CN212003523U - Miniature piezoelectric pump module - Google Patents

Abstract

A micro piezoelectric pump module comprises a piezoelectric pump, a microprocessor, a driving component, a current detector and a feedback circuit; the drive component, the current detector and the feedback circuit are electrically connected between the microprocessor and the piezoelectric pump, the microprocessor drives the piezoelectric pump to operate through the drive component, and the feedback circuit and the current detector confirm the operation condition of the piezoelectric pump, so that the actuation frequency, the working voltage and the consumed power of the piezoelectric pump are adjusted.

Description

Miniature piezoelectric pump module

[ technical field ] A method for producing a semiconductor device

The present disclosure relates to a micro piezoelectric pump module, and more particularly, to a micro piezoelectric pump module capable of adjusting a working voltage and quickly determining an operating frequency thereof.

[ background of the invention ]

With the development of technology, the applications of fluid delivery devices are becoming more diversified, such as industrial applications, biomedical applications, medical care, electronic heat dissipation … …, etc., and even the image of a hot wearable device is seen recently, which means that the conventional pump tends to be miniaturized, but the size of the conventional pump is difficult to be reduced to the centimeter level, so that the conventional micro fluid delivery device can only use a piezoelectric pump structure as the micro fluid delivery device.

The piezoelectric pump applies voltage to the piezoelectric element, the piezoelectric element deforms due to piezoelectric effect, and the internal pressure of the piezoelectric element changes to drive the pump for conveying the fluid, so that the performance of the piezoelectric pump is influenced greatly by the working voltage on the piezoelectric element, but the floating and insufficient working voltage can be caused by the influence of loss, heat source and the like on the working voltage supplied to the piezoelectric element at present, and the problem that the performance of the conventional piezoelectric pump is unstable or the performance is reduced is caused.

Moreover, when the piezoelectric pump is continuously operated, since the piezoelectric element is rapidly deformed at a very high frequency, a large amount of heat energy is generated, which affects the actuation frequency of the piezoelectric element, and further affects the efficiency of the piezoelectric pump, and when the actuation frequency of the piezoelectric pump is distorted, it is necessary to confirm the actuation frequency of the piezoelectric pump again, which is time-consuming and the piezoelectric pump cannot operate at a better actuation frequency when confirming the actuation frequency, which will reduce the efficiency of the piezoelectric pump.

[ Utility model ] content

The main objective of the present disclosure is to provide a micro piezoelectric pump structure, which obtains a working voltage of a piezoelectric element through a feedback circuit and transmits the working voltage back to a microprocessor, so that the microprocessor can control the working voltage of the piezoelectric element.

To achieve the above object, a micro piezoelectric pump module according to a broader aspect of the present invention includes: a piezoelectric pump having a first electrode, a second electrode and a piezoelectric element; a microprocessor for outputting a control signal and a modulation signal; a drive assembly electrically connected between the microprocessor and the piezoelectric pump, the drive assembly comprising: a voltage transformer for receiving the modulation signal and outputting a working voltage to the piezoelectric pump; the inverter receives the control signal, adjusts the first electrode and the second electrode of the piezoelectric pump to receive the working voltage or be grounded by the control signal, and when the first electrode receives the working voltage, the second electrode is grounded; when the first electrode is grounded, the second electrode receives the working voltage; the piezoelectric element of the piezoelectric pump generates deformation due to piezoelectric effect through the voltage difference between the first electrode and the second electrode, so as to convey fluid; and a current detector, connect electrically between the pressure changing piece and the inversion piece, detect the current value when the piezoelectric pump actuates; and a feedback circuit, electrically connected between the piezoelectric pump and the microprocessor, for generating a feedback voltage by the working voltage of the piezoelectric pump; wherein, the microprocessor outputs the control signal with a first frequency interval, the inverter makes the piezoelectric pump move in the first frequency interval according to the control signal, the current detector transmits the current value to the microprocessor, the microprocessor selects the frequency corresponding to the maximum current value of the piezoelectric pump in the first frequency interval as a first central frequency, the microprocessor takes the first central frequency as the reference, each frequency section is taken as a second frequency interval to adjust the control signal in the front and back, the inverter makes the piezoelectric pump move in the second frequency interval according to the control signal, and the current detector transmits the current value to the microprocessor, the microprocessor selects the frequency corresponding to the maximum current value of the piezoelectric pump in the second frequency interval as a second central frequency, the microprocessor takes the second central frequency as the reference, the front and the back of each primary frequency section are used as a third frequency interval to adjust the control signal, the inverter enables the piezoelectric pump to act in the third frequency interval according to the control signal, and the current detector transmits the current value to the microprocessor, the microprocessor selects the frequency corresponding to the maximum current value of the piezoelectric pump in the third frequency interval as an actuating frequency, the microprocessor transmits the control signal with the actuating frequency to the inverter, the inverter drives the piezoelectric pump to operate at the actuating frequency, and after the piezoelectric pump is actuated, every interval of actuating time is provided, the inverter outputs a control signal having the third frequency interval to the inverter to drive the piezoelectric pump to operate in the third frequency interval, taking the frequency corresponding to the maximum current value in the third frequency interval as the actuating frequency, and enabling the piezoelectric pump to operate under the actuating frequency; in addition, the microprocessor can adjust the working voltage of the piezoelectric pump output by the voltage transformation element according to the feedback voltage, and can also adjust the working voltage to adjust the power consumption of the piezoelectric pump.

[ description of the drawings ]

Fig. 1 is a block diagram of a micro piezoelectric pump module according to the present disclosure.

Fig. 2 is a schematic circuit diagram of the present miniature piezoelectric pump module.

Fig. 3A is an equivalent circuit diagram of the feedback circuit in the first control step.

Fig. 3B is an equivalent circuit diagram of the feedback circuit in the second control step.

[ detailed description ] embodiments

Embodiments that embody the features and advantages of this disclosure will be described in detail in the description that follows. It will be understood that the present disclosure is capable of various modifications without departing from the scope of the disclosure, and that the description and drawings are to be regarded as illustrative in nature, and not as restrictive.

Referring to fig. 1, a micro piezoelectric pump module 100 includes: a microprocessor 1, a driving device 2, a piezoelectric pump 3 and a feedback circuit 4. The microprocessor 1 outputs a control signal and a modulation signal to the driving component 2, the driving component 2 is electrically connected to the piezoelectric pump 3 and provides a working voltage for the piezoelectric pump 3 to operate by the control signal and the modulation signal, the feedback circuit 4 provides an actuating working voltage of the piezoelectric pump 3 for feedback to the microprocessor 1, and the microprocessor 1 enables the driving component 2 to adjust the working voltage of the piezoelectric pump 3 by the control signal and the modulation signal, so that the actuating voltage of the piezoelectric pump 3 is correspondingly adjusted, wherein the actuating voltage is the voltage of the piezoelectric pump 3 during actual actuation.

Referring to fig. 1 and 2, the microprocessor 1 has a control unit 11, a conversion unit 12 and a communication unit 13. The driving assembly 2 has a voltage converter 21, an inverter 22 and a current detector 23. The piezoelectric pump 3 has a first electrode 31, a second electrode 32 and a piezoelectric element 33. The communication unit 13 is electrically connected to the transformer 21 for outputting a modulation signal to the transformer 21. The voltage transformer 21 modulates the voltage into a working voltage according to the modulation signal, and then transmits the working voltage to the inverter 22. The control unit 11 is electrically connected to the inverter 22, and is configured to control the first electrode 31 and the second electrode 32 of the piezoelectric pump 3 to receive the working voltage or ground through the inverter 22, so as to adjust the operating frequency of the piezoelectric pump 3.

The current detector 23 is electrically connected between the voltage transformation element 21 and the inverter element 22, and detects a current value of the piezoelectric pump 3 during operation to the microprocessor 1, in this case, the current detector 23 will return the current value of the piezoelectric pump 3 during operation at each frequency to be determined by the microprocessor 1.

As shown in fig. 2, the feedback circuit 4 is electrically connected between the piezoelectric pump 3 and the microprocessor 1, and the feedback circuit 4 includes a first resistor R1, a second resistor R2, a third resistor R3, and a capacitor C. The first resistor R1 has a first contact 41a and a second contact 41 b. The second resistor R2 has a third node 42a and a fourth node 42 b. The third resistor R3 has a fifth node 43a and a sixth node 43 b. The capacitor C has a seventh contact 44a and an eighth contact 44 b. The first junction 41a of the first resistor R1 is electrically connected to the first electrode 31 of the piezoelectric pump 3, the third junction 42a of the second resistor R2 is electrically connected to the second electrode 32 of the piezoelectric pump 3, the sixth junction 43b of the third resistor R3 is electrically connected to the eighth junction 44b of the capacitor C and grounded, the fifth junction 43a of the third resistor R3 is electrically connected to the seventh junction 44a of the capacitor C, so that the third resistor R3 is electrically connected to the second junction 41b of the first resistor R1, the fourth junction 42b of the second resistor R2 and the microprocessor 1 after being connected in parallel with the capacitor C, and the working voltage between the first electrode 31 and the second electrode 32 of the piezoelectric pump 3 is divided to generate the feedback voltage to be fed back to the converting unit 12 of the microprocessor 1. The first resistor R1 and the second resistor R2 have the same resistance, but not limited thereto. In addition, the capacitor C functions as a filter to prevent noise from interfering with the feedback voltage.

In view of the above, the voltage transformer 21 further includes a voltage output terminal 211, a voltage transformation feedback terminal 212 and a voltage transformation feedback circuit 213. The voltage output terminal 211 is electrically connected to the inverter 22 via the current detector 23. The transformer feedback circuit 213 is electrically connected between the microprocessor 1 and the transformer feedback terminal 212, wherein the transformer feedback circuit 213 comprises a fourth resistor R4 and a fifth resistor R5, the fourth resistor R4 has a first end 213a and a second end 213b, and the fifth resistor R5 has a third end 213c and a fourth end 213 d. The first terminal 213a of the fourth resistor R4 is electrically connected to the voltage output terminal 211. The third terminal 213c of the fifth resistor R5 is electrically connected to the second terminal 213b of the fourth resistor R4 and the transformer feedback terminal 212, and the fourth terminal 213d of the fifth resistor R5 is grounded. In the embodiment, the fifth resistor R5 is a variable resistor, and in the embodiment, the fifth resistor R5 is a digital variable resistor and has a communication interface 213e, and the communication interface 213e is electrically connected to the communication unit 13 of the microprocessor 1, so that the communication unit 13 can transmit the modulation signal to the digital variable resistor (the fifth resistor R5) to adjust the resistance thereof. After the working voltage output by the voltage output end 211 of the voltage transformation element 21 is divided by the fourth resistor R4 and the fifth resistor R5 of the voltage transformation feedback circuit 213, the divided working voltage is transmitted back to the voltage transformation element 21 from the voltage transformation feedback end 212, so that the voltage transformation element 21 can refer to whether the output working voltage meets the ideal working voltage or not, if the working voltage is different from the ideal working voltage, the output working voltage is modulated again to be continuously adjusted to approach the ideal working voltage, and finally the working voltage is adjusted to be consistent with the ideal working voltage. The working voltage is the actual voltage outputted by the voltage output terminal 211 of the voltage transformer 21, and the ideal working voltage is the modulation signal transmitted by the microprocessor 1.

Referring to fig. 2, the inverter 22 includes: a buffer gate 221, an inverter 222, a first P-type mosfet 223, a second P-type mosfet 224, a first N-type mosfet 225, and a second N-type mosfet 226. The buffer gate 221 has a buffer input 221a and a buffer output 221 b. The inverter 222 has an inverting input 222a and an inverting output 222 b. The first P-type mosfet 223, the second P-type mosfet 224, the first N-type mosfet 225 and the second N-type mosfet 226 each have a gate G, a drain D and a source S, respectively. The buffer input 221a of the buffer gate 221 and the inverting input 222a of the inverter 222 are electrically connected to the control unit 11 of the microprocessor 1 for receiving a control signal, which may be, but is not limited to, a Pulse Width Modulation (PWM) signal. The buffer output 221b of the buffer gate 221 is electrically connected to the gate G of the first P-type mosfet 223 and the gate G of the first N-type mosfet 225. The inverted output 222b of the inverter 222 is electrically connected to the gate G of the second P-type mosfet 224 and the gate G of the second N-type mosfet 226. The source S of the first P-type mosfet 223 and the source S of the second P-type mosfet 224 are electrically connected to the voltage output terminal 211 of the voltage transformer 21 through the current detector 23 to receive the operating voltage output by the voltage transformer 21. The drain D of the first P-type mosfet 223 is electrically connected to the drain D of the first N-type mosfet 225 and the second electrode 32 of the piezoelectric pump 3. The drain D of the second P-type mosfet 224 is electrically connected to the drain D of the second N-type mosfet 226 and the first electrode 31 of the piezoelectric pump 3. The source S of the first N-type MOSFET 225 is electrically connected to the source S of the second N-type MOSFET 226 and grounded.

As mentioned above, the first P-type mosfet 223, the second P-type mosfet 224, the first N-type mosfet 225 and the second N-type mosfet 226 form an H-bridge structure for converting the operating voltage (dc) output from the voltage transformer 21 into ac to the piezoelectric pump 3, so that the first P-type mosfet 223 and the second P-type mosfet 224 need to receive opposite signals, the first N-type mosfet 225 and the second N-type mosfet 226 also need to receive the same signals, so that the control signal transmitted by the microprocessor 1 is transmitted to the second P-type mosfet 224 through the inverter 222, the control signal of the second P-type mosfet 224 is opposite to the first P-type mosfet 223, but the first P-type mosfet 223 and the second P-type mosfet 224 need to be connected to the control signal together, therefore, a buffer gate 221 is disposed in front of the first P-type mosfet 223, so that the first P-type mosfet 223 and the second P-type mosfet 224 can be synchronously connected to opposite signals, and the first N-type mosfet 225 and the second N-type mosfet 226 are also the same; in the first control step, when the first P-type mosfet 223 and the second N-type mosfet 226 are turned on and the second P-type mosfet 224 and the first N-type mosfet 225 are turned off, the operating voltage is transmitted to the second electrode 32 of the piezoelectric pump 3 through the first P-type mosfet 223, and the first electrode 31 of the piezoelectric pump 3 is grounded due to the second N-type mosfet 226 being turned on. In the second control step, when the first P-type mosfet 223 and the second N-type mosfet 226 are turned off and the second P-type mosfet 224 and the first N-type mosfet 225 are turned on, the operating voltage is transmitted to the first electrode 31 of the piezoelectric pump 3 through the second P-type mosfet 224, and the second electrode 32 of the piezoelectric pump 3 is grounded due to the first N-type mosfet 225 being turned on. By repeating the above first control step and the second control step, the piezoelectric element 33 of the piezoelectric pump 3 can be deformed by the piezoelectric effect due to the working voltage received by the first electrode 31 and the second electrode 32 or the grounding, and the pressure of the chamber (not shown) inside the piezoelectric pump 3 is driven to change, so as to continuously transmit the fluid.

The feedback circuit 4 continuously receives the working voltages of the first electrode 31 and the second electrode 32 of the piezoelectric pump 3 or the ground. In the first control step, the second electrode 32 is at the operating voltage, the first electrode 31 is at the ground, and the equivalent circuit of the feedback circuit 4 is as shown in fig. 3A, the first resistor R1 is connected in parallel with the third resistor R3, and the feedback voltage is (R1// R3) ÷ [ (R1// R3) + R2] × operating voltage. In addition, in the second control step, the first electrode 31 is at the operating voltage, the second electrode 32 is at the ground, and the equivalent circuit of the feedback circuit 4 is as shown in fig. 3B, the second resistor R2 is connected in parallel with the third resistor R3, and the feedback voltage is (R2// R3) ÷ [ (R2// R3) + R1] × operating voltage. The feedback circuit 4 transmits the feedback voltage to the microprocessor 1, the microprocessor 1 receives the feedback voltage to determine the operating voltage of the current voltage pump 3, and compares the operating voltage with the feedback voltage, if the operating voltage is different from the operating voltage, the feedback voltage is converted into a digital signal by the conversion unit 12, and the modulation signal converted into the digital signal is transmitted from the communication unit 13 to the communication interface 213e to adjust the fifth resistor R5 (digital variable resistor). Finally, after the working voltage output by the voltage output end 211 of the voltage transformation element 21 is divided by the fourth resistor R4 and the fifth resistor R5 of the voltage transformation feedback circuit 213, the divided working voltage is transmitted back to the voltage transformation element 21 from the voltage transformation feedback end 212, so that the voltage transformation element 21 can refer to whether the output working voltage meets the ideal working voltage or not, if the working voltage is different from the ideal working voltage, the output working voltage is modulated again to be continuously adjusted to approach the ideal working voltage, and finally the working voltage is adjusted to be consistent with the ideal working voltage, so that the working voltage received by the piezoelectric pump 3 can be maintained at the ideal working voltage through the above steps, and the piezoelectric pump 3 can continuously operate under better performance.

Referring to fig. 1 and 2, first, the microprocessor 1 outputs a control signal having a first frequency range (e.g., 5KHz to 20KHz), and the inverter 22 sequentially activates the piezoelectric pump 3 at each frequency of the first frequency range. The current value of the piezoelectric pump 3 in all frequencies in the first frequency interval is transmitted to the microprocessor 1 by the current detector 23, the microprocessor 1 selects the maximum current value and the corresponding actuating frequency of the piezoelectric pump 3 as a first central frequency (for example, 20KHz), then uses the first central frequency as the central reference, and selects a frequency range (for example, 6KHz) from the front and the back of the first central frequency, and uses the frequency range of one frequency range from the front and the back of the first central frequency as a second frequency interval (for example, 14KHz to 26 KHz). The microprocessor 1 outputs a control signal having a second frequency interval. The inverter 22 controls the piezoelectric pump 3 to operate sequentially at each frequency in the second frequency interval, and the current detector 23 transmits the piezoelectric pump 3 operating at each frequency in the second frequency interval. The current value of the piezoelectric pump 3 in the second frequency interval is transmitted to the microprocessor 1 by the current detector 23, the microprocessor 1 selects the maximum current value and the corresponding actuating frequency of the piezoelectric pump 3 as a second center frequency (e.g. 24KHz), and then takes the second center frequency as the center reference, and takes the frequency ranges of the front and rear primary frequency ranges as a third frequency interval (e.g. 20KHz to 28 KHz). The microprocessor 1 outputs a control signal with a third frequency interval, the inverter 22 controls the piezoelectric pump 3 to sequentially operate under each frequency of the third frequency interval, the current value of the piezoelectric pump 3 during operation under all the frequencies in the third frequency interval is transmitted to the microprocessor 1 by the current detector 23, the microprocessor 1 selects the operating frequency of the piezoelectric pump 3 corresponding to the maximum current value as a third center frequency (such as 27KHz), and finally the third center frequency is used as the operating frequency of the piezoelectric pump 3 to drive the piezoelectric pump 3 to operate; in addition, the piezoelectric pump 3 will generate heat energy due to the rapid deformation of the piezoelectric element 33 during continuous operation, which will cause the problem of low efficiency, therefore, after the piezoelectric pump 3 is operated, every interval of an operation time, the microprocessor 1 will output a control signal in the aforementioned third frequency interval (20KHz to 28KHz), the inverter 22 controls the piezoelectric pump 3 to operate in sequence under each frequency of the third frequency interval, the current value of the piezoelectric pump 3 during operation under all frequencies in the third frequency interval is transmitted to the microprocessor 1 by the current detector 23, and the microprocessor 1 selects the frequency corresponding to the maximum current value as the operation frequency of the piezoelectric pump 3; the aforementioned data of the frequency interval and the center frequency are only for illustration purpose for easy understanding, and are not limited thereto.

In summary, the range of the first frequency interval is greater than the range of the second frequency interval, and the range of the second frequency interval is greater than the range of the third frequency interval.

In addition, the current detector 23 can obtain the current of the piezoelectric pump 3 during operation, the feedback circuit 4 can obtain the operating voltage of the piezoelectric pump 3, and the microprocessor 1 can adjust the operating voltage of the piezoelectric pump 3, so that when the power consumption of the piezoelectric pump 3 is too large, the power consumption of the piezoelectric pump 3 can be adjusted by reducing the operating voltage, a preset power value can also be set, and when the power consumption of the piezoelectric pump 3 is greater than (or equal to) the preset power value, the operating voltage output to the piezoelectric pump 3 is reduced, thereby avoiding the problem of power consumption of the piezoelectric pump 3.

In summary, the present invention provides a micro piezoelectric pump module, which confirms the operation condition of a piezoelectric pump through a current detector and a feedback circuit, wherein the current detector can obtain the current value of the piezoelectric pump during frequency sweep and operating at different frequencies to obtain the actuation frequency of the piezoelectric pump, and respectively obtain a first frequency interval, a second frequency interval and a third frequency interval, and when the actuation frequency of the piezoelectric pump is distorted due to long-time actuation, the third frequency interval is directly used to obtain the optimal actuation frequency, so as to greatly reduce the time for confirming the actuation frequency, thereby avoiding the problem of the decrease of the efficiency of the piezoelectric pump during searching the actuation frequency, so as to ensure to continuously maintain the optimal transmission efficiency, and the present invention can solve the problems of unstable, floating, or insufficient working voltage of the piezoelectric pump causing the efficiency to be incorrect and inconsistent in the prior art, when the working voltage is controlled, the power of the piezoelectric pump can be adjusted simultaneously, the power loss is reduced, and the method has great industrial application value and is applied by the following method.

Various modifications may be made by those skilled in the art without departing from the scope of the invention as defined by the appended claims.

[ notation ] to show

100: miniature piezoelectric pump module

1: microprocessor

11: control unit

12: conversion unit

13: communication unit

2: drive assembly

21: pressure changing piece

211: voltage output terminal

212: voltage transformation feedback terminal

213: voltage transformation feedback circuit

213 a: first end point

213 b: second end point

213 c: third endpoint

213 d: fourth terminal point

213 e: communication interface

22: inversion component

221: buffer brake

221 a: buffer input terminal

221 b: buffer output

222: inverter with a capacitor having a capacitor element

222 a: inverting input terminal

222 b: inverting output terminal

223: a first P-type metal oxide semiconductor field effect transistor

224: second P-type metal oxide semiconductor field effect transistor

225: a first N-type metal oxide semiconductor field effect transistor

226: second N-type metal oxide semiconductor field effect transistor

23: current detector

3: piezoelectric pump

31: a first electrode

32: second electrode

33: piezoelectric element

4: feedback circuit

41 a: first contact

41 b: second contact

42 a: third contact

42 b: fourth contact

43 a: fifth contact

43 b: the sixth contact

44 a: seventh junction

44 b: eighth contact

C: capacitor with a capacitor element

D: drain electrode

G: grid electrode

R1: a first resistor

R2: second resistance

R3: third resistance

R4: fourth resistor

R5: fifth resistor

S: source electrode

Claims (12)

1. A miniature piezoelectric pump module, comprising:

a piezoelectric pump having a first electrode, a second electrode and a piezoelectric element;

a microprocessor for outputting a control signal and a modulation signal;

a drive assembly electrically connected between the microprocessor and the piezoelectric pump, the drive assembly comprising:

a voltage transformer for receiving the modulation signal and outputting a working voltage to the piezoelectric pump; and

the inverter receives the control signal, adjusts the first electrode and the second electrode of the piezoelectric pump to receive the working voltage or be grounded by the control signal, and when the first electrode receives the working voltage, the second electrode is grounded; when the first electrode is grounded, the second electrode receives the working voltage; the piezoelectric element of the piezoelectric pump generates deformation due to piezoelectric effect through the voltage difference between the first electrode and the second electrode, so as to convey fluid; and

a current detector, electrically connected between the voltage transformation element and the inversion element, for detecting the current value of the piezoelectric pump during operation; and

a feedback circuit electrically connected between the piezoelectric pump and the microprocessor for generating a feedback voltage by the working voltage of the piezoelectric pump;

the microprocessor outputs the control signal with a first frequency interval, the inverter makes the piezoelectric pump operate in the first frequency interval according to the control signal, the current detector transmits the current value to the microprocessor, and in addition, the microprocessor can adjust the working voltage of the piezoelectric pump output by the voltage transformation element according to the feedback voltage and can also adjust the working voltage to improve the power consumption of the piezoelectric pump.

2. A miniature piezoelectric pump module as defined in claim 1, wherein the microprocessor outputs the control signal in a second frequency range, the inverter operates the piezoelectric pump in the second frequency range according to the control signal, and the current detector transmits the current value to the microprocessor; and

the microprocessor outputs the control signal in a third frequency interval, the inverter enables the piezoelectric pump to act in the third frequency interval according to the control signal, and the current detector transmits the current value of the piezoelectric pump to the microprocessor.

3. A miniature piezoelectric pump module as claimed in claim 2, wherein the first frequency interval is greater than the second frequency interval, and the second frequency interval is greater than the third frequency interval.

4. A miniature piezoelectric pump module according to claim 1, wherein the feedback circuit comprises a first resistor, a second resistor, a third resistor and a capacitor, the first resistor has a first node and a second node, the second resistor has a third node and a fourth node, the third resistor has a fifth node and a sixth node, the capacitor has a seventh node and an eighth node, the first node of the first resistor is electrically connected to the first electrode of the piezoelectric pump, the third node of the second resistor is electrically connected to the second electrode of the piezoelectric pump, the sixth node of the third resistor is electrically connected to the eighth node of the capacitor and grounded, the fifth node of the third resistor is electrically connected to the seventh node of the capacitor, so that the third resistor and the capacitor are electrically connected to the second node of the first resistor after being connected in parallel, The fourth connection point of the second resistor and the microprocessor divide the working voltage between the first electrode and the second electrode of the piezoelectric pump to generate the feedback voltage to be fed back to the microprocessor.

5. A miniature piezoelectric pump module as defined in claim 4, wherein the first resistor and the second resistor have the same resistance.

6. A miniature piezoelectric pump module as defined in claim 5, wherein the transformer further comprises a voltage output terminal, a voltage transforming feedback terminal and a voltage transforming feedback circuit, the voltage output terminal is electrically connected to the inverter through the current detector, and the voltage transforming feedback circuit is electrically connected between the microprocessor and the voltage transforming feedback terminal.

7. A miniature piezoelectric pump module as defined in claim 6, wherein the voltage-transforming feedback circuit comprises a fourth resistor and a fifth resistor, the fourth resistor has a first terminal and a second terminal, the fifth resistor has a third terminal and a fourth terminal, the first terminal of the fourth resistor is electrically connected to the voltage output terminal, the third terminal of the fifth resistor is electrically connected to the second terminal of the fourth resistor and the voltage-transforming feedback terminal, and the fourth terminal is grounded.

8. A miniature piezoelectric pump module as defined in claim 7, wherein the fifth resistor is a variable resistor.

9. A miniature piezoelectric pump module as defined in claim 8, wherein the fifth resistor is a digital variable resistor.

10. A miniature piezoelectric pump module as defined in claim 9, wherein the microprocessor further comprises a conversion unit and a communication unit, the communication unit is connected to the digital variable resistor, the conversion unit receives the feedback voltage, converts the feedback voltage into the modulation signal of the digital signal, and transmits the modulation signal to the digital variable resistor via the communication unit, and the digital variable resistor is changed to modulate the working voltage output by the transformer, so that the working voltage approaches an ideal working voltage.

11. A miniature piezoelectric pump module as defined in claim 9, wherein the inverter comprises:

a buffer gate having a buffer input terminal and a buffer output terminal;

an inverter having an inverting input terminal and an inverting output terminal;

a first P-type metal oxide semiconductor field effect transistor, a second P-type metal oxide semiconductor field effect transistor, a first N-type metal oxide semiconductor field effect transistor and a second N-type metal oxide semiconductor field effect transistor, wherein the first P-type metal oxide semiconductor field effect transistor, the second P-type metal oxide semiconductor field effect transistor, the first N-type metal oxide semiconductor field effect transistor and the second N-type metal oxide semiconductor field effect transistor are respectively provided with a grid electrode, a drain electrode and a source electrode;

wherein the buffer input terminal of the buffer gate and the inverting input terminal of the inverter are electrically connected to the microprocessor for receiving the control signal, the buffer output terminal of the buffer gate is electrically connected to the gate of the first P-type MOSFET and the gate of the first N-type MOSFET, the inverting output terminal of the inverter is electrically connected to the gate of the second P-type MOSFET and the gate of the second N-type MOSFET, the source of the first P-type MOSFET and the source of the second P-type MOSFET are electrically connected to the voltage output terminal of the transformer through a current detector for receiving the operating voltage, the drain of the first P-type MOSFET is electrically connected to the drain of the first N-type MOSFET and the second electrode of the MOS pump, the drain of the second P-type MOSFET is electrically connected to the drain of the second N-type MOSFET and the piezoelectric device The source of the first N-type metal oxide semiconductor field effect transistor is electrically connected with the source of the second N-type metal oxide semiconductor field effect transistor and is grounded.

12. A miniature piezoelectric pump module as defined in claim 11, wherein the control signal is a pulse width modulation signal.

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