Touch screen control circuit of sputum excretion machine

Abstract

The utility model discloses a touch screen control circuit of a sputum excretion machine, which comprises a master control module, a touch screen module and a power supply module, the touch screen control circuit further comprises a power supply switch control module, a first output end of the power supply module is connected with the master control module, and a second output end of the power supply module is connected with the touch screen module. The second output end of the power module is connected with the first input end of the power switch control module, the output end of the main control module is connected with the second input end of the power switch control module, and the output end of the power switch control module is connected with the power end of the touch screen module; when the sputum excretion machine is started, the power supply module supplies power to the main control module, then the main control module controls the power switch control module to be switched on so that the power supply module supplies power to the touch screen module, and the power supply of the touch screen module is enabled and controlled by the main control module of the sputum excretion machine. After the main control module is initialized, the touch screen module is powered on, so that the problem of invalid touch control of the touch screen is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of medical equipment, in particular to a touch screen control circuit of a sputum removal machine. Background Art

[0002] High-frequency vibration expectoration machines use the principle of physical vibration to promote the blockage of respiratory secretions outside the lungs. High-frequency vibration expectoration machines generally have touch operation functions. However, during the development of high-frequency vibration expectoration machines, researchers found that the touch screen would fail to work after turning on the machine or upgrading the program through USB. After analysis, the reason is that the touch screen power supply of existing high-frequency vibration expectoration machines has a pull-up function. When the high-frequency vibration expectoration machine is turned on, the touch screen will be powered on to perform operations such as touch screen initialization, and the main control chip will also perform initialization operations. In the process from power-on to completion of initialization of the main control chip of some high-frequency vibration expectoration machines, due to the characteristics of the main control chip itself, a pull-down signal may appear, which will cause the touch screen to lose power, resulting in touch failure. Utility Model Content

[0003] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a touch screen control circuit for a sputum discharge machine, which can change the power supply mode of the touch screen of the sputum discharge machine to prevent the touch screen from malfunctioning.

[0004] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0005] A touch screen control circuit for a sputum removal machine, the touch screen control circuit comprising a main control module, a touch screen module and a power module, the touch screen control circuit further comprising a power switch control module, the first output end of the power module being connected to the main control module, the second output end of the power module being connected to the first input end of the power switch control module, the output end of the main control module being connected to the second input end of the power switch control module, and the output end of the power switch control module being connected to the power end of the touch screen module;

[0006] When the sputum removal machine is turned on, the power module supplies power to the main control module, and then the main control module controls the power switch control module to be turned on so that the power module supplies power to the touch screen module.

[0007] In the touch screen control circuit of the sputum removal machine, the power supply module includes a first power supply filter unit and / or a second power supply filter unit, and the output ends of the first power supply filter unit and the second power supply filter unit are connected to the first input end of the power switch control module; the power supply module also includes a first power supply unit for outputting a first voltage and a second power supply unit for outputting a second voltage;

[0008] When the sputum removal machine is turned on, the first power supply unit supplies power to the main control module, the first voltage is supplied to the power switch control module via the first power filter unit or the second voltage is supplied to the power switch control module via the second power filter unit, and the main control module controls the power switch control module to be turned on so that the first voltage or the second voltage supplies power to the touch screen module.

[0009] In the touch screen control circuit of the sputum removal machine, the power switch control module includes a switch protection unit and a first filtering unit. When the switch protection unit receives the touch screen enable signal output by the main control module, the first voltage or the second voltage is output to the first filtering unit, and the touch screen module is powered after filtering by the first filtering unit.

[0010] In the touch screen control circuit of the sputum removal machine, the switch protection unit includes a first MOS tube, a second MOS tube, a first resistor, a second resistor and a third resistor. The gate of the first MOS tube is connected to the main control module through the first resistor and is also grounded through the second resistor. The source of the first MOS tube is grounded, the drain of the first MOS tube is connected to the gate of the second MOS tube and is also connected to the first power supply filter unit, the second power supply filter unit and the source of the second MOS tube through the third resistor. The drain of the second MOS tube is connected to the first filter unit.

[0011] In the touch screen control circuit of the sputum removal machine, the first voltage is 3.3V and the second voltage is 5V.

[0012] In the touch screen control circuit of the sputum removal machine, the first MOS tube is an N-communication MOS tube, and the second MOS tube is a P-communication MOS tube.

[0013] In the touch screen control circuit of the sputum removal machine, the first filtering unit includes a first capacitor and a second capacitor, one end of the first capacitor is connected to the drain of the second MOS tube and the power supply end of the touch screen module, the other end of the first capacitor is grounded, and the second capacitor is connected in parallel with the first capacitor.

[0014] In the touch screen control circuit of the sputum removal machine, the first power supply filter unit includes a first magnetic bead, the second power supply filter unit includes a second magnetic bead and a third capacitor, one end of the first magnetic bead is connected to the source of the second MOS tube, one end of the second magnetic bead and one end of the third resistor, the other end of the first magnetic bead is connected to the first power supply unit for outputting the first voltage, the other end of the second magnetic bead is connected to the second power supply unit for outputting the second voltage and is also grounded through the third capacitor, the first voltage is lower than the second voltage, and the first magnetic bead or the second magnetic bead is not welded.

[0015] In the touch screen control circuit of the sputum removal machine, the touch screen module includes a touch screen interface, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor and a tenth resistor. The first pin of the touch screen interface is connected to the main control module through the fourth resistor. The second pin of the touch screen interface is the power supply end of the touch screen module, which is connected to the drain of the second MOS tube. The third pin of the touch screen interface is grounded. The fourth pin of the touch screen interface is connected to the main control module through the fifth resistor and is also connected to the DVCC+3.3V power supply end through the sixth resistor. The fifth pin of the touch screen interface is connected to the main control module through the seventh resistor and is also connected to the DVCC+3.3V power supply end through the eighth resistor. The sixth pin of the touch screen interface is connected to the main control module through the ninth resistor and is also connected to the DVCC+3.3V power supply end through the tenth resistor.

[0016] In the touch screen control circuit of the sputum removal machine, the touch screen module also includes a second filtering unit, and the second filtering unit includes a fourth capacitor, a fifth capacitor, a sixth capacitor and a seventh capacitor, one end of the fourth capacitor is connected to the 4th pin of the touch screen interface, one end of the fifth capacitor is connected to the 5th pin of the touch screen interface, one end of the sixth capacitor is connected to the 6th pin of the touch screen interface, one end of the seventh capacitor is connected to the 1st pin of the touch screen interface, and the other end of the fourth capacitor, the other end of the fifth capacitor, the other end of the sixth capacitor and the other end of the seventh capacitor are grounded.

[0017] Compared with the prior art, the utility model provides a touch screen control circuit for a sputum removal machine. When the sputum removal machine is turned on, the power module first supplies power to the main control module. After the power-on initialization of the main control module is completed, the main control module controls the power switch control module to be turned on so that the power module supplies power to the touch screen module. By enabling the power supply of the touch screen module by the main control module of the sputum removal machine, the touch screen module is powered on after the main control module is initialized, thereby avoiding the problem of invalid touch screen. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a structural block diagram of the touch screen control circuit of the sputum removal machine provided by the utility model.

[0019] Figure 2 The utility model provides a circuit schematic diagram of the touch screen control circuit of the sputum removal machine.

[0020] Description of Reference Numerals

[0021] The main control module 10, the touch screen module 20, the power module 30, the first output terminal 1 of the power module, the second output terminal 2 of the power module, the power switch control module 40, the first input terminal 1' of the power switch control module, the second input terminal 2' of the power switch control module, the output terminal 3' of the power switch control module, the first power filter unit 31, the second power filter unit 32, the first power supply unit 33, the second power supply unit 34, the switch protection unit 41, the first filter unit 42, the first MOS tube Q1, the second MOS tube Q2, the first resistor R1, the second The second resistor R2, the third resistor R3, the first capacitor C1, the second capacitor C2, the first magnetic bead L1, the second magnetic bead L2, the third capacitor C3, the touch screen interface J1, the fourth resistor R4, the fifth resistor R5, the sixth resistor R6, the seventh resistor R7, the eighth resistor R8, the ninth resistor R9, the tenth resistor R10, the second filtering unit 21, the fourth capacitor C4, the fifth capacitor C5, the sixth capacitor C6, the seventh capacitor C7, the ESD test protection unit 22, the first ESD tube D1, the second ESD tube D2, the third ESD tube D3, the fourth ESD tube D4 DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0023] See also Figure 1 and Figure 2 , which are respectively a structural block diagram and a circuit schematic diagram of the touch screen control circuit of the sputum removal machine provided by the utility model. As shown in the figure, in the touch screen control circuit of the sputum removal machine provided by the utility model, the sputum removal machine includes a main control module 10, a touch screen module 20, a power module 30 and a power switch control module 40. The main control module 10 includes a main control chip of the sputum removal machine (not shown in the figure) and its peripheral circuits. The power module 30 is used to provide the voltage required for the main control module 10 and the power switch control module 40 to work. The first output terminal 1 of the power module 30 is connected to the input terminal of the main control module 10, the second output terminal 2 of the power module 30 is connected to the first input terminal 1′ of the power switch control module 40, the output terminal of the main control module 10 is connected to the second input terminal 2′ of the power switch control module 40, and the output terminal 3′ of the power switch control module 40 is connected to the power terminal of the touch screen module 20.

[0024] When the sputum removal machine is turned on, the power module 30 outputs a first power supply voltage (such as 3.3V) to first power the main control module 10. After the main control module 10 is powered on and initialized, the main control module 10 controls the power switch control module 40 to turn on so that the power module 30 supplies power to the touch screen module 20. The power supply of the touch screen module 20 is enabled and controlled by the main control module 10 of the sputum removal machine, so that the touch screen module 20 is powered on after the main control module 10 is initialized, thereby avoiding the problem of invalid touch screen.

[0025] Please continue reading Figure 1 and Figure 2 In an optional embodiment, the power supply module 30 includes a first power supply filter unit 31 and / or a second power supply filter unit 32. The output ends of the first power supply filter unit 31 and the second power supply filter unit 32 are the second output ends 2 of the power supply module 30, which are connected to the first input end 1′ of the power switch control module 40. The first power supply filter unit 31 and the second power supply filter unit both play a voltage filtering role, and are used to provide a stable voltage to the power switch control module 40.

[0026] The power module 30 further includes a first power supply unit 33 and a second power supply unit 34. The first power supply unit 33 is used to output a first voltage (such as 3.3V). The output end of the first power supply unit 33 is the first output end 1 of the power module 30, which is connected to the input end of the main control module 10 and the input end of the first power filter unit 31, and is used to provide the main control module 10 with the voltage required for its operation. The second power supply unit 34 is used to output a second voltage (such as 5V). The output end of the second power supply unit 34 is connected to the input end of the second power filter unit 32.

[0027] When the sputum removal machine is turned on, the first power supply unit 33 first outputs a first voltage (such as 3.3V) to power the main control module 10, so that the main control module 10 is powered on and initialized first. At the same time, the first voltage output by the first power supply unit 33 is filtered by the first power supply filter unit 31, or the second voltage output by the second power supply unit 34 is filtered by the second power supply filter unit 32 to power the power switch control module 40. After the main control module 10 completes the initialization, the main control module 10 controls the power switch control module 40 to conduct so that the first voltage provided by the first power supply unit 33 or the second voltage provided by the second power supply unit 34 is used to power the touch screen module 20. Therefore, according to the parameters of the touch screen module 20 (such as the working voltage of the touch screen module 20), the main control module 10 of the sputum removal machine can enable control so that the corresponding power supply unit can power the touch screen module 20.

[0028] In a specific embodiment, the touch screen control circuit is arranged on a circuit board (not shown in the figure), and the electronic components of the main control module 10, touch screen module 20, power module 30, power switch control module 40 and other modules can be arranged on the circuit board by STM mounting, welding and other methods. This is a prior art and will not be described in detail here.

[0029] Please continue reading Figure 1 , Figure 2 The power switch control module 40 includes a switch protection unit 41 and a first filter unit 42. The switch protection unit 41 is connected to the first power filter unit 31, the second power filter unit 32, the main control module 10 and the first filter unit 42. When the switch protection unit 41 receives the touch screen enable signal output by the main control module 10, the first voltage or the second voltage is output to the first filter unit 42, and the touch screen module 20 is powered after filtering by the first filter unit 42.

[0030] Optionally, the first voltage is 3.3V and the second voltage is 5V. In specific implementation, the components of the first power filter unit 31 or the second power filter unit 32 can be selected and mounted on the circuit board according to the power supply voltage requirements of the touch screen, and the touch screen is powered by the corresponding power supply unit. The utility model selects the corresponding power supply unit for power supply according to different types of touch screens, thereby realizing that one circuit board can be compatible with two power supply methods, thereby improving the compatibility of the touch screen control circuit.

[0031] The switch protection unit 41 includes a first MOS tube Q1, a second MOS tube Q2, a first resistor R1, a second resistor R2 and a third resistor R3. The gate of the first MOS tube Q1 is connected to the main control module 10 through the first resistor R1 and is also grounded through the second resistor R2. The source of the first MOS tube Q1 is grounded. The drain of the first MOS tube Q1 is connected to the gate of the second MOS tube Q2 and is also connected to the first power filter unit 31, the second power filter unit 32 and the source of the second MOS tube Q2 through the third resistor R3. The drain of the second MOS tube Q2 is connected to the first filter unit 42.

[0032] The first MOS tube Q1 is an N-type MOS tube, and the second MOS tube Q2 is a P-type MOS tube. The first resistor R1 is a current limiting resistor, and the second resistor R2 is a pull-down resistor. When the touch screen signal enable signal output by the main control module 10 is at a high level, the first MOS tube Q1 is turned on to connect the gate voltage of the second MOS tube Q2 to a low level and turn it on. At this time, the power supply voltage output by the power module supplies power to the touch screen interface.

[0033] The present invention adopts the method of using N MOS tube and P MOS tube to form a switch circuit, which can increase the driving ability of the switch circuit, and is used to realize a small current signal to control a large current signal, and a high voltage enable signal drives the MOS tube, and the cooperation of the dual MOS tubes will not damage the main control chip and other components. For example, when the second power supply unit 34 is used to supply power first, the 5V drive signal is filtered by the second power filter unit 32 to remove the peak voltage and then loaded on the source of the P MOS tube. When the main control chip outputs the enable signal, the 5V power supply voltage will not damage the MOS tube and the main control chip.

[0034] The first filter unit 42 includes a first capacitor C1 and a second capacitor C2, one end of the first capacitor C1 is connected to the drain of the second MOS tube Q2 and the power supply end of the touch screen module, the other end of the first capacitor C1 is grounded, and the second capacitor C2 is connected in parallel with the first capacitor C1. The first capacitor C1 and the second capacitor C2 are both filter capacitors, which are used to filter out the peak signal when the MOS tube is turned on, so as to protect the touch screen.

[0035] Of course, during the power-on initialization process of the main control chip in the main control module 10, if no pull-down signal appears, the gate of the first MOS tube can also be connected to a pull-up resistor (such as Figure 2 The dotted line resistor in the circuit board can be used to reserve the pads for the dotted line resistors, and then choose whether to weld according to the initialization characteristics of the main control chip. Figure 2 The dotted resistor in the figure improves the compatibility of the expectorant circuit board.

[0036] It should be noted that the first power supply unit 33 and the second power supply unit 34 can directly utilize the two step-down chips (such as AMS1117 step-down chip, etc.) in the power module of the sputum removal machine, and the main control chip can also directly utilize the existing main control of the sputum removal machine, and only needs to use one of its IO ports to output high-level or low-level signals. This is the prior art, so the utility model does not describe the specific circuits of the first and second power supply units and the main control module in detail.

[0037] The first power supply filter unit 31 includes a first magnetic bead L1, and the second power supply filter unit 32 includes a second magnetic bead L2 and a third capacitor C3. One end of the first magnetic bead L1 is connected to the source of the second MOS tube Q2, one end of the second magnetic bead L2 and one end of the third resistor R3. The other end of the first magnetic bead L1 is connected to a first power supply unit for outputting a first voltage, and the other end of the second magnetic bead L2 is connected to a second power supply unit for outputting a second voltage and is also grounded through the third capacitor C3. The first voltage is lower than the second voltage. The first magnetic bead L1 or the second magnetic bead L2 is not welded, that is, when the first magnetic bead L1 is set on the circuit board, the second magnetic bead L2 is not mounted or welded on the circuit board.

[0038] In specific implementation, when the electronic components are mounted on the circuit board through SMT equipment, the first magnetic bead L1 or the second magnetic bead L2 can be selected according to the power supply requirements of the touch screen. That is, after installing a power filter unit, when the second MOS tube Q2 is turned on, the first voltage or the second voltage is filtered by the corresponding magnetic beads to power the touch screen.

[0039] The touch screen module 20 includes a touch screen interface J1, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9 and a tenth resistor R10. The first pin of the touch screen interface J1 is connected to the main control module 10 through the fourth resistor R4. The second pin of the touch screen interface J1 is the power supply end of the touch screen module 20, which is connected to the drain of the second MOS tube Q2. The third pin of the touch screen interface J1 is grounded. The fourth pin of the touch screen interface J1 is connected to the main control module 10 through the fifth resistor R5 and is also connected to the DVCC+3.3V power supply end through the sixth resistor R6. The fifth pin of the touch screen interface J1 is connected to the main control module 10 through the seventh resistor R7 and is also connected to the DVCC+3.3V power supply end through the eighth resistor R8. The sixth pin of the touch screen interface J1 is connected to the main control module 10 through the ninth resistor R9 and is also connected to the DVCC+3.3V power supply end through the tenth resistor R10.

[0040] Among them, the fourth resistor R4, the fifth resistor R5, the seventh resistor R7 and the ninth resistor R9 are current limiting resistors. The control signal output by the main control chip is loaded to the corresponding pin of the touch screen interface J1 after current limiting by the corresponding resistors to communicate with the touch screen. The sixth resistor R6, the eighth resistor R8 and the tenth resistor R10 are pull-up resistors, which are used to connect the 4th, 5th and 6th pins of the touch screen interface J1 to a 3.3V high level under normal circumstances.

[0041] The utility model changes the control mode of the existing touch screen interface J1 power pin being powered up and pulled up to a high level for self-starting into a mode of enabling control by the main control chip (that is, the power on and power off of the touch screen interface J1 are both controlled by the main control chip), so that the touch screen module 20 is powered on after the main control module 10 is initialized, thereby avoiding the problem of invalid touch screen due to a low level signal when the main control module 10 is initialized.

[0042] The touch screen module 20 also includes a second filtering unit 21, which includes a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6 and a seventh capacitor C7. One end of the fourth capacitor C4 is connected to the 4th pin of the touch screen interface J1, one end of the fifth capacitor C5 is connected to the 5th pin of the touch screen interface J1, one end of the sixth capacitor C6 is connected to the 6th pin of the touch screen interface J1, one end of the seventh capacitor C7 is connected to the 1st pin of the touch screen interface J1, and the other end of the fourth capacitor C4, the other end of the fifth capacitor C5, the other end of the sixth capacitor C6 and the other end of the seventh capacitor C7 are grounded.

[0043] The fourth capacitor C4, the fifth capacitor C5, the sixth capacitor C6 and the seventh capacitor C7 are all filter capacitors, which are used for filtering the 1st, 4th, 5th and 6th pins of the touch screen interface J1, and are used to filter out the peak signal when the main control chip passes through the touch shield, so as to ensure reliable communication between the main control chip and the touch screen.

[0044] The touch screen module 20 also includes an ESD test protection unit 22, which includes a first ESD tube D1, a second ESD tube D2, a third ESD tube D3 and a fourth ESD tube D4. One end of the first ESD tube D1 is connected to the 4th pin of the touch screen interface J1, one end of the second ESD tube D2 is connected to the 5th pin of the touch screen interface J1, one end of the third ESD tube D3 is connected to the 6th pin of the touch screen interface J1, one end of the fourth ESD tube D4 is connected to the 1st pin of the touch screen interface J1, and the other end of the first ESD tube D1, the other end of the second ESD tube D2, the other end of the third ESD tube D3 and the other end of the fourth ESD tube D4 are grounded.

[0045] The first ESD tube D1, the second ESD tube D2, the third ESD tube D3 and the fourth ESD tube D4 are ESD (Electrostatic Discharge Protection Devices) electrostatic protection tubes, which are used to protect the touch screen from being damaged during ESD testing.

[0046] In summary, the utility model enables the power supply of the touch screen module by the main control module of the sputum removal machine, so that the touch screen module is powered on after the main control module is initialized, thereby avoiding the problem of invalid touch screen.

[0047] Furthermore, according to different types of touch screens, a corresponding power supply unit is selected to supply power, so that one circuit board can be compatible with two power supply modes, thereby improving the compatibility of the touch screen control circuit.

[0048] The utility model also adopts a method of jointly forming a switch circuit with an N MOS tube and a P MOS tube, which can increase the driving ability of the switch circuit and is used to realize a small current signal to control a large current signal. When the main control chip outputs an enable signal, the high power supply voltage will not damage the MOS tube and the main control chip.

[0049] In addition, the touch screen control circuit of the sputum ejector of the present invention only uses several conventional electronic components, which improves the stability of the touch screen performance of the sputum ejector while reducing costs, and is suitable for popularization and use.

[0050] It is understandable that those skilled in the art can make equivalent substitutions or changes based on the technical solution and utility model concept of the utility model, and all these changes or substitutions should fall within the protection scope of the claims attached to the utility model.

Claims

1. A touch screen control circuit for a sputum removal machine, the touch screen control circuit comprising a main control module, a touch screen module and a power module, characterized in that: The touch screen control circuit also includes a power switch control module, a first output end of the power module is connected to the main control module, a second output end of the power module is connected to a first input end of the power switch control module, an output end of the main control module is connected to a second input end of the power switch control module, and an output end of the power switch control module is connected to a power end of the touch screen module; The power module supplies power to the main control module, and the main control module controls the power switch control module to be turned on so that the power module supplies power to the touch screen module.

2. The touch screen control circuit of the sputum removal machine according to claim 1, characterized in that: The power supply module includes a first power supply filter unit and / or a second power supply filter unit, and the output ends of the first power supply filter unit and the second power supply filter unit are connected to the first input end of the power switch control module; the power supply module also includes a first power supply unit for outputting a first voltage and a second power supply unit for outputting a second voltage; the first power supply unit is connected to the main control module and the input end of the first power supply filter unit; the second power supply unit is connected to the second power supply filter unit; When the sputum removal machine is turned on, the first power supply unit supplies power to the main control module, the first voltage is supplied to the power switch control module via the first power filter unit or the second voltage is supplied to the power switch control module via the second power filter unit, and the main control module controls the power switch control module to be turned on so that the first voltage or the second voltage supplies power to the touch screen module.

3. The touch screen control circuit of the sputum removal machine according to claim 2, characterized in that: The power switch control module includes a switch protection unit and a first filtering unit. When the switch protection unit receives the touch screen enable signal output by the main control module, the first voltage or the second voltage is output to the first filtering unit, and the touch screen module is powered after filtering by the first filtering unit.

4. The touch screen control circuit of the sputum removal machine according to claim 3, characterized in that: The switch protection unit includes a first MOS tube, a second MOS tube, a first resistor, a second resistor and a third resistor. The gate of the first MOS tube is connected to the main control module through the first resistor and is also grounded through the second resistor. The source of the first MOS tube is grounded. The drain of the first MOS tube is connected to the gate of the second MOS tube and is also connected to the first power filter unit, the second power filter unit and the source of the second MOS tube through the third resistor. The drain of the second MOS tube is connected to the first filter unit.

5. The touch screen control circuit of the sputum removal machine according to claim 2, characterized in that: The first voltage is 3.3V, and the second voltage is 5V.

6. The touch screen control circuit of the sputum removal machine according to claim 4, characterized in that: The first MOS tube is an N-type MOS tube, and the second MOS tube is a P-type MOS tube.

7. The touch screen control circuit of the sputum removal machine according to claim 4, characterized in that: The first filtering unit includes a first capacitor and a second capacitor, one end of the first capacitor is connected to the drain of the second MOS tube and the power supply end of the touch screen module, the other end of the first capacitor is grounded, and the second capacitor is connected in parallel with the first capacitor.

8. The touch screen control circuit of the sputum removal machine according to claim 4, characterized in that: The first power supply filter unit includes a first magnetic bead, and the second power supply filter unit includes a second magnetic bead and a third capacitor. One end of the first magnetic bead is connected to the source of the second MOS tube, one end of the second magnetic bead and one end of the third resistor. The other end of the first magnetic bead is connected to a first power supply unit for outputting the first voltage, and the other end of the second magnetic bead is connected to a second power supply unit for outputting the second voltage and is also grounded through the third capacitor. The first voltage is lower than the second voltage, and the first magnetic bead or the second magnetic bead is not welded.

9. The touch screen control circuit of the sputum removal machine according to claim 4, characterized in that: The touch screen module includes a touch screen interface, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor and a tenth resistor. The first pin of the touch screen interface is connected to the main control module through the fourth resistor. The second pin of the touch screen interface is the power supply end of the touch screen module and is connected to the drain of the second MOS tube. The third pin of the touch screen interface is grounded. The fourth pin of the touch screen interface is connected to the main control module through the fifth resistor and is also connected to the DVCC+3.3V power supply end through the sixth resistor. The fifth pin of the touch screen interface is connected to the main control module through the seventh resistor and is also connected to the DVCC+3.3V power supply end through the eighth resistor. The sixth pin of the touch screen interface is connected to the main control module through the ninth resistor and is also connected to the DVCC+3.3V power supply end through the tenth resistor.

10. The touch screen control circuit of the sputum removal machine according to claim 9, characterized in that: The touch screen module also includes a second filtering unit, which includes a fourth capacitor, a fifth capacitor, a sixth capacitor and a seventh capacitor, one end of the fourth capacitor is connected to the 4th pin of the touch screen interface, one end of the fifth capacitor is connected to the 5th pin of the touch screen interface, one end of the sixth capacitor is connected to the 6th pin of the touch screen interface, one end of the seventh capacitor is connected to the 1st pin of the touch screen interface, and the other end of the fourth capacitor, the other end of the fifth capacitor, the other end of the sixth capacitor and the other end of the seventh capacitor are grounded.

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