Concentration detection circuit and system

Abstract

The utility model discloses a concentration detection circuit and system, the concentration detection circuit is connected with an electrode probe, the electrode probe contacts with a solution to be detected and generates a sensing signal representing concentration based on the solution to be detected, the concentration detection circuit comprises a transformer, a sampling module, a control module and a display module, the transformer is connected with the electrode probe, and the sampling module is connected with the control module. The sampling module is connected with the transformer and used for generating a sampling signal based on the voltage signal, and the period of the sampling signal changes along with the sensing signal. The control module is connected with the sampling module and used for generating a control signal based on the sampling signal, and the display module is connected with the control module and used for generating a display signal based on the control signal. The electrode probe is installed and makes contact with the liquid to be detected, the electrode probe and the concentration detection circuit form a complete detection system, and when the concentration of the liquid to be detected changes, the concentration of the liquid to be detected is represented through periodic changes of sampling signals so as to achieve concentration detection.

Description

TECHNICAL FIELD

[0001] The utility model belongs to sensing detection technical field, and specifically about a concentration detection circuit and system. BACKGROUND

[0002] In the current cleaning equipment, the detergent adding mode is usually to add a fixed amount of detergent at a fixed time according to the washing mode, and the accuracy of the detergent adding amount is not high.

[0003] Especially for the washing machine, the washing mode is too general, and if the amount of clothes placed in the washing machine is inconsistent under the same washing mode, the liquid level in the washing machine will also be inconsistent, and therefore the amount of detergent required needs to be adaptively adjusted.

[0004] Therefore, in view of the above technical problems, it is necessary to provide a concentration detection circuit and system. CONTENT OF UTILITY MODEL

[0005] The utility model aims at providing a concentration detection circuit and system, which can represent the concentration of the to-be-measured liquid by the periodical change of the sampling signal to realize concentration detection.

[0006] In order to realize the above-mentioned purpose, the technical scheme provided by a specific embodiment of the utility model is as follows:

[0007] A concentration detection circuit is connected with an electrode probe, the electrode probe contacts a to-be-measured solution, and generates a sensing signal representing concentration based on the to-be-measured solution, the concentration detection circuit comprises a transformer, a sampling module, a control module and a display module, the transformer is connected between the electrode probe and the sampling module, and is used for generating a voltage signal based on the sensing signal, the sampling module is connected with the transformer, and is used for generating a sampling signal based on the voltage signal, the sampling signal is a square wave signal, and the period of the sampling signal changes with the sensing signal, the control module is connected with the sampling module, and is used for generating a control signal based on the sampling signal, and the display module is connected with the control module, and is used for generating a display signal based on the control signal.

[0008] In one or more embodiments of the utility model, the electrode probe comprises a first electrode and a second electrode, and the transformer comprises a primary winding and a secondary winding; wherein,

[0009] The first end of the primary winding is connected with the first electrode, and the second end is connected with the second electrode;

[0010] The first end and the second end of the secondary winding are connected with the sampling module.

[0011] In one or more embodiments of the utility model, the sampling module includes a resonance unit, a first voltage division unit and a second voltage division unit, the first voltage division unit has a first voltage division node, and the second voltage division unit has a second voltage division node; wherein,

[0012] The first end of the first voltage division unit is connected with a working voltage, the first voltage division node is connected with the second end of the secondary winding, and the second end of the first voltage division unit is connected with a discharge pin of the resonance unit;

[0013] The first end of the second voltage division unit is connected with an output pin of the resonance unit, the second end is connected with a ground potential, and the second voltage division node is connected with the control module;

[0014] The comparison input pin and the trigger input pin of the resonance unit are connected with the first end of the secondary winding.

[0015] In one or more embodiments of the utility model, the first voltage division unit includes a first voltage division resistor and a second voltage division resistor; wherein,

[0016] The first end of the first voltage division resistor is used for forming the first end of the first voltage division unit, the second end of the first voltage division resistor is connected with the first end of the second voltage division resistor to form the first voltage division node, and the second end of the second voltage division resistor is used for forming the second end of the first voltage division unit; and / or

[0017] The second voltage division unit includes a third voltage division resistor and a fourth voltage division resistor, the first end of the third voltage division resistor is used for forming the first end of the second voltage division unit, the second end of the third voltage division resistor is connected with the first end of the fourth voltage division resistor to form the second voltage division node, and the second end of the fourth voltage division resistor is used for forming the second end of the second voltage division unit.

[0018] In one or more embodiments of the utility model, the resonance unit includes an NE555P chip.

[0019] In one or more embodiments of the utility model, the control module includes a master control chip, a first crystal unit and a second crystal unit; wherein,

[0020] The first crystal unit is connected with the master control chip and is used for generating a first oscillation signal;

[0021] The second crystal unit is connected with the master control chip and is used for generating a second oscillation signal.

[0022] In one or more embodiments of the utility model, the first crystal unit includes first crystal oscillator, first filter resistance, first filter capacitance and second filter capacitance, the first crystal oscillator is parallelly connected with first filter resistance, and both ends of first crystal oscillator are connected with first crystal oscillator input pin and first crystal oscillator output pin of master control chip respectively, the first end of first filter capacitance is connected with the first end of first crystal oscillator, and the second end is connected with ground potential, the first end of second filter capacitance is connected with the second end of first crystal oscillator, and the second end is connected with ground potential, and / or

[0023] The second crystal unit includes second crystal oscillator, second filter resistance, third filter capacitance and fourth filter capacitance, the second crystal oscillator is parallelly connected with second filter resistance, and both ends of second crystal oscillator are connected with second crystal oscillator input pin and second crystal oscillator output pin of master control chip respectively, the first end of third filter capacitance is connected with the first end of second crystal oscillator, and the second end is connected with ground potential, the first end of fourth filter capacitance is connected with the second end of second crystal oscillator, and the second end is connected with ground potential.

[0024] In one or more embodiments of the utility model, the display module includes LED nixie tube, first transistor, second transistor and third transistor, wherein,

[0025] The control end of first transistor is connected with control module, the first end is connected with ground potential, and the second end is connected with the first end of LED nixie tube;

[0026] The control end of second transistor is connected with control module, the first end is connected with ground potential, and the second end is connected with the second end of LED nixie tube;

[0027] The control end of third transistor is connected with control module, the first end is connected with ground potential, and the second end is connected with the third end of LED nixie tube.

[0028] In one or more embodiments of the utility model, the concentration detection circuit further includes input module, and the input module is connected with control module.

[0029] The utility model discloses another specific embodiment provides the technical scheme as follows:

[0030] A concentration detection system, the concentration detection system includes electrode probe and concentration detection circuit, the electrode probe contacts solution to be measured, and the sensing signal of concentration characterization is generated based on the solution to be measured, the concentration detection circuit includes transformer, sampling module, control module and display module, the transformer is connected between electrode probe and sampling module, is used for generating voltage signal based on sensing signal, the sampling module is connected with the transformer, is used for generating sampling signal based on voltage signal, the sampling signal is square wave signal, and the sampling signal period follows sensing signal change, the control module is connected with sampling module, is used for generating control signal based on sampling signal, the display module is connected with control module, is used for generating display signal based on control signal.

[0031] Compared with the prior art, the concentration detection circuit and system of the utility model, through install electrode probe, electrode probe and concentration detection circuit constitute complete detection system, detect the concentration of liquid to be measured, when the concentration of liquid to be measured changes, sampling module generates sampling signal of different frequency, and the concentration of liquid to be measured is characterized by the period change of sampling signal to realize accurate concentration measurement.

[0032] The utility model discloses through setting up display module, user receives liquid concentration change of measurement in real time to execute detergent adding operation. ACCURACY

[0033] In order to more clearly illustrate the technical scheme in the embodiment of the utility model or prior art, the following will be to the embodiment or prior art description needed to use the drawing briefly introduced, obviously, the following description in the drawing only is some embodiments in the utility model, for the ordinary skilled person in the art comes, under the premise of not paying creative labor, can also obtain other drawings according to these drawings.

[0034] Figure 1 It is the structural schematic diagram of concentration detection system in an embodiment of the utility model;

[0035] Figure 2 It is the first power module circuit diagram of concentration detection circuit in an embodiment of the utility model;

[0036] Figure 3 It is the transformer, sampling module circuit diagram of concentration detection circuit in an embodiment of the utility model;

[0037] Figure 4 It is the control module schematic diagram of concentration detection circuit in an embodiment of the utility model;

[0038] Figure 5 It is the display module schematic diagram of concentration detection circuit in an embodiment of the utility model;

[0039] Figure 6The second power module circuit diagram of the concentration detection circuit in an embodiment of the utility model;

[0040] Figure 7 The input module circuit diagram of the concentration detection circuit in an embodiment of the utility model. DETAILED DESCRIPTION

[0041] In order to make the personnel in the technical field better understand the technical scheme in the utility model, the technical scheme in the embodiment of the utility model will be described clearly and completely in the following by combining with the drawings in the embodiment of the utility model. Obviously, the described embodiment is only a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment in the utility model, all other embodiments obtained by the person skilled in the art without creative labor should belong to the protection scope of the utility model.

[0042] Unless otherwise explicitly indicated, in the entire specification and claims, the term "comprise" or its variants such as "contain" or "include" and the like will be understood to include the stated element or component, but not exclude other elements or components.

[0043] In the specification, "coupling" or "connection" or "connection" includes both direct connection and indirect connection. Indirect connection is the connection through an intermediate medium, such as the connection through an electrically conductive medium, which can have a parasitic inductance or a parasitic capacitance; indirect connection can also include the connection through other active devices or passive devices on the basis of achieving the same or similar functional purposes, such as the connection through circuits or components such as switches, follower circuits, etc. In addition, in the utility model, for example, the words "first", "second" and the like are mainly used to distinguish one technical feature from another technical feature, and do not necessarily require or imply a certain actual relationship, quantity or order between the technical features.

[0044] In the detailed description of the specification, the drawings forming a part thereof are referred to, wherein the same reference signs always represent the same components, and wherein the exemplary embodiments can be shown by way of example. It should be understood that other embodiments can be utilized without departing from the scope of the present disclosure, and structural or logical changes can be made. Therefore, the following detailed description should not be regarded as limiting.

[0045] The various operations in the specification may be described as multiple discrete actions or operations in a manner that is most helpful in understanding the claimed subject matter. However, the order of description should not be interpreted as implying that these operations must be sequentially related. Specifically, these operations may not be performed in the order presented. The described operations may be performed in an order different from the described embodiments. Various additional operations may be performed and / or the described operations may be omitted in additional embodiments.

[0046] For the purposes of this disclosure, the phrase "A and / or B" means (A), (B), or (A and B). For the purposes of this disclosure, the phrase "A, B and / or C" means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C).

[0047] Various components and devices may be referred to or shown in the singular form in this document (for example, "MOS tube", "transistor", "switch", etc.), but this is only for convenience of discussion, and any element referred to in the singular form may include multiple such elements according to the teachings of this document.

[0048] The specification uses the phrases "in one embodiment," "in other embodiments," or "in some embodiments," which can each refer to one or more of the same or different embodiments. In addition, the terms "including," "comprising," "having," etc. used with respect to the embodiments of the present disclosure are synonymous.

[0049] like Figure 1 As shown, the concentration detection system in one embodiment of the present invention includes an electrode probe 10 and a concentration detection circuit 20, wherein the concentration detection circuit 20 includes a first power supply module 21, a transformer 22, a sampling module 23, a control module 24, a display module 25, a first power supply module 26 and an input module 27.

[0050] The concentration detection system in the present application is suitable for cleaning equipment. This embodiment is illustrated by taking a washing machine as an example. The electrode probe 10 can be arranged at the bottom of the washing machine. The electrode probe 10 includes a first electrode PR1 and a second electrode PR2, wherein the first ends of the first electrode PR1 and the second electrode PR2 are in contact with the liquid to be tested, and the second ends of the first electrode PR1 and the second electrode PR2 are respectively connected to the two ends of the primary winding of the transformer 22. The electrode probe 10 is used to generate a sensing signal representing the concentration based on the solution to be tested.

[0051] The transformer 22 is connected to the electrode probe 10, and is configured to generate a voltage signal based on the sensing signal. The sampling module 23 is connected to the transformer 22, and is configured to generate a sampling signal PROBE based on the voltage signal. The period of the sampling signal PROBE follows the change of the voltage signal, i.e. follows the change of the sensing signal. The control module 24 is connected to the sampling module 23, and is configured to generate a control signal based on the sampling signal. The display module 25 is connected to the control module 24, and is configured to generate a display signal based on the control signal. The input module 27 is connected to the control module 24, and is configured to input a signal to the control module 24.

[0052] The first power module 21 is connected to a power voltage (24V) to convert the power voltage into a working voltage (5V) required by other modules.

[0053] As shown in Figure 2 , the first power module 21 includes a voltage conversion chip U1 and its peripheral circuit. The model of the voltage conversion chip U1 is preferably MP2303. The first power module 21 in the embodiment further includes a first diode D1, wherein the anode of the first diode D1 is connected to the power voltage (24V), the cathode is connected to the IN pin 2 of the voltage conversion chip U1, and the SW pin 3 of the voltage conversion chip U1 outputs the working voltage (5V). The first diode D1 is configured to prevent the power voltage (24V) from being connected reversely.

[0054] As shown in Figure 3 , the electrode probe 10 includes a first electrode PR1 and a second electrode PR2, and the transformer 22 Trans Cup1 includes a primary winding and a secondary winding. The electrode probe 10 in the embodiment can adopt a double-needle water level electrode, such as DM143-SC. The first end of the primary winding is connected to the first electrode PR1, and the second end is connected to the second electrode PR2. The first end and the second end of the secondary winding are connected to the sampling module 23. Further, the transformer 22 in the embodiment is connected to the electrode probe 10 through the connector Header2.

[0055] As shown in Figure 3 , the sampling module 23 in the embodiment includes a resonance unit U11, a first voltage division unit and a second voltage division unit, the first voltage division unit has a first voltage division node, and the second voltage division unit has a second voltage division node. The resonance unit U11 in the embodiment is preferably a NE555P chip.

[0056] The first end of the first voltage divider unit is connected to the operating voltage (5V), the first voltage divider node is connected to the second end of the secondary winding, and the second end of the first voltage divider unit is connected to the DISC discharge pin 7 of the resonant unit U11. The first end of the second voltage divider unit is connected to the OUT output pin 3 of the resonant unit U11, the second end is connected to ground potential, and the second voltage divider node PR3 is connected to the control module 24. The THRS comparison input pin 6 and TRIG trigger input pin 2 of the resonant unit are connected to the first end of the secondary winding.

[0057] like Figure 3 As shown, in this embodiment, the first voltage-dividing unit includes a first voltage-dividing resistor R34 and a second voltage-dividing resistor R35. The first end of the first voltage-dividing resistor R34 is used to form the first end of the first voltage-dividing unit. The second end of the first voltage-dividing resistor R34 is connected to the first end of the second voltage-dividing resistor R35 to form a first voltage-dividing node. The second end of the second voltage-dividing resistor R35 is used to form the second end of the first voltage-dividing unit. The second voltage-dividing unit includes a third voltage-dividing resistor R36 and a fourth voltage-dividing resistor R37. The first end of the third voltage-dividing resistor R36 is used to form the first end of the second voltage-dividing unit. The second end of the third voltage-dividing resistor R36 is connected to the first end of the fourth voltage-dividing resistor R37 to form a second voltage-dividing node PR3. The second end of the fourth voltage-dividing resistor R37 is used to form the second end of the second voltage-dividing unit.

[0058] First and second electrodes PR1 and PR2 are inserted into the liquid in the washing machine. Due to the addition of detergent to the liquid, an equivalent capacitance is formed between the first and second electrodes PR1 and PR2. This, combined with the transformer and NE555P peripheral circuitry, forms an equivalent capacitance / inductance / resistance complex. Electrode probe 10 is used to generate a sensing signal representing the concentration of the solution being tested. Specifically, a potential difference is generated across the primary winding of transformer Trans Cup 1. The secondary winding of transformer Trans Cup 1 is connected to the NE555P chip, generating a square wave signal PROBE_5V with a certain period at output pin OUT. This signal, after passing through a second voltage divider, generates a sampling signal PROBE. In this embodiment, sampling signal PROBE is a square wave signal. When the concentration of detergent changes, the effective value of the equivalent capacitance / inductance / resistance complex formed between the first and second electrodes PR1 and PR2 changes, causing its charge and discharge cycle to change, thereby causing the NE555P resonant frequency to change. This means the period of sampling signal PROBE changes. Based on the measured period of sampling signal PROBE, control module 24 generates a control signal representing the concentration.

[0059] Specifically, after the resonant unit is started, the equivalent capacitor formed between the first electrode PR1 and the second electrode PR2 begins to charge, and its voltage gradually increases. When the voltage of the equivalent capacitor formed between the first electrode PR1 and the second electrode PR2 reaches the comparison threshold, the resonant unit will output a high level and simultaneously turn off the discharge tube, causing the equivalent capacitor to stop charging. When the voltage of the equivalent capacitor drops to the reset threshold, the resonant unit will output a low level and simultaneously turn on the discharge tube, causing the equivalent capacitor to start discharging. Cycle timing: When the voltage of the equivalent capacitor drops below the comparison threshold, the resonant unit will restart the charging cycle, thereby forming a periodic square wave. When the equivalent capacitance value changes, the above-mentioned charging cycle and discharge cycle change, and the period of the square wave signal changes.

[0060] The transformer in this embodiment also plays an isolation role. When a short circuit occurs between the first electrode PR1 and the second electrode PR2, the circuit board of the concentration detection circuit will not be damaged.

[0061] like Figure 4 As shown, in this embodiment, the control module 24 includes a main control chip U6 and its peripheral circuits, a first crystal oscillator unit 241 and a second crystal oscillator unit 242 .

[0062] The first crystal oscillator unit 241 is connected to the main control chip and is used to generate a first oscillation signal. The second crystal oscillator unit 242 is connected to the main control chip and is used to generate a second oscillation signal.

[0063] The first crystal oscillator unit 241 includes a first crystal oscillator Y1, a first filter resistor R8, a first filter capacitor C22 and a second filter capacitor C19. The first crystal oscillator Y1 is connected in parallel with the first filter resistor R8, and the two ends of the first crystal oscillator Y1 are respectively connected to the first crystal oscillator input pin 8 and the first crystal oscillator output pin 9 of the main control chip U6. The first end of the first filter capacitor C22 is connected to the first end of the first crystal oscillator Y1, and the second end is connected to the ground potential. The first end of the second filter capacitor C19 is connected to the second end of the first crystal oscillator Y1, and the second end is connected to the ground potential.

[0064] The second crystal oscillator unit 242 includes a second crystal oscillator Y2, a second filter resistor R27, a third filter capacitor C46 and a fourth filter capacitor C24. The second crystal oscillator Y2 is connected in parallel with the second filter resistor, and the two ends of the second crystal oscillator Y2 are respectively connected to the second crystal oscillator input pin 12 and the second crystal oscillator output pin 13 of the main control chip U6. The first end of the third filter capacitor C46 is connected to the first end of the second crystal oscillator Y2, and the second end is connected to the ground potential. The first end of the fourth filter capacitor C24 is connected to the second end of the second crystal oscillator Y2, and the second end is connected to the ground potential.

[0065] The model of the master control chip U6 in the embodiment is preferably GD32F103VET6. The control module 24 in the embodiment further includes an analog-to-digital conversion unit, which is configured to convert the analog sampling signal PROBE into a digital sampling signal, and the master control chip U6 generates a control signal based on the digital sampling signal.

[0066] As shown in Figure 5 the display module 25 in the embodiment includes an LED nixie tube U4 and its peripheral circuit, a first transistor Q1, a second transistor Q2, and a third transistor Q3. The model of the LED nixie tube U4 is preferably SP420281N.

[0067] The control end of the first transistor Q1 is connected to the control module 24, the first end is connected to the ground potential, and the second end is connected to the first end of the LED nixie tube. The control end of the second transistor Q2 is connected to the control module 24, the first end is connected to the ground potential, and the second end is connected to the second end of the LED nixie tube. The control end of the third transistor Q3 is connected to the control module 24, the first end is connected to the ground potential, and the second end is connected to the third end of the LED nixie tube U4.

[0068] It can be known in combination Figure 4 that the LED nixie tube U4 and its peripheral circuit, the first transistor Q1, the second transistor Q2, and the third transistor Q3 are connected to the master control chip of the control module 24, and a corresponding display signal is generated based on the control signal, that is, the concentration of the liquid to be measured is represented by the LED nixie tube.

[0069] As shown in Figure 6 the second power module 26 is connected to the working voltage (5V) to convert the working voltage (5V) into an input voltage (3.3V) required by other modules.

[0070] The second power module 26 includes a voltage conversion chip U3 and its peripheral circuit. The model of the voltage conversion chip U3 is preferably AMS1117-3.3. The second power module 26 in the embodiment further includes a third diode D3, a capacitor C12, a resistor R15, and a diode LED1. The anode of the third diode D3 is connected to the ground potential, and the cathode is connected to the input voltage (3.3V). The first end of the capacitor C12 is connected to the ground potential, and the second end is connected to the input voltage (3.3V). The cathode of the diode LED1 is connected to the ground potential, the anode is connected to the first end of the resistor R15, and the second end of the resistor R15 is connected to the input voltage (3.3V).

[0071] As shown in Figure 7 the input module 27 is connected to the control module 24. The input module 27 includes a first switching unit, a second switching unit, and a third switching unit.

[0072] The first switch unit includes switches S1, R9 and S4. The first end of R9 is connected with the input voltage (3.3V), the second end of R9, the first end of S1 and the first end of S4 are connected with the pin 59 of the main control chip U6 to generate the first switch signal KEY_SET, and the second end of S1 and the second end of S4 are connected with the ground potential.

[0073] The second switch unit includes S2 and R10. The first end of R10 is connected with the input voltage (3.3V), the second end of R10 and the first end of S2 are connected with the pin 58 of the main control chip U6 to generate the second switch signal KEY_LEFT, and the second end of S2 is connected with the ground potential.

[0074] The third switch unit includes S3 and R11. The first end of R11 is connected with the input voltage (3.3V), the second end of R11 and the first end of S3 are connected with the pin 55 of the main control chip U6 to generate the third switch signal KEY_RIGHT, and the second end of S3 is connected with the ground potential.

[0075] By controlling the on-off of S1, S2, S3 and S4, different first switch signal KEY_SET, second switch signal KEY_LEFT and third switch signal KEY_RIGHT can be input to the main control chip U6 to control the main control chip U6. In an embodiment, the main control chip U6 can perform initial calibration of the concentration detection circuit based on the control of the first switch signal KEY_SET, the second switch signal KEY_LEFT and the third switch signal KEY_RIGHT, or set the minimum concentration threshold of the detergent based on the control of the first switch signal KEY_SET, the second switch signal KEY_LEFT and the third switch signal KEY_RIGHT.

[0076] In actual work process, the 24V input power voltage is converted into 5V working voltage by the first power module, and the 5V input working voltage is converted into 3.3V input voltage by the second power module 10. After the concentration detection system is powered on, the main control chip U6 can start the initial calibration of the concentration detection circuit based on the control of the first switch signal KEY_SET, the second switch signal KEY_LEFT and the third switch signal KEY_RIGHT, for example, 1ml of detergent and 10ml of detergent are added in 100ml of water, the concentration is detected based on the electrode probe 10, the transformer 22 and the sampling module 23 to obtain the corresponding sampling signal, and the liquid concentration calculated by the control chip U6 (i.e. display signal) is viewed through the display module, and whether the calibration is completed is judged by calculating the ratio of the two groups of liquid concentrations.

[0077] After calibration, the electrode probe 10 generates a sensing signal representing the concentration based on the to-be-measured solution (i.e. the mixed liquid of water and detergent in the washing machine), the transformer 22 generates a voltage signal based on the sensing signal, the sampling module 23 generates a sampling signal PROBE based on the voltage signal, and the control chip U6 generates a control signal based on the sampling signal PROBE. The display module 80 displays the concentration of the detergent in the to-be-measured liquid based on the control signal, and the user can adjust the concentration of the detergent in the washing machine by viewing the concentration in real time and adding detergent or water.

[0078] From the above technical solutions, the utility model has the following beneficial effects:

[0079] By installing the electrode probe, the electrode probe and the concentration detection circuit form a complete detection system to detect the concentration of the to-be-measured liquid. When the concentration of the to-be-measured liquid changes, the sampling module generates a sampling signal of different frequency, and the period change of the sampling signal represents the concentration of the to-be-measured liquid to realize accurate measurement of the concentration and ensure the accuracy of the detergent addition amount. The utility model sets the display module, and the user receives the concentration change of the to-be-measured liquid in real time to perform the detergent addition operation.

[0080] The utility model solves the problem of fixed detergent addition amount, can obtain the detergent concentration, and then accurately controls the detergent addition amount according to the specific liquid level in the cleaning equipment. In addition, the utility model feeds back the concentration detection result to the user in time through the display module, which is convenient for the user to add detergent in time.

[0081] For those skilled in the art, it is obvious that the utility model is not limited to the details of the above exemplary embodiments, and can be realized in other specific forms without departing from the spirit or basic characteristics of the utility model. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting, and the scope of the utility model is defined by the appended claims rather than the above description, and therefore all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the utility model. Any reference signs in the claims should not be regarded as limiting the claims involved.

[0082] In addition, it should be understood that, although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be combined appropriately to form other embodiments that those skilled in the art can understand.

Claims

1. A concentration detection circuit, connected to an electrode probe, wherein the electrode probe contacts a solution to be tested and generates a sensor signal representing the concentration of the solution to be tested, characterized in that: The concentration detection circuit includes a transformer, a sampling module, a control module and a display module. The transformer is connected between the electrode probe and the sampling module and is used to generate a voltage signal based on the sensor signal. The sampling module is connected to the transformer and is used to generate a sampling signal based on the voltage signal. The sampling signal is a square wave signal, and the sampling signal period follows the change of the sensor signal. The control module is connected to the sampling module and is used to generate a control signal based on the sampling signal. The display module is connected to the control module and is used to generate a display signal based on the control signal.

2. The concentration detection circuit according to claim 1, characterized in that: The electrode probe includes a first electrode and a second electrode, and the transformer includes a primary winding and a secondary winding; wherein, The first end of the primary winding is connected to the first electrode, and the second end is connected to the second electrode; The first end and the second end of the secondary winding are connected to the sampling module.

3. The concentration detection circuit according to claim 2, characterized in that: The sampling module includes a resonance unit, a first voltage dividing unit and a second voltage dividing unit, wherein the first voltage dividing unit has a first voltage dividing node and the second voltage dividing unit has a second voltage dividing node; wherein, The first end of the first voltage dividing unit is connected to the operating voltage, the first voltage dividing node is connected to the second end of the secondary winding, and the second end of the first voltage dividing unit is connected to the discharge pin of the resonant unit; A first end of the second voltage dividing unit is connected to the output pin of the resonant unit, a second end is connected to the ground potential, and the second voltage dividing node is connected to the control module; The comparison input pin and the trigger input pin of the resonance unit are connected to the first end of the secondary winding.

4. The concentration detection circuit according to claim 3, characterized in that: The first voltage-dividing unit includes a first voltage-dividing resistor and a second voltage-dividing resistor, the first end of the first voltage-dividing resistor is used to form a first end of the first voltage-dividing unit, the second end of the first voltage-dividing resistor is connected to the first end of the second voltage-dividing resistor to form a first voltage-dividing node, and the second end of the second voltage-dividing resistor is used to form a second end of the first voltage-dividing unit; and / or The second voltage-dividing unit includes a third voltage-dividing resistor and a fourth voltage-dividing resistor, the first end of the third voltage-dividing resistor is used to form the first end of the second voltage-dividing unit, the second end of the third voltage-dividing resistor is connected to the first end of the fourth voltage-dividing resistor to form a second voltage-dividing node, and the second end of the fourth voltage-dividing resistor is used to form the second end of the second voltage-dividing unit.

5. The concentration detection circuit according to claim 3, characterized in that: The resonance unit includes a NE555P chip.

6. The concentration detection circuit according to claim 1, wherein: The control module includes a main control chip, a first crystal oscillator unit and a second crystal oscillator unit; wherein, The first crystal oscillator unit is connected to the main control chip and is used to generate a first oscillation signal. The second crystal oscillator unit is connected to the main control chip and is used to generate a second oscillation signal.

7. The concentration detection circuit according to claim 6, characterized in that: The first crystal oscillator unit includes a first crystal oscillator, a first filter resistor, a first filter capacitor and a second filter capacitor, the first crystal oscillator and the first filter resistor are connected in parallel, and the two ends of the first crystal oscillator are respectively connected to the first crystal oscillator input pin and the first crystal oscillator output pin of the main control chip, the first end of the first filter capacitor is connected to the first end of the first crystal oscillator, and the second end is connected to the ground potential, the first end of the second filter capacitor is connected to the second end of the first crystal oscillator, and the second end is connected to the ground potential; and / or The second crystal oscillator unit includes a second crystal oscillator, a second filter resistor, a third filter capacitor and a fourth filter capacitor. The second crystal oscillator is connected in parallel with the second filter resistor, and the two ends of the second crystal oscillator are respectively connected to the second crystal oscillator input pin and the second crystal oscillator output pin of the main control chip. The first end of the third filter capacitor is connected to the first end of the second crystal oscillator, and the second end is connected to the ground potential. The first end of the fourth filter capacitor is connected to the second end of the second crystal oscillator, and the second end is connected to the ground potential.

8. The concentration detection circuit according to claim 1, wherein: The display module includes an LED digital tube, a first transistor, a second transistor and a third transistor; wherein, The control end of the first transistor is connected to the control module, the first end is connected to the ground potential, and the second end is connected to the first end of the LED digital tube; The control end of the second transistor is connected to the control module, the first end is connected to the ground potential, and the second end is connected to the second end of the LED digital tube; The control end of the third transistor is connected to the control module, the first end is connected to the ground potential, and the second end is connected to the third end of the LED digital tube.

9. The concentration detection circuit according to claim 1, wherein: The concentration detection circuit further includes an input module, which is connected to the control module.

10. A concentration detection system, characterized in that: The concentration detection system includes an electrode probe and a concentration detection circuit. The electrode probe contacts the solution to be tested and generates a sensor signal representing the concentration based on the solution to be tested. The concentration detection circuit includes a transformer, a sampling module, a control module and a display module. The transformer is connected between the electrode probe and the sampling module and is used to generate a voltage signal based on the sensor signal. The sampling module is connected to the transformer and is used to generate a sampling signal based on the voltage signal. The sampling signal is a square wave signal, and the sampling signal period follows the change of the sensor signal. The control module is connected to the sampling module and is used to generate a control signal based on the sampling signal. The display module is connected to the control module and is used to generate a display signal based on the control signal.

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