A vacuum pump control circuit and a vacuum pump control method

Abstract

The present application discloses a vacuum pump control circuit and a vacuum pump control method. In this vacuum pump control circuit, the first end of a control button is connected to a power supply, the second end of the control button is connected to the first end of a first resistor, the second end of the first resistor is grounded, and the first end and the second end of the control button are respectively connected to a controller; a first interface of the controller is used to be connected to a first switching element, the first end of the first switching element is connected to the first end of an electric vacuum pump, the second end of the first switching element is connected to the first end of a current detection resistor, the second end of the electric vacuum pump is connected to the power supply, and the second end of the current detection resistor is grounded; a second interface of the controller is connected to the output of an operational amplifier, the first end of the current detection resistor is connected to the non-inverting input of the operational amplifier, the first end of a second resistor is connected to the output of the operational amplifier, the second end of the second resistor is connected to the inverting input of the operational amplifier, and the first end of a third resistor is connected to the inverting input of the operational amplifier and the second end is grounded.

Description

Technical Field

[0001] The present invention relates to the field of vacuum pumps, and in particular to a vacuum pump control circuit and a vacuum pump control method. Background Art

[0002] Household electric vacuum pumps are currently widely used in food preservation and item storage. Its core structure consists of an electric air pump, a sealed connector connecting to the space to be evacuated, a power supply, a control / indicator circuit, and a pressure sensor for detecting the vacuum degree. Its working principle is as follows: After connecting the sealed connector to the space to be evacuated, start the control circuit to drive the electric air pump to work, extract the air inside the space to be evacuated, and increase the vacuum degree inside it. The control circuit monitors the negative pressure value inside the extraction space in real time through a pressure sensor (or pressure switch). When the vacuum degree increases to the set value, stop the electric air pump, that is, complete a vacuum pumping operation.

[0003] In actual design, the pressure sensor has a high cost and a large volume, which requires a large space, and a connecting pipeline needs to be designed for it to realize the sampling of the internal pressure of the space to be evacuated. This pressure sensor is not conducive to the miniaturization design of the product, making the product assembly complex and costly. Moreover, since the sensor needs to be calibrated for pressure in specific applications, the welding operation is likely to cause parameter drift, which may lead to low product qualification rate and problems in product quality. Summary of the Invention

[0004] The first aspect of the present application provides a vacuum pump control circuit, which includes: a power supply, a controller, a control button, an electric vacuum pump, a first switching element, a first resistor, a current detection resistor, an operational amplifier, a second resistor, and a third resistor. The first end of the control button is connected to the power supply, the second end of the control button is connected to the first end of the first resistor, the second end of the first resistor is grounded, and the first end and the second end of the control button are respectively connected to the controller; the controller includes a first interface and a second interface. The first interface is used to connect to the first switching element. The first end of the first switching element is connected to the first end of the electric vacuum pump, the second end of the first switching element is connected to the first end of the current detection resistor, the second end of the electric vacuum pump is connected to the power supply, and the second end of the current detection resistor is grounded; the second interface of the controller is connected to the output of the operational amplifier, the first end of the current detection resistor is connected to the non-inverting input of the operational amplifier, the first end of the second resistor is connected to the output of the operational amplifier, the second end of the second resistor is connected to the inverting input of the operational amplifier, and the first end of the third resistor is connected to the inverting input of the operational amplifier and the second end is grounded. In the vacuum pump control circuit provided by the present application, the controller can detect the current of the electric vacuum pump through the current detection resistor, thereby obtaining the power of the electric vacuum pump, and further obtaining the negative pressure value corresponding to the vacuum pump power, so as to determine whether the set vacuum degree is reached. It is not necessary to use a pressure sensor to judge whether the preset negative pressure value is reached, nor is it necessary to design a connection pipeline for the pressure sensor, which is beneficial to the miniaturization design of the vacuum pump product, can save the assembly cost, and can improve the product qualification rate.

[0005] Optionally, in combination with the first aspect, the vacuum pump control circuit further includes: a voltage sampling network, which includes: a fourth resistor, a fifth resistor, and a first capacitor. The controller further includes a third interface. The first end of the fourth resistor is connected to the power supply, the second end of the fourth resistor is connected to the third interface, the first end of the fifth resistor is connected to the third interface, the second end of the fifth resistor is grounded, the first end of the first capacitor is connected to the third interface, and the second end of the first capacitor is grounded.

[0006] Optionally, in combination with the first aspect, the vacuum pump control circuit further includes: a boost circuit, and the boost circuit includes: a second capacitor, a third capacitor, a first voltage stabilizing element, a sixth resistor, a first diode, a seventh resistor, an eighth resistor, and a fourth capacitor. The first voltage stabilizing element includes a first pin, a second pin, a third pin, a fourth pin, and a fifth pin. The first end of the second capacitor is connected to the power supply, and the second end of the second capacitor is grounded. The first end of the third capacitor is connected to the first pin, and the second end of the third capacitor is grounded. The second pin is connected to the power supply, and the third pin is grounded. The first end of the sixth resistor is connected to the power supply, the second end of the sixth resistor is connected to the positive electrode of the first diode, the positive electrode of the first diode is connected to the fourth pin, the negative electrode of the first diode is connected to the first end of the fourth capacitor, and the second end of the fourth capacitor is grounded. The first end of the seventh resistor is connected to the negative electrode of the first diode, the second end of the seventh resistor is connected to the fifth pin, the first end of the eighth resistor is connected to the fifth pin, and the second end of the eighth resistor is grounded.

[0007] Optionally, in combination with the first aspect, the vacuum pump control circuit further includes: a voltage dividing circuit and a fifth capacitor. The voltage dividing circuit includes a ninth resistor, a potentiometer, and a tenth resistor. The inverting input of the operational amplifier is connected to the slidable end of the potentiometer, the slidable end of the operational amplifier is connected to the first end of the fifth capacitor, the second end of the fifth capacitor is grounded, the first end of the ninth resistor is connected to the positive power supply, the second end of the ninth resistor is connected to the first end of the potentiometer, the second end of the potentiometer is connected to the first end of the tenth resistor, and the second end of the tenth resistor is grounded.

[0008] Optionally, in combination with the first aspect, the vacuum pump control circuit further includes a voltage stabilizing circuit, and the voltage stabilizing circuit includes: a sixth capacitor, a voltage stabilizing element, and a seventh capacitor. The first end of the sixth capacitor is connected to the positive power supply, the second end of the sixth capacitor is grounded, the first end of the voltage stabilizing element is connected to the first end of the sixth capacitor, the second end of the voltage stabilizing element is connected to the first end of the seventh capacitor, the second end of the seventh capacitor is grounded, and the first end of the seventh capacitor is connected to the first end of the control button.

[0009] Optionally, in combination with the first aspect, the first switching element includes a metal oxide semiconductor field effect transistor, a triode, or an insulated gate bipolar transistor.

[0010] The second aspect of the present application provides a vacuum pump control method, which is implemented by the vacuum pump control circuit described in the first aspect of the present application. The method includes: when an operation instruction is obtained, obtaining the real-time current value of the vacuum pump; determining the real-time power of the vacuum pump according to the real-time current value; obtaining the negative pressure value corresponding to the real-time power of the vacuum pump, and determining whether the negative pressure value is greater than or equal to a preset negative pressure threshold; when the negative pressure value is greater than or equal to the preset negative pressure threshold, stopping the operation of the vacuum pump. This method can detect the real-time current value of the vacuum pump, thereby obtaining the real-time power of the vacuum pump. Then, the negative pressure value corresponding to the real-time power is determined. When the negative pressure value is greater than or equal to the preset negative pressure threshold, the operation of the vacuum pump is stopped. The vacuum pump control circuit adopted by this vacuum pump control method does not need to judge whether the preset negative pressure value is reached through a pressure sensor, nor does it need to design a connection pipeline for the pressure sensor, which is beneficial to the miniaturized design of the vacuum pump product, can save the assembly cost, and can improve the product qualification rate.

[0011] Optionally, in combination with the second aspect, before determining the real-time power of the vacuum pump according to the real-time current value, the method further includes: obtaining the real-time voltage value of the vacuum pump; the step of determining the real-time power of the vacuum pump according to the real-time current value specifically includes: determining the real-time power of the vacuum pump according to the real-time current value and the real-time voltage value of the vacuum pump.

[0012] Optionally, in combination with the second aspect, the voltage value of the vacuum pump is preset, and the step of determining the real-time power of the vacuum pump according to the real-time current value specifically includes: determining the real-time power of the vacuum pump according to the real-time current value of the vacuum pump and the preset voltage value of the vacuum pump.

[0013] Optionally, in combination with the second aspect, there is a preset corresponding relationship between the power of the vacuum pump and the negative pressure value. The step of obtaining the negative pressure value corresponding to the real-time power of the vacuum pump includes: determining the negative pressure value corresponding to the real-time power of the vacuum pump according to the power of the vacuum pump and the corresponding relationship. Description of the Drawings

[0014] Figure 1 is a schematic structural diagram of a vacuum pump control circuit provided by the present application;

[0015] Figure 2 is a schematic structural diagram of a vacuum pump control circuit provided by the present application;

[0016] Figure 3 is a schematic structural diagram of a vacuum pump control circuit provided by the present application;

[0017] Figure 4 is a schematic flowchart of a vacuum pump control method provided by the present application. Detailed implementation manners

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present invention.

[0019] The terms "first", "second", etc. in the specification, claims and above-mentioned drawings of this application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments described here can be implemented in an order different from that shown or described here. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or modules does not necessarily have to be limited to those steps or modules clearly listed, but may include other steps or modules not clearly listed or inherent to these processes, methods, products or devices.

[0020] Household electric vacuum pumps are currently widely used in food preservation and item storage. Its core structure consists of an electric air pump, a sealed connection piece connecting to the space to be evacuated, a power supply, a control / indicator circuit, and a pressure sensor for detecting the vacuum degree. Its working principle is as follows: After connecting the sealed connection piece to the space to be evacuated, start the control circuit to drive the electric air pump to work, pump out the air in the space to be evacuated, and increase the vacuum degree inside it. The control circuit monitors the negative pressure value in the evacuated space in real time through a pressure sensor (or pressure switch). When the vacuum degree increases to the set value, stop the electric air pump, that is, complete a vacuum pumping operation.

[0021] In actual design, the pressure sensor has a high cost and a large volume, which requires a large amount of space, and a connection pipeline needs to be designed for it to realize the sampling of the internal pressure of the space to be evacuated. This pressure sensor is not conducive to the miniaturization design of the product, making the product assembly complex and costly. Moreover, since the sensor needs to be calibrated for pressure in specific applications, the welding operation is likely to cause parameter drift, which may lead to a low product qualification rate and problems in product quality.

[0022] Therefore, Embodiment 1 of this application provides a vacuum pump control circuit. Please refer to Figure 1 , and this vacuum pump control circuit includes:

[0023] Power supply (DC+), controller (U2), control button (K1), electric vacuum pump (M1), first switching element (Q1), first resistor (R1), current detecting resistor (R7), operational amplifier (U3), second resistor (R4), third resistor (R5).

[0024] The first terminal of the control button (K1) is connected to the power supply (DC+), the second terminal of the control button (K1) is connected to the first terminal of the first resistor (R1), the second terminal of the first resistor (R1) is grounded, and the first and second terminals of the control button (K1) are respectively connected to the controller (U2). It should be noted that the controller (U2) can be a microcontroller unit (MCU). Exemplarily, the selected product model can be SN8P2722.

[0025] The controller (U2) includes a first interface (DRV) and a second interface (ADC1). The first interface (DRV) is used to connect to the first switching element (Q1). The first terminal of the first switching element (Q1) is connected to the first terminal of the electric vacuum pump (M1), the second terminal of the first switching element (Q1) is connected to the first terminal of the current detecting resistor (R7), the second terminal of the electric vacuum pump (M1) is connected to the power supply (DC+), and the second terminal of the current detecting resistor (R7) is grounded. It should be noted that the first switching element (Q1) can be a metal oxide semiconductor (MOS) transistor, or a triode or an insulated gate bipolar transistor (IGBT). If the first switching element (Q1) is a MOS transistor, the gate of the MOS transistor is connected to the first interface (DRV). By operating the control button (K1), the electric vacuum pump (M1) can be started or stopped through the first interface (DRV), and the power supply of the electric vacuum pump (M1) can be connected or disconnected to start or stop its operation.

[0026] The second interface (ADC1) of the controller (U2) is connected to the output of the operational amplifier (U3). The first terminal of the current detecting resistor (R7) is connected to the non-inverting input of the operational amplifier (U3). The first terminal of the second resistor (R4) is connected to the output of the operational amplifier, and the second terminal of the second resistor (R4) is connected to the inverting input of the operational amplifier (U3). The first terminal of the third resistor (R5) is connected to the inverting input of the operational amplifier (U3), and the second terminal is grounded.

[0027] When the electric vacuum pump (M1) is working, the current flows from the power supply (DC+) through the electric vacuum pump (M1), the first switching element (Q1) and the current detecting resistor (R7) back to the power supply ground, generating a voltage drop across the current detecting resistor (R7).

[0028] The operational amplifier (U3), optional models including but not limited to LM358, can amplify the voltage signal on the current sensing resistor (R7), and its output signal characterizes the current value on the electric vacuum pump (M1) through the second interface (ADC1) and is input to the controller (U2) for detection. The resistance values of the second resistor (R4) and the third resistor (R5) determine the amplification factor of the operational amplifier (U3). Specifically, the amplification factor of this operational amplifier (U3) = 1 + (R4 / R5).

[0029] In addition, please refer to Figure 1 , the resistor R6 and the capacitor C4 form an RC filter network, which filters the voltage on the current sensing resistor (R7). The current on the motor has rich fluctuations, which is not conducive to the MCU for detection. Filtering here can filter out the interference signals.

[0030] The vacuum pump control circuit further includes: a voltage sampling network, and this voltage sampling network includes: a fourth resistor (R2), a fifth resistor (R3) and a first capacitor (C3). The controller (U2) further includes a third interface (ADC2).

[0031] The first end of the fourth resistor (R2) is connected to the power supply (DC+), the second end of the fourth resistor (R2) is connected to the third interface (ADC2), the first end of the fifth resistor (R3) is connected to the third interface (ADC2), the second end of the fifth resistor (R3) is grounded, the first end of the first capacitor (C3) is connected to the third interface (ADC2), and the second end of the first capacitor (C3) is grounded.

[0032] It should be noted that the voltage of the power supply (DC+) in the circuit is higher than the voltage of the controller (U2). If the power supply (DC+) voltage is directly connected to the controller (U2), it will exceed the recognition range of the controller (U2) (the input range of ADC2), and even damage the controller (U2). Therefore, the fourth resistor (R2) and the fifth resistor (R3) are used to divide the voltage of the power supply (DC+), that is, the voltage at the third interface (ADC2) = the voltage of the power supply (DC+) × R3 / (R3 + R4). The capacitor C3 is used for filtering to filter out the interference clutter from the power supply (DC+).

[0033] The controller (U2) can obtain the voltage value of the power supply (DC+) by detecting the third interface (ADC2). As one of the data for calculating the power of the electric vacuum pump (M1). At the same time, the controller (U2) can also use the voltage value of the power supply (DC+) to judge whether the power supply (DC+) is normal. When the voltage value is too low, the electric vacuum pump (M1) can be prohibited to ensure that the system works in a normal state, or to protect the battery in the case of battery power supply.

[0034] The detection values of the second interface (ADC1) and the third interface (ADC2) by the controller (U2) respectively correspond to the real-time current and real-time voltage of the electric vacuum pump (M1). The controller (U2) can multiply the real-time current and real-time voltage of the electric vacuum pump (M1) to obtain the real-time power.

[0035] Before the implementation of this circuit, the power of the electric vacuum pump at different negative pressure values in the electric vacuum pump system can be detected and statistically analyzed, and the corresponding relationship between the power and the negative pressure value can be determined, fitted into a calculation formula, or a database can be established for look-up and call.

[0036] In this circuit, the operation of the electric vacuum pump (M1) can be started or stopped by operating the control button (K1). During the operation of the electric vacuum pump (M1), the power value of the electric vacuum pump (M1) is monitored in real time, and the corresponding negative pressure value is determined according to this corresponding relationship. This negative pressure value can represent the degree of vacuum. When the negative pressure value reaches the set value, the operation of the electric vacuum pump (M1) is automatically stopped.

[0037] It should be noted that Figure 1 the first interface (DRV), the second interface (ADC1), and the third interface (ADC2) of the left part controller (U2) of the vacuum pump control circuit in Figure 1 are respectively connected to DRV, ADC1, and ADC2 marked in the right part (

[0038] not shown in

[0039] In addition, preferably, in order to stabilize the voltage of the controller (U2), a voltage stabilizing circuit can also be added to the vacuum pump control circuit.

[0040] The voltage stabilizing circuit includes: a sixth capacitor (C1), a voltage stabilizing element (U1), and a seventh capacitor (C2).

[0041] The first end of the sixth capacitor (C1) is connected to the positive pole of the power supply (DC+), the second end of the sixth capacitor (C1) is grounded, the first end of the voltage stabilizing element (U1) is connected to the first end of the sixth capacitor (C1), the second end of the voltage stabilizing element (U1) is connected to the first end of the seventh capacitor (C2), the second end of the seventh capacitor (C2) is grounded, and the first end of the seventh capacitor (C2) is connected to the first end of the control button (K1).

[0041] In the vacuum pump control circuit provided by this application, the controller can detect the current of the electric vacuum pump through a current-sensing resistor, obtain the real-time voltage of the electric vacuum pump, thereby obtain the power of the electric vacuum pump, and further obtain the negative pressure value corresponding to the vacuum pump power, so as to determine whether the set vacuum degree is reached. There is no need to use a pressure sensor to judge whether the preset negative pressure value is reached, nor is it necessary to design a connecting pipeline for the pressure sensor, which is beneficial to the miniaturized design of the vacuum pump product, can save the assembly cost, and can improve the product qualification rate.

[0042] In another embodiment, the vacuum pump control circuit may not collect the voltage of the electric vacuum pump (M1) in real time. In an ideal state, the voltage value of the electric vacuum pump (M1) can be preset in advance. Thus, it is only necessary to measure the current of the electric vacuum pump to determine the power of the electric vacuum pump (M1). However, this method is relatively idealized. In the actual implementation process, the voltage value of the electric vacuum pump (M1) may be unstable. If only the current of the electric vacuum pump (M1) is collected, a voltage stabilizing circuit needs to be added to the vacuum pump control circuit. Specifically, please refer to Figure 2 , Embodiment 2 provides a vacuum pump control circuit, and the vacuum pump control circuit includes:

[0043] Power supply (DC+), controller (U4), control button (K1), electric vacuum pump (M1), first switching element (Q1), first resistor (R8), current-sensing resistor (R7), operational amplifier (U3), second resistor (R4), third resistor (R5),

[0044] The first end of the control button (K1) is connected to the power supply (DC+), the second end of the control button (K1) is connected to the first end of the first resistor (R8), the second end of the first resistor (R8) is grounded, and the first end and the second end of the control button (K1) are respectively connected to the controller; it should be noted that the controller (U4) can be a microcontroller unit (MCU). Exemplarily, the selected product model can be SN8P2722.

[0045] The controller (U4) includes a first interface (DRV) and a second interface (ADC1). The first interface (DRV) is used to connect to the first switching element (Q1). The first end of the first switching element (Q1) is connected to the first end of the electric vacuum pump (M1). The second end of the first switching element (Q1) is connected to the first end of the current sensing resistor (R7). The second end of the electric vacuum pump (M1) is connected to the power supply (DC+). The second end of the current sensing resistor (R7) is grounded. It should be noted that the first switching element (Q1) can be a metal oxide semiconductor (MOS) transistor, or a triode or an insulated gate bipolar transistor (IGBT). If the first switching element (Q1) is a MOS transistor, the gate of the MOS transistor is connected to the first interface (DRV). By operating the control button (K1), the electric vacuum pump (M1) can be started or stopped through the first interface (DRV), and the power supply of the electric vacuum pump (M1) can be turned on or off to start or stop its operation.

[0046] The second interface (ADC1) of the controller (U4) is connected to the output of the operational amplifier (U3). The first end of the current sensing resistor (R7) is connected to the non-inverting input of the operational amplifier (U3). The first end of the second resistor (R4) is connected to the output of the operational amplifier (U3). The second end of the second resistor (R4) is connected to the inverting input of the operational amplifier (U3). The first end of the third resistor (R5) is connected to the inverting input of the operational amplifier (U3), and the second end is grounded.

[0047] When the electric vacuum pump (M1) is working, the current flows from the power supply (DC+) through the electric vacuum pump (M1), the first switching element (Q1) and the current sensing resistor (R7) back to the power supply ground, generating a voltage drop across the current sensing resistor (R7).

[0048] The operational amplifier (U3), the optional models include but are not limited to LM358, can amplify the voltage signal on the current sensing resistor (R7). Its output signal characterizes the current value on the electric vacuum pump (M1) through the second interface (ADC1) and is input to the controller (U4) for detection. The resistance values of the second resistor (R4) and the third resistor (R5) determine the amplification factor of the operational amplifier (U3). Specifically, the amplification factor of the operational amplifier (U3) = 1 + (R4 / R5).

[0049] The vacuum pump control circuit further includes: a boost circuit, and the boost circuit includes: a second capacitor (C1), a third capacitor (C2), a first voltage stabilizing element (U1), a sixth resistor (L1), a first diode (D1), a seventh resistor (R1), an eighth resistor (R2), a fourth capacitor (C3). The first voltage stabilizing element (U1) includes a first pin (VCC), a second pin (EN), a third pin (GND), a fourth pin (EX), and a fifth pin (FB).

[0050] The first end of the second capacitor (C1) is connected to the power supply (DC+), the second end of the second capacitor (C1) is grounded, the first end of the third capacitor (C2) is connected to the first pin (VCC), the second end of the third capacitor (C2) is grounded, the second pin (EN) is connected to the power supply (DC+), the third pin (GND) is grounded, the first end of the sixth resistor (L1) is connected to the power supply (DC+), the second end of the sixth resistor (L1) is connected to the positive electrode of the first diode (D1), the positive electrode of the first diode (D1) is connected to the fourth pin (EX), the negative electrode of the first diode (D1) is connected to the first end of the fourth capacitor (C3), and the second end of the fourth capacitor (C3) is grounded. The first end of the seventh resistor (R1) is connected to the negative electrode of the first diode (D1), the second end of the seventh resistor (R1) is connected to the fifth pin (FB), the first end of the eighth resistor (R2) is connected to the fifth pin (FB), and the second end of the eighth resistor (R2) is grounded.

[0051] This boost circuit has a voltage stabilizing function, which can ensure that even if the voltage of the power supply (DC+) fluctuates, the output voltage of this circuit can still remain stable. In this way, the power of the electric vacuum pump (M1) only depends on the current flowing through the electric vacuum pump (M1). The controller (U4) only needs to judge the current of the electric vacuum pump (M1) to determine the power of the electric vacuum pump (M1), and thus determine the pressure value extracted by the electric vacuum pump (M1).

[0052] Before implementing this circuit, the power of the electric vacuum pump at different negative pressure values in the electric vacuum pump system can be detected and statistically analyzed, and the corresponding relationship between the power and the negative pressure value can be determined, fitted into a calculation formula, or a database can be established for table lookup and call.

[0053] In this circuit, the operation of the electric vacuum pump (M1) can be started or stopped by operating the control button (K1). During the operation of the electric vacuum pump (M1), the power value of the electric vacuum pump (M1) is monitored in real time, and the corresponding negative pressure value is determined according to this corresponding relationship. This negative pressure value can represent the degree of vacuum. When the negative pressure value reaches the set value, the operation of the electric vacuum pump (M1) is automatically stopped.

[0054] It should be noted that Figure 2The first interface (DRV) and the second interface (ADC1) of the right - hand part controller (U4) of the medium vacuum pump control circuit are respectively connected to the DRV and ADC1 marked on the left - hand part ( Figure 2 not shown in

[0055] In addition, preferably, in order to stabilize the voltage of the controller (U4), a voltage - stabilizing circuit can also be added to the vacuum pump control circuit.

[0056] The voltage - stabilizing circuit includes: a sixth capacitor (C6), a voltage - stabilizing element (U3), and a seventh capacitor (C7).

[0057] The first end of the sixth capacitor (C6) is connected to the positive pole of the power supply (DC+), the second end of the sixth capacitor (C6) is grounded, the first end of the voltage - stabilizing element (U3) is connected to the first end of the sixth capacitor (C6), the second end of the voltage - stabilizing element (U3) is connected to the first end of the seventh capacitor (C7), the second end of the seventh capacitor (C7) is grounded, and the first end of the seventh capacitor (C7) is connected to the first end of the control button (K1).

[0058] In the vacuum pump control circuit provided by this application, the controller can detect the current of the electric vacuum pump through a current - detecting resistor, and according to a preset voltage value, obtain the power of the electric vacuum pump, and then obtain the negative - pressure value corresponding to the vacuum pump power, so as to determine whether the set vacuum degree is reached. It is not necessary to use a pressure sensor to judge whether the preset negative - pressure value is reached, nor is it necessary to design a connecting pipeline for the pressure sensor, which is beneficial to the miniaturization design of the vacuum pump product, can save the assembly cost, and can improve the product qualification rate.

[0059] In a special embodiment, the vacuum pump control circuit can also obtain the corresponding pressure value through a potentiometer to achieve automatic stop of extraction. Please refer to Figure 3 Example 3 provides a vacuum pump control circuit, which is based on the vacuum pump control circuit provided in Example 2. The vacuum pump control circuit further includes: a voltage - dividing circuit, a fifth capacitor (C5), and the voltage - dividing circuit includes a ninth resistor (R5), a potentiometer (RP1), and a tenth resistor (R6).

[0060] The inverting input of the operational amplifier (U2) is connected to the slidable end of the potentiometer (RP1), the slidable end of the operational amplifier (U2) is connected to the first end of the fifth capacitor (C5), the second end of the fifth capacitor (C5) is grounded, the first end of the ninth resistor (R5) is connected to the positive pole of the power supply (DC+), the second end of the ninth resistor (R5) is connected to the first end of the potentiometer (RP1), the second end of the potentiometer (RP1) is connected to the first end of the tenth resistor (R6), and the second end of the tenth resistor (R6) is grounded.

[0061] The operational amplifier (U2) is a voltage comparator, and its two input terminals are respectively the voltage value of R4 and the voltage value of the sliding end of the potentiometer (RP1). The voltage value on R4 represents the current flowing through the electric vacuum pump (M1), and the voltage value of the sliding end of the potentiometer (RP1) is the voltage value of the voltage dividing circuit composed of the ninth resistor (R5), the potentiometer (RP1), and the tenth resistor (R6). Thus, the stable voltage from U3 can be divided. A variable voltage value can be obtained through the sliding end of the potentiometer (RP1). The voltage comparator can compare the voltage values of its two input terminals in real time. When the pressure extracted by the electric vacuum pump (M1) reaches a certain value, the level of the output terminal (DI) of the voltage comparator jumps. The output terminal (DI) of this voltage comparator is connected to the interface (DI) of the controller (U4). The controller (U4) can determine whether the electric vacuum pump (M1) reaches the set value according to the jump situation. Specifically, if the current of M1 is larger when the vacuum degree is higher, then the voltage at the front (+) terminal of the voltage comparator is < the voltage at the (-) terminal before extraction, and the output of DI is at a low level; during the extraction process, the voltage at the (+) terminal rises continuously with the current on M1. When the vacuum degree reaches the set value and the voltage at the (+) terminal > the voltage at the (-) terminal, DI jumps to a high level. When the controller (U4) detects that DI changes from low to high, it determines that the vacuum degree reaches the set value. When the controller (U4) determines that the pressure of the electric vacuum pump (M1) reaches the set value, the extraction is automatically stopped. The potentiometer (RP1) can be used to set different pressure values, so that the electric vacuum pump (M1) can automatically stop extraction at different pressures. That is, the extraction pressure can be freely set by the operator.

[0062] In view of the three vacuum pump control circuits provided in the above Embodiment 1 to Embodiment 3 of the present application, Embodiment 4 of the present application further provides a vacuum pump control method, which can be implemented by the above vacuum pump control circuit. Please refer to Figure 4 , and the method includes:

[0063] 101. When an operation instruction is obtained, obtain the real-time current value of the vacuum pump.

[0064] When an operation instruction is obtained, obtain the real-time current value of the vacuum pump. Specifically, the operation instruction is obtained through the control button in the above vacuum pump control circuit. When the operation button is pressed, the circuit is turned on. The controller can obtain the real-time current value of the vacuum pump through the second interface (ADC1).

[0065] 102. Determine the real-time power of the vacuum pump according to the real-time current value.

[0066] Determine the real-time power of the vacuum pump according to the real-time current value.

[0067] In one embodiment, referring to the vacuum pump control circuit provided in Embodiment 1, before determining the real-time power of the vacuum pump according to the real-time current value, the method further includes: obtaining the real-time voltage value of the vacuum pump through a third interface (ADC2); specifically, determining the real-time power of the vacuum pump according to the real-time current value includes: determining the real-time power of the vacuum pump according to the real-time current value and the real-time voltage value of the vacuum pump.

[0068] In another embodiment, referring to the vacuum pump control circuit provided in Embodiment 2, the vacuum pump control circuit can stabilize the voltage of the vacuum pump through a boost circuit, so that the voltage value can be preset. Specifically, determining the real-time power of the vacuum pump according to the real-time current value includes: determining the real-time power of the vacuum pump according to the real-time current value of the vacuum pump and the preset voltage value of the vacuum pump.

[0069] 103. Obtain the negative pressure value corresponding to the real-time power of the vacuum pump, and determine whether the negative pressure value is greater than or equal to a preset negative pressure threshold.

[0070] It should be noted that before the implementation of this circuit, the power of the electric vacuum pump at different negative pressure values in the electric vacuum pump system can be detected and statistically analyzed, and the corresponding relationship between the power and the negative pressure value can be determined, fitted into a calculation formula, or a database can be established for look-up and call.

[0071] After obtaining the real-time power of the vacuum pump, the negative pressure value corresponding to the power of the vacuum pump can be determined through a preset corresponding relationship. And determine whether the negative pressure value is greater than or equal to a preset negative pressure threshold.

[0072] 104. When the negative pressure value is greater than or equal to the preset negative pressure threshold, stop the operation of the vacuum pump.

[0073] When in step 103, the obtained negative pressure value is greater than or equal to the preset negative pressure threshold, stop the operation of the vacuum pump.

[0074] The vacuum pump control method provided in this application can detect the real-time current value of the vacuum pump, thereby obtaining the real-time power of the vacuum pump. Thus, the negative pressure value corresponding to the real-time power is determined. When the negative pressure value is greater than or equal to the preset negative pressure threshold, stop the operation of the vacuum pump. The vacuum pump control circuit adopted by this vacuum pump control method does not need to judge whether the preset negative pressure value is reached through a pressure sensor, nor does it need to design a connecting pipeline for the pressure sensor, which is beneficial to the miniaturized design of the vacuum pump product, can save the assembly cost, and can improve the product qualification rate.

[0075] The above has introduced in detail a vacuum pump control circuit and a vacuum pump control method provided by an embodiment of the present invention. Specific examples are used in this article to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present application.

Claims

1. A vacuum pump control circuit, characterized in that, The vacuum pump control circuit includes: a power supply, a controller, a control button, an electric vacuum pump, a first switching element, a first resistor, a current detection resistor, an operational amplifier, a second resistor, a third resistor, and a filter capacitor C4. The first end of the control button is connected to the power supply, the second end of the control button is connected to the first end of the first resistor, the second end of the first resistor is grounded, and the first end and the second end of the control button are respectively connected to the controller. The controller includes a first interface and a second interface. The first interface is used to connect to the first switching element. The first end of the first switching element is connected to the first end of the electric vacuum pump, the second end of the first switching element is connected to the first end of the current detection resistor, the second end of the electric vacuum pump is connected to the power supply, and the second end of the current detection resistor is grounded. The second interface of the controller is connected to the output of the operational amplifier. The first end of the current detection resistor is connected to the non-inverting input of the operational amplifier. The first end of the second resistor is connected to the output of the operational amplifier, the second end of the second resistor is connected to the inverting input of the operational amplifier, the first end of the third resistor is connected to the inverting input of the operational amplifier, and the second end is grounded.

2. The vacuum pump control circuit according to claim 1, characterized in that, The vacuum pump control circuit further includes: a voltage sampling network, and the voltage sampling network includes: a fourth resistor, a fifth resistor, and a first capacitor. The controller further includes a third interface. The first end of the fourth resistor is connected to the power supply, the second end of the fourth resistor is connected to the third interface, the first end of the fifth resistor is connected to the third interface, the second end of the fifth resistor is grounded, the first end of the first capacitor is connected to the third interface, and the second end of the first capacitor is grounded.

3. The vacuum pump control circuit according to claim 1, characterized in that, The vacuum pump control circuit further includes: a boost circuit, and the boost circuit includes: a second capacitor, a third capacitor, a first voltage stabilizing element, a sixth resistor, a first diode, a seventh resistor, an eighth resistor, and a fourth capacitor. The first voltage stabilizing element includes a first pin, a second pin, a third pin, a fourth pin, and a fifth pin. The first end of the second capacitor is connected to the power supply, the second end of the second capacitor is grounded, the first end of the third capacitor is connected to the first pin, the second end of the third capacitor is grounded, the second pin is connected to the power supply, the third pin is grounded, the first end of the sixth resistor is connected to the power supply, the second end of the sixth resistor is connected to the positive electrode of the first diode, the positive electrode of the first diode is connected to the fourth pin, the negative electrode of the first diode is connected to the first end of the fourth capacitor, the second end of the fourth capacitor is grounded, the first end of the seventh resistor is connected to the negative electrode of the first diode, the second end of the seventh resistor is connected to the fifth pin, the first end of the eighth resistor is connected to the fifth pin, and the second end of the eighth resistor is grounded.

4. The vacuum pump control circuit according to claim 3, characterized in that, The vacuum pump control circuit further includes: a voltage dividing circuit and a fifth capacitor. The voltage dividing circuit includes a ninth resistor, a potentiometer, and a tenth resistor. The inverting input of the operational amplifier is connected to the slidable end of the potentiometer. The slidable end of the operational amplifier is connected to the first end of the fifth capacitor. The second end of the fifth capacitor is grounded. The first end of the ninth resistor is connected to the positive power supply. The second end of the ninth resistor is connected to the first end of the potentiometer. The second end of the potentiometer is connected to the first end of the tenth resistor, and the second end of the tenth resistor is grounded.

5. The vacuum pump control circuit according to any one of claims 1 to 4, characterized in that, The vacuum pump control circuit further includes a voltage stabilizing circuit, which includes: a sixth capacitor, a voltage stabilizing element, and a seventh capacitor. The first end of the sixth capacitor is connected to the positive power supply. The second end of the sixth capacitor is grounded. The first end of the voltage stabilizing element is connected to the first end of the sixth capacitor. The second end of the voltage stabilizing element is connected to the first end of the seventh capacitor. The second end of the seventh capacitor is grounded. The first end of the seventh capacitor is connected to the first end of the control button.

6. The vacuum pump control circuit according to claim 5, characterized in that, The first switching element includes a metal oxide semiconductor field effect transistor, a triode, or an insulated gate bipolar transistor.

7. A vacuum pump control method, characterized in that, The vacuum pump control method is implemented by the vacuum pump control circuit according to any one of claims 1 to 5. The method includes: When an operation instruction is obtained, obtain the real-time current value of the vacuum pump. Determine the real-time power of the vacuum pump according to the real-time current value. Obtain the negative pressure value corresponding to the real-time power of the vacuum pump, and determine whether the negative pressure value is greater than or equal to a preset negative pressure threshold. When the negative pressure value is greater than or equal to the preset negative pressure threshold, stop the operation of the vacuum pump.

8. The vacuum pump control method according to claim 7, characterized in that, Before determining the real-time power of the vacuum pump according to the real-time current value, the method further includes: Obtain the real-time voltage value of the vacuum pump. Determining the real-time power of the vacuum pump according to the real-time current value specifically includes: Determine the real-time power of the vacuum pump according to the real-time current value and the real-time voltage value of the vacuum pump.

9. The vacuum pump control method according to claim 7, characterized in that, The voltage value of the vacuum pump is preset. Determining the real-time power of the vacuum pump according to the real-time current value specifically includes: Determine the real-time power of the vacuum pump according to the real-time current value of the vacuum pump and the preset voltage value of the vacuum pump.

10. The vacuum pump control method according to any one of claims 7 to 9, characterized in that, There is a preset corresponding relationship between the power of the vacuum pump and the negative pressure value. Obtaining the negative pressure value corresponding to the real-time power of the vacuum pump includes: Determine the negative pressure value corresponding to the real-time power of the vacuum pump according to the corresponding relationship between the power of the vacuum pump and the negative pressure value.

Images