Programmable linear bipolar high-voltage ultrasonic device

Abstract

The invention provides a programmable linear bipolar high-voltage ultrasonic driving device which comprises a ZYNQ and DAC driving module used for executing analog signal output for converting digital quantity into analog quantity according to a waveform file; wherein the ZYNQ module executes data reading according to a waveform file and sends a data port to the DAC driving module; the method further comprises the steps of generating a time-sharing switching signal; the DAC driving module is used for converting the digital quantity voltage value into analog waveform voltage and outputting the analog waveform voltage; the DAC driving module converts a digital signal into an analog electric signal, and the passive low-pass filtering unit performs signal filtering to obtain sine wave output; and the bipolar linear power amplification module is used for converting the analog waveform voltage into ultrasonic high voltage according to the analog waveform voltage. The problems that the service life of an energy converter is affected and the energy converter is easily damaged due to the fact that rectangular pulse square waves can generate large resonance current under abrupt-change high voltage, main lobes and side lobes of echo signals are difficult to distinguish, and the position of a head wave is difficult to judge are solved.

Description

Technical Field

[0001] The invention belongs to the field of ultrasonic high voltage, and in particular relates to a programmable linear bipolar high voltage ultrasonic driving device. Background Art

[0002] The ultrasonic transducer driving circuit in the prior art CN202311354223.3 is designed with a more traditional driving solution, which cannot be applied to geological or concrete flaw detectors with voltages up to 1000V. The driving form is single, and it is impossible to customize the commonly used waveforms, such as sine waves, triangle waves, etc., and it is impossible to linearly amplify the amplitude. It can only simply transmit full-amplitude rectangular pulse waves. Rectangular pulse waves and square waves will generate large resonant currents under sudden high voltages, affecting the service life of the transducer and making it easy to be damaged. In addition, the side lobes of the echo signal are difficult to distinguish from the main lobes, affecting its first wave determination. Summary of the invention

[0003] The purpose of this embodiment is to provide a programmable linear bipolar high-voltage ultrasonic device to solve the problem that rectangular pulse waves and square waves will generate large resonant currents under sudden high voltages, affecting the service life of the transducer and making it easy to be damaged, and to weaken the trailing side lobes of the echo signal from the transmission source, thereby greatly reducing the probability of misjudgment of the first wave.

[0004] A programmable linear bipolar high-voltage ultrasonic device, comprising:

[0005] ZYNQ and DAC driver module: used to convert digital quantity into analog quantity according to waveform file and output analog signal; wherein the ZYNQ module performs data reading and sends data port to DAC driver module according to waveform file; and also includes generating time-sharing switch signal, wherein the time-sharing switch signal includes PULSE1 pulse signal and PULSE2 pulse signal, wherein the PULSE1 pulse signal is the positive half-cycle pulse signal of the analog waveform, and the PULSE2 pulse signal is the negative half-cycle pulse signal of the analog waveform; the DAC driver module is used to convert digital quantity voltage value into analog waveform voltage output, wherein the analog waveform voltage is ultrasonic waveform voltage, wherein the ultrasonic waveform is a sine wave; the DAC driver module performs digital signal conversion into analog electrical signal and the passive low-pass filter unit performs signal filtering to obtain sine wave output;

[0006] Bipolar linear power amplifier module: used for converting the analog waveform voltage into ultrasonic high voltage; including;

[0007] Time-sharing switch module: used to perform time-sharing conduction according to the positive half cycle and negative half cycle of the analog waveform voltage, divided into a positive half cycle switch circuit and a negative half cycle switch circuit. If the positive half cycle passes through zero, the positive half cycle switch is turned on, and if the negative half cycle passes through zero, the negative half cycle switch is turned on;

[0008] Medium voltage amplification module: used to execute the medium voltage to high voltage instruction; including a medium voltage operational amplifier circuit and a constant current source circuit;

[0009] Power output module: used to execute the high-voltage to ultrasonic transducer instruction; wherein the ultrasonic transducer includes U9 executing high-voltage output of the ultrasonic positive half cycle, and U14 executing high-voltage output of the ultrasonic negative half cycle;

[0010] Impedance matching module: used for performing impedance matching between the output high voltage and the ultrasonic transducer to ensure that the optimal high voltage obtains a resonant output with the ultrasonic transducer, wherein the resonance includes LC resonance, the LC resonance includes parallel resonance and series resonance, wherein L is an inductor, wherein C includes C33 and CX, wherein CX is an ultrasonic transducer, and the L includes L6 and L9, wherein the L6 is connected in series with the ultrasonic transducer CX and C33 to form a series resonance circuit, and the L9 is connected in parallel with the series resonance circuit to form a parallel resonance;

[0011] High voltage generator module: used to generate the extremely high voltage required by the ultrasonic transducer.

[0012] Furthermore, the ZYNQ and DAC driving module also includes a first signal amplification unit and a second signal amplification unit for performing two-stage amplification of the analog waveform voltage; the first signal amplification unit executes a differential to single-ended instruction, and the second signal amplification unit executes a low voltage to medium voltage instruction.

[0013] Furthermore, the ultrasonic transducer has two feed terminals and one common ground terminal.

[0014] Furthermore, the positive half-cycle and negative half-cycle switching circuits are preferably full-bridge low-side drive circuits, including the UCC53XX series.

[0015] Furthermore, the medium-voltage operational amplifier circuit includes a positive half-cycle medium-voltage amplifier circuit composed of U10.1, Q7, R9, and R8, and a negative half-cycle medium-voltage amplifier circuit composed of U10.2, Q11, R10, and R11, wherein the first pin of R9 or R10 is connected to the first feed source or the second feed source of the ultrasonic transducer, the second pin of R9 or R10 is connected to the same-direction input end of U10.1 or U10.2, the first pin of R8 or R11 is connected to the same-direction input end of U10.1 or U10.2, and the second pin of R8 or R11 is grounded, wherein the third pin of the ultrasonic transducer is connected to the first pin end of R14, and the second pin of R14 is connected to the output end of the full-bridge low-side drive circuit.

[0016] Furthermore, the gain formula of the medium voltage amplifier circuit in the positive half cycle is:

[0017] Au=(R9+R8) / R8; wherein Au is the amplification factor.

[0018] Furthermore, the gain formula of the negative half-cycle medium voltage amplifier circuit is:

[0019] Au=(R10+R11) / R11; wherein Au is the amplification factor.

[0020] Furthermore, the high voltage generator module comprises:

[0021] A DC boost module is used to convert the battery or power adapter into a DC high voltage;

[0022] Voltage doubler module: used to generate extremely high voltage output through voltage doubler circuit based on boost circuit and complementary drive signal;

[0023] High-voltage comparison module: used for adjusting the duty cycle of the PWM module signal to execute the output high-voltage voltage-limiting output, so as to ensure that the output high voltage is the design indicator voltage.

[0024] Further, the high voltage boosting circuit including the TL494 series PWM standard circuit and Q13, Q14, Q15, L12, C13, and C14 is converted into a DC high voltage according to the battery or power adapter;

[0025] The voltage boost formula of the PWM standard circuit includes:

[0026] VCC=VCC_IN*(T on +T off ) / T off ; Where VCC is the output voltage, VCC_I N is the input voltage, T on 、T off is the on-time and off-time of the switch tube.

[0027] Furthermore, the voltage doubling module includes a voltage doubling circuit composed of a capacitor, a diode and a transformer, and the calculation formula of the voltage doubling circuit is:

[0028] HV_OUT=K·Vs; wherein K is the number of stack levels of capacitors and diodes in series; Vs is the voltage after the transformer is stepped up; wherein Vs=N·Vp; wherein Vp is the primary voltage of the transformer, wherein N is the transformer turns ratio, and HV_OUT is the extremely high voltage.

[0029] The programmable linear bipolar high-voltage ultrasonic device provided by the present invention solves the problem that rectangular pulse waves and square waves will generate a large resonant current under a sudden high voltage, which will affect the service life of the transducer and make it easy to be damaged.

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 : A device structure diagram of a programmable linear bipolar high-pressure ultrasonic device provided in an embodiment of the present invention;

[0032] Figure 2 : A device working flow diagram of a programmable linear bipolar high-pressure ultrasonic device provided by an embodiment of the present invention;

[0033] Figure 3 : A DAC driving circuit diagram of a programmable linear bipolar high-voltage ultrasonic device provided in an embodiment of the present invention;

[0034] Figure 4 : A bipolar linear power amplifier circuit diagram of a programmable linear bipolar high-voltage ultrasonic device provided by an embodiment of the present invention;

[0035] Figure 5 : A waveform driving schematic diagram of a programmable linear bipolar high-voltage ultrasonic device provided in an embodiment of the present invention;

[0036] Figure 6 : An impedance matching circuit diagram of a programmable linear bipolar high-voltage ultrasonic device provided by an embodiment of the present invention;

[0037] Figure 7 : A block diagram of a high voltage generator circuit of a programmable linear bipolar high voltage ultrasonic device provided in an embodiment of the present invention;

[0038] Figure 8 : A DC boost circuit diagram of a programmable linear bipolar high-voltage ultrasonic device provided in an embodiment of the present invention;

[0039] Fig. 9 : A complementary driving circuit diagram of a programmable linear bipolar high-voltage ultrasonic device provided by an embodiment of the present invention;

[0040] Fig.10 : A transformer and voltage doubling circuit diagram of a programmable linear bipolar high-voltage ultrasonic device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present invention will be described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0042] ZYNQ and DAC driver module: used to convert digital quantity into analog quantity according to waveform file and output analog signal (see Figure 3); the ZYNQ module performs data reading according to the waveform file and sends the data port to the DAC driver module; and also includes generating a time-sharing switch signal, wherein the time-sharing switch signal includes a PULSE1 pulse signal and a PULSE2 pulse signal, wherein the PULSE1 pulse signal is a positive half-cycle pulse signal of an analog waveform, and the PULSE2 pulse signal is a negative half-cycle pulse signal of an analog waveform; the DAC driver module is used to convert the digital voltage value into an analog waveform voltage output, wherein the analog waveform voltage is an ultrasonic waveform voltage, wherein the ultrasonic waveform is a sine wave;

[0043] In the figure, DAB[7:0] is connected to ZYNQ, and the digital signal transmitted by ZYNQ is driven by the AD9708 chip. The REFIO port is grounded after passing through a small capacitor, and the voltage generated inside the chip is used as the reference voltage of the chip. The noise reduction port COMP1 is grounded after passing through a small capacitor, which effectively improves the chip's anti-noise ability. The two current output ports IOUTA and IOUTB output the analog signals generated by the chip digital signal conversion. Since AD9708 is a current output DAC, it directly provides current output. The analog signal required by this device is in voltage form, so the conversion from output current to voltage is completed by connecting the load resistors R43 and R44 to the output terminal. C23, C24, L5, and L7 form an LC passive low-pass filter network through capacitors and inductors to perform filtering according to the signal output by AD9708 to ensure that the output signal is a pure sine wave with a center cutoff frequency of approximately 10MHZ. The DAC output amplifier circuit includes a 2-channel LMH6643 chip, which implements the following functions: the first channel is used to convert the differential signal output by the filter circuit into a single-ended signal, and the second channel is used to increase the signal peak value to 15V. Figure 3 Among them, PULSE1 and PULSE2 are time-sharing pulse switch signals, which are used to output the positive and negative half-cycle pulses of the analog waveform in a time-sharing manner. PULSE1 outputs the positive half-cycle pulse of the analog waveform, and PULSE2 outputs the negative half-cycle pulse of the analog waveform.

[0044] Bipolar linear power amplifier module (see Figure 4): used to convert the analog waveform voltage into ultrasonic high voltage, the circuit includes medium voltage amplification, power amplification, feedback, bias, and time-sharing switch parts. In this embodiment, the left and right parts of the circuit have the same function, and the left part of the circuit is used for explanation: voltage amplification is realized by the high-voltage power transistor Q7. The power amplification part is composed of the power MOS tube MD3N150. The front input end of the circuit adopts a voltage series feedback structure composed of the operational amplifier chip U10.1, R9, and R8. The output voltage OUT_2 is divided and fed back to the positive input end of the U10.1 high-speed operational amplifier chip through resistors R9 and R8. The voltage gain of the entire circuit is determined by the resistance values ​​of the two resistors R9 and R8, and the voltage gain Au=(R9+R8) / R8 is used to perform 15V voltage amplification. The current source is composed of resistors R27, R28, R29 and the high-voltage transistor U8, providing a static constant current of about several mA. This constant current source provides a relatively ideal collector load for the voltage amplifier tube Q7, so that the loop voltage gain is very high. R30, R31 and transistor Q9 form the gate bias circuit of power MOS tube U9. By changing the resistance value of RP3, the voltage difference between the collector and emitter of Q9 is adjusted, that is, the gate turn-on voltage of MOS tube U9 is adjusted. U6 is the gate driver, responsible for driving U7 to drive the full bridge oppositely.

[0045] Bipolar linear power amplifier module: used to convert the analog waveform voltage into ultrasonic high voltage (see Figure 4 );include;

[0046] Time-sharing switch module: used to perform time-sharing conduction according to the positive half-cycle and negative half-cycle of the analog waveform voltage, divided into a positive half-cycle switch circuit and a negative half-cycle switch circuit. If the voltage of the loaded signal passes through zero, the positive half-cycle switch is turned on, and if the voltage of the loaded signal is less than zero, the negative half-cycle switch is turned on; in the figure, the PULSE1 and PULSE2 signals are provided by the IO pin of ZYNQ, and the time-sharing control of the positive half-cycle and negative half-cycle of the analog waveform is provided by U6 and U15 to perform the time-sharing switch function. U6 controls the conduction of the positive half-cycle, and U15 provides the conduction of the negative half-cycle of the analog waveform. U6 and U15 are the same circuits and have the same functions. They are all full-bridge low-side drive control switches. When the voltage of the loaded signal passes through zero, PULSE1 outputs a high level and PULSE2 outputs a low level. U6 controls U7 to turn on and conduct. When the voltage of the loaded signal is less than zero, PULSE1 outputs a low level and PULSE2 outputs a high level. U15 controls U16 to turn on and conduct. Figure 4It can be seen that OUT_1 and OUT_2 are complementary high-voltage signals; PULSE1 and PULSE2 are the driving levels of MOS tubes U7 and U16, high level turns on and low level turns off; Vsyth is the voltage waveform at both ends of the transducer. In the first half of the cycle, U7 is turned on and U16 is turned off, and OUT_1 output by the amplifier circuit acts on the transducer in a positive direction; in the second half of the cycle, U16 is turned on and U7 is turned off, and OUT_2 output by the amplifier circuit acts on the transducer in a negative direction. The voltage waveform at both ends of the transducer in one cycle is shown as Vsyth;

[0047] PULSE1 and PULSE2 control full-bridge low-side drive start timing see Figure 5 . Among them, OUT_1 is the voltage waveform output by the unipolar power amplifier 1 on the right, and OUT_2 is the voltage waveform output by the unipolar power amplifier 2 on the left. The waveform driving timing is as follows: The bipolar driving waveform generated by matlab is processed by ZYNQ to flip the negative half-cycle waveform to above 0V. The flipped waveform is processed by the ADC driver and the buffer amplifier and injected into the input terminals DAC_OUT of the two unipolar power amplifiers at the same time. ZYNQ, based on the matlab waveform data, enables PULSE1 to be high level and then turns on the low-side MOS driver 1 corresponding to the unipolar power amplifier 1 when the waveform data is in the range of t0 to t1, that is, greater than the 0V baseline. At this time, U7 is turned on and U16 is turned off, so that the bridge arm 1 forms a path and outputs the positive half cycle of the amplified waveform. Similarly, when the waveform data of MATLAB is in the range of t1~t2, that is, less than the 0V baseline, PULSE2 is enabled to be high level and then the low-side MOS driver 2 corresponding to the unipolar power amplifier 2 is turned on. At this time, U16 is turned on and U7 is turned off to make the bridge arm 2 form a path to output the negative half cycle of the amplified waveform. Finally, the voltage waveform formed at both ends of the transducer in one cycle is shown as Vsyth.

[0048] Medium voltage amplification module: used to execute the medium voltage to high voltage instruction; includes a medium voltage operational amplifier circuit and a constant current source circuit; in this embodiment, the functions of the left and right parts of the circuit are the same, and the left part of the circuit is used for explanation: voltage amplification is achieved by the high voltage resistant power transistor Q7. Voltage gain Au = (R9 + R8) / R8 is used to perform 15V voltage amplification. The current source is composed of resistors R27, R28, R29 and a high voltage resistant transistor U8, providing a static constant current of about several mA. This constant current source provides a relatively ideal collector load for the voltage amplifier Q7, making the loop voltage gain very high. Figure 4The operational amplifier circuit includes a positive half-cycle medium-voltage amplifier circuit composed of U10.1, Q7, R9, and R8, and a negative half-cycle medium-voltage amplifier circuit composed of U10.2, Q11, R10, and R11, wherein the first pin of R9 or R10 is connected to the first feed source or the second feed source of the ultrasonic transducer, the second pin of R9 or R10 is connected to the same-direction input end of U10.1 or U10.2, the first pin of R8 or R11 is connected to the same-direction input end of U10.1 or U10.2, and the second pin of R8 or R11 is grounded, wherein the third pin of the ultrasonic transducer is connected to the first pin end of R14, and the second pin of R14 is connected to the output end of the full-bridge low-side drive circuit. The full-bridge low-side drive circuit is composed of two full-bridge bridge arm low-end drive standard circuits composed of U6 and U7 or U15 and U16 respectively, and the chip model is UCC5350MCDR.

[0049] Power output module: used to execute the high voltage to ultrasonic transducer instruction; wherein the ultrasonic transducer includes U9 executing high voltage output of the ultrasonic positive half cycle, and U14 executing high voltage output of the ultrasonic negative half cycle; in the embodiment Figure 4 The power amplifier part in the circuit is composed of the power MOS tube MD3N150. The circuit front input adopts a voltage series feedback structure composed of the operational amplifier chip U10.1, R9, and R8. The output voltage OUT_2 is divided and fed back to the positive input terminal of the U10.1 high-speed operational amplifier chip through resistors R9 and R8. The voltage gain of the entire circuit is determined by the resistance values ​​of the two resistors R9 and R8. R30, R31 and transistor Q9 form the gate bias circuit of the power MOS tube U9. By changing the resistance value of RP3 to adjust the voltage difference between the collector and the emitter of Q9, the gate turn-on voltage of the MOS tube U9 is adjusted.

[0050] Impedance matching module (see Figure 6 ): used for performing impedance matching between the output high voltage and the ultrasonic transducer to ensure that the optimal high voltage obtains a resonant output with the ultrasonic transducer. In this embodiment, the ultrasonic transducer is two feed ends and one common ground end, wherein the resonance includes LC resonance, and the LC resonance includes parallel resonance and series resonance, wherein L is an inductor, wherein C includes C33 and CX, wherein CX is an ultrasonic transducer, and the L includes L6 and L9, wherein the L6 is connected in series with the ultrasonic transducer CX and C33 to form a series resonance circuit, and the L9 is connected in parallel with the series resonance circuit to form a parallel resonance;

[0051] In this embodiment, the ultrasonic transducer is a key component of the high-voltage transmitting circuit, which is related to whether a good echo signal can be obtained. The equivalent model analysis of the transducer shows that no matter it works at the series resonant frequency or the parallel resonant frequency, the transducer is capacitive to the outside. Therefore, an impedance matching circuit is required to make the transducer present a pure resistance to the excitation circuit, reduce the reactive power consumption in the circuit, and improve the electro-acoustic conversion efficiency. Theoretical analysis shows that the impedance of the transducer is the smallest when it is at the series resonant frequency. Therefore, this circuit is designed based on the series resonant equivalent circuit of the transducer. x , R x are the equivalent capacitance and resistance of the transducer, which can be measured by the instrument. L6, L9 and C33 are external power passive components.

[0052] High voltage generator module: used to generate the extremely high voltage required by the ultrasonic transducer; Figure 7 This is the block diagram of the high voltage generator, including:

[0053] The DC boost module is used when the battery (voltage range 16 ~ 28V) or adapter (stable input 24V) is used as the input power source. The circuit adjusts the input voltage at the front end of the transformer by pulse width modulation boosting according to the data changes of the sampled voltage to keep it constant.

[0054] In this embodiment, the DC boost module is composed of a pulse width modulation component, which is a voltage type pulse width modulation chip TL494 produced by TI. Figure 8 The figure shows the schematic diagram of the DC boost circuit, which works as follows:

[0055] Pin 1 of TL494 is connected to the HV_OUT voltage output by the transformer and voltage doubler module through the voltage divider point of resistors R64 and R17 to feedback and adjust the voltage pulse width output by the chip, and indirectly control the output voltage. VrefA is connected to pins 2 and 3 after voltage division by resistors R74 and R75, and the reference level of the inverting end of the control comparator is established. Pin 3 is connected to the voltage after voltage division by resistors R73 and R72, and its main function is to change the gain of the error. Pin 4 is connected to VrefA after voltage division by resistors to establish the level of the DTC pin. Pins 5 and 6 are connected to the internal oscillator, and RP7 and C38 are connected externally. The oscillation frequency required by the device is selected by adjusting RP7. Pin 7 is the GND terminal. Pins 8 and 11 are the collectors of the connected subsequent circuits. Pins 9 and 10 are connected as the emitters of the subsequent circuits. Pin 12 is VCC_12, which is the chip operating voltage. When working normally, the reference voltage VrefA is generated externally through pin 14. Pin 13 is the GND terminal. Pin 15 can establish a reference level after the voltage is divided by VrefA, and is the inverting terminal of the comparator. Pin 16 is grounded through resistor R71 and is the positive terminal of the comparator. VCC_I N is the input voltage of the device, VCC is the output voltage generated by the DC boost circuit, and VCC_12V is the 12V power supply generated after the input power supply VCC_IN is stepped down, which supplies power to the chip. This boost circuit uses Boost for DC-DC conversion, and controls the output voltage by adjusting the duty cycle of the switch tube Q15. The switch tube is turned off and on alternately, and the inductor L12 will alternately store and release energy. After the inductor L12 stores energy, the voltage rises. The capacitor C keeps the output voltage balanced, and the output-input voltage relationship is: VCC=VCC_I N*(Ton+Toff) / Toff, where VCC is the output voltage, VCC_I N is the input voltage, Ton and Toff are the switch tube on and off time, and the PWM duty cycle is automatically adjusted by the internal voltage comparator pin 1 of TL494 according to the output voltage.

[0056] Complementary driving module: In this embodiment, two half-bridge structures are used, and two front-stage driving chips respectively generate driving signals for the half-bridge structures;

[0057] In this embodiment, the complementary driving module is a complementary driving unit circuit (see Fig. 9 ), the complementary PWM wave signal generated by ZYNQ is transmitted to the PWM_Pi n and PWM_Ni n pins, and after being driven and amplified by the IR4427 gate driver chip, the complementary signals PWM_M and PWM_N after driving and amplification are generated by controlling the MOSFET field effect tubes Q1 and Q2, which are used for the primary side signal input of the high voltage circuit transformer (see Fig.10), R1 and R2 are current limiting resistors to protect the IO port of ZYNQ, and R3, R4, R6, and R7 are pull-down resistors to ensure that ZYNQ has a certain level when the device is unstable to prevent malfunction.

[0058] Voltage doubler module: used to generate extremely high voltage output through voltage doubler circuit based on boost circuit and complementary drive signal.

[0059] In this embodiment, the voltage doubling module is composed of a voltage doubling circuit (see 10) composed of a capacitor, a diode and a transformer. After obtaining the constant voltage output of the DC boost circuit and the complementary PWM drive signal, the boost circuit is required to output a voltage of about 1000V. The implementation principle is to use a transformer to boost the voltage and use capacitors and diodes to rectify and double the voltage.

[0060] In the figure, PWM_P and PWM_N are the signals after the complementary PWM wave is output and driven by the half-bridge control circuit (see Fig. 9 ), VCC is the controllable constant voltage generated by the boost circuit, HV_OUT is the 1kV high voltage signal output terminal after voltage doubling, which is used to energize the energy storage capacitor, L4 is a transformer, the left side is the primary side, the primary side voltage is Vp, and the right side is the secondary side, the voltage is Vs.

[0061] The principle of this circuit is as follows:

[0062] Assuming that the transformer turns ratio is N, the voltage after the transformer boost is Vs=N·Vp, then the output voltage HV_OUT=K·Vs=K·N·Vp, where K is the number of stack levels of the series combination of capacitors and diodes.

[0063] Assuming that a positive voltage is generated on the lower side of the transformer after boosting, C5 will be charged to Vs due to the conduction of D6, forming a DC input type rectification. After the complementary PWM wave is commutated, a positive voltage is generated on the upper side of the transformer after boosting, so C8 is charged, and its voltage is the superposition of C5 voltage and the positive voltage of the transformer. At this time, the terminal voltage is 2Vs. Then the complementary PWM wave continues to commutate, and a positive voltage is generated on the lower side of the transformer after boosting, and C4 begins to be charged. However, at this time, since the voltage on the lower side of the transformer is Vs, the voltage of C8 is 2Vs, and the voltage of C5 is Vs, Kirchhoff's law shows that the voltage of C4 is 2Vs. The above process is cyclically operated, so that only the voltage of capacitor C5 is Vs, and the others are all 2Vs. The final discharge voltage is 6Vs.

[0064] The programmable linear bipolar high-voltage ultrasonic device provided by the present invention solves the problem that rectangular pulse waves and square waves will generate a large resonant current under a sudden high voltage, which will affect the service life of the transducer and make it easy to be damaged.

[0065] The above description is only an embodiment of the present invention and is not intended to limit the scope of protection of the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A programmable linear bipolar high-voltage ultrasonic device, characterized in that: include: ZYNQ and DAC driver module: used to convert digital quantity into analog quantity according to waveform file and output analog signal; The ZYNQ module performs data reading and sends the data port to the DAC driver module according to the waveform file; and also includes generating a time-sharing switch signal, wherein the time-sharing switch signal includes a PULSE1 pulse signal and a PULSE2 pulse signal, wherein the PULSE1 pulse signal is the positive half-cycle pulse signal of the analog waveform, and the PULSE2 pulse signal is the negative half-cycle pulse signal of the analog waveform; the DAC driver module is used to convert the digital quantity voltage value into an analog waveform voltage output, wherein the analog waveform voltage is an ultrasonic waveform voltage, wherein the ultrasonic waveform is a sine wave; the DAC driver module performs digital signal conversion into an analog electrical signal and the passive low-pass filter unit performs signal filtering to obtain a sine wave output; Bipolar linear power amplifier module: used for converting the analog waveform voltage into ultrasonic high voltage; include; Time-sharing switch module: used to perform time-sharing conduction according to the positive half cycle and negative half cycle of the analog waveform voltage, divided into a positive half cycle switch circuit and a negative half cycle switch circuit. If the positive half cycle passes through zero, the positive half cycle switch is turned on, and if the negative half cycle passes through zero, the negative half cycle switch is turned on; Medium voltage amplification module: used to execute the medium voltage to high voltage instruction; including a medium voltage operational amplifier circuit and a constant current source circuit; Power output module: used to execute the high-voltage to ultrasonic transducer instruction; wherein the ultrasonic transducer includes U9 executing high-voltage output of the ultrasonic positive half cycle, and U14 executing high-voltage output of the ultrasonic negative half cycle; Impedance matching module: used for performing impedance matching between the output high voltage and the ultrasonic transducer to ensure that the optimal high voltage obtains a resonant output with the ultrasonic transducer, wherein the resonance includes LC resonance, the LC resonance includes parallel resonance and series resonance, wherein L is an inductor, wherein C includes C33 and CX, wherein CX is an ultrasonic transducer, and the L includes L6 and L9, wherein the L6 is connected in series with the ultrasonic transducer CX and C33 to form a series resonance circuit, and the L9 is connected in parallel with the series resonance circuit to form a parallel resonance; High voltage generator module: used to generate the extremely high voltage required by the ultrasonic transducer.

2. The programmable linear bipolar high-voltage ultrasonic device according to claim 1, characterized in that: The ZYNQ and DAC driving module also includes a first signal amplification unit and a second signal amplification unit for performing two-stage amplification of the analog waveform voltage; the first signal amplification unit executes a differential to single-ended instruction, and the second signal amplification unit executes a low voltage to medium voltage instruction.

3. The programmable linear bipolar high-voltage ultrasonic device according to claim 1, characterized in that: The ultrasonic transducer comprises two feed terminals and a common ground terminal.

4. The programmable linear bipolar high-voltage ultrasonic device according to claim 1, characterized in that: The positive half-cycle and negative half-cycle switching circuits are preferably full-bridge low-side drive circuits, including the UCC53XX series.

5. The programmable linear bipolar high-voltage ultrasonic device according to claim 1 or 4, characterized in that: The medium-voltage operational amplifier circuit includes a positive half-cycle medium-voltage amplifier circuit composed of U10.1, Q7, R9, and R8, and a negative half-cycle medium-voltage amplifier circuit composed of U10.2, Q11, R10, and R11, wherein the first pin of R9 or R10 is connected to the first feed source or the second feed source of the ultrasonic transducer, the second pin of R9 or R10 is connected to the same-direction input end of U10.1 or U10.2, the first pin of R8 or R11 is connected to the same-direction input end of U10.1 or U10.2, and the second pin of R8 or R11 is grounded, wherein the third pin of the ultrasonic transducer is connected to the first pin end of R14, and the second pin of R14 is connected to the output end of the full-bridge low-side drive circuit.

6. The programmable linear bipolar high-voltage ultrasonic device according to claim 5, characterized in that: The gain formula of the positive half-cycle medium voltage amplifier circuit is: Au=(R9+R8) / R8; wherein Au is the amplification factor.

7. The programmable linear bipolar high-voltage ultrasonic device according to claim 1, characterized in that: The gain formula of the negative half-cycle medium voltage amplifier circuit is: Au=(R10+R11) / R11; wherein Au is the amplification factor.

8. The programmable linear bipolar high-voltage ultrasonic device according to claim 1, characterized in that: The high voltage generator module comprises: A DC boost module is used to convert the battery or power adapter into a DC high voltage; Voltage doubler module: used to generate extremely high voltage output through voltage doubler circuit based on boost circuit and complementary drive signal; High-voltage comparison module: used for adjusting the duty cycle of the PWM module signal to execute the output high-voltage voltage-limiting output, so as to ensure that the output high voltage is the design indicator voltage.

9. The programmable linear bipolar high-voltage ultrasonic device according to claim 1, characterized in that: The high voltage boost circuit comprising a TL494 series PWM standard circuit and Q13, Q14, Q15, L12, C13, and C14 is converted into a DC high voltage according to the battery or power adapter; The voltage boost formula of the PWM standard circuit includes: VCC=VCC_IN*(T on +T off ) / T off ; Where VCC is the output voltage, VCC_IN is the input voltage, T on 、T off is the on-time and off-time of the switch tube.

10. The programmable linear bipolar high-voltage ultrasonic device according to claim 1, characterized in that: The voltage doubling module includes a voltage doubling circuit composed of a capacitor, a diode and a transformer. The calculation formula of the voltage doubling circuit is: HV_OUT=K·Vs; wherein K is the number of stack levels of capacitors and diodes in series; Vs is the voltage after the transformer is stepped up; wherein Vs=N·Vp; wherein Vp is the primary voltage of the transformer, wherein N is the transformer turns ratio, and HV_OUT is the extremely high voltage.

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