switches are electrically connected to the boost units respectively, the second end of the Mth switch is electrically connected to the first end of the Mth inductor, and the second end of the Nth inductor is electrically connected to the ultrasonic transducer, wherein 1≤M≤N, N≥2.

[0039] In a specific embodiment, Figure 2 As shown, N=3, the three switches are respectively the first switch S1, the second switch S2 and the third switch S3, and the three inductors are respectively the first inductor L2, the second inductor L3 and the third inductor L4. When the first switch S1 is turned on and the second switch S2 and the third switch S3 are turned off, L2, L3 and L4 are connected in series with the transducer Y1 to form a resonant network, which is used to match the low-frequency transducer; when the second switch S2 is turned on and the first switch S1 and the third switch S3 are turned off, L3 and L4 are connected in series with the transducer Y1 to form a resonant network, which is used to match the intermediate-frequency transducer; when the third switch S3 is turned on and the first switch S1 and the second switch S2 are turned off, L4 and the transducer Y1 form a resonant network, which is used to match the high-frequency transducer. It should be noted that N=3 in this embodiment is exemplary. In actual applications, the size of N can be set according to the number of distinguished frequency bands. For example, if 6 frequency bands are distinguished, 6 switches and 6 inductors are set accordingly.

[0040] In one embodiment of the present application, Figure 1 and Figure 2 As shown, the boost unit 50 includes an H-bridge driving unit 51, an H-bridge 52 and a transformer 53. The H-bridge driving unit 51 has an input end and an output end, and the input end of the H-bridge driving unit 51 is electrically connected to the output end of the signal modulation unit 40; the H-bridge 52 has an input end and an output end, and the input end of the H-bridge 52 is electrically connected to the output end of the H-bridge driving unit 51; the transformer 53 has a primary coil and a secondary coil, and the primary coil of the transformer 53 is electrically connected to the H-bridge 52, and the secondary coil of the transformer 53 is electrically connected to the resonant network unit 10. Under the joint action of the H-bridge driving unit 51, the H-bridge 52, the transformer 53 and the resonant network unit 10, a stable sinusoidal wave signal is output.

[0041] In one embodiment of the present application, Figure 2As shown, the H-bridge 52 includes a first MOS transistor Q1, a second MOS transistor Q2, a third MOS transistor Q3 and a fourth MOS transistor Q4, the gate of the first MOS transistor is electrically connected to the first output terminal BHO of the H-bridge driving unit 51, the gate of the second MOS transistor is electrically connected to the second output terminal BLO of the H-bridge driving unit 51, the gate of the third MOS transistor is electrically connected to the third output terminal ALO of the H-bridge driving unit 51, the gate of the fourth MOS transistor is electrically connected to the fourth output terminal AHO of the H-bridge driving unit 51, the drain of the first MOS transistor and the drain of the fourth MOS transistor are electrically connected to the power supply terminal VCC respectively, the source of the first MOS transistor is electrically connected to the drain of the second MOS transistor, the source of the fourth MOS transistor is electrically connected to the drain of the third MOS transistor, and the source of the second MOS transistor and the source of the third MOS transistor are grounded. The same-name end of the primary coil of the transformer is electrically connected to the drain of the third MOS tube, and is electrically connected to the first upper bridge arm reference floating ground end AHS of the H-bridge driving unit; the opposite-name end of the primary coil of the transformer is electrically connected to the drain of the second MOS tube, and is electrically connected to the second upper bridge arm reference floating ground end BHS of the H-bridge driving unit. The AHS end of the H-bridge driving unit is connected to the power supply end VDD through the capacitor C2 and the diode D2, and the BHS end is connected to the power supply end VDD through the capacitor C1 and the diode D1.

[0042] The H-bridge driving unit is used to drive the H-bridge and has a strong driving capability, further ensuring the stability of the sine wave adjusted by the resonant network unit.

[0043] like Figure 2 As shown, a signal PWM1 is input to an input terminal BL1 of the H-bridge driving unit 51, a signal PWM2 is input to an input terminal AL1 of the H-bridge driving unit 51, a diode D1 is connected to a terminal BHB of the H-bridge driving unit 51, a first output terminal BHO of the H-bridge driving unit 51 is electrically connected to the gate of the first MOS tube through a resistor R1, a second output terminal BLO of the H-bridge driving unit 51 is electrically connected to the gate of the second MOS tube through a resistor R2, a third output terminal ALO of the H-bridge driving unit 51 is electrically connected to the gate of the third MOS tube through a resistor R3, and a fourth output terminal AHO of the H-bridge driving unit 51 is electrically connected to the gate of the fourth MOS tube through a resistor R4.

[0044] In one embodiment of the present application, Figure 2As shown, the resonant voltage detection unit 20 includes a first resistor module R11, a second resistor module R12, a third resistor module R13, a first diode D4, a first electrolytic capacitor module C5 and a first capacitor module C6, the first end of the first resistor module is electrically connected to the first end of the ultrasonic transducer, the second end of the first resistor module is electrically connected to the first end of the second resistor module and the positive electrode of the first diode respectively, the second end of the second resistor module is grounded, the negative electrode of the first diode is electrically connected to the first end of the third resistor module, the first end of the first electrolytic capacitor module and the first end of the first capacitor module are electrically connected to the second end of the third resistor module respectively, and the second end of the first electrolytic capacitor module and the second end of the first capacitor module are grounded.

[0045] In one embodiment of the present application, Figure 2 As shown, the resonant current detection unit 30 includes a fourth resistor module R9, a fifth resistor module R10, a second diode D3, a second electrolytic capacitor module C3 and a second capacitor module C4, the first end of the fourth resistor module is grounded, the second end of the fourth resistor module is electrically connected to the second end of the ultrasonic transducer and the positive electrode of the second diode, respectively, the negative electrode of the second diode is electrically connected to the first end of the fifth resistor module, the second end of the fifth resistor module is electrically connected to the first end of the second electrolytic capacitor module and the first end of the second capacitor module, respectively, and the second end of the second electrolytic capacitor module and the second end of the second capacitor module are grounded.

[0046] In one embodiment of the present application, Figure 2As shown, N=3, the three switches are respectively a first switch S1, a second switch S2 and a third switch S3, the three inductors are respectively a first inductor L2, a second inductor L3 and a third inductor L4, and the frequency of the output PWM signal is adjusted according to the resonant voltage and the resonant current, including: controlling the first switch to be closed, the second switch and the third switch to be disconnected, and outputting a PWM signal in a first frequency range, and controlling the frequency of the PWM signal to increase with a first step length, and obtaining the first resonant voltage and the first resonant current of the ultrasonic transducer in real time; when the first condition is met, determining that the resonant frequency of the ultrasonic transducer is within a first sub-frequency range, the first sub-frequency range is expressed as Q+A×P~Q+(A+1)×P, wherein Q represents the minimum value of the first frequency range, A is a positive integer, and P represents the first step length, and the first condition is that the first resonant voltage is greater than a first voltage threshold, and the first resonant current is greater than a first current threshold; when the first condition is not met, controlling the second switch to be closed, the first switch and the third switch to be disconnected, and adjusting the frequency of the PWM signal. Specifically, the first frequency range can be set to 20kHz-100kHz, and P can be set to 10. When A is equal to 1, the first sub-frequency range is expressed as 30kHz~40kHz, and the first voltage threshold and the first current threshold can be set according to the properties of the ultrasonic transducer and the operating environment. The first frequency range is a low frequency range. When only the first switch is closed, the first inductor, the second inductor and the third inductor are connected in series, and the total inductance value is the largest at this time; when only the second switch is closed, the second inductor and the third inductor are connected in series, and the total inductance value at this time is smaller than the total inductance value when only the first switch is closed. It should be noted that N=3 in this embodiment is exemplary. In actual applications, the size of N can be set according to the number of distinguished frequency bands. For example, 6 frequency bands are distinguished, and 6 switches and 6 inductors are set accordingly.

[0047] In one embodiment of the present application, when the first condition is not met, the second switch is controlled to be closed, the first switch and the third switch are disconnected, and the frequency of the PWM signal is adjusted, including: outputting a PWM signal in the second frequency range, and controlling the frequency of the PWM signal to increase with a second step length, and obtaining the second resonant voltage and the second resonant current of the ultrasonic transducer in real time, wherein the minimum value of the second frequency range is greater than the maximum value of the first frequency range; when the second condition is met, determining that the resonant frequency of the ultrasonic transducer is within the second sub-frequency range, the second sub-frequency range is expressed as R+B×S~R+(B+1)×S, wherein R represents the minimum value of the second frequency range, M is a positive integer, S represents the second step length, the second condition is that the second resonant voltage is greater than the second voltage threshold, and the second resonant current is greater than the second current threshold, wherein the size of the first step length and the second step length is determined by the corresponding frequency range; when the second condition is not met, the third switch is controlled to be closed, the first switch and the second switch are disconnected, and the frequency of the PWM signal is adjusted again. Specifically, the second frequency range can be set to 100kHz-500kHz, and S can be set to 50. When B is equal to 1, the second sub-frequency range is represented as 150kHz to 200kHz, and the second voltage threshold and the second current threshold can be set according to the properties and operating environment of the ultrasonic transducer. The second frequency range is a medium frequency range.

[0048] In one embodiment of the present application, when the second condition is not met, the third switch is controlled to be closed, the first switch and the second switch are disconnected, and the frequency of the PWM signal is adjusted again, including: outputting a PWM signal in a third frequency range, and controlling the frequency of the PWM signal to increase with a third step length, and detecting the third resonant voltage and the third resonant current of the ultrasonic transducer in real time, wherein the minimum value of the third frequency range is greater than the maximum value of the second frequency range; when the third condition is met, determining that the resonant frequency of the ultrasonic transducer is within the third sub-frequency range, and the third sub-frequency range is expressed as U+W×V~U+(W+1)×V, wherein U represents the minimum value of the third frequency range, W is a positive integer, and V represents the third step length, and the third condition is that the third resonant voltage is greater than the third voltage threshold, and the third resonant current is greater than the third current threshold, wherein the size of the third step length and the second step length is determined by the corresponding frequency range; when the third condition is not met, an alarm prompt message is issued. Specifically, the second frequency range can be set to 500kHz-1000kHz, and V can be set to 50. When W is equal to 1, the second sub-frequency range is represented as 550kHz to 600kHz, and the third voltage threshold and the third current threshold can be set according to the properties of the ultrasonic transducer and the operating environment. The third frequency range is a high frequency range. When only the third switch is closed, the third inductor is connected in series in the circuit, and the total inductance value at this time is smaller than the total inductance value when only the second switch is closed.

[0049] In one embodiment of the present application, the signal modulation unit is further used to perform the following steps: after determining that the resonant frequency of the ultrasonic transducer is within the first sub-frequency range, control the frequency of the PWM signal to increase with a fourth step length, and obtain the fourth resonant current of the ultrasonic transducer in real time, wherein the fourth step length is smaller than the first step length; compare the three fourth resonant currents obtained continuously; when the fourth resonant current obtained for the second time is greater than the fourth resonant current obtained for the first time and the fourth resonant current obtained for the third time, determine that the frequency of the PWM signal corresponding to the fourth resonant current obtained for the second time is the resonant frequency of the ultrasonic transducer. Specifically, the fourth step length is equal to 1. That is, after determining that the resonant frequency of the ultrasonic transducer is within the first sub-frequency range, further determine the resonant frequency point.

[0050] In one embodiment of the present application, the signal modulation unit is further used to perform the following steps: determine whether the fourth resonant current obtained for the second time is greater than a predetermined current; if yes, reduce the duty cycle of the PWM signal. That is, set the fourth resonant current warning value to perform power protection on the ultrasonic transducer. For example, the duty cycle of the PWM signal can be reduced from 50% to 45%.

[0051] Example

[0052] This embodiment relates to a specific method for determining the natural frequency (resonant frequency) of an ultrasonic transducer, which includes two stages: a fine scanning stage and a rough scanning stage. The flow chart of the rough scanning stage is as follows: Figure 3 As shown, the inherent resonant frequency range of the current transducer can be locked; I_CHECK is the actual detected resonant current value, and U_CHECK is the actual detected resonant voltage value; when I_CHECK is greater than the first preset threshold (U10, U11, U12), and U_CHECK is greater than the second preset threshold (U20, U21, U22), it indicates that the current resonant network parameters can match the current transducer, and the fine scanning mode can be entered. The flow chart of the fine scanning stage is shown in Figure 4 As shown, the current natural resonant frequency of the transducer can be accurately locked and the appropriate ultrasonic power can be output; wherein I_CHECK1, I_CHECK2, and I_CHECK3 correspond to the resonant current values ​​of frequencies f1, f2, and f3, respectively. When the driving frequency f is the same as the natural resonant frequency of the transducer, the maximum I_CHECK value can be obtained at this time; U111 is the required target power limit.

[0053] Specifically, the steps include:

[0054] The specific implementation steps are as follows:

[0055] Step 1: After connecting the transducer, start the machine and enter the rough scanning mode;

[0056] Step 2: Connect Figure 2 S1 in the circuit, disconnect S2 and S3, Figure 2 PWM1 and PWM2 in the output are at the preset frequency f0 = 20kHz and the duty cycle D = 50%;

[0057] Step 3: When I_CHECK>U10 and U_CHECK>U20, go to step 12 fine scanning mode; otherwise go to step 4;

[0058] Step 4: Execute f0=f0+10. If f0>100kHz, go to step 5, otherwise return to step 3.

[0059] Step 5: Connect Figure 2 S2 is in the middle, S1 and S3 are disconnected, PWM1 and PWM2 are output at the preset frequency f0 = 100kHz, duty cycle D = 50%;

[0060] Step 6: When I_CHECK>U11 and U_CHECK>U21, go to step 12 fine scanning mode; otherwise go to step 7;

[0061] Step 7: Execute f0=f0+50. If f0>500kHz, go to step 8, otherwise return to step 6.

[0062] Step 8: Connect Figure 2 In S3, S1 and S2 are disconnected, and PWM1 and PWM2 are output at the preset frequency f0 = 500kHz and duty cycle D = 50%;

[0063] Step 9: When I_CHECK>U12 and U_CHECK>U22, enter step 12 fine scanning mode; otherwise, enter step 10;

[0064] Step 10: Execute f0=f0+50. If f0>1000kHz, go to step 11, otherwise return to step 9.

[0065] Step 11: Alarm, indicating that the match cannot be made.

[0066] Step 12: Fine scanning mode, when f0<100, assign N=0 and go to step 13, otherwise assign M=0 and go to step 17;

[0067] Step 13: f1 = f0 + N, f2 = f0 + N + 1, f3 = f0 + N + 2, PWM1 and PWM2 are outputted at f1, f2, f3, duty cycle D = 50%, and I_CHECK1, I_CHECK2, I_CHECK3 are obtained respectively;

[0068] Step 14: When I_CHECK1≤I_CHECK2, go to step 15, otherwise go to step 21;

[0069] Step 15: When I_CHECK2≤I_CHECK3, go to step 16, otherwise go to step 22;

[0070] Step 16: Execute N=N+1. When N≤7, return to step 13, otherwise go to step 23;

[0071] Step 17: f1 = f0 + M, f2 = f0 + M + 5, f3 = f0 + M + 10, PWM1 and PWM2 are outputted at f1, f2, f3, duty cycle D = 50%, and I_CHECK1, I_CHECK2, I_CHECK3 are obtained respectively;

[0072] Step 18: When I_CHECK1≤I_CHECK2, go to step 19, otherwise go to step 21;

[0073] Step 19: When I_CHECK2≤I_CHECK3, go to step 20, otherwise go to step 22;

[0074] Step 20: Execute M=M+5. When M≤35, return to step 17; otherwise, go to step 23.

[0075] Step 21: Assign I_CHECK=I_CHECK1, and proceed to step 24;

[0076] Step 22: assign I_CHECK=I_CHECK2, and proceed to step 24;

[0077] Step 23: Assign I_CHECK=I_CHECK3, and proceed to step 24;

[0078] Step 24: When I_CHECK>U111, go to step 25, otherwise go to step 26;

[0079] Step 25: Assign D=D-5, and return to step 24;

[0080] Step 26: Stabilize the output at the frequency and duty cycle.

[0081] This embodiment locks the required resonance parameters of the corresponding transducer through the coarse scanning mode, and finally locks the inherent resonance frequency point of the transducer through the fine scanning mode, and controls the duty cycle of the driving signal according to the required target power by detecting the resonance state, so as to achieve the corresponding cleaning effect.

[0082] From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:

[0083] The ultrasonic device of the present application adopts an ultrasonic device composed of a resonant network unit, a resonant voltage detection unit, a resonant current detection unit, a signal modulation unit and a boost unit. The duty cycle and frequency of the output PWM signal are adjusted according to the above-mentioned resonant voltage and the above-mentioned resonant current, so as to achieve accurate determination of the resonant frequency of the ultrasonic transducer.

[0084] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An ultrasonic device, characterized in that: include: The resonant network unit is composed of an inductor module with adjustable inductance value and an ultrasonic transducer connected in series; a resonance voltage detection unit, electrically connected to the ultrasonic transducer, and used to detect the resonance voltage of the ultrasonic transducer; a resonant current detection unit, electrically connected to the ultrasonic transducer, and used to detect the resonant current of the ultrasonic transducer; A signal modulation unit having an input end and an output end, wherein the input end of the signal modulation unit is electrically connected to the resonant voltage detection unit and the resonant current detection unit, respectively, and is used to adjust the duty cycle and frequency of the output PWM signal according to the resonant voltage and the resonant current; A boost unit having an input end and an output end, wherein the input end of the boost unit is electrically connected to the output end of the signal modulation unit, and the output end of the boost unit is electrically connected to the resonant network unit; The inductor module includes N switches and N inductors, the N inductors are connected in series, the first ends of the N switches are electrically connected to the boost units respectively, the second end of the Mth switch is electrically connected to the first end of the Mth inductor, and the second end of the Nth inductor is electrically connected to the ultrasonic transducer, wherein 1≤M≤N, and N≥2; N=3, the three switches are respectively a first switch, a second switch and a third switch, the three inductors are respectively a first inductor, a second inductor and a third inductor, and the frequency of the output PWM signal is adjusted according to the resonant voltage and the resonant current, including: Controlling the first switch to be closed, the second switch and the third switch to be opened, and outputting a PWM signal in a first frequency range, and controlling the frequency of the PWM signal to increase with a first step length, so as to obtain a first resonant voltage and a first resonant current of the ultrasonic transducer in real time; When the first condition is met, it is determined that the resonant frequency of the ultrasonic transducer is within a first sub-frequency range, and the first sub-frequency range is expressed as Q+A×P~Q+(A+1)×P, wherein Q represents the minimum value of the first frequency range, A is a positive integer, and P represents the first step length, and the first condition is that the first resonant voltage is greater than a first voltage threshold, and the first resonant current is greater than a first current threshold; When the first condition is not met, the second switch is controlled to be closed, the first switch and the third switch are controlled to be opened, and the frequency of the PWM signal is adjusted.

2. The device according to claim 1, characterized in that The boost unit comprises: An H-bridge driving unit having an input end and an output end, wherein the input end of the H-bridge driving unit is electrically connected to the output end of the signal modulation unit; An H-bridge having an input end and an output end, wherein the input end of the H-bridge is electrically connected to the output end of the H-bridge driving unit; The transformer has a primary coil and a secondary coil, wherein the primary coil of the transformer is electrically connected to the H bridge, and the secondary coil of the transformer is electrically connected to the resonant network unit.

3. The device according to claim 2, characterized in that The H-bridge includes a first MOS tube, a second MOS tube, a third MOS tube and a fourth MOS tube, a gate of the first MOS tube is electrically connected to the first output end of the H-bridge driving unit, a gate of the second MOS tube is electrically connected to the second output end of the H-bridge driving unit, a gate of the third MOS tube is electrically connected to the third output end of the H-bridge driving unit, a gate of the fourth MOS tube is electrically connected to the fourth output end of the H-bridge driving unit, a drain of the first MOS tube and a drain of the fourth MOS tube are electrically connected to a power supply end respectively, a source of the first MOS tube is electrically connected to the drain of the second MOS tube, a source of the fourth MOS tube is electrically connected to the drain of the third MOS tube, a source of the second MOS tube and a source of the third MOS tube are grounded, a like-name end of the primary coil of the transformer is electrically connected to the drain of the third MOS tube, and is electrically connected to a first upper bridge arm reference floating end of the H-bridge driving unit; an opposite-name end of the primary coil of the transformer is electrically connected to the drain of the second MOS tube, and is electrically connected to a second upper bridge arm reference floating end of the H-bridge driving unit.

4. The device according to any one of claims 1 to 3, characterized in that The resonant voltage detection unit includes a first resistance module, a second resistance module, a third resistance module, a first diode, a first electrolytic capacitor module and a first capacitor module, the first end of the first resistance module is electrically connected to the first end of the ultrasonic transducer, the second end of the first resistance module is electrically connected to the first end of the second resistance module and the positive electrode of the first diode respectively, the second end of the second resistance module is grounded, the negative electrode of the first diode is electrically connected to the first end of the third resistance module, the first end of the first electrolytic capacitor module and the first end of the first capacitor module are electrically connected to the second end of the third resistance module respectively, and the second end of the first electrolytic capacitor module and the second end of the first capacitor module are grounded.

5. The device according to any one of claims 1 to 3, characterized in that The resonant current detection unit includes a fourth resistor module, a fifth resistor module, a second diode, a second electrolytic capacitor module and a second capacitor module. The first end of the fourth resistor module is grounded, the second end of the fourth resistor module is electrically connected to the second end of the ultrasonic transducer and the positive electrode of the second diode, respectively, the negative electrode of the second diode is electrically connected to the first end of the fifth resistor module, the second end of the fifth resistor module is electrically connected to the first end of the second electrolytic capacitor module and the first end of the second capacitor module, respectively, and the second end of the second electrolytic capacitor module and the second end of the second capacitor module are grounded.

6. The device according to claim 1, characterized in that When the first condition is not met, controlling the second switch to be closed, the first switch and the third switch to be opened, and adjusting the frequency of the PWM signal includes: Outputting a PWM signal in a second frequency range, and controlling the frequency of the PWM signal to increase with a second step length, and acquiring a second resonant voltage and a second resonant current of the ultrasonic transducer in real time, wherein a minimum value of the second frequency range is greater than a maximum value of the first frequency range; When the second condition is met, it is determined that the resonant frequency of the ultrasonic transducer is within a second sub-frequency range, and the second sub-frequency range is expressed as R+B×S~R+(B+1)×S, wherein R represents the minimum value of the second frequency range, M is a positive integer, S represents the second step size, and the second condition is that the second resonant voltage is greater than a second voltage threshold, and the second resonant current is greater than a second current threshold; When the second condition is not met, the third switch is controlled to be closed, the first switch and the second switch are opened, and the frequency of the PWM signal is adjusted again.

7. The device according to claim 6, characterized in that When the second condition is not met, controlling the third switch to be closed, the first switch and the second switch to be opened, and adjusting the frequency of the PWM signal again, comprises: Output a PWM signal in a third frequency range, and control the frequency of the PWM signal to increase with a third step length, and detect a third resonant voltage and a third resonant current of the ultrasonic transducer in real time, wherein the minimum value of the third frequency range is greater than the maximum value of the second frequency range; when a third condition is met, determine that the resonant frequency of the ultrasonic transducer is within a third sub-frequency range, and the third sub-frequency range is expressed as U+W×V~U+(W +1)×V, wherein U represents the minimum value of the third frequency range, W is a positive integer, V represents a third step length, and the third condition is that the third resonant voltage is greater than a third voltage threshold, and the third resonant current is greater than a third current threshold; If the third condition is not met, an alarm prompt message is issued.

8. The device according to claim 1, characterized in that The signal modulation unit is also used to perform the following steps: After determining that the resonant frequency of the ultrasonic transducer is within the first sub-frequency range, controlling the frequency of the PWM signal to increase with a fourth step length, and acquiring a fourth resonant current of the ultrasonic transducer in real time, wherein the fourth step length is smaller than the first step length; comparing three fourth resonant currents obtained continuously; When the fourth resonant current obtained for the second time is greater than both the fourth resonant current obtained for the first time and the fourth resonant current obtained for the third time, the frequency of the PWM signal corresponding to the fourth resonant current obtained for the second time is determined to be the resonant frequency of the ultrasonic transducer.

9. The device according to claim 8, characterized in that The signal modulation unit is also used to perform the following steps: determining whether the fourth resonant current obtained for the second time is greater than a predetermined current; If yes, the duty cycle of the PWM signal is reduced.

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