WO2023206175A1

WO2023206175A1 - Outdoors portable piezoelectric ceramic air pump

Info

Publication number: WO2023206175A1
Application number: PCT/CN2022/089674
Authority: WO
Inventors: 李春云
Original assignee: 深圳市兴日生实业有限公司
Priority date: 2022-04-27
Filing date: 2022-04-27
Publication date: 2023-11-02

Abstract

An outdoors portable piezoelectric ceramic air pump, comprising a DC-AC inverter and a piezoelectric ceramic air pump body. An output end of the DC-AC inverter is used for electrically connecting to a piezoelectric ceramic piece in the piezoelectric ceramic air pump body to provide an alternating current for the piezoelectric ceramic piece, wherein the alternating current drives the piezoelectric ceramic piece to vibrate. The DC-AC inverter comprises an MCU control circuit, an inverter bridge circuit, and a step-up transformer; the MCU control circuit is electrically connected to an input end of the inverter bridge circuit, and an output end of the inverter bridge circuit is electrically connected to an input end of the step-up transformer; and the MCU control circuit outputs a pair of PWM pulse control signals having opposite polarities to the inverter bridge circuit, wherein the pair of PWM pulse control signals having opposite polarities are used for controlling the frequency and amplitude of the alternating current output by the inverter bridge circuit. The built-in DC-AC inverter enables the piezoelectric ceramic air pump to be suitable for a power supply for supplying a direct current, thereby expanding application scenarios of the piezoelectric ceramic air pump, so that the piezoelectric ceramic air pump is not limited to alternating current supply scenarios.

Description

Portable piezoelectric ceramic air pump for outdoor use

Technical field

This application relates to a piezoelectric ceramic air pump suitable for outdoor portable application scenarios, and in particular, to an outdoor portable piezoelectric ceramic air pump suitable for DC power supply.

Background technique

In outdoor or portable applications without AC power supply, battery-driven air pumps used for outdoor operations (such as fishing enthusiasts) can be roughly divided into several categories. One of them is the electromagnetic vibration type that uses electromagnetic principles to repeatedly compress the leather bowl. Air pump; the second one is a DC motor air pump that uses a small DC motor to drive an eccentric to compress the cup. The energy consumption of the electromagnetic vibrating air pump is high, the service life of the rubber cup is short, and the hardness of the rubber cup changes with the change of ambient temperature, which affects the unstable performance of the air pump. In addition, it has a large appearance, is inconvenient to carry, has low efficiency, and has a relatively short working time when powered by batteries. The DC motor air pump uses a small DC motor and can be driven by a DC power supply such as a battery. However, the high-speed rotating motor usually has a lot of noise and a short life. The performance of the rubber cup of the air pump will change with changes in the ambient temperature, causing the air pump to malfunction. The performance is unstable and the working time on battery power is relatively short. Conventional DC batteries can support the operation time of the above two air pumps for about 3-4 hours, and batteries with large capacity can support a slightly longer time of only 5-6 hours. These shortcomings are also a pity for outdoor workers.

Piezoelectric pumps are a new type of fluid actuator. It does not require an additional drive motor, but uses the inverse piezoelectric effect of piezoelectric ceramics to deform the piezoelectric vibrator, and then the deformation produces a volume change in the pump cavity to achieve fluid output or uses the piezoelectric vibrator to generate fluctuations to transmit fluid. Piezoelectric The pump has features that traditional pumps do not have. The piezoelectric ceramic air pump can directly convert alternating current energy into kinetic energy without the need to drive components to rotate through electromagnetic field conversion. Its energy conversion efficiency is naturally higher than that of electromagnetic vibration air pumps and DC motor air pumps.

The patent application number CN201620097997, titled Piezoelectric Ceramic Air Pump, describes a piezoelectric ceramic air pump. The piezoelectric pump consists of a piezoelectric vibrator, a pump valve and a pump body. During operation, when AC power U is applied to both ends of the piezoelectric vibrator, the piezoelectric vibrator is radially compressed under the action of the electric field, and tensile stress is generated internally, causing the piezoelectric vibrator to bend and deform. When the piezoelectric vibrator bends forward, the piezoelectric vibrator stretches, the volume of the pump cavity increases, the fluid pressure in the cavity decreases, the pump valve opens, and the fluid enters the pump cavity; when the piezoelectric vibrator bends in the reverse direction, the piezoelectric vibrator Contraction, the volume of the pump chamber decreases, the fluid pressure in the chamber increases, the pump valve closes, and the fluid in the pump chamber is squeezed out, forming a gentle, continuous directional flow. Piezoelectric ceramic air pumps are usually used in micro air pumps. Piezoelectric ceramic air pumps made of piezoelectric ceramic materials have high electromechanical conversion rates, strong heat dissipation stability, high strength, good toughness, strong oxidation resistance, and many other advantages. Simple, fast response, small size, no noise and other characteristics. However, since piezoelectric ceramic sheets need to be driven by alternating current to move, this feature limits the application of piezoelectric ceramic pumps in outdoor scenes. The piezoelectric pump in this application is a piezoelectric ceramic pump.

Contents of the invention

The technical problem to be solved by this application is to avoid the above-mentioned shortcomings of the prior art in being unable to provide an air pump with low power consumption and strong endurance that is suitable for outdoor portable application scenarios, and to propose a piezoelectric ceramic that is suitable for outdoor portable applications. The air pump can directly use DC power supply, has low power consumption, low noise, and high energy conversion efficiency. It is suitable for a variety of application scenarios, especially outdoor portable scenarios.

The technical solution to solve the above technical problems in this application is a piezoelectric ceramic air pump suitable for outdoor portable use, including a DC-AC inverter and a piezoelectric ceramic air pump main body; the DC-AC inverter is used to convert the energy provided by an external DC power supply Direct current is converted into alternating current; the input end of the DC-AC inverter is used to electrically connect to an external DC power supply to obtain DC input; the output end of the DC-AC inverter is used to electrically connect to the piezoelectric ceramic sheet in the main body of the piezoelectric ceramic air pump. The connection provides alternating current to the piezoelectric ceramic piece, and the alternating current drives the piezoelectric ceramic piece to vibrate.

The DC-AC inverter includes an MCU control circuit, an inverter bridge circuit and a step-up transformer; the MCU control circuit is electrically connected to the input end of the inverter bridge circuit, and the output end of the inverter bridge circuit is to the input of the step-up transformer. terminals are electrically connected; the MCU control circuit outputs a pair of PWM pulse control signals with opposite polarity to the inverter bridge circuit; the pair of PWM pulse control signals with opposite polarity are used to control the frequency and amplitude of the alternating current output by the inverter bridge circuit.

The MCU control circuit is also provided with a frequency adjustment interface; the frequency adjustment interface is used to receive external frequency adjustment instructions, and the MCU control circuit adjusts the frequency of the PWM pulse control signal output by the MCU control circuit according to the received frequency adjustment instructions; or the MCU control circuit is also set There is a frequency adjustment switch, and the MCU control circuit adjusts the frequency of the PWM pulse control signal output by the MCU control circuit according to the frequency adjustment switch state; the frequency of the PWM pulse control signal determines the frequency of the voltage signal output by the inverter bridge circuit.

The MCU control circuit is also provided with a voltage adjustment interface; the voltage adjustment interface is used to receive external voltage adjustment instructions, and the MCU control circuit adjusts the duty cycle of the PWM pulse control signal output by the MCU control circuit according to the received voltage adjustment instructions; or MCU control The circuit is also equipped with a duty cycle regulator. The MCU control circuit adjusts the duty cycle of the PWM pulse control signal output by the MCU control circuit according to the status of the duty cycle regulator; the duty cycle of the PWM pulse control signal determines the output of the inverter bridge circuit. voltage.

The piezoelectric ceramic air pump suitable for outdoor portable use also includes a power supply switch; the power supply switch is used to control the connection relationship between the piezoelectric ceramic piece in the piezoelectric ceramic air pump body and the external power supply; the power supply switch In the first state, the piezoelectric ceramic piece in the main body of the piezoelectric ceramic air pump is electrically connected to the output end of the DC-AC inverter. At this time, the piezoelectric ceramic air pump can be powered by the DC power supply connected to the DC-AC inverter. ; In the second state of the power supply switch, the piezoelectric ceramic sheet in the piezoelectric ceramic air pump body is electrically disconnected from the output end of the DC-AC inverter, and the piezoelectric ceramic sheet in the piezoelectric ceramic air pump body is electrically disconnected from the external The AC power supply is electrically connected. At this time, the piezoelectric ceramic air pump can be powered by an external AC power supply.

The piezoelectric ceramic air pump suitable for outdoor portable use also includes a low-voltage DC power supply; the output terminal of the low-voltage DC power supply is electrically connected to the input terminal of the DC-AC inverter.

The low-voltage DC power supply is a power supply with a safety voltage lower than 36V, including any one of dry batteries, lithium batteries, lead-acid batteries or battery packs.

The low-voltage DC power supply is a power supply device that can provide a safe voltage lower than 36V, including any one of a vehicle charging power supply, a USB power supply, or an AC-DC adapter.

The piezoelectric ceramic air pump suitable for outdoor portable use also includes an AC-DC switching power supply and a charging management circuit; the AC-DC switching power supply is used to obtain electric energy from an external AC power supply; the AC-DC switching power supply is electrically connected to the MCU control circuit , the AC-DC switching power supply supplies power to the MCU control circuit; the AC-DC switching power supply is electrically connected to the charging management circuit, and the charging management circuit is electrically connected to the low-voltage DC power supply; the low-voltage DC power supply is electrically connected to obtain electric energy from the external AC power supply through the charging management circuit. Charge.

The piezoelectric ceramic air pump suitable for outdoor portable use also includes an AC detection circuit and a power switching circuit; one end of the AC detection circuit is electrically connected to the AC-DC switching power supply; the other end of the AC detection circuit is electrically connected to the MCU control circuit; The MCU control circuit obtains the connection status of the external AC power supply through the AC detection circuit; the power switching circuit includes a switch tube Q1, a relay and a single-pole double-throw switch. The switch tube Q1 is electrically connected to the MCU control circuit; the switch tube Q1 is electrically connected to the relay, and the relay Controls the connection status of the SPDT switch; one terminal of the SPDT switch is electrically connected to the inverter bridge circuit, one terminal of the SPDT switch is used to electrically connect to the low-voltage DC power supply, and one terminal of the SPDT switch is used to and AC-DC switching power supply is electrically connected; the MCU control circuit controls the state of the switch tube Q1 according to the obtained connection status of the external AC power supply, and the switch tube Q1 controls the state of the relay; when the MCU control circuit obtains the connection status of the external AC power supply, there is When the external AC power supply is connected, the state of the single-pole double-throw switch will electrically connect the inverter bridge circuit and the AC-DC switching power supply; when the MCU control circuit obtains the connection state of the external AC power supply and there is no external AC power supply connection state, the single-pole double-throw switch will The state of the double-throw switch electrically connects the inverter bridge circuit to the low-voltage DC source.

Compared with the existing technology, one of the beneficial effects of the technical solution in this application is the built-in DC-AC inverter, which makes the piezoelectric ceramic air pump suitable for DC power supply, expanding the applicable scenarios of the piezoelectric ceramic air pump. It is no longer limited to AC power supply situations.

Compared with the existing technology, the second beneficial effect of the technical solution in this application is that the built-in low-voltage DC power supply can make the piezoelectric ceramic air pump suitable for outdoor or other portable applications without AC power supply; and it can exert The piezoelectric ceramic air pump has the advantages of high energy conversion efficiency, power saving and low noise. It is very suitable for pumping gas into buckets filled with fish during outdoor fishing. Since the piezoelectric ceramic air pump directly converts alternating current energy into mechanical vibration, without the need for other electromagnetic intermediate conversion processes, its energy conversion efficiency is higher, and it consumes less power when pumping the same amount of air and is more energy-saving; therefore, it is more energy-saving when pumping the same amount of air. Under the condition of low-voltage DC power supply, the piezoelectric ceramic air pump can keep working for a longer time. And because there is no electric motor, the overall operating noise of the air pump is also very low, which is very suitable for fishing and other occasions that require a quiet environment.

Compared with the existing technology, the third beneficial effect of the technical solution in this application is that the frequency of the voltage signal output by the inverter bridge circuit can be adjusted by adjusting the frequency of the PWM pulse control signal output by the MCU control circuit, thereby adjusting the piezoelectric The working frequency of the ceramic air pump enables the working frequency of the piezoelectric ceramic air pump to be adjusted to the most suitable frequency, thereby improving the energy conversion efficiency of the piezoelectric ceramic air pump.

Compared with the existing technology, the fourth beneficial effect of the technical solution in this application is that the amplitude of the voltage signal output by the inverter bridge circuit can be adjusted through the duty cycle of the PWM pulse control signal, thereby adjusting the output of the piezoelectric ceramic air pump. The vibration amplitude enables the vibration amplitude of the piezoelectric ceramic air pump to be adjusted to the most suitable vibration amplitude, thereby improving the energy conversion efficiency of the piezoelectric ceramic air pump.

Compared with the existing technology, the fifth beneficial effect of the technical solution in this application is that the setting of the power supply switch allows the piezoelectric ceramic air pump to seamlessly switch between AC power supply and DC power supply scenarios. In situations where AC power supply is available, it can be easily switched to AC power supply by plug-and-play, and its built-in low-voltage DC power supply can be charged through AC power without the need to disassemble the built-in low-voltage DC power supply.

Compared with the existing technology, the sixth beneficial effect of the technical solution in this application is that when external AC power is supplied, the frequency and occupancy of the PWM pulse control signal can also be controlled through the MCU control circuit, the inverter bridge circuit and the step-up transformer. The air ratio is controlled to control the AC frequency and amplitude output by the inverter bridge circuit, so that the piezoelectric ceramic air pump can work at the optimal operating frequency and amplitude, further improving the working efficiency of the piezoelectric ceramic air pump.

Description of drawings

Figure 1 is a schematic diagram of the connection between a portable piezoelectric ceramic air pump suitable for outdoor use and an external low-voltage DC power supply;

Figure 2 is one of the schematic block diagrams of the connection between the DC-AC inverter and the piezoelectric ceramic sheet;

Figure 3 is the second schematic block diagram of the connection between the DC-AC inverter and the piezoelectric ceramic sheet;

Figure 4 is a schematic diagram of the connection between the inverter bridge and the step-up transformer in the DC-AC inverter;

Figure 5 is one of the schematic block diagrams of a piezoelectric ceramic air pump that can be applied to both DC power supply and AC power supply;

Figure 6 is the second schematic block diagram of a piezoelectric ceramic air pump that can be applied to both DC power supply and AC power supply;

Figure 7 is a schematic diagram of a piezoelectric pump in an actual application scenario.

Detailed ways

The embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

As shown in Figures 1 and 2, an embodiment of an outdoor portable piezoelectric ceramic air pump includes a DC-AC inverter and a piezoelectric ceramic air pump body; the DC-AC inverter is used to convert an external DC power supply The provided direct current is converted into alternating current; the input end of the DC-AC inverter is used to electrically connect to an external DC power supply to obtain direct current input; the output end of the DC-AC inverter is used to connect to the piezoelectric ceramics in the piezoelectric ceramic air pump body. The chip electrical connection provides alternating current to the piezoelectric ceramic piece, and the alternating current drives the piezoelectric ceramic piece to vibrate.

As shown in Figures 1 and 2, in an embodiment of a portable piezoelectric ceramic air pump suitable for outdoor use, the DC-AC inverter includes an MCU control circuit, an inverter bridge circuit and a step-up transformer; the MCU control circuit and The input end of the inverter bridge circuit is electrically connected, and the output end of the inverter bridge circuit is electrically connected to the input end of the step-up transformer; the MCU control circuit outputs a pair of PWM pulse control signals with opposite polarity to the inverter bridge circuit; the pair The PWM pulse control signal with opposite polarity is used to control the AC frequency output by the inverter bridge circuit.

In some embodiments of piezoelectric ceramic air pumps suitable for outdoor portable use not shown in the drawings, the MCU control circuit is also provided with a frequency adjustment interface; the frequency adjustment interface is used to receive external frequency adjustment instructions, and the MCU control circuit responds to the received The frequency adjustment instruction adjusts the frequency of the PWM pulse control signal output by the MCU control circuit; the frequency of the PWM pulse control signal determines the frequency of the voltage signal output by the inverter bridge circuit. The MCU control circuit is also equipped with a voltage adjustment interface; the voltage adjustment interface is used to receive external voltage adjustment instructions. The MCU control circuit adjusts the duty cycle of the PWM pulse control signal output by the MCU control circuit according to the received voltage adjustment instructions. PWM pulse control The duty cycle of the signal determines the voltage output by the inverter bridge circuit.

As shown in Figure 3, in an embodiment of a piezoelectric ceramic air pump suitable for outdoor portable use, the MCU control circuit is also provided with a frequency adjustment switch. The MCU control circuit adjusts the PWM pulse control signal output by the MCU control circuit according to the frequency adjustment switch state. frequency; the MCU control circuit is also equipped with a duty cycle regulator, and the MCU control circuit adjusts the duty cycle of the PWM pulse control signal output by the MCU control circuit according to the status of the duty cycle regulator.

Piezoelectric pumps on the market usually supply power at power frequency AC, and the frequency cannot be changed. In actual use, it is found that the optimal working frequency of the piezoelectric ceramic disc is often not the power frequency, and the one-way valve disc has different materials and thicknesses. The optimal working frequency is often not the power frequency. By adjusting the period of the PWM pulse control signal and changing the working frequency of the pump, the pump performance can be maximized. The MCU control circuit is connected to the inverter bridge circuit and provides a pair of PWM pulse control signals with opposite polarity to the inverter bridge circuit. The period or frequency of the PWM pulse control signal can be artificially set by the microprocessor inside the MCU or externally. Instructions or frequency adjustment switches are used to ensure that the piezoelectric ceramic disc and one-way valve disc work at the optimal operating frequency.

The flow and pressure of piezoelectric pumps on the market are generally not adjustable; in this application, by changing the duty cycle of the PWM pulse signal, the power supply voltage at both ends of the piezoelectric ceramic piece can be changed. The size of the power supply voltage at both ends of the piezoelectric ceramic piece will determine The vibration amplitude of the piezoelectric ceramic piece determines the flow rate of the piezoelectric pump; in this application, the flow and pressure adjustable functions of the piezoelectric pump are realized by changing the duty cycle of the PWM pulse signal.

As shown in Figure 4, in an embodiment of a piezoelectric ceramic air pump suitable for outdoor portable use, the inverter bridge circuit includes two sets of MOS tubes, and one PWM signal controls one set of MOS tubes; when PWM1 is positive, PWM2 is negative When PWM1 is negative, VT2 and VT3 are on, and VT1 and VT4 are off; when PWM1 is negative and PWM2 is positive, VT1 and VT4 are on, and VT2 and VT3 are off. Since the two PWM signals are complementary, the two sets of MOS tubes are turned on alternately and repeatedly to complete the DC to AC conversion. The inverter bridge circuit switches and connects the primary of the step-up transformer according to the PWM pulse control signal output by the MCU control circuit. The secondary of the step-up transformer boosts the pulsating primary voltage to provide the piezoelectric ceramic sheet in the piezoelectric ceramic pump. Providing power, the frequency of the voltage output by the secondary of the step-up transformer is related to the period of the PWM, and the volt value of the voltage is related to the duty cycle of the PWM.

In some embodiments of an outdoor portable piezoelectric ceramic air pump not shown in the drawings, the MCU control circuit is also provided with a communication module for communicating with an external terminal to obtain external control instructions.

As shown in Figure 5, an embodiment of a piezoelectric ceramic air pump suitable for outdoor portable use also includes a power supply switch; the power supply switch is used to control the connection between the piezoelectric ceramic sheet in the main body of the piezoelectric ceramic air pump and the power supply. Connection relationship; in the first state of the power supply switch, the piezoelectric ceramic piece in the main body of the piezoelectric ceramic air pump is electrically connected to the output end of the DC-AC inverter. At this time, the piezoelectric ceramic air pump can be powered by an external DC power supply; At this time, as shown in Figure 5, the output terminal b-1 of the step-up transformer is electrically connected to the a-1 terminal of the piezoelectric ceramic piece, and the output terminal b-2 of the step-up transformer is electrically connected to the a-2 terminal of the piezoelectric ceramic piece. connect. In the second state of the power supply switch, the piezoelectric ceramic piece in the piezoelectric ceramic air pump body is electrically disconnected from the output end of the DC-AC inverter, and the piezoelectric ceramic piece in the piezoelectric ceramic air pump body is connected to an AC power supply. Electrical connection. At this time, the piezoelectric ceramic air pump can be powered by an external AC power supply. At this time, the output terminal c-1 of the external AC power supply is electrically connected to the a-1 terminal of the piezoelectric ceramic sheet. The output terminals c-2 and The a-2 terminal of the piezoelectric ceramic piece is electrically connected.

As shown in Figures 1 and 2, an embodiment of a piezoelectric ceramic air pump suitable for outdoor portable use also includes a low-voltage DC power supply; the output end of the low-voltage DC power supply is electrically connected to the input end of the DC-AC inverter.

In some embodiments of an outdoor portable piezoelectric ceramic air pump not shown in the drawings, the low-voltage DC power supply is a power supply with a safe voltage lower than 36V, including dry batteries, lithium batteries, lead-acid batteries or battery packs. any of them.

In some embodiments of a portable piezoelectric ceramic air pump suitable for outdoor use not shown in the drawings, the low-voltage DC power supply is a power supply device that can provide a safe voltage lower than 36V, including a vehicle charging power supply, USB power supply or AC -Any kind of DC adapter.

As shown in Figure 6, an embodiment of a piezoelectric ceramic air pump suitable for outdoor portable use also includes an AC-DC switching power supply and a charging management circuit; the AC-DC switching power supply is used to obtain power from an external AC power supply; the AC-DC switching power supply The DC switching power supply is electrically connected to the MCU control circuit. The AC-DC switching power supply supplies power to the MCU control circuit. The AC-DC switching power supply is electrically connected to the charging management circuit. The charging management circuit is electrically connected to the low-voltage DC power supply. The low-voltage DC power supply is electrically connected through charging. The management circuit obtains electrical energy from an external AC power source for charging.

As shown in Figure 6, an embodiment of a piezoelectric ceramic air pump suitable for outdoor portable use also includes an AC detection circuit and a power switching circuit; one end of the AC detection circuit is electrically connected to the AC-DC switching power supply; the AC detection circuit The other end is electrically connected to the MCU control circuit; the MCU control circuit obtains the connection status of the external AC power supply through the AC detection circuit; the power switching circuit includes a switch tube Q1, a relay and a single-pole double-throw switch, and the switch tube Q1 is electrically connected to the MCU control circuit; Switch tube Q1 is electrically connected to the relay, and the relay controls the connection state of the single-pole double-throw switch; one terminal of the single-pole double-throw switch is electrically connected to the inverter bridge circuit, and one terminal of the single-pole double-throw switch is used to electrically connect to the low-voltage DC power supply. One terminal of the double-throw switch is used to electrically connect to the AC-DC switching power supply; the MCU control circuit controls the state of the switch tube Q1 according to the obtained external AC power supply connection status, and the switch tube Q1 controls the state of the relay; when the MCU control circuit When the connection status of the external AC power source is obtained, the status of the SPDT switch will electrically connect the inverter bridge circuit and the AC-DC switching power supply; when the connection status of the external AC power source obtained by the MCU control circuit is When there is no external AC power connection, the state of the SPDT switch will electrically connect the inverter bridge circuit to the low-voltage DC power supply.

As shown in Figure 6, in a scenario with AC power supply, the AC power is converted into DC power VCC through the AC-DC switching power supply circuit. One channel of VCC passes through the charging management circuit to charge the low-voltage DC power supply, and the other channel passes through diode D1 to generate VDD to power the MCU control circuit. . When AC power is supplied, VCC provides a control signal to the MCU control circuit through the AC detection circuit. Q1 is cut off, the relay is powered off, and the switch terminals a and c are connected. VCC supplies power to the inverter bridge circuit through the switch terminals a and c. After boosting The transformer boosts the voltage and provides power to the piezoelectric ceramic piece.

As shown in Figure 6, when used in a scenario without AC power, the low-voltage DC power supply BT generates VDD through diode D2 to power the MCU control circuit. Because VCC = 0, the AC detection circuit cannot provide a control signal to the MCU control circuit. Q1 is turned on, the relay is closed, terminals a and b of the switch are connected, terminals a and c are disconnected, and the low-voltage DC power supply BT passes through terminals a and b. It supplies power to the inverter bridge and provides power to the piezoelectric ceramic chip after being boosted by the step-up transformer. This design makes the piezoelectric ceramic air pump suitable for both AC power supply and DC power supply. When powered by AC, the frequency and amplitude of the voltage signal output to both ends of the piezoelectric ceramic chip can be adjusted through the MCU control circuit and the inverter bridge circuit.

Figure 7 is a schematic diagram of a piezoelectric pump in an actual application scenario. The piezoelectric pump in Figure 7 is a piezoelectric ceramic pump, used to pump gas into water bodies. The piezoelectric pump in the figure has a built-in low-voltage DC power supply for independent operation. Power supply to maintain long-term application requirements in outdoor portable scenarios. Due to the high energy conversion efficiency of the piezoelectric pump, the capacity and volume of the built-in low-voltage DC power supply do not need to be too large, making the overall size of the piezoelectric pump and the low-voltage DC power supply smaller, making it more portable and more suitable for outdoor and requirements for portable application scenarios. In some applications, piezoelectric ceramic pumps are small in size and light in weight, making them very convenient to carry and use outdoors. When in use, it can be easily hung on the edge of the bucket, and it is very quiet because there is no noise from the motor.

The air pump using the design scheme in this application has the following advantages: it achieves low power consumption and low noise, and can be driven by battery power for a long time; the piezoelectric ceramic air pump is not affected by the ambient temperature, has stable working performance and long life. It can be used outdoors when there is no AC power, and can be charged through a power bank or car charger for battery life. The shape can be smaller and lighter, making it easy to carry when going out; it can be powered by low-voltage DC, making it safer to use; it can change the frequency of the piezoelectric ceramic chip power supply to make the piezoelectric ceramic chip and one-way valve work in the best condition. The voltage value of the piezoelectric ceramic chip power supply can be changed to adjust the flow and pressure of the pump.

The above are only examples of the present application, and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the application description and drawings may be directly or indirectly used in other related technical fields. , are all equally included in the patent protection scope of this application.

Claims

A portable piezoelectric ceramic air pump suitable for outdoor use, which is characterized by:

Including DC-AC inverter and piezoelectric ceramic air pump body;

DC-AC inverter is used to convert DC power provided by an external DC power supply into AC power;

The input end of the DC-AC inverter is used to electrically connect with an external DC power source to obtain DC input;

The output end of the DC-AC inverter is used to electrically connect with the piezoelectric ceramic sheet in the main body of the piezoelectric ceramic air pump to provide alternating current to the piezoelectric ceramic sheet, and the alternating current drives the piezoelectric ceramic sheet to vibrate.
The piezoelectric ceramic air pump suitable for outdoor portability according to claim 1, characterized in that:

The DC-AC inverter includes an MCU control circuit, an inverter bridge circuit and a step-up transformer;

The MCU control circuit is electrically connected to the input end of the inverter bridge circuit, and the output end of the inverter bridge circuit is electrically connected to the input end of the step-up transformer;

The MCU control circuit outputs a pair of PWM pulse control signals with opposite polarity to the inverter bridge circuit; the pair of PWM pulse control signals with opposite polarity are used to control the frequency and amplitude of the alternating current output by the inverter bridge circuit.
The piezoelectric ceramic air pump suitable for outdoor portability according to claim 2, characterized in that:

The MCU control circuit is also equipped with a frequency adjustment interface; the frequency adjustment interface is used to receive external frequency adjustment instructions, and the MCU control circuit adjusts the frequency of the PWM pulse control signal output by the MCU control circuit according to the received frequency adjustment instructions;

Or the MCU control circuit is also equipped with a frequency adjustment switch, and the MCU control circuit adjusts the frequency of the PWM pulse control signal output by the MCU control circuit according to the frequency adjustment switch state;

The frequency of the PWM pulse control signal determines the frequency of the voltage signal output by the inverter bridge circuit.
The piezoelectric ceramic air pump suitable for outdoor portability according to claim 2, characterized in that:

The MCU control circuit is also equipped with a voltage adjustment interface; the voltage adjustment interface is used to receive external voltage adjustment instructions, and the MCU control circuit adjusts the duty cycle of the PWM pulse control signal output by the MCU control circuit based on the received voltage adjustment instructions;

Or the MCU control circuit is also equipped with a duty cycle regulator, and the MCU control circuit adjusts the duty cycle of the PWM pulse control signal output by the MCU control circuit according to the status of the duty cycle regulator;

The duty cycle of the PWM pulse control signal determines the voltage output by the inverter bridge circuit.
The piezoelectric ceramic air pump suitable for outdoor portability according to claim 1, characterized in that:

Also included is a power supply switch;

The power supply switch is used to control the connection relationship between the piezoelectric ceramic piece in the piezoelectric ceramic air pump body and the external power supply;

In the first state of the power supply switch, the piezoelectric ceramic piece in the main body of the piezoelectric ceramic air pump is electrically connected to the output end of the DC-AC inverter. At this time, the piezoelectric ceramic air pump can be connected to the DC-AC inverter through DC power supply to obtain power supply;

In the second state of the power supply switch, the piezoelectric ceramic piece in the piezoelectric ceramic air pump body is electrically disconnected from the output end of the DC-AC inverter, and the piezoelectric ceramic piece in the piezoelectric ceramic air pump body communicates with the outside. The power supply is electrically connected, and the piezoelectric ceramic air pump can be powered by an external AC power supply.
The piezoelectric ceramic air pump suitable for outdoor portability according to claim 1, characterized in that:

Also includes low voltage DC power supply;

The output terminal of the low-voltage direct current power supply is electrically connected to the input terminal of the DC-AC inverter.
The piezoelectric ceramic air pump suitable for outdoor portability according to claim 6, characterized in that:

The low-voltage DC power supply is a power supply with a safety voltage lower than 36V, including any one of dry batteries, lithium batteries, lead-acid batteries or battery packs.
The piezoelectric ceramic air pump suitable for outdoor portability according to claim 6, characterized in that:

The low-voltage DC power supply is a power supply device that can provide a safe voltage lower than 36V, including any one of a vehicle charging power supply, a USB power supply, or an AC-DC adapter.
The piezoelectric ceramic air pump suitable for outdoor portability according to claim 6, characterized in that:

It also includes an AC-DC switching power supply and a charging management circuit; the AC-DC switching power supply is used to obtain power from an external AC power supply; the AC-DC switching power supply is electrically connected to the MCU control circuit, and the AC-DC switching power supply supplies power to the MCU control circuit;

The AC-DC switching power supply is electrically connected to the charging management circuit, and the charging management circuit is electrically connected to the low-voltage DC power supply. The low-voltage DC power supply is electrically connected to obtain electric energy from an external AC power supply through the charging management circuit for charging.
The piezoelectric ceramic air pump suitable for outdoor portability according to claim 9, characterized in that:

Also includes AC detection circuit and power switching circuit;

One end of the AC detection circuit is electrically connected to the AC-DC switching power supply; the other end of the AC detection circuit is electrically connected to the MCU control circuit; the MCU control circuit obtains the connection status of the external AC power supply through the AC detection circuit;

The power switching circuit includes switch tube Q1, a relay and a single-pole double-throw switch. The switch tube Q1 is electrically connected to the MCU control circuit; the switch tube Q1 is electrically connected to the relay, and the relay controls the connection status of the single-pole double-throw switch; one of the single-pole double-throw switch The terminals are electrically connected to the inverter bridge circuit, one terminal of the SPDT switch is used to electrically connect to the low-voltage DC power supply, and one terminal of the SPDT switch is used to electrically connect to the AC-DC switching power supply;

The MCU control circuit controls the state of the switch tube Q1 according to the obtained connection status of the external AC power supply, and the switch tube Q1 controls the state of the relay;

When the connection status of the external AC power obtained by the MCU control circuit is the connection status of the external AC power, the status of the SPDT switch will electrically connect the inverter bridge circuit and the AC-DC switching power supply;

When the connection status of the external AC power obtained by the MCU control circuit is that there is no external AC power connection, the status of the single-pole double-throw switch will electrically connect the inverter bridge circuit and the low-voltage DC power supply.