Control circuit of degassing pump

Abstract

The utility model provides a control circuit of a degassing pump, which relates to the technical field of electronic circuits and comprises a sensing module, a voltage dividing module, a comparison module, a switch module and a voltage stabilizing module. The sensing module is connected with the voltage dividing module, the voltage dividing module is connected with the comparison module, the comparison module is connected with the switch module, and the switch module is connected with the voltage stabilizing module; the sensing module comprises a vacuum air pressure sensor M1, the vacuum air pressure sensor M1 is connected with one end of a capacitor C8 and the voltage dividing module, and the other end of the capacitor C8 is grounded. According to the utility model, the problem that the degassing pump is frequently and instantly opened / closed is simply and efficiently solved.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic circuits, in particular to a degassing pump control circuit. Background Art

[0002] Chromatographic analytical instruments play an important role in scientific research, chemical industry, pharmaceutical industry and other fields. Among them, the removal of bubbles in the eluent of the liquid path is a key link to ensure the normal operation of the instrument and the accuracy of data analysis. At present, most chromatographic analytical instruments use online degassing technology to remove bubbles in the liquid path. This technology is realized through an online degassing system composed of a degassing pump, a control circuit, a degassing channel and a vacuum chamber.

[0003] The working principle of the online degassing system is: when the vacuum degree in the vacuum chamber drops below a certain threshold, the control circuit will start the degassing pump to perform the exhaust operation; and when the vacuum degree rises above another threshold, the control circuit will turn off the degassing pump. Due to the low bubble content in the chromatograph liquid path, the volume of the vacuum chamber required for degassing is also relatively small, usually only 10 to 30 mL. Therefore, the working time of the degassing pump motor is very short, and the upper and lower limits of the vacuum threshold can usually be completed within 1 to 5 seconds.

[0004] However, existing degassing pumps, whether domestic or imported, generally face a technical problem: due to the need to frequently complete the power-on / power-off cycle of the motor in a short period of time, the motor often cannot keep up with the switching speed of the current, resulting in the motor being unable to start and run normally after power is turned on, resulting in a "stuck" phenomenon. This not only affects the normal exhaust function of the degassing pump, but also causes the pump body to continue to heat up when powered on. Since most degassing pumps are built into the chassis, the heating phenomenon of the pump body is not easy to detect. Long-term overheating often causes damage to the pump body and even causes more serious safety problems.

[0005] Therefore, a degassing pump control circuit is proposed. Utility Model Content

[0006] This specification provides a degassing pump control circuit, which simply and efficiently solves the problem of frequent instantaneous opening / closing of the degassing pump.

[0007] This specification provides a degassing pump control circuit, including:

[0008] A sensing module, a voltage dividing module, a comparison module, a switch module, and a voltage stabilizing module; the sensing module is connected to the voltage dividing module, the voltage dividing module is connected to the comparison module, the comparison module is connected to the switch module, and the switch module is connected to the voltage stabilizing module;

[0009] The sensing module includes a vacuum pressure sensor M1. One end of a capacitor C8 and the voltage dividing module are respectively connected to the vacuum pressure sensor M1, and the other end of the capacitor C8 is grounded.

[0010] Optionally, the vacuum pressure sensor M1 includes an ADP5111 vacuum pressure sensor.

[0011] Optionally, it includes:

[0012] The voltage dividing module includes a resistor R8 connected to the vacuum pressure sensor M1. The resistor R8 is respectively connected to a resistor W1 and the comparison module, and the resistor W1 is respectively connected to a resistor R9 and the comparison module.

[0013] Optionally, it includes:

[0014] The comparison module includes a voltage comparator U1. One end of a capacitor C6, one end of a resistor R5, one end of a resistor R6, one end of a capacitor C7, and the resistor R8 are respectively connected to the voltage comparator U1. The other end of the capacitor C6 is grounded. The other end of the resistor R5 is connected to the switch module. The other end of the resistor R6 is connected to one end of a resistor R7, and the other end of the resistor R7 is grounded.

[0015] Optionally, the voltage comparator U1 includes a MAX931 voltage comparator.

[0016] Optionally, it includes:

[0017] The switch module includes a transistor Q2 connected to the resistor R5. The transistor Q2 is respectively connected to a transistor Q1 and a resistor R4. Both the transistor Q1 and the resistor R4 are grounded. The transistor Q1 is also connected to a slot P3. The slot P3 is respectively connected to a resistor R1, a capacitor C5, a diode D1, and the voltage stabilizing module.

[0018] Optionally, it includes:

[0019] The voltage stabilizing module includes a linear voltage regulator U2 connected to the slot P3. The voltage stabilizing module U2 is respectively connected to capacitors C1, C2, C3, and C4. Capacitors C1, C2, C3, and C4 are all grounded. The capacitor C1 is connected to an external power supply J1.

[0020] Optionally, the linear voltage regulator U2 includes an MC78L linear voltage regulator.

[0021] The degassing pump control circuit provided by the present utility model is simple and efficient, and solves the problem of the degassing pump frequently starting / stopping instantaneously. Description of the Drawings

[0022] The accompanying drawings described herein are used to provide a further understanding of the present utility model and form a part of this application. The schematic embodiments of the present utility model and their descriptions are used to explain the present utility model and shall not constitute an improper limitation to the present utility model. In the drawings:

[0023] Figure 1 is an overall structural block diagram of a degassing pump control circuit according to an embodiment of the present utility model;

[0024] Figure 2 is a circuit schematic diagram of a degassing pump control circuit according to an embodiment of the present utility model.

[0025] Illustration of the drawings: 10, sensing module; 20, voltage dividing module; 30, comparison module; 40, switching module; 50, voltage stabilizing module. Detailed implementation manners

[0026] The following description is used to disclose the present utility model so that those skilled in the art can implement the present utility model. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles defined in the following description of the present utility model can be applied to other implementation schemes, variant schemes, improvement schemes, equivalent schemes, and other technical schemes that do not deviate from the spirit and scope of the present utility model.

[0027] The following combines the attached Figure 1-2 Describe the exemplary embodiments of the present utility model more comprehensively. However, the exemplary embodiments can be implemented in various forms and should not be understood that the present utility model is limited to the embodiments described herein. On the contrary, providing these exemplary embodiments can make the present utility model more comprehensive and complete, and more convenient to fully convey the inventive concept of the utility model to those skilled in the art. The same reference numerals in the drawings represent the same or similar elements, components, or parts, and thus the repeated description thereof will be omitted.

[0028] On the premise of conforming to the technical concept of the present utility model, the features, structures, characteristics, or other details described in a specific embodiment may not be excluded from being combined in a suitable manner in one or more other embodiments.

[0029] In the description of specific embodiments, the features, structures, characteristics, or other details described in the present utility model are for those skilled in the art to fully understand the embodiments. However, it does not exclude that those skilled in the art can practice the technical solutions of the present utility model without one or more of the specific features, structures, characteristics, or other details.

[0030] The flowcharts shown in the accompanying drawings are only exemplary and do not necessarily include all the contents and operations / steps, nor do they necessarily have to be executed in the order described. For example, some operations / steps can be decomposed, and some operations / steps can be combined or partially combined, so the actual execution order may change according to actual conditions.

[0031] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities may be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0032] The term "and / or" or "and / or" includes all combinations of any one or more of the associated listed items.

[0033] This specification provides a degassing pump control circuit. Figure 1 This is an overall structural block diagram of a degassing pump control circuit according to an embodiment of the utility model. Figure 2 1 is a circuit diagram of a degassing pump control circuit according to an embodiment of the present utility model, comprising:

[0034] Sensing module, voltage divider module, comparison module, switch module, voltage stabilizing module; the sensing module is connected to the voltage divider module, the voltage divider module is connected to the comparison module, the comparison module is connected to the switch module, and the switch module is connected to the voltage stabilizing module; the sensing module includes a vacuum pressure sensor M1, the vacuum pressure sensor M1 includes an ADP5111 vacuum pressure sensor, which can measure 0 to -100Kpa, and the corresponding voltage output is 0 to 4V. The vacuum pressure sensor M1 is respectively connected to one end of the capacitor C8 and the voltage divider module, and the other end of the capacitor C8 is grounded.

[0035] The voltage divider module includes a resistor R8 connected to the vacuum pressure sensor M1, the resistor R8 is connected to the resistor W1 and the comparison module respectively, and the resistor W1 is connected to the resistor R9 and the comparison module respectively. The resistors R8, R9 and W1 divide the output voltage of the vacuum pressure sensor M1, and the required vacuum degree can be obtained through the voltage division of these three resistors.

[0036] The comparison module includes a voltage comparator U1, and the voltage comparator U1 includes a MAX931 voltage comparator with hysteresis function. The voltage comparator U1 is respectively connected to one end of a capacitor C6, one end of a resistor R5, one end of a resistor R6, one end of a capacitor C7, and a resistor R8. The other end of the capacitor C6 is grounded. The other end of the resistor R5 is connected to the switch module. The other end of the resistor R6 is connected to one end of a resistor R7, and the other end of the resistor R7 is grounded. The divided vacuum degree is input to the positive input terminal, pin 3, of the voltage comparator U1, and a reference voltage is input to pin 4 of the voltage comparator U1. The hysteresis voltage is input to the input terminal, pin 5, of the voltage comparator U1 after being divided by the resistors R6 and R7 in the circuit. By adjusting the resistance values of the resistors R6 and R7, the hysteresis voltage value can be adjusted, so as to avoid the frequent on / off of the vacuum pump for controlling the pipeline vacuum degree.

[0037] The switch module includes a transistor Q2 connected to the resistor R5. The transistor Q2 is respectively connected to a transistor Q1 and a resistor R4. Both the transistor Q1 and the resistor R4 are grounded. The transistor Q1 is also connected to a socket P3. The socket P3 is respectively connected to a resistor R1, a capacitor C5, a diode D1, and a voltage stabilization module. When the output voltage of the vacuum pressure sensor M1 after voltage division is less than the reference voltage of the voltage comparator U1, the voltage comparator U1 outputs a low level of 0V. This low level makes the transistor Q2 cut off, and further makes the transistor Q1 that drives the pump body motor coil cut off. Thus, the pump stops working. On the contrary, when the output voltage of the vacuum pressure sensor M1 after voltage division is greater than the reference voltage of the voltage comparator U1, the voltage comparator U1 outputs a high level of 5V. This high level makes the transistor Q2 conduct, and further makes the transistor Q1 that drives the pump body motor coil conduct. The pump body motor works to suck air and create a vacuum in the liquid path until the voltage input to the positive input terminal, pin 3, of the voltage comparator U1 after being divided by the resistors R8, R9, and potentiometer W1 from the output voltage of the vacuum pressure sensor M1 is greater than the reference voltage input to pin 4 of the voltage comparator U1, and then the pump stops working. The voltage comparator U1 circuit makes the pump body motor stop working when the pipeline vacuum degree is greater than the set value. When the vacuum degree is less than the set value, the pump body motor starts to work.

[0038] The voltage stabilization module includes a linear voltage regulator U2 connected to the socket P3. The linear voltage regulator U2 includes an MC78L linear voltage regulator. The voltage stabilization module U2 is respectively connected to capacitors C1, C2, C3, and C4. The capacitors C1, C2, C3, and C4 are all grounded. The capacitor C1 is connected to an external power supply J1.

[0039] The specific control principle is as follows: The hysteresis voltage value divided by the resistance values of resistor R6 and resistor R7 is about 1.1V. The reference voltage input to pin 4 of voltage comparator U1 in the circuit is 1.2V. Obviously, the reference voltage is greater than the hysteresis voltage. According to the previous working principle analysis, when the vacuum degree voltage after voltage division is greater than the reference voltage, the degassing pump stops working. However, when the vacuum degree voltage value after voltage division is less than the reference voltage, due to the introduction of the hysteresis voltage, the degassing pump cannot start working immediately. Only when the vacuum degree continues to decrease, causing the output voltage of the vacuum degree sensor to drop to a value less than the hysteresis voltage value of the comparator when input to voltage comparator U1, can the degassing pump be driven to work. In short, by introducing the hysteresis voltage of voltage comparator U1, the degassing pump can be prevented from frequently starting / stopping instantaneously. By adjusting the resistance values of resistor R6 and resistor R7, the hysteresis voltage can be adjusted. Furthermore, the working threshold of the vacuum degree can be adjusted. Therefore, the degassing pump control circuit provided by the present utility model is simple and efficient, and solves the problem of the degassing pump frequently starting / stopping instantaneously.

[0040] In the specific embodiments described above, the purpose, technical solution and beneficial effects of the present utility model have been further described in detail. It should be understood that the present utility model is not inherently related to any specific computer, virtual device or electronic device, and various general-purpose devices can also implement the present utility model. The above are only specific embodiments of the present utility model and are not used to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

[0041] Each embodiment in this specification is described in a progressive manner. The same or similar parts among the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments.

[0042] The above are only embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

Claims

1. A degassing pump control circuit, characterized in that, Comprising: A sensing module (10), a voltage dividing module (20), a comparison module (30), a switching module (40), and a voltage stabilizing module (50); the sensing module (10) is connected to the voltage dividing module (20), the voltage dividing module (20) is connected to the comparison module (30), the comparison module (30) is connected to the switching module (40), and the switching module (40) is connected to the voltage stabilizing module (50); The sensing module (10) includes a vacuum pressure sensor M1, the vacuum pressure sensor M1 is respectively connected to one end of a capacitor C8 and the voltage dividing module (20), and the other end of the capacitor C8 is grounded; The comparison module (30) includes a voltage comparator U1, the voltage comparator U1 includes a MAX931 voltage comparator, the voltage comparator U1 is respectively connected to one end of a capacitor C6, one end of a resistor R5, one end of a resistor R6, one end of a capacitor C7, and the resistor R8, the other end of the capacitor C6 is grounded, the other end of the resistor R5 is connected to the switching module (40), the other end of the resistor R6 is connected to one end of a resistor R7, and the other end of the resistor R7 is grounded.

2. The degassing pump control circuit according to claim 1, wherein The vacuum pressure sensor M1 includes an ADP5111 vacuum pressure sensor.

3. The degassing pump control circuit according to claim 1, characterized in that, Comprising: The voltage dividing module (20) includes a resistor R8 connected to the vacuum pressure sensor M1, the resistor R8 is respectively connected to a resistor W1 and the comparison module, and the resistor W1 is respectively connected to a resistor R9 and the comparison module (30).

4. The degassing pump control circuit according to claim 3, characterized in that, Comprising: The switching module (40) includes a transistor Q2 connected to the resistor R5, the transistor Q2 is respectively connected to a transistor Q1 and a resistor R4, the transistor Q1 and the resistor R4 are both grounded, the transistor Q1 is also connected to a socket P3, and the socket P3 is respectively connected to a resistor R1, a capacitor C5, a diode D1, and the voltage stabilizing module (50).

5. The degassing pump control circuit according to claim 4, wherein, Comprising: The voltage stabilizing module (50) includes a linear voltage regulator U2 connected to the socket P3, the voltage stabilizing module U2 is respectively connected to capacitors C1, C2, C3, and C4, the capacitors C1, C2, C3, and C4 are all grounded, and the capacitor C1 is connected to an external power supply J1.

6. The degassing pump control circuit according to claim 5, wherein The linear voltage regulator U2 includes an MC78L linear voltage regulator.

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