Ultrasonic cleaning machine and frequency sweeping circuit and frequency sweeping method thereof

Abstract

The invention discloses an ultrasonic cleaning machine and a frequency sweeping circuit and method thereof.The frequency sweeping circuit comprises a control unit, a first conduction unit, a second conduction unit, a sampling unit and a transformer, and the output end of the control unit is connected with the trigger end of the first conduction unit and the trigger end of the second conduction unit; the drain ends of the first conduction unit and the second conduction unit are respectively connected with a primary winding of a transformer, the source ends of the first conduction unit and the second conduction unit are respectively connected with the input end of the sampling unit, and the output end of the sampling unit is connected with the input end of the control unit; according to the frequency sweeping circuit disclosed by the invention, the control unit can change the current frequency of the primary winding of the transformer by adjusting the working states of the first conduction unit and the second conduction unit, so that the frequency output of ultrasonic waves is further influenced, and the ultrasonic cleaning machine can be automatically adjusted to the optimal frequency sweeping range according to different cleaning requirements; therefore, the cleaning efficiency and quality are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of ultrasonic cleaning, and particularly relates to an ultrasonic cleaner, a frequency sweeping circuit thereof, and a frequency sweeping method. Background Art

[0002] When operating an ultrasonic cleaner, fluctuations in the water level or replacement of the water tank may cause the offset of the optimal frequency point of the device. This offset will increase the impedance of the ultrasonic loop, thereby causing fluctuations in the ultrasonic power output; the instability of the power output directly affects the cleaning effect, and further reduces the cleaning efficiency and quality. To ensure the optimal cleaning effect, users or professionals need to regularly calibrate the device and adjust the frequency point. However, this process is inconvenient to operate and requires high professional knowledge, which undoubtedly reduces the user experience.

[0003] It can be seen that the existing technology still needs to be improved. Summary of the Invention

[0004] In view of the deficiencies of the above-mentioned prior art, the purpose of the present invention is to provide an ultrasonic cleaner, which can automatically adjust to the optimal frequency sweeping range according to different cleaning requirements through the cooperation of a control unit, a first conduction unit, and a second conduction unit, thereby improving the cleaning efficiency and quality.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions:

[0006] A frequency sweeping circuit of an ultrasonic cleaner includes a control unit, a first conduction unit, a second conduction unit, a sampling unit, and a transformer. The output end of the control unit is respectively connected to the trigger end of the first conduction unit and the trigger end of the second conduction unit. The drain end of the first conduction unit and the drain end of the second conduction unit are respectively connected to the primary winding of the transformer. The source end of the first conduction unit and the source end of the second conduction unit are respectively connected to the input end of the sampling unit. The output end of the sampling unit is connected to the input end of the control unit. The secondary winding of the transformer is used to output ultrasonic waves.

[0007] In the frequency sweeping circuit of the ultrasonic cleaner, the first conduction unit includes a first voltage dividing part and a first field effect transistor Q1. One end of the first voltage dividing part is connected to the output end of the control unit, and the other end of the first voltage dividing part is connected to the gate of the first field effect transistor Q1. The drain of the first field effect transistor Q1 is connected to the pin 1 of the primary winding of the transformer, and the source of the first field effect transistor Q1 is connected to the input end of the sampling unit.

[0008] In the frequency sweep circuit of the ultrasonic cleaner described above, the second conduction unit includes a second voltage division part and a second field effect transistor Q2. One end of the second voltage division part is connected to the output end of the control unit, the other end of the second voltage division part is connected to the gate of the second field effect transistor Q2, the drain of the second field effect transistor Q2 is connected to pin 3 of the primary winding of the transformer, and the source of the second field effect transistor Q2 is connected to the input end of the sampling unit; pin 2 of the primary winding of the transformer is used to connect the input voltage.

[0009] In the frequency sweep circuit of the ultrasonic cleaner described above, the sampling unit includes a voltage drop part and a filtering part. The input end of the voltage drop part is respectively connected to the source of the first field effect transistor Q1 and the source of the second field effect transistor Q2. The output end of the voltage drop part is connected to the input end of the filtering part, and the output end of the filtering part is connected to the input end of the control unit.

[0010] In the frequency sweep circuit of the ultrasonic cleaner described above, an oscillation part and a connector CSB are further included. The secondary winding of the transformer is connected to the connector CSB through the oscillation part, and the connector CSB is used to output ultrasonic waves.

[0011] The present invention also correspondingly provides a frequency sweep method for an ultrasonic cleaner, and the frequency sweep method is implemented based on the frequency sweep circuit described in any one of the above; the frequency sweep method includes:

[0012] Obtain the optimal ultrasonic frequency point of the device and the actual resolution of the control unit;

[0013] Confirm the frequency sweep range according to the optimal ultrasonic frequency point and the actual resolution;

[0014] Adjust the working states of the first conduction unit and the second conduction unit based on the confirmed frequency sweep range to perform frequency sweep operations;

[0015] When the preset number of frequency sweep operations is completed, confirm the pause time according to the voltage information fed back by the sampling unit;

[0016] When the frequency sweep stop time reaches the confirmed pause time, return to execute the frequency sweep operation.

[0017] In the frequency sweep method of the ultrasonic cleaner described above, the step of confirming the frequency sweep range according to the optimal ultrasonic frequency point and the actual resolution specifically includes:

[0018] Obtain the required percentage and the adjustment natural number, and confirm the start point and the end point of the frequency sweep according to the required percentage, the adjustment natural number and the optimal ultrasonic frequency point;

[0019] Decrease or increase the adjusted natural number, and integrate the adjusted natural number after the decrease or increase, the ultrasonic optimal frequency point, and the actual resolution to obtain multiple frequencies to be scanned;

[0020] Integrate the end point and start point of the frequency sweep and the multiple frequencies to be scanned to obtain the frequency sweep range.

[0021] In the frequency sweep circuit of the ultrasonic cleaner, adjusting the working states of the first conduction unit and the second conduction unit based on the confirmed frequency sweep range to perform a frequency sweep operation, specifically including:

[0022] Adopt a sequence generation algorithm to generate a frequency sweep scheme based on the end point and start point of the frequency sweep and the multiple frequencies to be scanned;

[0023] Adjust the conduction states of the first conduction unit and the second conduction unit in sequence based on the generated frequency sweep scheme to perform a frequency sweep operation, thereby adjusting the frequency of the PWM signal.

[0024] In the frequency sweep circuit of the ultrasonic cleaner, when the preset number of frequency sweep operations is completed, confirming the pause time according to the voltage information fed back by the sampling unit, specifically including:

[0025] Obtain the preset number, count the number of frequency sweep operations, and compare the counted number with the preset number;

[0026] When the comparison result indicates that the current frequency sweep operation is the last frequency sweep operation, obtain the voltage signal fed back by the sampling unit;

[0027] Obtain the resistance characteristic of the control unit, and confirm the real-time ultrasonic power according to the voltage information and the resistance characteristic;

[0028] Obtain the rated ultrasonic power, the rated pause time, and the preset time adjustment value, and compare the rated ultrasonic power with the real-time ultrasonic power;

[0029] If the real-time ultrasonic power is greater than the rated ultrasonic power, increase the rated pause time based on the preset time adjustment value to obtain the pause time;

[0030] If the real-time ultrasonic power is less than the rated ultrasonic power, reduce the rated pause time based on the preset time adjustment value to obtain the pause time;

[0031] If the real-time ultrasonic power is equal to the rated ultrasonic power, use the rated pause time as the pause time.

[0032] The present invention also correspondingly provides an ultrasonic cleaner, including a housing, a PCB board is arranged inside the housing, and the frequency sweep circuit of the ultrasonic cleaner as described in any one of the above is printed on the PCB board.

[0033] Beneficial effects:

[0034] The present invention provides a frequency sweeping circuit for an ultrasonic cleaner. By adjusting the working states of the first conduction unit and the second conduction unit, the control unit can change the current frequency of the primary winding of the transformer, thereby affecting the frequency output of the ultrasonic wave, enabling the ultrasonic cleaner to automatically adjust to the optimal frequency sweeping range according to different cleaning requirements, thereby improving the cleaning efficiency and quality; further, the control unit can also monitor the working state of the circuit in real time and perform self-regulation through the information fed back by the sampling unit to ensure the stability and reliability of the entire frequency sweeping process, and can ensure that the power of the output ultrasonic wave can meet the usage requirements. Description of the drawings

[0035] Figure 1 It is a circuit structure diagram of the first conduction unit, the second conduction unit, the sampling unit and the transformer provided by the present invention;

[0036] Figure 2 It is a circuit structure diagram of the control unit provided by the present invention;

[0037] Figure 3 It is a logic flow chart of the frequency sweeping method provided by the present invention.

[0038] Description of the main component symbols: 1 - the first conduction unit, 2 - the second conduction unit, 3 - the sampling unit, 4 - the oscillation part. Detailed implementation manners

[0039] The present invention provides an ultrasonic cleaner and its frequency sweeping circuit and frequency sweeping method. To make the purpose, technical solution and effects of the present invention clearer and more definite, the following examples are given with reference to the drawings to further elaborate the present invention in detail.

[0040] In the description of the present invention, it should be understood that terms such as "installation" and "connection" should be understood in a broad sense. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0041] Please refer to Figure 1 and Figure 2, the present invention provides a frequency sweep circuit for an ultrasonic cleaner, including a control unit, a first conduction unit 1, a second conduction unit 2, a sampling unit 3 and a transformer. The output end of the control unit is respectively connected to the trigger end of the first conduction unit 1 and the trigger end of the second conduction unit 2. The drain ends of the first conduction unit 1 and the second conduction unit 2 are respectively connected to the primary winding of the transformer. The source ends of the first conduction unit 1 and the second conduction unit 2 are respectively connected to the input end of the sampling unit 3. The output end of the sampling unit 3 is connected to the input end of the control unit. The secondary winding of the transformer is used to output ultrasonic waves.

[0042] This application discloses a frequency sweep circuit for an ultrasonic cleaner. By adjusting the working states of the first conduction unit 1 and the second conduction unit 2, the control unit can change the current frequency of the primary winding of the transformer, thereby affecting the frequency output of the ultrasonic waves, enabling the ultrasonic cleaner to automatically adjust to the optimal frequency sweep range according to different cleaning requirements, so as to improve the cleaning efficiency and quality. Further, the control unit can also monitor the working state of the circuit in real time and perform self-regulation through the information fed back by the sampling unit 3 to ensure the stability and reliability of the entire frequency sweep process, and can ensure that the power of the output ultrasonic waves can meet the usage requirements.

[0043] In this embodiment, the control unit includes a first control chip U1, and the control unit is a single-chip microcomputer.

[0044] Further, please refer to Figure 1 , the first conduction unit 1 includes a first voltage division part and a first field effect transistor Q1. One end of the first voltage division part is connected to the output end of the control unit, the other end of the first voltage division part is connected to the gate of the first field effect transistor Q1, the drain of the first field effect transistor Q1 is connected to pin 1 of the primary winding of the transformer, and the source of the first field effect transistor Q1 is connected to the input end of the sampling unit 3.

[0045] In this embodiment, the first voltage division part includes a first resistor R1 and a third resistor R3. The input end of the first resistor R1 is connected to pin 5 of the first control chip U1. The other end of the first resistor R1 is respectively connected to one end of the third resistor R3 and the gate of the first field effect transistor Q1. The other end of the third resistor R3 is grounded. By setting the first voltage division part, the stability of the first field effect transistor Q1 switching between the on and off states is ensured, and the reliability of the output PWM signal is improved.

[0046] Further, please refer to Figure 1, the second conduction unit 2 includes a second voltage division part and a second field effect transistor Q2. One end of the second voltage division part is connected to the output end of the control unit, the other end of the second voltage division part is connected to the gate of the second field effect transistor Q2, the drain of the second field effect transistor Q2 is connected to pin 3 of the primary winding of the transformer, and the source of the second field effect transistor Q2 is connected to the input end of the sampling unit 3; Pin 2 of the primary winding of the transformer is used to connect the input voltage.

[0047] In this embodiment, the second voltage division part includes a second resistor R2 and a fourth resistor R4. The input end of the second resistor R2 is connected to pin 4 of the first control chip U1, the other end of the second resistor R2 is respectively connected to one end of the fourth resistor R4 and the gate of the second field effect transistor Q2, and the other end of the fourth resistor R4 is grounded; By setting the second voltage division part, the stability of the second field effect transistor Q2 switching between the on and off states is ensured, and the reliability of the output PWM signal is improved.

[0048] Further, please refer to Figure 1 , the sampling unit 3 includes a voltage drop part and a filtering part. The input end of the voltage drop part is respectively connected to the source of the first field effect transistor Q1 and the source of the second field effect transistor Q2, the output end of the voltage drop part is connected to the input end of the filtering part, and the output end of the filtering part is connected to the input end of the control unit.

[0049] In this embodiment, the voltage drop part includes a fifth resistor R5, and the filtering part includes a sixth resistor R6 and a first capacitor C1. One end of the fifth resistor R5 is respectively connected to the source of the first field effect transistor Q1 and the source of the second field effect transistor Q2, the other end of the fifth resistor R5 is connected to one end of the sixth resistor R6, and the other end of the sixth resistor R6 is respectively connected to one end of the first capacitor C1 and pin 6 of the first control chip U1.

[0050] In this embodiment, the fifth resistor R5 is located at the connection point of the two windings included in the primary of the transformer and is responsible for monitoring and limiting the current flowing through these two windings; When current passes through the fifth resistor R5, a voltage drop proportional to the current magnitude will be generated, and this voltage drop is a key signal in the circuit, which reflects the current intensity in the primary winding; The voltage signal generated by the fifth resistor R5 is first further current-limited and voltage-adjusted by the sixth resistor R6, and then filtered by the first capacitor C1 to remove possible noise and fluctuations, ensuring that the voltage signal fed back to the CS terminal of the first control chip U1 becomes relatively stable, that is, a reliable reference voltage is provided.

[0051] Further, please refer to Figure 1, the frequency sweep circuit of the ultrasonic cleaner further includes an oscillation part 4 and a connector CSB. The secondary winding of the transformer is connected to the connector CSB through the oscillation part 4, and the connector CSB is used to output ultrasonic waves.

[0052] In this embodiment, the oscillation part 4 includes a first inductor L1 and a second capacitor C2. The pin 5 of the secondary winding of the transformer is connected to the pin 3 of the connector CSB through the first inductor L1, and the pin 4 of the secondary winding of the transformer is connected to the pin 1 of the connector CSB through the second capacitor C2.

[0053] Please refer to Figure 3 , the present invention also correspondingly provides a frequency sweep method for an ultrasonic cleaner, and the frequency sweep method is implemented based on the frequency sweep circuit described in any one of the above; the frequency sweep method includes:

[0054] 100. Obtain the optimal ultrasonic frequency point of the device and the actual resolution of the control unit;

[0055] In this embodiment, the optimal ultrasonic frequency point is set as A, and its unit is kHz; the optimal ultrasonic frequency point refers to the frequency point when the ultrasonic impedance is the smallest. The smaller the impedance, the greater the power. That is to say, point A is the frequency point when the power of the ultrasonic cleaner is the largest, and it can be selected through actual impedance analysis and testing; further, the resolution of the single-chip microcomputer is set as B, and the resolution of the single-chip microcomputer is determined by the performance of the single-chip microcomputer, that is, determined by the performance of the first control chip U1.

[0056] 200. Confirm the frequency sweep range according to the optimal ultrasonic frequency point and the actual resolution;

[0057] 300. Adjust the working states of the first conduction unit 1 and the second conduction unit 2 based on the confirmed frequency sweep range to perform a frequency sweep operation;

[0058] 400. When the preset number of frequency sweep operations is completed, confirm the pause time according to the voltage information fed back by the sampling unit 3;

[0059] 500. When the frequency sweep stop time reaches the confirmed pause time, return to execute the frequency sweep operation.

[0060] In this embodiment, the step 200 specifically includes:

[0061] 201. Obtain the required percentage and the adjustment natural number, and confirm the start point and the end point of the frequency sweep according to the required percentage, the adjustment natural number and the optimal ultrasonic frequency point;

[0062] In this embodiment, the adjusted natural numbers include m and n, and the adjusted natural numbers m and n can be selected through actual impedance analysis test; the required percentage is 70%, if the percentage is too low, the overall power of the ultrasonic cleaning machine is low, and the ultrasonic cleaning effect is poor; if the percentage is too high, the overall power of the ultrasonic cleaning machine is high, and the ultrasonic cleaning effect is better, but the instantaneous current is large, and the electric control board and ultrasonic waves generate large heat; the required percentage can be adjusted according to actual customer needs.

[0063] 202. Decrease or increase the adjusted natural number, integrate the decreased or increased adjusted natural number, the ultrasonic optimal frequency point and the actual resolution, and obtain a plurality of frequency points to be scanned;

[0064] 203. Integrate the end point and the starting point of the frequency sweep and a plurality of frequency points to be swept to obtain a frequency sweep range;

[0065] In this embodiment, assuming that the frequency sweep range is F, two frequency points are searched above and below the frequency of point A respectively. These two points correspond to 70% of the power of point A respectively, namely A+nB and A-mB, which will serve as the starting point and end point of the frequency sweep; then the frequency sweep range F includes a series of frequency points to be swept, such as A-mB, A-(m-1)B, A-(m-2)B...A-2B, AB, A, A+B, A+2B...A+(n-2)B, A+(n-1)B, A+nB, etc.

[0066] In this embodiment, step 300 specifically includes:

[0067] 301. Using a sequence generation algorithm, a frequency sweeping scheme is generated based on an end point and a starting point of the frequency sweeping and a plurality of frequency points to be swept;

[0068] 302. Based on the generated frequency sweeping scheme, sequentially adjust the conduction states of the first conduction unit 1 and the second conduction unit 2 to perform a frequency sweeping operation, thereby adjusting the frequency of the PWM signal;

[0069] In this embodiment, when designing a frequency sweep scheme, a sequence generation algorithm may be used to create a specific frequency sweep mode; in this mode, the frequency sweep range F is defined as a series of frequency points, which are arranged at a specific interval B, starting from A-mB and extending to A+nB; in this process, the frequency sweep is not monotonically increasing or decreasing, but can be performed back and forth, that is, after reaching A+nB, the frequency sweep can start from A-mB again, forming a reciprocating frequency sweep process, and the frequency sweep process is to rotate the frequency points to be swept within the frequency sweep range once in a short period of time, and the displayed power is the average value of the frequency sweep range; the total time of this back and forth sweep is called the on time Ton.

[0070] For the generated frequency sweep scheme, there is no strict limit on the duration of each frequency band, which can be adjusted according to actual needs. This means that some frequency bands can last for a longer time, while others may be shorter, or the duration of all frequency bands can be evenly distributed. This flexibility enables the frequency sweep scheme to adapt to different test and application requirements. In addition, the frequency sweep scheme also allows skipping certain specific frequency points. For example, the frequency sweep sequence can be {A, A + 6B... A + (n - 1)B, A + nB}. In this sequence, the frequency points from A + 2B to A + 5B are skipped and not scanned. This ability to skip specific frequency points enables the frequency sweep scheme to focus more on specific frequency bands or avoid frequency ranges that are known not to require testing. Finally, the frequency sweep scheme also supports repeated scanning of certain frequency points. For example, the frequency sweep sequence can be {A, A, A, A + B, A + B... A, A + (n - 1)B, A + nB}. In this sequence, the frequency A is scanned four times repeatedly, and the frequency A + B is scanned twice. This characteristic of repeated scanning enables the frequency sweep scheme to conduct a more in-depth analysis of the frequency points of interest.

[0071] In this embodiment, step 400 specifically includes:

[0072] 401. Obtain a preset number of times, count the number of frequency sweep operations, and compare the counted number with the preset number of times;

[0073] In this embodiment, the preset number of times can be once or multiple times.

[0074] 402. When the comparison result indicates that the current frequency sweep operation is the last frequency sweep operation, obtain the voltage signal fed back by the sampling unit 3;

[0075] 403. Obtain the resistance characteristic of the control unit, and confirm the real-time ultrasonic power according to the voltage information and the resistance characteristic;

[0076] In this embodiment, the resistance characteristic is used as the denominator, the voltage signal is used as the numerator, to calculate the real-time ultrasonic power.

[0077] 404. Obtain the rated ultrasonic power, the rated pause time, and the preset time adjustment value, and compare the rated ultrasonic power with the real-time ultrasonic power;

[0078] In this embodiment, after one or multiple consecutive frequency sweeps, it is necessary to pause for a period of time Toff. The rated pause time Toff should not be too large to maintain the continuity of the ultrasonic wave. The rated pause time is usually several hundred microseconds to several tens of milliseconds.

[0079] In this embodiment, when the real-time ultrasonic power is too high or too low, the swept frequency will still have a power that is too high or too low. Therefore, it is necessary for the U1 single-chip microcomputer to detect the voltage value at the CS terminal before the end of the swept frequency, so as to judge the magnitude of the real-time ultrasonic power. If the power is too large, increase Toff; if the power is too small, decrease Toff. In this way, the power deviation can be compensated, ensuring that the ultrasonic cleaner can maintain a stable ultrasonic power output under different load conditions, effectively improving the cleaning efficiency and quality, and at the same time extending the service life of the ultrasonic cleaner; in addition, according to different cleaning requirements, the size of Toff can be flexibly adjusted to adapt to cleaning objects of different materials and shapes.

[0080] 405. If the real-time ultrasonic power is greater than the rated ultrasonic power, increase the rated pause time based on a preset time adjustment value to obtain a pause time.

[0081] 406. If the real-time ultrasonic power is less than the rated ultrasonic power, reduce the rated pause time based on a preset time adjustment value to obtain a pause time.

[0082] 407. If the real-time ultrasonic power is equal to the rated ultrasonic power, use the rated pause time as the pause time.

[0083] In this embodiment, assume that the rated ultrasonic power is 20W, the on-time is Ton, and the pause time is Toff; when the device is full of water, the power is 20W, and when the device is half full of water, the power is too low at 15W; therefore, when the device is in the half-full water state, it is necessary to reduce the pause time, that is, the denominator of Ton / (Ton + Toff) of the on-time ratio to the total time is reduced, that is, the duty cycle is increased to increase the ultrasonic power. Conversely, increase the pause time to reduce the power, so as to realize the adjustment of the real-time ultrasonic power and ensure the cleaning effect; since the duration of Ton is determined by the swept frequency range, therefore, Toff is adjusted preferentially.

[0084] Further, when adjusting Toff, it is necessary to detect the voltage signal at the CS terminal to judge whether the real-time ultrasonic power exceeds the rated range. When it exceeds the rated value, it is necessary to control the length of the pause period Toff, that is, to control the size of the duty cycle Ton / (Ton + Toff). The duty cycle accuracy can be high or low. The higher the accuracy, the less obvious the intuitive feeling of power compensation, and the longer the adjustment time. The lower the accuracy, the more obvious the user's intuitive feeling, and the shorter the adjustment time. For example: adjusting 5% of the duty cycle of Ton / (Ton + Toff) every 500mS takes up to 10S to finish, and adjusting 20% of the duty cycle of Ton / (Ton + Toff) each time takes up to 2.5S to finish.

[0085] The present invention also correspondingly provides an ultrasonic cleaning machine, which includes a housing, a PCB board is arranged inside the housing, and a frequency sweeping circuit of the ultrasonic cleaning machine as described in any one of the above is printed on the PCB board.

[0086] It can be understood that for those of ordinary skill in the art, equivalent substitutions or changes can be made according to the technical solutions and inventive concepts of the present invention, and all such changes or substitutions should fall within the protection scope of the present invention.

Claims

1. A frequency sweeping circuit for an ultrasonic cleaning machine, characterized in that: The invention comprises a control unit, a first conduction unit, a second conduction unit, a sampling unit and a transformer, wherein the output end of the control unit is respectively connected to the trigger end of the first conduction unit and the trigger end of the second conduction unit, the drain end of the first conduction unit and the drain end of the second conduction unit are respectively connected to the primary winding of the transformer, the source end of the first conduction unit and the source end of the second conduction unit are respectively connected to the input end of the sampling unit, the output end of the sampling unit is connected to the input end of the control unit, and the secondary winding of the transformer is used to output ultrasonic waves.

2. The frequency sweeping circuit of an ultrasonic cleaning machine according to claim 1, characterized in that: The first conduction unit includes a first voltage divider and a first field effect transistor Q1, one end of the first voltage divider is connected to the output end of the control unit, the other end of the first voltage divider is connected to the gate of the first field effect transistor Q1, the drain of the first field effect transistor Q1 is connected to pin 1 of the primary winding of the transformer, and the source of the first field effect transistor Q1 is connected to the input end of the sampling unit.

3. The frequency sweeping circuit of an ultrasonic cleaning machine according to claim 2, characterized in that: The second conduction unit includes a second voltage divider and a second field effect transistor Q2, one end of the second voltage divider is connected to the output end of the control unit, the other end of the second voltage divider is connected to the gate of the second field effect transistor Q2, the drain of the second field effect transistor Q2 is connected to the pin 3 of the primary winding of the transformer, and the source of the second field effect transistor Q2 is connected to the input end of the sampling unit; pin 2 of the primary winding of the transformer is used to connect the input voltage.

4. The frequency sweeping circuit of an ultrasonic cleaning machine according to claim 3, characterized in that: The sampling unit includes a voltage drop part and a filter part, the input end of the voltage drop part is respectively connected to the source level of the first field effect transistor Q1 and the source level of the second field effect transistor Q2, the output end of the voltage drop part is connected to the input end of the filter part, and the output end of the filter part is connected to the input end of the control unit.

5. The frequency sweeping circuit of an ultrasonic cleaning machine according to claim 1, characterized in that: It also includes an oscillating part and a connector CSB, the secondary winding of the transformer is connected to the connector CSB through the oscillating part, and the connector CSB is used to output ultrasonic waves.

6. A frequency sweeping method for an ultrasonic cleaning machine, characterized in that: The frequency sweeping method is implemented based on the frequency sweeping circuit according to any one of claims 1 to 5; the frequency sweeping method comprises: Obtain the optimal ultrasonic frequency point of the device and the actual resolution of the control unit; Determine the frequency sweep range according to the ultrasonic optimal frequency point and the actual resolution; Adjusting the working states of the first conduction unit and the second conduction unit based on the confirmed frequency sweep range to perform a frequency sweep operation; When the preset number of frequency sweep operations is completed, the pause time is determined according to the voltage information fed back by the sampling unit; When the frequency sweep stop time reaches the confirmed pause time, the frequency sweep operation is returned to execution.

7. A frequency sweeping method for an ultrasonic cleaning machine according to claim 6, characterized in that: Determining the frequency sweep range according to the ultrasonic optimal frequency point and the actual resolution specifically includes: Obtaining the required percentage and the adjusted natural number, and confirming the starting point and the end point of the frequency sweep according to the required percentage, the adjusted natural number and the ultrasonic optimal frequency point; Decreasing or increasing the adjusted natural number, integrating the decreased or increased adjusted natural number, the ultrasonic optimal frequency point and the actual resolution, to obtain a plurality of frequency points to be scanned; The end point and the start point of the frequency sweep and a plurality of frequency points to be swept are integrated to obtain a frequency sweep range.

8. A frequency sweeping method for an ultrasonic cleaning machine according to claim 7, characterized in that: The step of adjusting the working states of the first conduction unit and the second conduction unit based on the confirmed frequency sweep range to perform the frequency sweep operation specifically includes: A sequence generation algorithm is used to generate a frequency sweeping scheme based on the end point and the starting point of the frequency sweeping and a plurality of frequency points to be swept; The conduction states of the first conduction unit and the second conduction unit are adjusted in sequence based on the generated sweep frequency scheme to perform a sweep frequency operation, thereby adjusting the frequency of the PWM signal.

9. The frequency sweeping method of an ultrasonic cleaning machine according to claim 6, characterized in that: When the preset number of frequency sweep operations are completed, the pause time is determined according to the voltage information fed back by the sampling unit, specifically including: Obtaining a preset number of times, counting the number of frequency sweep operations, and comparing the counted number of times with the preset number of times; When the comparison result indicates that the current frequency sweep operation is the last frequency sweep operation, a voltage signal fed back by the sampling unit is obtained; Acquire the resistance characteristic of the control unit, and confirm the real-time ultrasonic power according to the voltage information and the resistance characteristic; Acquire the ultrasonic rated power, the rated pause time and the preset time adjustment value, and compare the ultrasonic rated power with the real-time ultrasonic power; If the real-time ultrasonic power is greater than the ultrasonic rated power, the rated pause time is increased based on a preset time adjustment value to obtain a pause time; If the real-time ultrasonic power is less than the ultrasonic rated power, the rated pause time is reduced based on a preset time adjustment value to obtain a pause time; If the real-time ultrasonic power is equal to the ultrasonic rated power, the rated pause time is used as the pause time.

10. An ultrasonic cleaning machine, characterized in that: It comprises a shell, a PCB board is arranged in the shell, and the PCB board is printed with the sweeping frequency circuit of the ultrasonic cleaning machine according to any one of claims 1 to 5.

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