Dual-pwm variable frequency control high voltage resonant piezoelectric buzzer drive circuit and system

Abstract

The application relates to the technical field of electric motors, and provides a high-voltage resonant piezoelectric buzzer driving circuit and system of a double-PWM variable-frequency control, wherein the driving circuit comprises a first switching unit, a second switching unit, a resonant unit and a power supply unit; a voltage output end P1 is electrically connected to the input end of the first switching unit; the output end of the first switching unit is electrically connected to the input end of the resonant unit; a voltage output end P2 is electrically connected to the input end of the second switching unit; the output end of the second switching unit is electrically connected to the input end of the resonant unit; the output end of the resonant unit is electrically connected to the buzzer; the output signal of an MCU is a complementary signal output simultaneously in two ways; and the output end signal of the power supply unit is connected to the first switching unit and the second switching unit. The application can make the buzzer emit high volume, and can solve the problem that the traditional circuit cannot provide sufficient driving voltage for the buzzer, which easily leads to insufficient volume of the buzzer.

Description

Technical Field

[0001] This application relates to the technical field of electronic circuits, and in particular to a high-voltage resonant piezoelectric buzzer drive circuit and system with dual PWM frequency conversion control. Background Technology

[0002] A buzzer boost drive circuit is an electronic circuit used to drive a buzzer. Its main function is to increase the input voltage to the operating voltage required by the buzzer through boost technology, thereby enhancing the various sound parameters of the buzzer.

[0003] With the current trend of miniaturization and intelligentization of electronic devices, higher requirements are placed on various sound parameters of the driving circuit. Traditional driving circuits usually use simple transistors or MOSFETs to directly drive the buzzer. Their output voltage is limited by the power supply voltage and cannot provide sufficient driving voltage, which easily leads to insufficient buzzer volume. They perform poorly, especially in application scenarios that require high volume, and cannot well adapt to the development needs of modern electronic devices.

[0004] In view of the above-mentioned technologies, in order to overcome the problem that traditional drive circuits cannot control the buzzer to emit high volume and to meet the growing market demand, this application provides a buzzer boost drive circuit. Utility Model Content

[0005] In order to make the buzzer emit a high volume, this application provides a buzzer boost drive circuit and a system including a buzzer and a boost drive circuit.

[0006] Firstly, this application provides a buzzer boost drive circuit, which adopts the following technical solution: A buzzer boost drive circuit includes a first switching unit, a second switching unit, and a resonant unit. A voltage output terminal P1 is electrically connected to the input terminal IN1 of the first switching unit, and the output terminal OUT1 of the first switching unit is electrically connected to the input terminal IN3 of the resonant unit. A voltage output terminal P2 is electrically connected to the input terminal IN2 of the second switching unit, and the output terminals OUT2 of the second switching unit are both electrically connected to the input terminal IN4 of the resonant unit. The output terminal of the resonant unit is electrically connected to the buzzer. The MCU output signals are two complementary PWM signals output simultaneously, namely PWM1 and PWM2. The voltage output terminal P1 receives and forwards PWM1, and the voltage output terminal P2 receives and forwards PWM2.

[0007] By adopting the above technical solution, when the PWM1 signal output from voltage output terminal P1 is high and the PWM2 signal output from voltage output terminal P2 is low, the first switching unit is turned on and the second switching unit is turned off. At this time, the voltage of voltage output terminal P1 is transmitted to the input terminal IN3 of the resonant unit through the turned-on first switching unit. After processing the input voltage, the resonant unit outputs a positive driving voltage to the buzzer, thereby driving the buzzer to work in the positive direction. When the PWM1 signal output from voltage output terminal P1 is low and the PWM2 signal output from voltage output terminal P2 is high, the first switching unit is turned off and the second switching unit is turned on. At this point, the voltage at the output terminal P2 is transmitted to the input terminal IN4 of the resonant unit through the conducting second switching unit. After processing, the resonant unit outputs a reverse driving voltage to the buzzer, causing the buzzer to work in reverse. Thus, the buzzer is driven in both forward and reverse directions through two complementary PWM signals PMW1 and PMW2. After the switching unit switches and the resonant unit boosts the voltage, the circuit converts the input signal into a high-voltage sine wave. The buzzer receives a voltage much higher than the power supply voltage. This high voltage acts on the piezoelectric buzzer, making its inverse piezoelectric effect more pronounced, generating a larger amplitude mechanical vibration, and thus producing a louder sound. The circuit designed in this application achieves precise control of various sound parameters of the piezoelectric buzzer while having lower power consumption and stronger anti-interference capabilities, and can adapt to the complex needs of different application scenarios.

[0008] Preferably, the first switching unit includes a switching transistor Q1, a switching transistor Q2, a power supply terminal VCC, and a diode D1; the voltage output terminal P1 is electrically connected to both the control terminal and the output terminal of the switching transistor Q1; the input terminal of the switching transistor Q1 is electrically connected to both the input terminal and the control terminal of the switching transistor Q2; the input terminal of the switching transistor Q1 is electrically connected to the cathode of the diode D1, and the anode of the diode D1 is electrically connected to the output terminal of the switching transistor Q2; the voltage output terminal of the power supply terminal VCC is electrically connected to the input terminal of the switching transistor Q2, and the output terminal of the switching transistor Q2 is electrically connected to the input terminal IN3 of the resonant unit.

[0009] By adopting the above technical solution, the first switching unit processes the voltage signal from the voltage output terminal P1 through resistor voltage division and other processes, and then controls the switching of the switching transistors Q1 and Q2. With the unidirectional conduction characteristic of the diode D1, the voltage of the power supply terminal VCC is finally stably delivered to the input terminal IN3 of the resonant unit, thereby realizing the functions of processing the input signal and providing stable power supply to the resonant unit.

[0010] Preferably, the switching transistors Q1 and Q2 are NMOS transistors.

[0011] By adopting the above technical solution, the NMOS transistor is a voltage-controlled device, which controls the voltage between the gate and source (V). GS To control the drain current (I) D When V GS Reaching a certain threshold voltage (V) TH Only when the voltage output terminal P1 is reached will a conductive channel be formed, allowing the NMOS transistor to conduct. This design can efficiently process and control the input signal at the voltage output terminal P1.

[0012] Preferably, the second switching unit includes a switching transistor Q3, a switching transistor Q4, a power supply terminal VCC, and a diode D2; the voltage output terminal P2 is electrically connected to both the control terminal and the output terminal of the switching transistor Q3; the input terminal of the switching transistor Q3 is electrically connected to both the input terminal and the control terminal of the switching transistor Q4, the input terminal of the switching transistor Q3 is electrically connected to the cathode of the diode D2, and the anode of the diode D2 is electrically connected to the output terminal of the switching transistor Q4; the voltage output terminal of the power supply terminal VCC is electrically connected to the input terminal of the switching transistor Q4, and the output terminal of the switching transistor Q4 is electrically connected to the input terminal IN4 of the resonant unit.

[0013] By adopting the above technical solution, the second switching unit processes the voltage signal from the voltage output terminal P2 through a resistor divider, and then controls the switching of the switching transistors Q3 and Q4. In conjunction with the unidirectional conduction characteristic of the diode D2, the voltage of the power supply terminal VCC is stably delivered to the input terminal IN3 of the resonant unit, thereby realizing the functions of processing the input signal and reliably powering the resonant unit.

[0014] Preferably, the switching transistors Q3 and Q4 are NMOS transistors.

[0015] By adopting the above technical solution, the NMOS transistor is a voltage-controlled device, which controls the voltage between the gate and source (V). GS To control the drain current (I) D When V GS Reaching a certain threshold voltage (V) TH Only when the voltage output terminal P1 is reached will a conductive channel be formed, allowing the NMOS transistor to conduct. This design can efficiently process and control the input signal at the voltage output terminal P1.

[0016] Preferably, the resonant unit includes a capacitor C, a positive voltage terminal J3, a negative voltage terminal J5, and an inductor L. The output terminal OUT1 of the first switching unit is electrically connected to one end of the inductor L, the other end of the inductor L is electrically connected to one end of the capacitor C and the positive voltage terminal J3, and the other end of the capacitor C is electrically connected to the negative voltage terminal J5 and the output terminal OUT2 of the second switching unit.

[0017] By adopting the above technical solution, the signals output by the first switching unit and the second switching unit can resonate in the resonant circuit composed of inductor L and capacitor C, and the positive voltage terminal J3 and the negative voltage terminal J5 can be used to provide voltage for the buzzer.

[0018] Preferably, the power supply unit includes an enable terminal, a voltage input terminal, a voltage output terminal, a switching transistor Q5, and a switching transistor Q6. The enable terminal is signal-connected to the switching transistor Q5, and the switching transistor Q5 is simultaneously signal-connected to the switching transistor Q6. The power input terminal of the switching transistor Q6 is connected to the power signal BOOST_OUT, and the output terminal of the switching transistor Q6 outputs a high voltage signal, which is input to the power supply terminals of the first switching unit and the second switching unit.

[0019] By adopting the above technical solution, the power supply unit receives the power signal BOOST_OUT, and after being triggered at the enable terminal, the switching transistor Q6 is turned on by the conduction of the switching transistor Q5, thereby achieving the purpose of boosting the low voltage signal to a high voltage signal, so that the first switching unit and the second switching unit can directly use the boosted high voltage signal to drive the buzzer.

[0020] Secondly, the high-voltage resonant piezoelectric buzzer drive system with dual PWM frequency conversion control provided in this application adopts the following technical solution: A high-voltage resonant piezoelectric buzzer drive system with dual PWM frequency conversion control includes a buzzer and the aforementioned buzzer boost drive circuit. The positive terminal of the buzzer is electrically connected to the positive voltage terminal J3, and the negative terminal of the buzzer is electrically connected to the negative voltage terminal J5. The buzzer boost drive circuit is used to boost the signal output by the MCU and then drive the buzzer to produce sound.

[0021] By adopting the above technical solution, the buzzer boost drive circuit boosts the output signal of the MCU, which can effectively drive the buzzer to produce sound.

[0022] In summary, this application includes at least one of the following beneficial technical effects: 1. Through the switching of the switching unit and the boosting effect of the resonant unit, the circuit converts the input signal into a high-voltage sine wave. The buzzer will receive a voltage much higher than the power supply voltage. This high voltage acts on the piezoelectric buzzer, making its inverse piezoelectric effect more obvious, producing a larger amplitude mechanical vibration, and thus emitting a louder sound. 2. The first and second switching units receive two complementary PWM signals output by the MCU to achieve rapid signal switching and voltage boosting, providing a stable input signal for the resonant unit, thereby efficiently driving the sound parameters of the buzzer; When a buzzer is connected in a series resonant circuit with an inductor, the buzzer's equivalent capacitor resonates with the inductor in the resonant state. The inductor continuously converts magnetic energy into electrical energy, generating periodically changing current and voltage in the circuit. Due to the resonant voltage boost effect, the buzzer receives a voltage much higher than the power supply voltage. This high voltage acts on the piezoelectric buzzer element, making its inverse piezoelectric effect more pronounced, producing a larger amplitude mechanical vibration, and thus emitting a louder sound. The circuit uses PMW1 and PMW2 to drive the buzzer in both forward and reverse directions. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the principle of this application; Figure 2 This is the circuit diagram of this application; Figure 3 This is the circuit diagram of the power supply unit.

[0024] Reference numerals in the attached figures: 1. First switching unit; 2. Second switching unit; 3. Resonant unit; 4. Power supply unit. Detailed Implementation

[0025] The following is in conjunction with the appendix Figures 1-2 This application will be described in further detail.

[0026] This application discloses a buzzer boost drive circuit.

[0027] Reference Figure 1 and 2 The MCU output signal is simultaneously output to two complementary PWM signals, namely PWM1 and PWM2. The voltage output terminals P1 and P2 are electrically connected to the two output terminals of the MCU, respectively, to receive and forward the two complementary PWM signals.

[0028] A high-voltage resonant piezoelectric buzzer drive circuit with dual PWM frequency conversion control includes a first switching unit 1, a second switching unit 2, and a resonant unit 3. The voltage output terminal P1 is electrically connected to the input terminal IN1 of the first switching unit 1, and the output terminal OUT1 of the first switching unit is electrically connected to the input terminal IN3 of the resonant unit. The voltage output terminal P2 is electrically connected to the input terminal IN2 of the second switching unit, and the output terminal OUT2 of the second switching unit is electrically connected to the input terminal IN4 of the resonant unit. The output terminal OUT3 of the resonant unit 3 is electrically connected to the buzzer.

[0029] When the PWM1 signal received at voltage output terminal P1 is high and the PWM2 signal output at voltage output terminal P2 is low, the first switching unit 1 is turned on and the second switching unit 2 is turned off. At this time, the voltage at voltage output terminal P1 is transmitted to the input terminal of resonant unit 3 through the turned-on first switching unit 1. After processing the input voltage, resonant unit 3 outputs a positive driving voltage to the buzzer, thereby driving the buzzer to work in the forward direction. When the PWM1 signal output at voltage output terminal P1 is low and the PWM2 signal output at voltage output terminal P2 is high, the first switching unit 1 is turned off and the second switching unit 2 is turned on. At this time, the voltage at voltage output terminal P2 is transmitted to the input terminal of resonant unit 3 through the turned-on second switching unit 2. After processing, resonant unit 3 outputs a reverse driving voltage to the buzzer, causing the buzzer to work in the reverse direction. Thus, the buzzer is driven in both forward and reverse directions through PWM1 and PWM2.

[0030] In practical applications, the voltage input terminal of the aforementioned buzzer boost drive circuit can accept low-voltage signals up to 30V. These signals are then boosted to a high-voltage signal of 100V by the first switching unit 1 and the second switching unit 2. This high-voltage signal is then used to drive the piezoelectric buzzer, thereby increasing its sound pressure level. Simultaneously, the voltage across the piezoelectric buzzer is a sampled sine wave, allowing for a smooth adjustment of the sound pressure level without sudden changes. Furthermore, in the non-operating state of the piezoelectric buzzer, the circuit's power consumption is extremely low, effectively reducing power consumption when the product is battery powered. Because the voltage and current in the drive circuit do not change abruptly, EMC radiation is reduced. The sampling of the I / O control of the two MCUs enhances anti-interference capabilities and reduces the likelihood of false triggering.

[0031] The first switching unit 1 includes a switching transistor Q1, a switching transistor Q2, a power supply terminal VCC, and a diode D1; wherein, both switching transistors Q1 and Q2 are NMOS transistors.

[0032] The voltage output terminal P1 is electrically connected to both the source and gate of switching transistor Q1. The drain of switching transistor Q1 is electrically connected to both the drain and gate of switching transistor Q2. The drain of switching transistor Q1 is electrically connected to the cathode of diode D1, and the anode of diode D1 is electrically connected to the source of switching transistor Q2. Diode D1 is used to prevent reverse voltage from damaging the circuit. The voltage output terminal VCC is electrically connected to the drain of switching transistor Q2, and the source of switching transistor Q2 is electrically connected to the input terminal IN3 of resonant unit 3.

[0033] In practical applications, operators can configure resistors and other devices according to the different models of the selected components to ensure the circuit operates normally. In the first switching unit 1, the resistor serves to limit current, divide voltage, and improve anti-interference capabilities, ensuring that the switching transistor Q1 operates stably and reliably, thereby providing a stable input signal to the resonant unit 3. The second switching unit 2 includes switching transistors Q3 and Q4, a power supply terminal VCC, and a diode D2; wherein, both switching transistors Q3 and Q4 are NMOS transistors.

[0034] The voltage output terminal P2 is electrically connected to both the gate and source of switching transistor Q3. The drain of switching transistor Q3 is electrically connected to both the drain and gate of switching transistor Q4. The drain of switching transistor Q3 is electrically connected to the cathode of diode D2, and the anode of diode D2 is electrically connected to the source of switching transistor Q4. Diode D2 is used to prevent reverse voltage damage. The voltage output terminal VCC is electrically connected to the drain of switching transistor Q4, and the source of switching transistor Q4 is electrically connected to the input terminal IN4 of resonant unit 3. In this embodiment, the power supply terminal VCC outputs a 12V voltage.

[0035] In practical applications, operators can install resistors and other devices according to the different models of each component to ensure the circuit operates normally. Resistor R in the first switching unit 2 serves to limit current, divide voltage, and improve anti-interference capabilities, ensuring that the switching transistor Q3 can operate stably and reliably, thereby providing a stable input signal path for the resonant unit 3.

[0036] The resonant unit 3 includes a capacitor C, a positive voltage terminal J3, a negative voltage terminal J5, and an inductor L. The output terminal OUT1 of the first switching unit 1 is electrically connected to one end of the inductor L. The other end of the inductor L is simultaneously electrically connected to one end of the capacitor C and the positive voltage terminal J3. The other end of the capacitor C is simultaneously electrically connected to the negative voltage terminal J5 and the output terminal OUT2 of the second switching unit 2.

[0037] When PWM1 is low, the voltage output terminal P1 is low, the switch Q1 is not conducting, the switch Q2 is conducting, and the voltage at the positive voltage terminal J3 is high. Resonance occurs through the inductor and the buzzer (equivalent to a capacitor), and the voltage at the positive voltage terminal J3 is multiplied. When PWM2 is high, the voltage output terminal P2 is high, the switch Q1 is conducting, the switch Q2 is not conducting, the voltage at the negative voltage terminal J5 is low, the voltage at the positive voltage terminal J3 of the buzzer is high, and the voltage at the negative voltage terminal J5 is low.

[0038] When PWM1 is high, the voltage output terminal P1 is high, the switching transistor Q1 is on, the switching transistor Q2 is off, and the voltage at the positive voltage terminal J3 is low. When PWM2 is low, the voltage output terminal P2 is low, the switching transistor Q1 is off, the switching transistor Q2 is on, the voltage at the negative voltage terminal J5 is high, the voltage at the negative voltage terminal J5 of the buzzer is high, and the voltage at the positive voltage terminal J3 is low.

[0039] By continuously alternating the high and low levels of PWM1 and PWM2, the voltage difference across the buzzer changes periodically. After the voltage difference across the positive voltage terminal J3 and the negative voltage terminal J5 changes, a sinusoidal voltage signal is finally obtained across the buzzer. This periodically changing sinusoidal voltage signal can continuously drive the buzzer to produce regular mechanical vibrations, thereby emitting a stable and loud sound.

[0040] In the embodiments of this application, reference is made to Figure 3 The power supply unit includes an enable terminal BUZZER_POWER_EN, a voltage input terminal BOOST_OUT, a voltage output terminal BUZZER_POWER, and switching transistors Q5 and Q6. Switch Q5 can be an NPN transistor, and switch Q6 can be a PNP transistor. The enable terminal BUZZER_POWER_EN is connected to the base of switch Q5, the collector of switch Q5 is connected to the base of switch Q6, and the emitter of switch Q5 is grounded. The emitter of switch Q6 is connected to the power supply signal, and the collector of switch Q6 outputs a high-voltage signal, which is also grounded. The high-voltage signal output by switch Q6 provides power to the first and second switching units.

[0041] The implementation principle of this application embodiment is as follows: by using the resonant boost effect of the inductor and the equivalent capacitor of the piezoelectric buzzer, and in conjunction with the PWM1 and PWM2 signals output by the MCU, forward and reverse driving is achieved, so that the piezoelectric buzzer emits a louder sound.

[0042] This application also discloses a high-voltage resonant piezoelectric buzzer drive system with dual PWM frequency conversion control.

[0043] A high-voltage resonant piezoelectric buzzer drive system with dual PWM frequency conversion control includes a buzzer and the aforementioned buzzer boost drive circuit. The positive terminal of the buzzer is electrically connected to the positive voltage terminal J3, and the negative terminal of the buzzer is electrically connected to the negative voltage terminal J5. The buzzer boost drive circuit is used to boost the signal output by the MCU and then drive the buzzer to produce sound.

[0044] A piezoelectric buzzer can be used. In a circuit, a piezoelectric buzzer can be equivalent to a capacitor. When a piezoelectric buzzer is connected in a series resonant circuit with an inductor, the inductor (i.e., the piezoelectric buzzer) continuously converts magnetic energy into electrical energy during resonance. This energy conversion generates periodically changing current and voltage in the circuit. Due to the resonant voltage boost effect, the piezoelectric buzzer receives a voltage much higher than the voltage at the power supply terminal VCC. This high voltage acts on the piezoelectric buzzer element, making its inverse piezoelectric effect more pronounced—that is, electrical energy is more effectively converted into mechanical energy, resulting in a larger amplitude mechanical vibration and ultimately making the piezoelectric buzzer emit a louder sound.

[0045] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A high-voltage resonant piezoelectric buzzer drive circuit with dual PWM frequency conversion control, characterized in that, The system includes a first switching unit (1), a second switching unit (2), a resonant unit (3), and a power supply unit (4). The voltage output terminal P1 is electrically connected to the input terminal IN1 of the first switching unit (1), and the output terminal OUT1 of the first switching unit (1) is electrically connected to the input terminal IN3 of the resonant unit (3). The voltage output terminal P2 is electrically connected to the input terminal IN2 of the second switching unit (2), and the output terminal OUT2 of the second switching unit (2) is electrically connected to the input terminal IN4 of the resonant unit (3). The output terminal OUT3 of the resonant unit (3) is electrically connected to a buzzer. The output signal of the MCU is two complementary PWM signals that are output simultaneously, namely PWM1 and PWM2. The voltage output terminal P1 receives and forwards PWM1, and the voltage output terminal P2 receives and forwards PWM2. The output signal of the power supply unit (4) is connected to the first switching unit (1) and the second switching unit (2).

2. The high-voltage resonant piezoelectric buzzer drive circuit with dual PWM frequency conversion control according to claim 1, characterized in that, The first switching unit (1) includes a switching transistor Q1, a switching transistor Q2, a power supply terminal VCC, and a diode D1; the voltage output terminal P1 is simultaneously electrically connected to the control terminal and the output terminal of the switching transistor Q1; the input terminal of the switching transistor Q1 is simultaneously electrically connected to the input terminal and the control terminal of the switching transistor Q2; the input terminal of the switching transistor Q1 is electrically connected to the cathode of the diode D1, and the anode of the diode D1 is electrically connected to the output terminal of the switching transistor Q2; the voltage output terminal of the power supply terminal VCC is electrically connected to the input terminal of the switching transistor Q2, and the output terminal of the switching transistor Q2 is electrically connected to the input terminal IN3 of the resonant unit (3).

3. The high-voltage resonant piezoelectric buzzer drive circuit with dual PWM frequency conversion control according to claim 2, characterized in that, Both the switching transistors Q1 and Q2 are NMOS transistors.

4. The high-voltage resonant piezoelectric buzzer drive circuit with dual PWM frequency conversion control according to claim 1, characterized in that, The second switching unit (2) includes a switching transistor Q3, a switching transistor Q4, a power supply terminal VCC, and a diode D2; the voltage output terminal P2 is simultaneously electrically connected to the control terminal and the output terminal of the switching transistor Q3; the input terminal of the switching transistor Q3 is simultaneously electrically connected to the input terminal and the control terminal of the switching transistor Q4, the input terminal of the switching transistor Q3 is electrically connected to the cathode of the diode D2, and the anode of the diode D2 is electrically connected to the output terminal of the switching transistor Q4; the voltage output terminal of the power supply terminal VCC is electrically connected to the input terminal of the switching transistor Q4, and the output terminal of the switching transistor Q4 is electrically connected to the input terminal IN4 of the resonant unit (3).

5. The high-voltage resonant piezoelectric buzzer drive circuit with dual PWM frequency conversion control according to claim 4, characterized in that, Both the switching transistors Q3 and Q4 are NMOS transistors.

6. The high-voltage resonant piezoelectric buzzer drive circuit with dual PWM frequency conversion control according to claim 1, characterized in that, The resonant unit (3) includes a capacitor C, a positive voltage terminal J3, a negative voltage terminal J5, and an inductor L. The output terminal OUT1 of the first switching unit (1) is electrically connected to one end of the inductor L. The other end of the inductor L is electrically connected to one end of the capacitor C and the positive voltage terminal J3. The other end of the capacitor C is electrically connected to the negative voltage terminal J5 and the output terminal OUT2 of the second switching unit (2).

7. The high-voltage resonant piezoelectric buzzer drive circuit with dual PWM frequency conversion control according to claim 5, characterized in that, The power supply unit (4) includes an enable terminal, a voltage input terminal, a voltage output terminal, a switch Q5, and a switch Q6. The enable terminal is signal-connected to the switch Q5, and the switch Q5 is simultaneously signal-connected to the switch Q6. The power input terminal of the switch Q6 is connected to a power signal, and the output terminal of the switch Q6 outputs a high voltage signal, which is input to the power supply terminals of the first switch unit (1) and the second switch unit (2).

8. A high-voltage resonant piezoelectric buzzer drive system with dual PWM frequency conversion control, characterized in that, The device includes a buzzer and a high-voltage resonant piezoelectric buzzer drive circuit with dual PWM frequency conversion control as described in any one of claims 1-6. The positive terminal of the buzzer is electrically connected to the positive voltage terminal J3, and the negative terminal of the buzzer is electrically connected to the negative voltage terminal J5. The buzzer boost drive circuit is used to boost the signal output by the MCU and then drive the buzzer to produce sound.

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