Tds detection device, control method and controller thereof, and water purification device

Abstract

The application discloses a TDS detection device and a control method, a controller and a water purification device thereof, and relates to the technical field of water purification. The control method of the TDS detection device comprises the following steps: a first voltage is applied to the first detection unit, and a second voltage is applied to the second detection unit for TDS detection, wherein the first voltage is smaller than the second voltage; when the first detection unit and the second detection unit are reversed, after the voltage applied to one of the detection units is changed, the voltage applied to the other detection unit is changed after a preset time delay. The application can effectively improve the precision of the TDS detection device.

Description

Technical Field

[0001] This invention relates to the field of water purification technology, and in particular to a TDS detection device and its control method, controller and water purification device. Background Technology

[0002] TDS (Total Dissolved Solids) analyzers are used to measure the total dissolved solids (TDS) in water to evaluate its purity. Simply put, the TDS value detected by a TDS analyzer represents the amount of dissolved impurities in the water; a higher TDS value indicates a higher impurity content, and vice versa. TDS analyzers come in different types to meet various needs. For ordinary consumers, simple, portable, and low-cost TDS analyzers, such as water quality test pens, are generally sufficient to understand the quality of their drinking water. However, while these types of TDS analyzers are inexpensive, their accuracy is relatively low, and therefore, their accuracy needs further improvement. Summary of the Invention

[0003] In order to overcome the above-mentioned defects of the prior art, the technical problem to be solved by the embodiments of the present invention is to provide a TDS detection device and its control method and controller, which can effectively improve the accuracy of the TDS detection device.

[0004] The specific technical solution of this invention is as follows:

[0005] A control method for a TDS detection device,

[0006] The TDS detection device includes a first detection unit and a second detection unit;

[0007] The control method for the TDS detection device includes,

[0008] Step S1: Apply a first voltage to the first detection unit and a second voltage to the second detection unit to perform TDS detection, wherein the first voltage is less than the second voltage;

[0009] Step S2: When reversing the polarity of the first detection unit and the second detection unit, after changing the voltage applied to one of the detection units, delay for a preset time, and then change the voltage applied to the other detection unit.

[0010] Preferably, step S2 specifically includes,

[0011] When the first detection unit and the second detection unit are reversed, after applying the first voltage to the second detection unit, there is a first preset time delay, and then the voltage applied to the first detection unit is changed to the second voltage.

[0012] Preferably, the control method of the TDS detection device further includes,

[0013] Step S301: Maintain the first voltage applied to the second detection unit and the second voltage applied to the first detection unit to perform TDS detection;

[0014] Step S401: When the first detection unit and the second detection unit are reversed again, after applying the first voltage to the first detection unit, delay for a second preset time, and then change the voltage applied to the second detection unit to the second voltage.

[0015] Preferably, steps S1, S2, S301, and S401 are executed sequentially in a loop.

[0016] Preferably, step S2 specifically includes,

[0017] When the first detection unit and the second detection unit are reversed, after applying the second voltage to the first detection unit, there is a third preset time delay, and then the voltage applied to the second detection unit is changed to the first voltage.

[0018] Preferably, the control method of the TDS detection device further includes,

[0019] Step S302: Maintain the first voltage applied to the second detection unit and the second voltage applied to the first detection unit to perform TDS detection;

[0020] Step S402: When the first detection unit and the second detection unit are reversed again, after applying the second voltage to the second detection unit, delay for a fourth preset time, and then change the voltage applied to the first detection unit to the first voltage.

[0021] Preferably, steps S1, S2, S302, and S402 are executed sequentially in a loop.

[0022] Preferably, the first detection unit includes a first resistor and a first probe connected in series; the second detection unit includes a second resistor and a second probe connected in series.

[0023] In step S1, performing TDS detection includes: acquiring a first voltage value on the second probe to perform TDS detection; or

[0024] In step S302, performing TDS detection includes: obtaining a first voltage value on the first probe to perform TDS detection.

[0025] Preferably, the first detection unit includes a first resistor and a first probe connected in series; the second detection unit includes a second resistor and a second probe connected in series.

[0026] In step S1, performing TDS detection includes: acquiring a first voltage value on the second probe to perform TDS detection; or

[0027] In step S301, performing TDS detection includes: obtaining a first voltage value on the first probe to perform TDS detection.

[0028] Preferably, the first detection unit includes a first resistor and a first probe connected in series; the second detection unit includes a second resistor and a second probe connected in series.

[0029] The specific steps for performing TDS detection include:

[0030] Acquire first voltage values ​​on multiple first probes or second probes;

[0031] The second voltage value is obtained based on multiple first voltage values;

[0032] The TDS value is obtained based on the second voltage value and the correspondence between the voltage value and the TDS value.

[0033] Preferably, the specific process for obtaining the second voltage value based on multiple first voltage values ​​is as follows:

[0034] AD=K1×AD1+K2×AD2+K3×AD3+……+KN×ADN,

[0035] Where AD represents the second voltage value, N represents the number of first voltage values, AD1, AD2...ADN represent multiple first voltage values, and K1, K2...KN represent different weighting coefficients assigned to the multiple first voltage values.

[0036] Preferably, K1, K2...KN decrease sequentially.

[0037] Preferably, the step of obtaining the TDS value based on the second voltage value and the correspondence between the voltage value and the TDS value specifically includes:

[0038] The second voltage value is corrected based on the temperature of the liquid being measured to obtain the third voltage value.

[0039] The TDS value is obtained based on the third voltage value and the correspondence between the voltage value and the TDS value.

[0040] Preferably, the process of correcting the second voltage value based on the temperature of the liquid to be measured to obtain the third voltage value is as follows:

[0041] AD0 = AD / (1+a(T-25)),

[0042] Where T represents the temperature T of the liquid to be tested, AD represents the second voltage value, AD0 represents the third voltage value, and a represents the compensation constant.

[0043] Preferably, based on the third voltage value and the correspondence between the voltage value and the TDS value, the specific process for obtaining the TDS value is as follows:

[0044] TDS = k × AD0 + b,

[0045] Wherein, AD0 represents the third voltage value, TDS represents the TDS value of the liquid to be tested, k represents a variable, and b represents a constant.

[0046] Preferably, when the third voltage value is in the first numerical range, the value of k is k1, and when the third voltage value is in the second numerical range, the value of k is k2.

[0047] When the minimum value of the first numerical interval is greater than the maximum value of the second numerical interval, k1 is greater than k2.

[0048] A controller configured to perform a control method for a TDS detection device as described in any of the preceding claims.

[0049] Preferably, the controller includes a chip.

[0050] A TDS detection device includes: a controller as described in any of the preceding claims, a first detection unit, and a second detection unit; the first detection unit includes: a first resistor and a first probe connected in series; the second detection unit includes: a second resistor and a second probe connected in series.

[0051] The controller is used to apply voltage to the first detection unit and the second detection unit.

[0052] The first resistor is connected in series between the first voltage output port of the controller and the first probe.

[0053] The second resistor is connected in series between the second voltage output port of the controller and the second probe.

[0054] Preferably, the resistance value of the first resistor is equal to the resistance value of the second resistor.

[0055] Preferably, the TDS detection device further includes a sampling circuit, wherein the sampling point of the sampling circuit is electrically connected to the first probe or the second probe, and a third resistor is provided on the sampling circuit.

[0056] A water purification device, the water purification device comprising a TDS detection device as described in any of the above.

[0057] Preferably, the water purification device includes: a first detection device for detecting the TDS value of the filtered purified water; and a second detection device for detecting the TDS value of the raw water before filtration.

[0058] The first detection device uses the TDS detection device, and / or the second detection device uses the TDS detection device.

[0059] Preferably, the water purification device further includes:

[0060] First filtration unit;

[0061] A first water passage connected to the raw water inlet of the first filtration unit;

[0062] A second water path connected to the purified water outlet of the first filtration unit;

[0063] The return water path has one end connected to the first water path at a first intersection point, and the other end connected to the second water path.

[0064] The first probe and the second probe of the second detection device are positioned between the first intersection of the first water path and the raw water inlet of the first filtration unit.

[0065] Preferably, the first filtration unit includes at least one of the following: a reverse osmosis membrane filtration unit and a nanofiltration membrane filtration unit.

[0066] Preferably, the water purification device has a first working state, in which the return water path returns the purified water flowing out of the purified water outlet to the first filtration unit;

[0067] After the water purifier finishes outputting purified water, it enters the first working state; after the first working state ends, and when the water purifier outputs purified water again, the second detection device performs TDS detection after at least a predetermined time.

[0068] Preferably, the water purification device further includes: a second filtration unit, which is a pre-filtration unit, and is disposed between the first intersection of the first water path and the raw water inlet of the first filtration unit; the first probe and the second probe of the second detection device are disposed between the second filtration unit and the raw water inlet of the first filtration unit.

[0069] Preferably, this applies when both the first detection device and the second detection device use the TDS detection device;

[0070] The resistance value of the first resistor in the first detection device is greater than the resistance value of the first resistor in the second detection device;

[0071] The resistance value of the second resistor in the first detection device is greater than the resistance value of the second resistor in the second detection device;

[0072] The resistance value of the first resistor in the first detection device is equal to the resistance value of the second resistor in the first detection device; the resistance value of the first resistor in the second detection device is equal to the resistance value of the second resistor in the second detection device.

[0073] The technical solution of the present invention has the following significant beneficial effects:

[0074] To reduce or avoid the impact of parasitic capacitance on the accuracy of TDS value detection, in the above control method, after the first execution of step 1, when reversing the polarity of the first and second detection units, the voltage applied to one detection unit is changed, delayed for a preset time, and then the voltage applied to the other detection unit is changed. This ensures that the voltages applied to the first and second detection units are equal during the preset delay time, thus eliminating the parasitic capacitance formed between the first and second detection units in the liquid being tested. After this polarity reversal is completed, the voltage values ​​obtained on the first or second probe will not be deviated due to parasitic capacitance, resulting in a more accurate TDS value.

[0075] Specific embodiments of the invention are disclosed in detail below with reference to the description and accompanying drawings, indicating how the principles of the invention can be employed. It should be understood that the embodiments of the invention are not therefore limited in scope. Features described and / or shown for one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments. Attached Figure Description

[0076] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely illustrative to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. Those skilled in the art, guided by the teachings of this invention, can select various possible shapes and proportions to implement the invention according to specific circumstances.

[0077] Figure 1 This is a schematic diagram of the TDS detection device in an embodiment of the present invention;

[0078] Figure 2 This is a flowchart of the control method of the TDS detection device in the first embodiment of the present invention;

[0079] Figure 3 This is a flowchart illustrating the steps of the control method for the TDS detection device in a second embodiment of the present invention.

[0080] Figure 4 This is a schematic diagram illustrating the voltage applied to the first detection unit and the voltage acquired on the probe in the first embodiment of the control method of the TDS detection device in this invention.

[0081] Figure 5a and Figure 5b This is a schematic diagram comparing the control method of the TDS detection device in this application embodiment with the voltage on the second probe obtained when performing TDS detection on the same liquid under the conventional reverse polarity method in the prior art;

[0082] Figure 6 This is a graph showing the relationship between the third voltage value and the corresponding TDS value when the third voltage value is in different ranges in an embodiment of the present invention;

[0083] Figure 7 This is a schematic diagram of the water purification device in an embodiment of the present invention.

[0084] The reference numerals in the above figures are as follows:

[0085] 1. First detection unit; 11. First resistor; 12. First probe; 2. Second detection unit; 21. Second resistor; 22. Second probe; 3. Acquisition circuit; 31. Third resistor; 4. Controller; 10. First filtration unit; 20. First water path; 30. Second water path; 40. First intersection point; 50. Return water path; 501. First check valve; 60. Second filtration unit; 70. First detection device; 80. Second detection device; 90. Third filtration unit; 110. Inlet solenoid valve; 120. Water pump; 130. Third water path; 1301. Throttling mechanism; 1302. Second check valve; 140. Wastewater path; 1401. Combination valve. Detailed Implementation

[0086] The details of the present invention can be more clearly understood by referring to the accompanying drawings and the description of specific embodiments. However, the specific embodiments of the present invention described herein are for illustrative purposes only and should not be construed as limiting the invention in any way. Under the teachings of this invention, those skilled in the art can conceive of any possible modifications based on the invention, all of which should be considered within the scope of the invention. It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or there may be an intervening element. The terms "mounted," "connected," and "connected" should be interpreted broadly, for example, they can refer to mechanical or electrical connections, or internal communication between two elements, and can be direct or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0087] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0088] To effectively improve the accuracy of TDS detection devices, this application proposes a control method for TDS detection devices. Figure 1 This is a schematic diagram of the TDS detection device in an embodiment of the present invention, as shown below. Figure 1 As shown, the TDS detection device may include a first detection unit 1 and a second detection unit 2. Alternatively, the first detection unit 1 may include a first resistor 11 and a first probe 12 connected in series; the second detection unit 2 may include a second resistor 21 and a second probe 22 connected in series. When the first detection unit 1 and the second detection unit 2 are simultaneously inserted into the water to be tested, TDS detection of the water is achieved by applying different voltages to the first detection unit 1 and the second detection unit 2 respectively.

[0089] Figure 2 This is a flowchart illustrating the steps of the control method for the TDS detection device in the first embodiment of the present invention. Figure 3This is a flowchart illustrating the steps of the control method for the TDS detection device in a second embodiment of the present invention, as shown below. Figures 2 to 3 As shown, the control method for the TDS detection device may include the following steps:

[0090] Step S1: Apply a first voltage to the first detection unit 1 and a second voltage to the second detection unit 2 to perform TDS detection, wherein the first voltage is less than the second voltage.

[0091] Figure 4 This is a schematic diagram illustrating the voltage applied to the first detection unit and the voltage acquired on the probe, respectively, in the first embodiment of the control method for the TDS detection device according to the present invention. Figure 4 As shown, a first voltage is applied to the first detection unit 1 and a second voltage is applied to the second detection unit 2 simultaneously for TDS detection, wherein the first voltage is less than the second voltage. Figure 4 Position 1 represents the voltage applied to the first detection unit 1, position 2 represents the voltage applied to the second detection unit 2, position 3 represents the voltage on the second probe 22 collected by the sampling circuit when performing TDS detection on a test liquid with a very low actual TDS value, and position 4 represents the voltage on the second probe 22 collected by the sampling circuit when performing TDS detection on a test liquid with a very high actual TDS value. For example, the first voltage can be low level and the second voltage can be high level; for ease of explanation, the first voltage may be 0V and the second voltage may be 5V.

[0092] Step S2: When the first detection unit 1 and the second detection unit 2 are reversed, after changing the voltage applied to one of the detection units, a preset time is delayed, and then the voltage applied to the other detection unit is changed.

[0093] like Figure 4 As shown, when the first detection unit 1 and the second detection unit 2 are reversed, during the second time period, the voltage applied to one of the detection units is first changed to become the voltage applied to the other detection unit. After a preset time delay, the voltage applied to the other detection unit is changed to become the voltage previously applied to one of the detection units.

[0094] In the first embodiment, step S2 may specifically include:

[0095] like Figure 4As shown, when the first detection unit 1 and the second detection unit 2 are reversed, after applying a first voltage to the second detection unit 2, there is a first preset time delay, and then the voltage applied to the first detection unit 1 is changed to a second voltage. That is, the voltage applied to the second detection unit 2 is first changed to the first voltage, for example, 0V, so that it becomes the voltage applied to the first detection unit 1 during the first time period. Then, after a first preset time delay, the voltage applied to the first detection unit 1 is changed to the second voltage, for example, 5V, so that it becomes the voltage previously applied to the second detection unit 2.

[0096] In the first embodiment, the control method for the TDS detection device may further include:

[0097] Step S301: As Figure 4 As shown, after step S2, the first voltage applied to the second detection unit 2 and the second voltage applied to the first detection unit 1 are maintained for TDS detection. In this step, the first voltage applied to the second detection unit 2 and the second voltage applied to the first detection unit 1 are maintained for a period of time, during which TDS detection is performed.

[0098] Step S401: As Figure 4 As shown, after step S301, when the first detection unit 1 and the second detection unit 2 are reversed again, after applying the first voltage to the first detection unit 1, a second preset time is delayed, and then the voltage applied to the second detection unit 2 is changed to the second voltage.

[0099] That is, after step S301, the voltage applied to the first detection unit 1 is first changed to a first voltage, for example, 0V, then delayed for a second preset time, and then the voltage applied to the second detection unit 2 is changed to a second voltage, for example, 5V.

[0100] As an option, the first preset time and the second preset time can be the same.

[0101] Then, steps S1, S2, S301, and S401 can be executed in sequence to continuously perform TDS detection and improve the accuracy of the detection.

[0102] In the second embodiment, step S2 may specifically include:

[0103] When the first detection unit 1 and the second detection unit 2 are reversed, after applying a second voltage to the first detection unit 1, a third preset time is delayed, and then the voltage applied to the second detection unit 2 is changed back to the first voltage. That is, the voltage applied to the first detection unit 1 is first changed to the second voltage, for example, 5V, so that it becomes the voltage applied to the second detection unit 2. Then, after a third preset time, the voltage applied to the second detection unit 2 is changed back to the first voltage, for example, 0V, so that it becomes the voltage previously applied to the first detection unit 1.

[0104] In a second embodiment, the control method for the TDS detection device may further include:

[0105] Step S302: After step S2, the first voltage applied to the second detection unit 2 and the second voltage applied to the first detection unit 1 are maintained for TDS detection. In this step, the first voltage applied to the second detection unit 2 and the second voltage applied to the first detection unit 1 are maintained for a period of time, during which TDS detection is performed.

[0106] Step S402: After step S401, when the first detection unit 1 and the second detection unit 2 are reversed again, after applying the second voltage to the second detection unit 2, a fourth preset time is delayed, and then the voltage applied to the first detection unit 1 is changed to the first voltage.

[0107] That is, after step S301, the voltage applied to the second detection unit 1 is first changed to a second voltage, for example, 5V, then delayed for a fourth preset time, and then the voltage applied to the first detection unit 1 is changed to a first voltage, for example, 0V.

[0108] As is feasible, the third preset time and the fourth preset time can be the same.

[0109] Then, steps S1, S2, S302, and S302 can be executed in sequence to continuously perform TDS detection, thereby improving the accuracy of detection by performing TDS detection multiple times.

[0110] After the first execution of step 1, if the first detection unit 1 and the second detection unit 2 are directly reversed, parasitic capacitance will form between them since they are inserted into the liquid to be tested. Therefore, the TDS value obtained after reversing the polarity of the first detection unit 1 and the second detection unit 2 will be affected by this parasitic capacitance. This is because TDS detection is specifically performed by obtaining the voltage value on the first probe 12 or the second probe 22 and then converting it. Due to the influence of parasitic capacitance, the obtained voltage value on the first probe 12 or the second probe 22 will have a certain deviation. This deviation will lead to an inaccurate TDS value obtained after reversing the polarity. Similarly, if a second reversal is performed after the first reversal, parasitic capacitance will still form between the first detection unit 1 and the second detection unit 2. Even if the voltage value on the first probe 12 or the second probe 22 is obtained again after this second reversal, there will still be a certain deviation, and the TDS value obtained in subsequent TDS detections will still be inaccurate. In particular, the higher the frequency of the reversal, the larger the parasitic capacitance formed between the first detection unit 1 and the second detection unit 2, and therefore the greater the impact on the TDS value obtained by TDS detection.

[0111] To reduce or avoid the impact of parasitic capacitance on the accuracy of TDS value detection, in the above control method, after the first execution of step 1, when reversing the polarity of the first detection unit 1 and the second detection unit 2, the voltage applied to one detection unit is changed, delayed for a preset time, and then the voltage applied to the other detection unit is changed. This ensures that the voltages applied to the first detection unit 1 and the second detection unit 2 are equal during the preset delay time, thus eliminating the parasitic capacitance formed between the first detection unit 1 and the second detection unit 2 in the test liquid. After this, once the polarity reversal is complete, the voltage values ​​obtained on the first probe 12 or the second probe 22 will not deviate due to parasitic capacitance, resulting in a more accurate TDS value. Similarly, if a second polarity reversal is performed after the first polarity reversal, the voltage applied to one detection unit can be changed, delayed for a period of time, and then the voltage applied to the other detection unit can be changed. During this time, the voltages applied to the first detection unit 1 and the second detection unit 2 are equal, again eliminating the parasitic capacitance formed between the first detection unit 1 and the second detection unit 2 in the test liquid. After this, even if the voltage values ​​obtained on the first probe 12 or the second probe 22 are subsequently not affected by parasitic capacitance and thus the calculated TDS value remains relatively more accurate. Especially when the reversal frequency is higher, the influence of the parasitic capacitance formed between the first detection unit 1 and the second detection unit 2 on TDS detection can be effectively eliminated, thereby achieving accurate detection of the TDS value of the liquid to be tested.

[0112] Since the reversal of the first detection unit 1 and the second detection unit 2 is continuous, the control method in this application can eliminate the parasitic capacitance formed between the first detection unit 1 and the second detection unit 2 in the liquid to be tested during each reversal. Therefore, the voltage values ​​on the first probe 12 or the second probe 22 obtained during TDS detection in each step will not be affected by the parasitic capacitance and will not deviate. Figure 5a and Figure 5b This is a schematic diagram comparing the control method of the TDS detection device in this embodiment with the voltage on the second probe obtained during TDS detection of the same liquid under the conventional polarity reversal method in the prior art. Figure 5a The upper part of the image shows the voltage on the second probe obtained during TDS detection of the same test liquid under the conventional reverse polarity method in the prior art. Figure 5a The lower half of the text represents the voltage on the second probe obtained in the control method of the TDS detection device in this embodiment of the application. Figure 5bThe diagram above shows the combined voltages on the second probe in the two scenarios described above, facilitating comparison. It can be seen that in the prior art, the voltage on the second probe 22 obtained during TDS detection using the conventional reversal method is reduced for a short period after reversal due to parasitic capacitance. The control method in this application eliminates the parasitic capacitance formed between the first detection unit 1 and the second detection unit 2 in the test liquid during each reversal. Therefore, the voltage value on the second probe 22 obtained during TDS detection is not reduced due to parasitic capacitance, thus preventing deviation.

[0113] Alternatively, in all the above steps, TDS detection may include: performing TDS detection by acquiring a first voltage value on the second probe 22; and / or, performing TDS detection by acquiring a first voltage value on the first probe 12.

[0114] Further, in step S1, performing TDS detection may include: acquiring a first voltage value on the second probe 22 to perform TDS detection. In step S301, performing TDS detection may include: acquiring a first voltage value on the first probe 12 to perform TDS detection. In step S302, performing TDS detection may include: acquiring a first voltage value on the first probe 12 to perform TDS detection.

[0115] In the above embodiment, in step S1, since a second voltage is applied to the second detection unit 2, which is greater than the first voltage, the value of the first voltage obtained by acquiring the value on the second probe 22 is much larger than the value of the first voltage obtained by acquiring the value on the first probe 12. Figure 4 As shown, if the second voltage is 5V and the first voltage is 0V, combined with the resistance values ​​of the first resistor 11 and the second resistor 21, and the actual TDS value in the liquid to be measured, the obtained first voltage value on the second probe 22 will be slightly less than 5V, for example, it may be around 4.7V, 4.5V, or 4.0V, but overall it will be close to 5V. However, the obtained first voltage value on the first probe 12 will be slightly greater than 0V, for example, it may be around 0.3V, 0.4V, or 0.5V. If the first voltage value is too small, the slight fluctuations and instability of the obtained value during the detection process will result in a large proportion of the first voltage value being fluctuated, and the error in the final calculated TDS will become quite large. Therefore, obtaining a larger first voltage value on the second probe 22 can avoid the above problem and improve the detection accuracy. The principle is the same in step S302, which will not be elaborated here.

[0116] Alternatively, in all the above steps, the TDS detection step may specifically include the following steps:

[0117] Obtain the first voltage value on multiple first probes 12 or second probes 22.

[0118] In the above steps, the first voltage value on the first probe 12 or the second probe 22 can be collected at regular intervals within a specific time period, such as every 75us, 100us, 150us, etc., and multiple collections can be performed continuously to obtain multiple first voltage values. The specific time period can be the period during which different first voltages and second voltages are applied to the first detection unit 1 and the second detection unit 2, and preferably the early part of that time period.

[0119] The second voltage value is obtained based on multiple first voltage values.

[0120] In this step, the specific process of obtaining the second voltage value based on multiple first voltage values ​​can be as follows:

[0121] AD=K1×AD1+K2×AD2+K3×AD3+……+KN×ADN,

[0122] Where AD represents the second voltage value, N represents the number of first voltage values, AD1, AD2...ADN represent multiple first voltage values, and K1, K2...KN represent different weighting coefficients assigned to the multiple first voltage values.

[0123] By assigning different weighting coefficients to the changing trends of multiple first voltage values ​​collected, the second voltage value corresponding to the converted TSD can be calculated. This method can avoid the impact of single-point fluctuations on the sampling accuracy.

[0124] Furthermore, K1, K2…KN decrease sequentially. For example… Figure 4 As shown, in the early part of the time period when the first detection unit 1 and the second detection unit 2 apply different first and second voltages, since the polarity reversal operation has just been performed, the liquid to be tested is still in the ion migration stage. Therefore, it can be seen that the obtained first voltage value is in a continuous change process. The more the first voltage value in the continuous change process can reflect the TDS value in the liquid to be tested, the larger the weight coefficient should be assigned to the first voltage value measured earlier, so that the second voltage value corresponding to the converted TDS is more reliable and accurate.

[0125] The TDS value is obtained based on the second voltage value and the correspondence between the voltage value and the TDS value.

[0126] After obtaining the second voltage value, it is substituted into the correspondence between voltage and TDS values ​​to obtain the corresponding TDS value. This calculated TDS value more accurately reflects the actual TDS value of the liquid being tested.

[0127] Furthermore, to avoid the influence of the temperature of the liquid being tested on the calculated TDS value, causing the calculated TDS value to deviate slightly from the actual TDS value of the liquid being tested due to temperature effects, the above steps may include the following:

[0128] The second voltage value is corrected based on the temperature of the liquid being tested to obtain the third voltage value.

[0129] The specific acquisition process in this step can be as follows:

[0130] AD0 = AD / (1+a(T-25)),

[0131] Where T represents the temperature T of the liquid being measured, AD represents the second voltage value, AD0 represents the third voltage value, and a represents the compensation constant. The compensation constant is not a fixed constant; it can have a corresponding relationship with AD.

[0132] The TDS value is obtained based on the third voltage value and the correspondence between the voltage value and the TDS value.

[0133] The specific acquisition process in this step can be as follows:

[0134] TDS = k × AD0 + b,

[0135] Where AD0 represents the third voltage value, TDS represents the TDS value of the liquid being tested, k represents a variable, and b represents a constant.

[0136] Figure 6 This is a graph showing the relationship between the third voltage value and the corresponding TDS value when the third voltage value is in different ranges according to an embodiment of the present invention, such as... Figure 6 As shown, when the third voltage value is in the first numerical interval, the value of k is k1; when the third voltage value is in the second numerical interval, the value of k is k2; when the minimum value of the first numerical interval is greater than the maximum value of the second numerical interval, k1 is less than k2. Since the slopes of different intervals differ significantly, a piecewise fitting method is needed to ensure that the relationship between the voltage value and the TDS value corresponds, thereby further improving the accuracy of the final calculated TDS.

[0137] This application also proposes a controller 4 configured to execute the control method of the TDS detection device as described above. The controller 4 may be in the form of a chip.

[0138] This application also proposes a TDS detection device, such as Figure 1 As shown, the TDS detection device may include: a controller 4, a first detection unit 1, and a second detection unit 2 as described above. The first detection unit 1 may include: a first resistor 11 and a first probe 12 connected in series. The second detection unit 2 includes: a second resistor 21 and a second probe 22 connected in series. The controller 4 is used to apply voltage to the first detection unit 1 and the second detection unit 2. The first voltage output port of the controller 4 is connected in series with the first resistor 11 between it and the first probe 12, and the second voltage output port of the controller 4 is connected in series with the second resistor 21 between it and the second probe 22.

[0139] The resistance of the first resistor 11 can be equal to or different from the resistance of the second resistor 21. Furthermore, when the resistance of the first resistor 11 equals the resistance of the second resistor 21, before the first probe 12 and the second probe 22 are inserted into the liquid to be tested to detect the TDS value, a first voltage is applied to the first detection unit 1 and a second voltage is applied to the second detection unit 2 before the polarity is reversed. After the polarity is reversed, the first voltage applied to the second detection unit 2 and the second voltage applied to the first detection unit 1 are maintained. Before the polarity is reversed, the potential on the first probe 12 is the same as the potential on the second probe 22 after the polarity is reversed. This effectively avoids the possibility that the probe with greater scaling will have excessive resistance or malfunction due to the larger scaling, thus improving the detection accuracy of the TDS detection device. In addition, when the resistance of the first resistor 11 equals the resistance of the second resistor 21, even if scaling gradually occurs on the first probe 12 and the second probe 22 with use, the degree of scaling on both sides is the same, and the scaling rate is slow. This effectively improves the overall service life of the TDS detection device.

[0140] To perform TDS detection, the TDS detection device may include a data acquisition circuit 3. The sampling points of the data acquisition circuit 3 are electrically connected to the first probe 12 or the second probe 22. A third resistor 31 is provided on the sampling circuit.

[0141] This application also proposes a water purification device, which includes any of the TDS detection devices described above. The TDS detection device allows for direct TDS testing of the water within the water purification device.

[0142] As an option, the water purification device may include: a first detection device 70 for detecting the TDS value of the filtered purified water; and a second detection device 80 for detecting the TDS value of the raw water before filtration. The first detection device 70 may be the TDS detection device described in this application, and / or the second detection device 80 may be the TDS detection device described in this application. With the above structure, the water purification device can directly obtain the TDS value of the filtered purified water and the TDS value of the raw water before filtration. This not only allows the user to know the TDS values ​​of the raw water before filtration and the filtered purified water, but also allows the user to determine whether the filtered purified water meets the standards and whether the filter unit of the water purification device needs to be replaced in a timely manner based on the TDS value of the filtered purified water. This is more accurate than determining whether the filter unit needs to be replaced based on the total filtered water volume, total filtration time, or the usage time of the water purification device. It also ensures that the filter unit is fully utilized and avoids premature replacement of the filter unit or situations where the filtration effect of the filter unit no longer meets the standards but replacement is not indicated.

[0143] As a feasible option, Figure 7 This is a schematic diagram of the water purification device in an embodiment of the present invention, such as... Figure 7As shown, the water purification device may include: a first filtration unit 10; a first water passage 20 connected to the raw water inlet of the first filtration unit 10; a second water passage 30 connected to the purified water outlet of the first filtration unit 10; a return water passage 50, one end of which is connected to the first water passage 20 at a first intersection 40, and the other end of which is connected to the second water passage 30; a first probe 12 and a second probe 22 of a second detection device 70 are disposed between the first intersection 40 of the first water passage 20 and the raw water inlet of the first filtration unit 10. The first probe 12 and the second probe 22 of the first detection device 70 can be disposed on the second water passage 30. A first one-way valve 501 may be provided on the return water passage 50, which allows flow from the second water passage 30 to the first water passage 20. For example, the first filtration unit 10 may include at least one of the following: a reverse osmosis membrane filtration unit, a nanofiltration membrane filtration unit, etc., which can filter raw water with high precision to form purified water that can be used by users, and the purified water may include pure water. Further, the water purification device may also include: a second filtration unit 60, a wastewater path 140, a combination valve 1401 with wastewater ratio function and on / off function, and a water pump 120. The second filtration unit 60 is a pre-filtration unit, and the second filtration unit 60 may be located between the first intersection 40 of the first water path 20 and the raw water inlet of the first filtration unit 10. The first probe 12 and the second probe 22 of the second detection device 80 are located between the second filtration unit 60 and the raw water inlet of the first filtration unit 10. Wastewater path 140 can be connected to the wastewater outlet of the first filter unit 10. A combination valve 1401 is installed on the wastewater path 140. The combination valve 1401 can include a wastewater ratio device and a first on / off valve connected in series, or it can include a wastewater ratio device, a first on / off valve, and a second on / off valve connected in parallel with the wastewater ratio device and the first on / off valve. The water pump 120 can be installed at any position on the circulating water path formed by the first filter unit 10 and the return water path 50, generally upstream of the first filter unit 10, such as between the first filter unit 10 and the second filter unit 60. The water purification device may also include a third filter unit 90, which is installed on the second water path 30. The third filter unit 90 can be a post-filter unit.

[0144] The inlet of the first water passage 20 can be connected to the water source via the inlet solenoid valve 110. The raw water from the water source flows into the first water passage 20, enters the raw water inlet of the first filter unit 10, and is filtered. The filtered clean water is discharged from the clean water outlet of the first filter unit 10 to the second water passage 30. The clean water is then treated by the third filter unit 90 before being discharged for user use. The wastewater formed after filtration by the first filter unit 10 is discharged after passing through the wastewater ratio device on the wastewater passage 140.

[0145] In the above structure, the water purification device can have a first operating state. In the first operating state, driven by the water pump 120, the return water path 50 can return the purified water flowing from the purified water outlet to the first filter unit 10. For example, the combination valve 1401 is initially in a closed state, and the return water path 50 can return the purified water flowing from the purified water outlet through the second filter unit 60 and then to the first filter unit 10. The water purification device may include a third water path 130, one end of which is connected to the wastewater outlet of the first filter unit 10, and the other end of which is connected between the first filter unit 10 and the second filter unit 60. The third water path 130 may be equipped with a second one-way valve 1302 that allows the wastewater outlet of the first filter unit 10 to flow to the other end of the third water path 130, and a throttling structure, which may include a small orifice. When the purified water flowing from the purified water outlet through the return water path 50 flows back through the second filter unit 60 and then to the first filter unit 10, the wastewater generated by the first filter unit 10 also flows back to the downstream of the second filter unit 60 through the third water path 130. At this time, the second filter unit 60 can be completely replaced with purified water. Then, the inlet solenoid valve 110 can be opened, and the combination valve 1401 is open or in wastewater ratio mode. The raw water from the water source pushes the purified water in the second filter unit 60 out, so that this part of purified water replaces the water on the raw water side of the filter membrane in the first filter unit 10. After that, the inlet solenoid valve 110 is closed.

[0146] After the water purifier finishes outputting purified water, it enters its first working state. In this state, the return water path 50 returns the purified water produced in the first filtration unit 10 to the first water path 20 and then back into the first filtration unit 10. This replaces the raw water on the raw water side of the filter membrane in the first filtration unit 10 with purified water, preventing raw water from seeping through the filter membrane to the purified water side when the purifier is not used for a long time. This would prevent the TDS of the purified water output from the purifier from being too high when it is used again. It also ensures that the second detection device 80 is in a purified water environment, improving the immersion water quality and preventing the second detection device 80 from being immersed in raw water for extended periods, which could negatively impact its lifespan.

[0147] Since the first water path 20 downstream of the second filtration unit 60, where the second detection device 80 is located, contains purified water generated by the first filtration unit 10 after the first working state ends, the TDS detection performed by the second detection device 80 at this time is not the TDS of the raw water, but the TDS of the purified water. Therefore, after the first working state ends and before the water purifier outputs purified water again, the second detection device 80 performs TDS detection after at least a predetermined time. Through this method, after the predetermined time delay, the raw water entering the water source will replace the purified water in the first water path 20. At this time, the TDS detection performed by the second detection device 80 will then obtain the TDS value of the raw water entering the water source, thus ensuring the reliability of the TDS value detected by the second detection device 80.

[0148] As a feasible configuration, when the first detection device 70 uses a TDS detection device and the second detection device 80 uses a TDS detection device, the resistance value of the first resistor 11 in the first detection device 70 is greater than the resistance value of the first resistor 11 in the second detection device 80; the resistance value of the second resistor 21 in the first detection device 70 is greater than the resistance value of the second resistor 21 in the second detection device 80. The resistance value of the first resistor 11 in the first detection device 70 is equal to the resistance value of the second resistor 21 in the first detection device 70; the resistance value of the first resistor 11 in the second detection device 80 is equal to the resistance value of the second resistor 21 in the second detection device 80.

[0149] Since the actual TDS value of the raw water is relatively large, it is equivalent to a relatively small resistance. The actual TDS value of the purified water is relatively small, which is equivalent to a relatively large resistance. Therefore, the above method can effectively improve the accuracy of the TDS value obtained by the first detection device 70 for purified water and the accuracy of the TDS value obtained by the second detection device 80 for raw water.

[0150] All articles and references disclosed herein, including patent applications and publications, are incorporated herein by reference for various purposes. The term “substantially constitutes…” used to describe a combination should include the identified element, component, part, or step, as well as other elements, components, parts, or steps that do not substantially affect the essential novelty of the combination. The use of the terms “comprising” or “including” to describe combinations of elements, components, parts, or steps herein also contemplates embodiments substantially constituted by such elements, components, parts, or steps. The use of the term “may” herein is intended to indicate that any described attribute “may” include is optional. Multiple elements, components, parts, or steps can be provided by a single integrated element, component, part, or step. Alternatively, a single integrated element, component, part, or step can be divided into multiple separate elements, components, parts, or steps. The disclosure of “a” or “an” used to describe an element, component, part, or step does not imply exclusion of other elements, components, parts, or steps.

[0151] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A control method for a TDS detection device, characterized in that, The TDS detection device includes a first detection unit and a second detection unit; The first detection unit includes: a first resistor and a first probe connected in series; the second detection unit includes: a second resistor and a second probe connected in series. The control method for the TDS detection device includes, Step S1: Apply a first voltage to the first detection unit and apply a second voltage to the second detection unit to perform TDS detection, wherein the first voltage is less than the second voltage; Step S2: When reversing the polarity of the first detection unit and the second detection unit, after changing the voltage applied to one of the detection units, delay for a preset time, and then change the voltage applied to the other detection unit. The specific steps for performing TDS detection include: First voltage values ​​are acquired on multiple first probes or second probes; second voltage values ​​are acquired based on the multiple first voltage values, and the specific acquisition process is as follows: AD=K1×AD1+K2×AD2+K3×AD3+……+KN×ADN, Where AD represents the second voltage value, N represents the number of first voltage values, AD1, AD2...ADN represent multiple first voltage values, and K1, K2...KN represent different weighting coefficients assigned to the multiple first voltage values. The TDS value is obtained based on the second voltage value and the correspondence between the voltage value and the TDS value.

2. The control method for the TDS detection device according to claim 1, characterized in that, Step S2 specifically includes, When the first detection unit and the second detection unit are reversed, after applying the first voltage to the second detection unit, there is a first preset time delay, and then the voltage applied to the first detection unit is changed to the second voltage.

3. The control method for the TDS detection device according to claim 2, characterized in that, The control method for the TDS detection device also includes Step S301: Maintain the first voltage applied to the second detection unit and the second voltage applied to the first detection unit to perform TDS detection; Step S401: When the first detection unit and the second detection unit are reversed again, after applying the first voltage to the first detection unit, delay for a second preset time, and then change the voltage applied to the second detection unit to the second voltage.

4. The control method for the TDS detection device according to claim 3, characterized in that, Steps S1, S2, S301, and S401 are executed sequentially in a loop.

5. The control method for the TDS detection device according to claim 1, characterized in that, Step S2 specifically includes, When the first detection unit and the second detection unit are reversed, after applying the second voltage to the first detection unit, there is a third preset time delay, and then the voltage applied to the second detection unit is changed to the first voltage.

6. The control method for the TDS detection device according to claim 5, characterized in that, The control method for the TDS detection device also includes Step S302: Maintain the first voltage applied to the second detection unit and the second voltage applied to the first detection unit to perform TDS detection; Step S402: When the first detection unit and the second detection unit are reversed again, after applying the second voltage to the second detection unit, delay for a fourth preset time, and then change the voltage applied to the first detection unit to the first voltage.

7. The control method for the TDS detection device according to claim 6, characterized in that, Steps S1, S2, S302, and S402 are executed sequentially in a loop.

8. The control method for the TDS detection device according to claim 6, characterized in that, The first detection unit includes: a first resistor and a first probe connected in series; the second detection unit includes: a second resistor and a second probe connected in series. In step S1, performing TDS detection includes: acquiring a first voltage value on the second probe to perform TDS detection; or In step S302, performing TDS detection includes: obtaining a first voltage value on the first probe to perform TDS detection.

9. The control method for the TDS detection device according to claim 3, characterized in that, The first detection unit includes: a first resistor and a first probe connected in series; the second detection unit includes: a second resistor and a second probe connected in series. In step S1, performing TDS detection includes: acquiring a first voltage value on the second probe to perform TDS detection; or In step S301, performing TDS detection includes: obtaining a first voltage value on the first probe to perform TDS detection.

10. The control method for the TDS detection device according to claim 1, characterized in that, K1, K2...KN decrease sequentially.

11. The control method for the TDS detection device according to claim 1, characterized in that, The step of obtaining the TDS value based on the second voltage value and the correspondence between the voltage value and the TDS value specifically includes: The second voltage value is corrected based on the temperature of the liquid being measured to obtain the third voltage value. The TDS value is obtained based on the third voltage value and the correspondence between the voltage value and the TDS value.

12. The control method for the TDS detection device according to claim 11, characterized in that, The specific process for obtaining the third voltage value by correcting the second voltage value based on the temperature of the liquid being measured is as follows: AD0 = AD / (1 + a(T-25)), Where T represents the temperature T of the liquid to be tested, AD represents the second voltage value, AD0 represents the third voltage value, and a represents the compensation constant.

13. The control method for the TDS detection device according to claim 11, characterized in that, Based on the third voltage value and the correspondence between the voltage value and the TDS value, the specific process for obtaining the TDS value is as follows: TDS = k × AD0 + b, Where AD0 represents the third voltage value, TDS represents the TDS value of the liquid to be tested, k represents a variable, and b represents a constant.

14. The control method for the TDS detection device according to claim 13, characterized in that, When the third voltage value is within the first numerical range, the value of k is k1; when the third voltage value is within the second numerical range, the value of k is k2. When the minimum value of the first numerical interval is greater than the maximum value of the second numerical interval, k1 is less than k2.

15. A controller, characterized in that, The controller is configured to perform a control method for the TDS detection device as described in any one of claims 1 to 14.

16. The controller according to claim 15, characterized in that, The controller includes a chip.

17. A TDS detection device, characterized in that, The TDS detection device includes: a controller as described in any one of claims 15 to 16, a first detection unit, and a second detection unit; the first detection unit includes: a first resistor and a first probe connected in series; the second detection unit includes: a second resistor and a second probe connected in series; The controller is used to apply voltage to the first detection unit and the second detection unit. The first resistor is connected in series between the first voltage output port of the controller and the first probe. The second resistor is connected in series between the second voltage output port of the controller and the second probe.

18. The TDS detection device according to claim 17, characterized in that, The resistance of the first resistor is equal to the resistance of the second resistor.

19. The TDS detection device according to claim 17, characterized in that, The TDS detection device further includes a data acquisition circuit, the sampling points of which are electrically connected to the first probe or the second probe, and a third resistor is provided on the data acquisition circuit.

20. A water purification device, characterized in that, The water purification device includes a TDS detection device as described in any one of claims 17 to 19.

21. The water purification device according to claim 20, characterized in that, The water purification device includes: a first detection device for detecting the TDS value of the filtered purified water; and a second detection device for detecting the TDS value of the raw water before filtration. The first detection device uses the TDS detection device, and the second detection device uses the TDS detection device.

22. The water purification device according to claim 21, characterized in that, The water purification device also includes: First filtration unit; A first water passage connected to the raw water inlet of the first filtration unit; A second water path connected to the purified water outlet of the first filtration unit; The return water path has one end connected to the first water path at a first intersection point, and the other end connected to the second water path. The first probe and the second probe of the second detection device are positioned between the first intersection of the first water path and the raw water inlet of the first filtration unit.

23. The water purification device according to claim 22, characterized in that, The first filtration unit includes at least one of the following: a reverse osmosis membrane filtration unit and a nanofiltration membrane filtration unit.

24. The water purification device according to claim 22, characterized in that, The water purification device has a first working state. In the first working state, the return water path will return the purified water flowing out of the purified water outlet to the first filtration unit. After the water purifier finishes outputting purified water, it enters the first working state; after the first working state ends, and when the water purifier outputs purified water again, the second detection device performs TDS detection after at least a predetermined time.

25. The water purification device according to claim 23, characterized in that, The water purification device further includes: a second filtration unit, which is a pre-filtration unit, and is disposed between the first intersection of the first water path and the raw water inlet of the first filtration unit; the first probe and the second probe of the second detection device are disposed between the second filtration unit and the raw water inlet of the first filtration unit.

26. The water purification device according to claim 21, characterized in that, When the first detection device uses the TDS detection device and the second detection device uses the TDS detection device; The resistance value of the first resistor in the first detection device is greater than the resistance value of the first resistor in the second detection device; The resistance value of the second resistor in the first detection device is greater than the resistance value of the second resistor in the second detection device; The resistance value of the first resistor in the first detection device is equal to the resistance value of the second resistor in the first detection device; The resistance value of the first resistor in the second detection device is equal to the resistance value of the second resistor in the second detection device.

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