A smart cleaning control circuit and system for the milk path of a coffee machine

Abstract

This invention discloses an intelligent cleaning control circuit for the milk path of a coffee machine, comprising a control circuit consisting of multiple control units. Each control unit includes a first connection terminal, a first resistor, a second resistor, a third resistor, a fourth resistor, a fourteenth resistor, a first transistor, a second MOSFET, a third MOSFET, a fourth MOSFET, a fifth transistor, a first thyristor, a second diode, a third thyristor, a fourth light-emitting diode, a fifth diode, a sixth diode, a seventh diode, an eighth thyristor, a ninth light-emitting diode, a first operational amplifier, and a second operational amplifier.

Description

Technical Field

[0001] This invention relates to the field of intelligent device control, and in particular to an intelligent cleaning control circuit and system for the milk path of a coffee machine. Background Technology

[0002] Milk coffee products are currently a popular beverage, especially fresh milk coffee, which is highly sought after. However, fresh milk has a short shelf life and is prone to spoilage at room temperature, causing hygiene problems. In addition, milk channels are prone to scale buildup and blockage with long-term use, affecting beverage preparation. Different coffee machines have different preparation methods and cleaning processes. Using only the programs set by the factory-installed products will be very limiting or will directly lead to incomplete cleaning. Therefore, an intelligent cleaning control circuit and system for the milk channel of coffee machines that can be adapted to different coffee machines is proposed. Summary of the Invention

[0003] To address the aforementioned technical problems, the purpose of this invention is to provide an intelligent cleaning control circuit for the milk path of a coffee machine. The circuit includes a control circuit composed of multiple control units, each control unit comprising a first connection terminal P1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fourteenth resistor R14, a first transistor Q1, a second MOSFET Q2, a third MOSFET Q3, a fourth MOSFET Q4, a fifth transistor Q5, a first thyristor D1, a second diode D2, a third thyristor D3, a fourth light-emitting diode D4, a fifth diode D5, a sixth diode D6, and a seventh diode. The transistors are: D7, D8 (eighth thyristor), D9 (ninth LED), U1 (first operational amplifier), and U2 (second operational amplifier). The collector of Q1 is connected to the power supply. The emitter of Q1 is connected to the source of Q2. The drain of Q2 is connected to the control terminal of D1 and one end of R1. The cathode of D1 and the anode of D2 are connected to the non-inverting input of U1. The anode of D1, the anode of D3, and the anode of D8 are connected. The cathode of D3 is connected to the inverting input of U2. The fourth LED D4 is connected to the anode. The third thyristor D3 is connected to the control electrode of the fifth diode D5 and the cathode of the fifth diode D5. One end of the second resistor R2 is connected. The anode of the fifth diode D5 is connected to the gate of the second MOSFET Q2. The sixth diode D6 is connected to the anode of the first connection terminal P1. The cathode of the sixth diode D6 is connected to one end of the third resistor R3. The other end of the third resistor R3 is connected to the drain of the fourth MOSFET Q4. The gate of the fourth MOSFET Q4 is connected to the output terminal of the first operational amplifier U1. The source of the fourth MOSFET Q4 is connected to the emitter of the fifth transistor Q5. The base of the fifth transistor Q5 is connected to the output terminal of the second operational amplifier U2. One end of resistor R14 is connected to the gate of the third MOSFET Q3. The drain of the third MOSFET Q3 is connected to the anode of the seventh diode D7. The cathode of the seventh diode D7 is connected to the base of the first transistor Q1. The collector of the fifth transistor Q5 is connected to the control electrode of the eighth thyristor D8 and one end of resistor R4. The cathode of the eighth thyristor D8 is connected to the anode of the ninth LED D9. The other end of resistor R1, the cathode of the second diode D2, the cathode of the fourth LED D4, the other end of resistor R2, the other end of resistor R14, the other end of resistor R4, the cathode of the ninth LED D9, and the ground terminal are connected.

[0004] Furthermore, the control unit also includes a second connection terminal P2, a fifth resistor R5, and a sixth transistor Q6. The emitter of the sixth transistor Q6 is connected to the power supply, the base of the sixth transistor Q6 is connected to the second connection terminal P2 and one end of the fifth resistor R5, the collector of the sixth transistor Q6 is connected to the anode of the eighth thyristor D8, and the other end of the fifth resistor R5 is connected to the ground terminal.

[0005] Furthermore, the control unit also includes a third connection terminal P3, a fourth connection terminal P4, a fifth connection terminal P5, a third operational amplifier U3, a fourth operational amplifier U4, and a fifth operational amplifier U5. The non-inverting input of the third operational amplifier U3 is connected to the cathode of the third thyristor D3, and the inverting input of the third operational amplifier U3 is connected to the inverting inputs of the first operational amplifier U1, the fourth operational amplifier U4, and the fifth operational amplifier U5. The output terminal of the third operational amplifier U3 is connected to the third connection terminal P3. The non-inverting input of the fourth operational amplifier U4 is connected to the cathode of the first thyristor D1, and the output terminal of the fourth operational amplifier U4 is connected to the fourth connection terminal P4. The non-inverting input of the fifth operational amplifier U5 is connected to the cathode of the eighth thyristor D8, and the output terminal of the fifth operational amplifier U5 is connected to the fifth connection terminal P5.

[0006] Furthermore, the control unit also includes a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, and a sixth decoder U6. One end of the sixth resistor R6 is connected to the third connection terminal P3 and pin 1 of the sixth decoder U6. One end of the seventh resistor R7 is connected to the fourth connection terminal P4 and pin 2 of the sixth decoder U6. One end of the eighth resistor R8 is connected to pin 3 of the sixth decoder U6 and the fifth connection terminal P5. One end of the ninth resistor R9 is connected to pin 6 of the sixth decoder U6. The other ends of the sixth resistor R6, the seventh resistor R7, the eighth resistor R8, and the ninth resistor R9 are connected to the ground terminal.

[0007] Furthermore, the control unit also includes a tenth resistor R10 and an eleventh resistor R11. One end of the tenth resistor R10 is connected to the power supply, and the other end of the tenth resistor R10 is connected to the non-inverting input of the second operational amplifier U2 and one end of the eleventh resistor R11. The other end of the eleventh resistor R11 is connected to the ground terminal.

[0008] Furthermore, the control unit also includes a twelfth resistor R12 and a thirteenth resistor R13. One end of the twelfth resistor R12 is connected to the power supply, and the other end of the twelfth resistor R12 is connected to the inverting input of the first operational amplifier U1. One end of the thirteenth resistor R13 is connected to the ground terminal.

[0009] Furthermore, the control unit also includes a fifteenth resistor R15, a sixteenth resistor R16, and a seventeenth resistor R17. One end of the fifteenth resistor R15 is connected to the drain of the fourth MOSFET Q4, and the other end of the fifteenth resistor R15 is connected to the ground terminal.

[0010] Furthermore, the control unit also includes a sixteenth resistor R16 and a seventeenth resistor R17. One end of the sixteenth resistor R16 is connected to the power supply, and the other end of the sixteenth resistor R16 is connected to the source of the third MOSFET Q3. One end of the seventeenth resistor R17 is connected to the ground terminal.

[0011] Furthermore, the control unit also includes an eighteenth resistor R18, one end of which is connected to the gate of the fourth MOS transistor Q4, and the other end of which is connected to the ground terminal.

[0012] Furthermore, an intelligent cleaning control system for the milk path of a coffee machine includes a chip, a control unit, and a timing unit. The timing unit includes multiple timing circuits, which are used to time and adjust the start time and sequence of each task in the cleaning process. The chip sends a pulse signal to the control unit based on the timing signal fed back by the timing circuit. The control unit starts the corresponding function based on the pulse signal or feeds back to the chip to start the function based on the timing.

[0013] The advantages of this invention compared to the prior art are: This invention allows for the rapid setup of cleaning programs, adaptable to different coffee machines and cleaning programs, reducing signal input and increasing response speed. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the prior art and embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 , Figure 2 and Figure 3 This is a schematic diagram of the control unit structure provided by the present invention. Detailed Implementation

[0016] To make the objectives and advantages of the present invention clearer, the present invention will be specifically described below in conjunction with embodiments. It should be understood that the following text is only used to describe one or more specific embodiments of the present invention and does not strictly limit the scope of protection specifically claimed by the present invention.

[0017] Referring to the accompanying drawings, this invention is an intelligent cleaning control circuit for the milk path of a coffee machine, including a control circuit composed of multiple control units. Each control unit includes a first connection terminal P1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fourteenth resistor R14, a first transistor Q1, a second MOSFET Q2, a third MOSFET Q3, a fourth MOSFET Q4, a fifth transistor Q5, a first thyristor D1, a second diode D2, a third thyristor D3, a fourth light-emitting diode D4, a fifth diode D5, a sixth diode D6, a seventh diode D7, and an eighth thyristor... The circuit consists of thyristor D8, ninth LED D9, first operational amplifier U1, second operational amplifier U2, first transistor Q1 (collector connected to power supply), first transistor Q1 (emitter connected to source of second MOSFET Q2), second MOSFET Q2 (drain connected to control terminal of first thyristor D1 and one end of first resistor R1), first thyristor D1 (cathode connected to anode of second diode D2 and non-inverting input of first operational amplifier U1), first thyristor D1 (anode connected to anode of third thyristor D3 and anode of eighth thyristor D8), third thyristor D3 (cathode connected to inverting input of second operational amplifier U2), and fourth LED D9. Diode D4's anode is connected to the ground plane. The control electrode of the third thyristor D3 and the cathode of the fifth diode D5 are connected to one end of the second resistor R2. The anode of the fifth diode D5 is connected to the gate of the second MOSFET Q2, the anode of the sixth diode D6, and the first connection terminal P1. The cathode of the sixth diode D6 is connected to one end of the third resistor R3, and the other end of the third resistor R3 is connected to the drain of the fourth MOSFET Q4. The gate of the fourth MOSFET Q4 is connected to the output terminal of the first operational amplifier U1. The source of the fourth MOSFET Q4 is connected to the emitter of the fifth transistor Q5. The base of the fifth transistor Q5 is connected to the output terminal of the second operational amplifier U2, and the fourteenth diode... One end of resistor R14 is connected to the gate of the third MOSFET Q3. The drain of the third MOSFET Q3 is connected to the anode of the seventh diode D7. The cathode of the seventh diode D7 is connected to the base of the first transistor Q1. The collector of the fifth transistor Q5 is connected to the control electrode of the eighth thyristor D8 and one end of the fourth resistor R4. The cathode of the eighth thyristor D8 is connected to the anode of the ninth LED D9. The other end of the first resistor R1, the cathode of the second diode D2, the cathode of the fourth LED D4, the other end of the second resistor R2, the other end of the fourteenth resistor R14, the other end of the fourth resistor R4, the cathode of the ninth LED D9, and the ground terminal are connected.

[0018] Specifically, the control unit further includes a second connection terminal P2, a fifth resistor R5, and a sixth transistor Q6. The emitter of the sixth transistor Q6 is connected to the power supply, the base of the sixth transistor Q6 is connected to the second connection terminal P2 and one end of the fifth resistor R5, the collector of the sixth transistor Q6 is connected to the anode of the eighth thyristor D8, and the other end of the fifth resistor R5 is connected to the ground terminal.

[0019] Specifically, the control unit further includes a third connection terminal P3, a fourth connection terminal P4, a fifth connection terminal P5, a third operational amplifier U3, a fourth operational amplifier U4, and a fifth operational amplifier U5. The non-inverting input of the third operational amplifier U3 is connected to the cathode of the third thyristor D3, and the inverting input of the third operational amplifier U3 is connected to the inverting inputs of the first operational amplifier U1, the fourth operational amplifier U4, and the fifth operational amplifier U5. The output terminal of the third operational amplifier U3 is connected to the third connection terminal P3. The non-inverting input of the fourth operational amplifier U4 is connected to the cathode of the first thyristor D1, and the output terminal of the fourth operational amplifier U4 is connected to the fourth connection terminal P4. The non-inverting input of the fifth operational amplifier U5 is connected to the cathode of the eighth thyristor D8, and the output terminal of the fifth operational amplifier U5 is connected to the fifth connection terminal P5.

[0020] Specifically, the control unit further includes a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, and a sixth decoder U6. One end of the sixth resistor R6 is connected to the third connection terminal P3 and pin 1 of the sixth decoder U6. One end of the seventh resistor R7 is connected to the fourth connection terminal P4 and pin 2 of the sixth decoder U6. One end of the eighth resistor R8 is connected to pin 3 of the sixth decoder U6 and the fifth connection terminal P5. One end of the ninth resistor R9 is connected to pin 6 of the sixth decoder U6. The other ends of the sixth resistor R6, the seventh resistor R7, the eighth resistor R8, and the ninth resistor R9 are connected to the ground terminal.

[0021] Specifically, the control unit further includes a tenth resistor R10 and an eleventh resistor R11. One end of the tenth resistor R10 is connected to the power supply, and the other end of the tenth resistor R10 is connected to the non-inverting input of the second operational amplifier U2 and one end of the eleventh resistor R11. The other end of the eleventh resistor R11 is connected to the ground terminal.

[0022] Specifically, the control unit further includes a twelfth resistor R12 and a thirteenth resistor R13. One end of the twelfth resistor R12 is connected to the power supply, and the other end of the twelfth resistor R12 is connected to the inverting input of the first operational amplifier U1. One end of the thirteenth resistor R13 is connected to the ground terminal.

[0023] Specifically, the control unit further includes a fifteenth resistor R15, a sixteenth resistor R16, and a seventeenth resistor R17. One end of the fifteenth resistor R15 is connected to the drain of the fourth MOS transistor Q4, and the other end of the fifteenth resistor R15 is connected to the ground terminal.

[0024] Specifically, the control unit further includes a sixteenth resistor R16 and a seventeenth resistor R17. One end of the sixteenth resistor R16 is connected to the power supply, and the other end of the sixteenth resistor R16 is connected to the source of the third MOSFET Q3. One end of the seventeenth resistor R17 is connected to the ground terminal.

[0025] Specifically, the control unit further includes an eighteenth resistor R18, one end of which is connected to the gate of the fourth MOS transistor Q4, and the other end of which is connected to the ground terminal.

[0026] Specifically, an intelligent cleaning control system for the milk path of a coffee machine includes a chip, a control unit, and a timing unit. The timing unit includes multiple timing circuits, which are used to time and adjust the start time and sequence of each task in the cleaning process. The chip sends pulse signals to the control unit based on the timing signals fed back by the timing circuits. The control unit starts the corresponding function based on the pulse signals or feeds back to the chip to start the function based on the timing.

[0027] The control unit in this invention is a 3-channel feedback control unit, with each channel corresponding to a function's start signal. These start signals include, but are not limited to, motors, pumps, or sensors. Start-up control can be achieved through direct connection (using a relay or contactor coil in the main circuit of the function) or by decoding with the sixth decoder U6 and feeding back to the chip for timing the start of the corresponding function. (The first method is direct start, corresponding to long-running functions or functions requiring a reset before shutdown; the second method is hybrid start, used when the start-up duration overlaps with subsequent tasks and requires multi-level timing.) Three or more function start signals can be connected in series by two or more control units. The series connection method involves connecting the eighth thyristor D8 of the first control unit... The cathode is connected to the first connection terminal P1 of the second control unit, and the second connection terminals P2 of all control units are connected in parallel. In the control unit, the second connection terminal P2 represents the reset signal, which is fed back from the fifth connection terminal P5 of the last control unit. The first connection terminal P1 represents the program start signal. The function start sequence can be configured according to requirements. For example, two control units complete five timing start tasks (the sixth task is fixed as the reset signal feedback). The five start task processes are: pill dispensing - hot water dissolving - stirring and mixing - cold water rinsing - water pump drainage - reset. Assume each function start time is 5 seconds (started sequentially; when task start times overlap, the difference is used). The chip output function start signal is generated by the second timing unit. When timing is performed by the unit, the difference value is used as the standard for parallel startup. The difference value is set to the highest frequency difference (starting is not performed through parallel connection of P-series signals). The timing circuit switches the signal of the first connection terminal P1 every 5 seconds (high level to low level or low level to high level). For example, the initial state of the first connection terminal P1 when there is no signal input is low potential. After the initial startup, the corresponding state every 5 seconds is 1-0-1-0-1-0 (after reset). After startup, the low level signal of the first connection terminal P1 also starts the function (it does not start after reset). When a task requires a long startup or the startup time needs to be until the reset before shutting down, the P-series signal of the corresponding function is disconnected from the sixth decoder U6 (the attached figure is only for 3-input 8-bit decoder). In this example, when there are multiple control units, the corresponding multi-input signal is replaced. The signal is directly connected to the start signal of other components such as the functional motor or water pump (the relay or contactor coil in the main circuit of the function). When the first connection terminal P1 receives the first input signal to start the circuit, the signal is fed back to the fourth LED D4 after passing through the fifth diode D5 and the third thyristor D3. The non-inverting input of the second operational amplifier U2 is set with a cutoff voltage. The voltage must be greater than the cathode potential when the third thyristor D3 is cut off. The second operational amplifier U2 is cut off, the third operational amplifier U3 is output, and the third MOSFET Q3 is turned on. At the same time, the second MOSFET Q2 is cut off because of the input at the first connection terminal P1, and the first thyristor D1 cannot be turned on, preventing skipped start-up.When the signal at the first connection terminal P1 changes, the second MOSFET Q2, the first thyristor D1, and the second diode D2 are turned on. The fourth operational amplifier U4 and the first operational amplifier U1 output, and the output of the first operational amplifier U1 turns on the fourth MOSFET Q4. When the signal at the first connection terminal P1 changes again, the signal from the first connection terminal P1 is fed back to the eighth thyristor D8 via the sixth diode D6, the third resistor R3, the fourth MOSFET Q4, and the fifth transistor Q5. The fifth operational amplifier U5 outputs a signal, and the signal output by the fifth operational amplifier U5 is fed back to the first connection terminal P1 in the second control unit. When the signal from connection terminal P1 is switched to the output of connection terminal P5 in the second control unit, the input signal from connection terminal P2 is reset (connecting connection terminal P2 to connection terminal P5 of the second control unit or providing feedback via a chip), completing the entire task startup. Since a low-level falling edge can be used as the function startup signal after the input signal from connection terminal P1, the number of signal inputs can be reduced. During reset, the input signal from connection terminal P2 causes the sixth transistor Q6 to turn off, thus turning off the eighth thyristor D8, the first thyristor D1, and the third thyristor D3. This also causes the third operational amplifier U3, the fourth operational amplifier U4, and the... Operational amplifier U5 does not output until a signal is input again to the first connection terminal P1. When within the chip voltage range, the connections of operational amplifiers U3, U4, and U5 can be removed for feedback. Resistors R12 and R13 are used as reference voltages for operational amplifiers U1, U3, U5, and U6, and can also be set individually. Resistors R6, R7, R8, and R9 are used to pull down the corresponding input signals of the sixth decoder U6. Pins Y0 to Y7 corresponding to output terminal 6 are connected to the chip. The chip starts up according to the decoded signal. Resistor 15, together with resistor R3, is used to divide the voltage for the fourth MOSFET Q4. Resistors R16 and R17 are used to divide the voltage for the third MOSFET Q3, and also to prevent the gate-drain voltage from being zero when the fourth MOSFET Q4 and the third MOSFET Q3 are turned on. Resistor R18 is used in the gate circuit of the fourth MOSFET Q4 to prevent parasitic capacitance oscillation. The timing circuit can be composed of an RC delay circuit and an adjustable potentiometer. The delay circuit is existing technology and will not be described in detail here.

[0028] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No markings in the claims should be construed as limiting the scope of the claims.

Claims

1. An intelligent cleaning control circuit for the milk path of a coffee machine, characterized in that, The system includes a control circuit composed of multiple control units. Each control unit is a three-way feedback control unit, with each channel corresponding to a function's start signal. The control unit includes a first connection terminal, a first resistor, a second resistor, a third resistor, a fourth resistor, a fourteenth resistor, a first transistor, a second MOSFET, a third MOSFET, a fourth MOSFET, a fifth transistor, a first thyristor, a second diode, a third thyristor, a fourth LED, a fifth diode, a sixth diode, a seventh diode, an eighth thyristor, a ninth LED, a first operational amplifier, and a second operational amplifier. The collector of the first transistor is connected to the power supply, the emitter of the first transistor is connected to the source of the second MOSFET, the drain of the second MOSFET is connected to the control terminal of the first thyristor, one end of the first resistor, the cathode of the first thyristor is connected to the anode of the second diode, the non-inverting input of the first operational amplifier is connected, the anode of the first thyristor is connected to the anode of the third thyristor, the anode of the eighth thyristor is connected, and the cathode of the third thyristor is connected to the inverting input of the second operational amplifier. The anodes of four LEDs are connected. The control electrode of the third thyristor and the cathode of the fifth LED are connected to one end of the second resistor. The anode of the fifth LED and the gate of the second MOSFET, the anode of the sixth LED, and the first connection terminal are connected. The cathode of the sixth LED and one end of the third resistor are connected. The other end of the third resistor is connected to the drain of the fourth MOSFET. The gate of the fourth MOSFET is connected to the output terminal of the first operational amplifier. The source of the fourth MOSFET and the emitter of the fifth transistor are connected. The base of the fifth transistor and the output terminal of the second operational amplifier, one end of the fourteenth resistor, and the gate of the third MOSFET are connected. The drain of the third MOSFET and the anode of the seventh LED are connected. The cathode of the seventh LED is connected to the base of the first transistor. The collector of the fifth transistor and the control electrode of the eighth thyristor are connected to one end of the fourth resistor. The cathode of the eighth thyristor and the anode of the ninth LED are connected. The other end of the first resistor, the cathode of the second LED, the cathode of the fourth LED, the other end of the second resistor, the other end of the fourteenth resistor, the other end of the fourth resistor, the cathode of the ninth LED, and the ground terminal are connected. The control unit also includes a second connection terminal, a fifth resistor, and a sixth transistor. The emitter of the sixth transistor is connected to the power supply, the base of the sixth transistor is connected to the second connection terminal and one end of the fifth resistor, the collector of the sixth transistor is connected to the anode of the eighth thyristor, and the other end of the fifth resistor is connected to the ground terminal. The control unit further includes a third connection terminal, a fourth connection terminal, a fifth connection terminal, a third operational amplifier, a fourth operational amplifier, and a fifth operational amplifier. The non-inverting input of the third operational amplifier is connected to the cathode of the third thyristor, the inverting input of the third operational amplifier is connected to the inverting inputs of the first, fourth, and fifth operational amplifiers, the output terminal of the third operational amplifier is connected to the third connection terminal, the non-inverting input of the fourth operational amplifier is connected to the cathode of the first thyristor, the output terminal of the fourth operational amplifier is connected to the fourth connection terminal, the non-inverting input of the fifth operational amplifier is connected to the cathode of the eighth thyristor, and the output terminal of the fifth operational amplifier is connected to the fifth connection terminal.

2. The intelligent cleaning control circuit for the milk path of a coffee machine according to claim 1, characterized in that, The control unit further includes a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, and a sixth decoder. One end of the sixth resistor is connected to the third connection terminal and pin 1 of the sixth decoder. One end of the seventh resistor is connected to the fourth connection terminal and pin 2 of the sixth decoder. One end of the eighth resistor is connected to pin 3 of the sixth decoder and the fifth connection terminal. One end of the ninth resistor is connected to pin 6 of the sixth decoder. The other ends of the sixth, seventh, eighth, and ninth resistors are connected to the ground terminal.

3. The intelligent cleaning control circuit for the milk path of a coffee machine according to claim 1, characterized in that, The control unit also includes a tenth resistor and an eleventh resistor. One end of the tenth resistor is connected to a power source, and the other end of the tenth resistor is connected to the non-inverting input of the second operational amplifier and one end of the eleventh resistor. The other end of the eleventh resistor is connected to a ground terminal.

4. The intelligent cleaning control circuit for the milk path of a coffee machine according to claim 1, characterized in that, The control unit also includes a twelfth resistor and a thirteenth resistor. One end of the twelfth resistor is connected to the power supply, and the other end of the twelfth resistor is connected to the inverting input of the first operational amplifier. One end of the thirteenth resistor is connected to the ground terminal.

5. The intelligent cleaning control circuit for the milk path of a coffee machine according to claim 1, characterized in that, The control unit also includes a fifteenth resistor, a sixteenth resistor, and a seventeenth resistor. One end of the fifteenth resistor is connected to the drain of the fourth MOS transistor, and the other end of the fifteenth resistor is connected to the ground terminal.

6. The intelligent cleaning control circuit for the milk path of a coffee machine according to claim 1, characterized in that, The control unit also includes a sixteenth resistor and a seventeenth resistor. One end of the sixteenth resistor is connected to the power supply, and the other end of the sixteenth resistor is connected to the source of the third MOS transistor. One end of the seventeenth resistor is connected to the ground terminal.

7. The intelligent cleaning control circuit for the milk path of a coffee machine according to claim 1, characterized in that, The control unit also includes an eighteenth resistor, one end of which is connected to the gate of the fourth MOS transistor, and the other end of which is connected to the ground terminal.

8. An intelligent cleaning control system for the milk path of a coffee machine, characterized in that, The device includes a chip, multiple control units as described in claim 1, and a timing unit. The timing unit includes multiple timing circuits. The timing circuits are used to time and adjust the start time and start sequence of each task in the cleaning process. The chip sends a pulse signal to the control unit based on the timing signal fed back by the timing circuit. The control unit starts the corresponding function based on the pulse signal or feeds back to the chip to start the function based on the timing.

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