CN115656267A

CN115656267A - TDS detection device, control method thereof, controller and water purification device

Info

Publication number: CN115656267A
Application number: CN202211399350.0A
Authority: CN
Inventors: 张娟利; 袁振
Original assignee: AO Smith China Water Heater Co Ltd; AO Smith China Environmental Products Co Ltd
Current assignee: AO Smith China Water Heater Co Ltd; AO Smith China Environmental Products Co Ltd
Priority date: 2022-11-09
Filing date: 2022-11-09
Publication date: 2023-01-31
Also published as: WO2024099289A1

Abstract

The invention discloses a TDS detection device and a control method thereof, a controller and a water purification device, and relates to the technical field of water purification, wherein the control method of the TDS detection device comprises the steps of applying a first voltage to a first detection unit and applying a second voltage to a second detection unit to carry out TDS detection, and the first voltage is less than the second voltage; when the first detection unit and the second detection unit are inverted, the voltage applied to one detection unit is delayed for a preset time after the voltage applied to the other detection unit is changed, and then the voltage applied to the other detection unit is changed. This application can effectively improve TDS detection device's precision.

Description

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

Technical Field

The invention relates to the technical field of water purification, in particular to a TDS detection device, a control method thereof, a controller and a water purification device.

Background

The TDS detection device is used to detect the Total Dissolved Solids (TDS) in the water to evaluate the purity of the water. Generally speaking, the TDS value detected by the TDS detection device represents the content of dissolved impurities in water, and the larger the TDS value is, the larger the content of impurities in water is, and otherwise, the content of impurities is small. The TDS detection device can be of different types to meet different requirements. As a common consumer, only a simple and portable TDS detection device with low cost, such as a water quality test pen, is needed to know the quality of drinking water, and such TDS detection device has low cost and low precision, so the precision performance needs to be further improved.

Disclosure of Invention

In order to overcome the above defects in the prior art, embodiments of the present invention provide a TDS detection apparatus, a control method thereof, and a controller, which can effectively improve the accuracy of the TDS detection apparatus.

The specific technical scheme of the embodiment of the invention is as follows:

a control method of a TDS detection device,

the TDS detection device comprises a first detection unit and a second detection unit;

the control method of the TDS detection device comprises the following steps,

step S1: applying a first voltage to the first detection unit and a second voltage to the second detection unit for TDS detection, the first voltage being less than the second voltage;

step S2: when the first detection unit and the second detection unit are inverted, the voltage applied to one detection unit is delayed for a preset time after the voltage applied to the other detection unit is changed, and then the voltage applied to the other detection unit is changed.

Preferably, the step S2 specifically includes,

when the first detection unit and the second detection unit are subjected to polarity reversal, a first preset time is delayed after the first voltage is applied to the second detection unit, and then the voltage applied to the first detection unit is changed to the second voltage.

Preferably, the control method of the TDS detecting device further comprises,

step S301: maintaining the first voltage applied to the second detection unit and the second voltage applied to the first detection unit for TDS detection;

step S401: and when the first detection unit and the second detection unit are subjected to polarity reversal again, delaying for a second preset time after the first voltage is applied to the first detection unit, and changing the voltage applied to the second detection unit to the second voltage.

Preferably, steps S1, S2, S301, S401 are performed cyclically in sequence.

Preferably, the step S2 specifically includes,

and when the first detection unit and the second detection unit are subjected to polarity reversal, delaying for a third preset time after the second voltage is applied to the first detection unit, and changing the voltage applied to the second detection unit to the first voltage.

Preferably, the control method of the TDS detecting apparatus further comprises,

step S302: maintaining the first voltage applied to the second detection unit and the second voltage applied to the first detection unit for TDS detection;

step S402: and when the first detection unit and the second detection unit are subjected to polarity reversal again, delaying for a fourth preset time after the second voltage is applied to the second detection unit, and changing the voltage applied to the first detection unit to the first voltage.

Preferably, steps S1, S2, S302, S402 are performed cyclically in sequence.

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;

in step S1, performing TDS detection includes: performing TDS detection by acquiring a first voltage value on the second probe; or

In step S302, performing TDS detection includes: TDS detection is performed by acquiring a first voltage value on the first probe.

In step S301, performing TDS detection includes: TDS detection is performed by acquiring a first voltage value on the first probe.

the TDS detection method specifically comprises the following steps:

acquiring a first voltage value on a plurality of the first probes or the second probes;

acquiring a second voltage value based on a plurality of first voltage values;

and acquiring the TDS value based on the second voltage value and the corresponding relation between the voltage value and the TDS value.

Preferably, the specific process of acquiring the second voltage value based on the plurality of first voltage values is as follows:

AD＝K1×AD1+K2×AD2+K3×AD3+……+KN×ADN，

wherein AD represents the second voltage value, N represents the number of the first voltage values, AD1, AD2 … ADN represent a plurality of the first voltage values, respectively, and K1, K2 … KN represent different weighting coefficients given to the plurality of the first voltage values, respectively.

Preferably, K1, K2 … KN decrease in order.

Preferably, the step of acquiring the TDS value based on the second voltage value and the corresponding relationship between the voltage value and the TDS value specifically includes,

correcting the second voltage value based on the temperature of the liquid to be measured to obtain a third voltage value,

and acquiring the TDS value based on the third voltage value and the corresponding relation between the voltage value and the TDS value.

Preferably, the second voltage value is corrected based on the temperature of the liquid to be measured, and a specific obtaining process of obtaining the third voltage value is as follows:

AD0＝AD/(1+a(T-25))，

wherein T represents the temperature T of the liquid to be measured, AD represents the second voltage value, AD0 represents the third voltage value, and a represents a compensation constant.

Preferably, based on the third voltage value and the corresponding relationship between the voltage value and the TDS value, a specific acquiring process of acquiring the TDS value is as follows:

TDS＝k×AD0+b，

and AD0 represents the third voltage value, TDS represents the TDS value of the liquid to be measured, k represents a variable, and b represents a constant.

Preferably, when the third voltage value is in a first value interval, the value of k is k1, and when the third voltage value is in a second value interval, the value of k is k2;

when the minimum value of the first numerical interval is larger than the maximum value of the second numerical interval, k1 is larger than k2.

A controller configured to perform the method of controlling a TDS detection apparatus as claimed in any of the above.

Preferably, the controller comprises a chip.

A TDS detection device, comprising: a controller, a first detection unit and a second detection unit as described in any of the above; 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 configured to apply a 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,

and the second resistor is connected in series between a second voltage output port of the controller and the second probe.

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

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

A purifier, purifier includes as above-mentioned arbitrary TDS detection device.

Preferably, the water purifying apparatus includes: first detecting means for detecting a TDS value of the filtered purified water; a second detection means for detecting a TDS value of the raw water before filtration;

the first detection device adopts the TDS detection device, and/or the second detection device adopts the TDS detection device.

Preferably, the water purification apparatus further comprises:

a first filter unit;

the first water channel is communicated with the raw water inlet of the first filtering unit;

the second water path is communicated with the purified water outlet of the first filtering unit;

one end of the water return waterway is connected with the first waterway at a first intersection point, and the other end of the water return waterway is connected with the second waterway;

the first probe and the second probe of the second detection device are arranged between the first intersection point of the first water path and the raw water inlet of the first filtering unit.

Preferably, the first filter unit comprises at least one of: a reverse osmosis membrane filtration unit and a nanofiltration membrane filtration unit.

Preferably, the water purifying 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 filtering unit;

after the purified water output by the water purifying device is finished, the first working state is entered; after the first working state is finished and when the water purifying device outputs purified water next time, the second detecting device carries out TDS detection after delaying at least preset time.

Preferably, the water purification apparatus further comprises: the second filtering unit is a front filtering unit, the second filtering unit is arranged between the first intersection point of the first water path and the raw water inlet of the first filtering unit, and the first probe and the second probe of the second detection device are arranged between the second filtering unit and the raw water inlet of the first filtering unit.

Preferably, when the first detection means employs the TDS detection means and the second detection means employs the TDS detection means;

the resistance value of the first resistor in the first detection device is larger than that of the first resistor in the second detection device;

the resistance value of a second resistor in the first detection device is larger than that of a second resistor in the second detection device;

the resistance value of a first resistor in the first detection device is equal to the resistance value of a 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.

The technical scheme of the invention has the following remarkable beneficial effects:

in order to reduce or avoid the influence of the parasitic capacitance on the detection accuracy of the TDS value, in the above control method, after step 1 is performed for the first time, when the first detection unit and the second detection unit are inverted, the voltage applied to one of the detection units is changed after a preset time is delayed, and the voltage applied to the other detection unit is changed. In this way, the voltages applied to the first detection unit and the second detection unit are equal within the preset time of the delay, so that the parasitic capacitance formed in the liquid to be measured between the first detection unit and the second detection unit before can be eliminated. After that, after the pole reversal is completed, the acquired voltage value on the first probe or the second probe is not deviated due to the parasitic capacitance, and the TDS value obtained through conversion is relatively more accurate.

Specific embodiments of the present invention are disclosed in detail with reference to the following description and drawings, indicating the manner in which the principles of the invention may be employed. It should be understood that the embodiments of the invention are not so limited in scope. Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments, in combination with or instead of the features of the other embodiments.

Drawings

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. In addition, the shapes, the proportional sizes, and the like of the respective members in the drawings are merely schematic for facilitating the understanding of the present invention, and do not specifically limit the shapes, the proportional sizes, and the like of the respective members of the present invention. Those skilled in the art, having the benefit of the teachings of this invention, may choose from the various possible shapes and proportional sizes to implement the invention as a matter of case.

FIG. 1 is a schematic structural diagram of a TDS detection device according to an embodiment of the present invention;

FIG. 2 is a flowchart illustrating a method for controlling a TDS detection device according to a first embodiment of the present invention;

FIG. 3 is a flowchart illustrating the steps of a TDS detection apparatus according to a second embodiment of the present invention;

FIG. 4 is a schematic diagram of the voltage applied to the first detection unit and the voltage obtained on the probe by the control method of the TDS detection device in the first embodiment of the present invention;

fig. 5a and 5b are schematic diagrams illustrating a comparison between a control method of the TDS detection apparatus in the embodiment of the present application and a voltage on the second probe obtained during TDS detection on the same liquid to be detected in the conventional reverse polarity manner in the prior art;

FIG. 6 is a graph illustrating the relationship between the third voltage and the corresponding TDS value when the third voltage is in different value ranges according to an embodiment of the present invention;

fig. 7 is a schematic diagram of a water purifying device in an embodiment of the invention.

Reference numerals of the above figures:

1. a first detection unit; 11. a first resistor; 12. a first probe; 2. a second detection unit; 21. a second resistor; 22. a second probe; 3. an acquisition circuit; 31. a third resistor; 4. a controller; 10. a first filter unit; 20. a first waterway; 30. a second waterway; 40. a first intersection point; 50. a water return waterway; 501. a first check valve; 60. a second filter unit; 70. a first detection device; 80. a second detection device; 90. a third filtering unit; 110. a water inlet electromagnetic valve; 120. a water pump; 130. a third waterway; 1301. a throttle mechanism; 1302. a second one-way valve; 140. a wastewater waterway; 1401. a combination valve.

Detailed Description

The details of the present invention can be more clearly understood in conjunction with the accompanying drawings and the description of the embodiments of the present invention. However, the specific embodiments of the present invention described herein are for the purpose of illustration only and are not to be construed as limiting the invention in any way. Any possible variations based on the present invention may be conceived by the skilled person in the light of the teachings of the present invention, and these should be considered to fall within the scope of the present invention. It will be understood that when an element is referred to as being "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "mounted," "connected," and "connected" are to be construed broadly and may include, for example, mechanical or electrical connections, communications between two elements, direct connections, indirect connections through intermediaries, and the like. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

Unless defined otherwise, 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 in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In order to effectively improve the accuracy of the TDS detection apparatus, a control method of the TDS detection apparatus is provided in this application, fig. 1 is a schematic structural diagram of the TDS detection apparatus in an embodiment of the present invention, and as shown in fig. 1, the TDS detection apparatus may include a first detection unit 1 and a second detection unit 2. As a possibility, 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 first detecting element 1 and second detecting element 2 insert simultaneously to waiting to detect the aquatic, through applying different voltages respectively to first detecting element 1 and second detecting element 2 to the realization is to waiting to detect the TDS of detecting the water.

Fig. 2 is a flowchart illustrating steps of a method for controlling a TDS detection apparatus according to a first embodiment of the present invention, and fig. 3 is a flowchart illustrating steps of a method for controlling a TDS detection apparatus according to a second embodiment of the present invention, and as shown in fig. 2 to 3, the method for controlling a TDS detection apparatus may include the following steps:

step S1: a first voltage is applied to the first detecting unit 1 and a second voltage is applied to the second detecting unit 2 for TDS detection, the first voltage being smaller than the second voltage.

Fig. 4 is a schematic diagram of the voltage applied to the first detection unit and the second detection unit and the voltage obtained on the probe in the first embodiment of the method for controlling the TDS detection apparatus according to the embodiment of the present invention, as shown in fig. 4, and the first voltage is applied to the first detection unit 1 and the second voltage is applied to the second detection unit 2 to perform TDS detection, where the first voltage is smaller than the second voltage. Position 1 in fig. 4 is the voltage that applys to first detecting element 1, and position 2 is the voltage that applys to second detecting element 2, and position 3 is the voltage on the second probe 22 that sampling circuit gathered when carrying out the TDS to the liquid that awaits measuring that the actual TDS value is very low, and position 4 is the voltage on the second probe 22 that sampling circuit gathered when carrying out the TDS to the liquid that awaits measuring that the actual TDS value is very high. For example, the first voltage may be a low level, and the second voltage may be a high level, for convenience of description, the first voltage is 0V, and the second voltage is 5V.

Step S2: when the first and second detecting

units

1 and 2 are reversed, the voltage applied to one of the detecting units is changed after a predetermined time is delayed after the voltage applied to the other detecting unit is changed.

As shown in fig. 4, when the first sensing cell 1 and the second sensing cell 2 are inverted, in the second period of time, the voltage applied to one of the sensing cells is changed to the voltage applied to the other sensing cell, and then delayed by a predetermined time, and the voltage applied to the other sensing cell is changed to the voltage applied to the one sensing cell.

In the first embodiment, step S2 may specifically include:

as shown in fig. 4, when the first sensing cell 1 and the second sensing cell 2 are inverted, the voltage applied to the first sensing cell 1 is changed to the second voltage after a first preset time is delayed after the first voltage is applied to the second sensing cell 2. That is, the voltage applied to the second sensing unit 2 is changed to a first voltage, for example, 0V, so that it is first changed to the voltage applied to the first sensing unit 1 for a first period of time, and then delayed for a first preset time, and then the voltage applied to the first sensing unit 1 is changed to a second voltage, for example, 5V, so that it is changed to the voltage previously applied to the second sensing unit 2.

In a first embodiment, the TDS detection apparatus control method may further include:

step S301: as shown in fig. 4, after step S2, TDS detection is performed by maintaining the first voltage applied to the second detecting unit 2 and the second voltage applied to the first detecting unit 1. In this step, the first voltage applied to the second sensing cell 2 and the second voltage applied to the first sensing cell 1 are maintained for a period of time during which TDS sensing is performed.

Step S401: as shown in fig. 4, after step S301, when the first and

second sensing cells

1 and 2 are again reversed, the voltage applied to the second sensing cell 2 is changed to the second voltage after a second preset time is delayed after the first voltage is applied to the first sensing cell 1.

That is, after step S301, the voltage applied to the first detecting unit 1 is changed to a first voltage, for example, 0V, and then the voltage applied to the second detecting unit 2 is changed to a second voltage, for example, 5V, after a second predetermined time.

As a matter of course, the first preset time and the second preset time may be the same.

After that, steps S1, S2, S301, and S401 may be sequentially executed in a loop, so that TDS detection may be continuously performed to improve the detection accuracy.

In the second embodiment, step S2 may specifically include:

when the first detecting unit 1 and the second detecting unit 2 are reversed, the voltage applied to the second detecting unit 2 is changed to the first voltage after the second voltage is applied to the first detecting unit 1 and the third preset time is delayed. That is, the voltage applied to the first sensing unit 1 is changed to the second voltage, for example, 5V, to be changed to the voltage applied to the second sensing unit 2, and then delayed for a third predetermined time, and the voltage applied to the second sensing unit 2 is changed to the first voltage, for example, 0V, to be changed to the voltage applied to the first sensing unit 1.

In a second embodiment, the TDS detection apparatus control method may further include:

step S302: after step S2, the TDS detection is performed by maintaining the first voltage applied to the second detecting unit 2 and the second voltage applied to the first detecting unit 1. In this step, the first voltage applied to the second sensing cell 2 and the second voltage applied to the first sensing cell 1 are maintained for a period of time during which TDS sensing is performed.

Step S402: after step S401, when the first sensing cell 1 and the second sensing cell 2 are again reversed, the voltage applied to the first sensing cell 1 is changed to the first voltage after a fourth preset time is delayed after the second voltage is applied to the second sensing cell 2.

That is, after step S301, the voltage applied to the second detecting unit 1 is changed to the second voltage, for example, 5V, and then the voltage applied to the first detecting unit 1 is changed to the first voltage, for example, 0V, after a fourth predetermined time.

As a matter of course, the third preset time and the fourth preset time may be the same.

Afterwards, steps S1, S2, S302 can be executed in a cycle in sequence, so that TDS detection can be continuously performed, and accuracy of detection can be improved by performing TDS detection for multiple times.

After step 1 is performed for the first time, if the first detection unit 1 and the second detection unit 2 are directly inverted, after step 1 is performed, since the first detection unit 1 and the second detection unit 2 are inserted into the liquid to be detected and parasitic capacitance is formed between the first detection unit 1 and the second detection unit 2, after the first detection unit 1 and the second detection unit 2 are inverted, the TDS value obtained by TDS detection is affected by the parasitic capacitance. This is because, when TDS detection is performed, specifically, the voltage value on the first probe 12 or the second probe 22 is obtained and then converted, and due to the influence of the parasitic capacitance, a certain deviation may occur in the obtained voltage value on the first probe 12 or the second probe 22, and the deviation may cause that the TDS value obtained by performing TDS detection after pole reversal is not accurate enough. Similarly, if the first time of the polarity inversion is completed and then the second time of the polarity inversion is performed, a parasitic capacitance still forms between the first detecting unit 1 and the second detecting unit 2, and even if a certain deviation still occurs in the voltage value of the first probe 12 or the second probe 22 acquired again, the TDS value obtained by the subsequent TDS detection is still not accurate enough. Particularly, as the frequency of the inversion is higher, the parasitic capacitance formed between the first detection unit 1 and the second detection unit 2 is larger, and thus the influence on the TDS value acquired by performing the TDS detection is larger.

In order to reduce or avoid the influence of the parasitic capacitance on the detection accuracy of the TDS value, in the above-described control method, after step 1 is performed for the first time, when the first detection unit 1 and the second detection unit 2 are inverted, the voltage applied to one of the detection units is changed after a preset time is delayed after the voltage applied to the other detection unit is changed. Thus, after a predetermined time of delay, the voltages applied to the first detecting unit 1 and the second detecting unit 2 are equal, so that the parasitic capacitance formed in the liquid to be measured between the first detecting unit 1 and the second detecting unit 2 before can be eliminated. After that, after the pole reversal is completed, the acquired voltage value on the first probe 12 or the second probe 22 will not be deviated due to the parasitic capacitance, so that the TDS value obtained by conversion is relatively more accurate. Similarly, if the polarity inversion is performed for the second time after the polarity inversion is completed, the voltage applied to one of the sensing cells may be changed after a delay, and then the voltage applied to the other sensing cell may be changed. In this way, the voltages applied to the first detecting unit 1 and the second detecting unit 2 are equal during the period of time, and the parasitic capacitance formed in the liquid to be detected between the first detecting unit 1 and the second detecting unit 2 before can be eliminated. Even if the voltage value on the first probe 12 or the second probe 22 is acquired again, the voltage value will not be affected by the parasitic capacitance and the TDS value converted by the voltage value will still be relatively accurate. Especially, when the frequency of pole changing is higher, can effectively eliminate the parasitic capacitance that forms between first detecting element 1 and the second detecting element 2 and carry out the influence that TDS detected, and then realize the accurate detection of the liquid TDS value that awaits measuring.

Because the first detection unit 1 and the second detection unit 2 are subjected to polarity inverting continuously, the control method in the application can eliminate the parasitic capacitance formed between the first detection unit 1 and the second detection unit 2 in the liquid to be detected when the polarity is inverted every time, and therefore, the voltage value on the first probe 12 or the second probe 22 obtained when the TDS detection is performed in each step cannot be influenced by the parasitic capacitance to cause deviation. Fig. 5a and 5b are schematic diagrams illustrating a comparison between a control method of the TDS detection apparatus in the embodiment of the present application and a voltage on the second probe acquired during TDS detection for the same liquid to be detected in the conventional reverse polarity manner in the prior art, an upper half portion of fig. 5a is a voltage on the second probe acquired during TDS detection for the same liquid to be detected in the conventional reverse polarity manner in the prior art, a lower half portion of fig. 5a is a voltage on the second probe acquired in the control method of the TDS detection apparatus in the embodiment of the present application, and fig. 5b is a schematic diagram illustrating a combination of voltages on the second probe in the two cases, so that comparison is convenient.

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

Further, in step S1, performing TDS detection may include: TDS detection is performed by acquiring a first voltage value on the second probe 22. In step S301, performing TDS detection includes: TDS detection is performed by acquiring a first voltage value on the first probe 12. In step S302, performing TDS detection may include: TDS detection is performed by acquiring a first voltage value on the first probe 12.

In the above embodiment, in step S1, since the second voltage is applied to the second detection unit 2 and is larger than the first voltage, the value of the first voltage value obtained on the second probe 22 is much larger than the value of the first voltage value obtained on the first probe 12, as shown in fig. 4, if the second voltage is 5V, the first voltage is 0V, and then, in combination with the resistance values of the first resistor 11 and the second resistor 21, the actual value of the TDS in the liquid to be detected, the value of the first voltage value obtained on the second probe 22 is a value slightly smaller than 5V, for example, may be 4.7V, 4.5V, 4.0V, and so on, but is generally close to 5V, but the value of the first voltage value obtained on the first probe 12 is slightly larger than 0V, for example, may be 0.3V, 0.4V, 0.5V, and so on, if the value of the first voltage value is obtained, the final floating value of the value obtained in the detection process, the final floating value of the first voltage may be slightly unstable and the final variation error may be calculated. Therefore, obtaining the first voltage value with a larger value on the second probe 22 can avoid the above problem, thereby improving the detection accuracy. In step S302, the same principle applies, and is not described in detail herein.

As a practical matter, among all the above steps, the step of performing TDS detection may specifically include the following steps:

a first voltage value is acquired on the plurality of first probes 12 or second probes 22.

In the above steps, the first voltage value on first probe 12 or second probe 22 may be collected once every certain time within a certain period of time, for example, once every 75us, 100us, 150us, etc., and collected multiple times in succession to obtain multiple first voltage values. The specific period of time may be a period of time during which different first and second voltages are applied to the first and

second detection units

1 and 2, respectively, as far as possible in an early part of the period of time.

Based on the plurality of first voltage values, a second voltage value is obtained.

In this step, based on the plurality of first voltage values, a specific obtaining process of obtaining the second voltage value may be 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 a plurality of first voltage values, respectively, and K1, K2 … KN represent different weight coefficients given to the plurality of first voltage values, respectively.

Different weight coefficients are given according to the variation trend of the plurality of acquired first voltage values, so that a second voltage value corresponding to the converted TSD is calculated, and the influence of the single-point volatility on the sampling accuracy can be avoided.

Further, K1 and K2 … KN are reduced in sequence. As shown in fig. 4, in the earlier stage of the time period when the first detection unit 1 and the second detection unit 2 apply different first voltage and second voltage, respectively, since the liquid to be measured is still in the ion migration stage just after the electrode inverting operation is performed, it can be seen that the acquired first voltage value is in the continuous change process, and the first voltage value in the continuous change process can reflect the TDS value in the liquid to be measured, the larger the weight coefficient needs to be given to the first voltage value measured in the earlier stage, so that the more reliable and accurate the second voltage value corresponding to the finally calculated converted TDS is.

After the second voltage value is acquired, the second voltage value is brought into the corresponding relation between the voltage value and the TDS value, so that the TDS value corresponding to the second voltage value is acquired. The TDS value obtained by calculation can reflect the actual TDS value of the liquid to be measured more accurately.

Further, in order to avoid the influence of the temperature of the liquid to be measured on the calculated TDS value, which causes the calculated TDS value to slightly deviate from the actual TDS value of the liquid to be measured due to the influence of the temperature, the above steps may include the following steps:

and correcting the second voltage value based on the temperature of the liquid to be measured to obtain a third voltage value.

In this step, the specific acquisition process may be as follows:

AD0＝AD/(1+a(T-25))，

wherein T represents the temperature T of the liquid to be measured, AD represents a second voltage value, AD0 represents a third voltage value, and a represents a compensation constant. The compensation constant is not a fixed constant and may have a corresponding relationship with AD.

In this step, the specific acquisition process may be as follows:

TDS＝k×AD0+b，

and AD0 represents a third voltage value, TDS represents a TDS value of the liquid to be measured, k represents a variable, and b represents a constant.

Fig. 6 is a graph showing a relationship between a third voltage value and a corresponding TDS value in different value ranges according to an embodiment of the present invention, as shown in fig. 6, when the third voltage value is in the first value range, the value of k is k1, and when the third voltage value is in the second value range, the value of k is k2; when the minimum value of the first numerical interval is larger than the maximum value of the second numerical interval, k1 is smaller than k2. Because the slope difference of different intervals is large, the relation between the voltage value and the TDS value needs to be corresponding through a piecewise fitting mode, and therefore the accuracy of the TDS obtained through final calculation is further improved.

Also proposed in the present application is a controller 4, which controller 4 is configured to perform the control method of the TDS detection apparatus as described above. The controller 4 may take the form of a chip.

Also proposed in the present application is a TDS detection device, which may include, as shown in fig. 1: such as the controller 4, the first detection unit 1 and the second detection unit 2 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 for applying voltage to the first detecting unit 1 and the second detecting unit 2, a first resistor 11 is connected in series between a first voltage output port of the controller 4 and the first probe 12, and a second resistor 21 is connected in series between a second voltage output port of the controller 4 and the second probe 22.

The resistance of the first resistor 11 may not be equal to the resistance of the second resistor 21, and may also be equal to the resistance of the second resistor 21. Further, when the resistance value of the first resistor 11 is equal to that of the second resistor 21, when the first probe 12 and the second probe 22 are inserted into the liquid to be detected to detect the TDS value, before the pole reversal, the first voltage is applied to the first detection unit 1 and the second voltage is applied to the second detection unit 2, after the pole reversal, 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 pole reversal, the potential on the first probe 12 is the same as that on the second probe 22 after the pole reversal, so that the possibility that one probe is over-scaled and the other probe is over-scaled to cause the over-resistance, malfunction and the like of the probe with a large scale degree can be effectively avoided, and the detection accuracy of the TDS detection device is improved. In addition, when the resistance of the first resistor 11 is equal to the resistance of the second resistor 21, even if scaling slowly occurs along with the use of the first probe 12 and the second probe 22, the structural degrees of both sides are the same, and the scaling speed is slow, so that the service life of the TDS detection device can be effectively prolonged as a whole.

In order to realize TDS detection, of course, the TDS detection apparatus may include an acquisition circuit 3, a sampling point of the acquisition circuit 3 is electrically connected to the first probe 12 or the second probe 22, and a third resistor 31 is disposed on the sampling circuit.

Still provide a purifier in this application, purifier includes the TDS detection device as above-mentioned arbitrary. Utilize TDS detection device can directly carry out the TDS to water and detect in purifier.

As a possibility, the water purification device may comprise: a first detecting device 70 for detecting a TDS value of the filtered purified water; and a second detecting means 80 for detecting the TDS value of the raw water before filtration. The first detection device 70 may employ a TDS detection device as described herein, and/or the second detection device 80 may employ a TDS detection device as described herein. Through above-mentioned structure, purifier can directly acquire the TDS value of the raw water after the filtration and the TDS value of the raw water before the filtration, not only can give the user with the TDS value of the raw water before the filtration and the TDS value reflection of the raw water after the filtration and know, can also judge whether the water purification after the filtration satisfies the standard through the TDS value of the purified water after the filtration, and whether purifier's filter unit needs in time to be changed. Whether the filter unit needs to be replaced more accurately is judged according to the total water amount of filtration or the total time of filtration or the service time of the water purifying device, the filter unit can be fully utilized, the phenomenon that the filter unit is replaced too early is avoided, or the filter effect of the filter unit does not accord with the standard yet the replacement is not prompted.

As a practical matter, fig. 7 is a schematic diagram of a water purifying device in an embodiment of the present invention, and as shown in fig. 7, the water purifying device may include: a first filter unit 10; a first water path 20 communicated with the raw water inlet of the first filtering unit 10; a second water path 30 communicated with the purified water outlet of the first filtering unit 10; one end of the water return waterway 50 is connected with the first waterway 20 to the first intersection point 40, and the other end of the water return waterway 50 is connected with the second waterway 30; the first probe 12 and the second probe 22 of the second sensing device 80 are disposed between the first intersection 40 of the first waterway 20 and the raw water inlet of the first filtering unit 10. The first probe 12 and the second probe 22 of the first detection device 70 may be disposed on the second waterway 30. The return water path 50 may be provided with a first check valve 501, and the first check valve 501 may be communicated from the second water path 30 to the first water path 20. For example, the first filter unit 10 may include at least one of: a reverse osmosis membrane filtration unit, a nanofiltration membrane filtration unit, or the like, which can filter raw water with high precision to form purified water that can be used by a user, which may include pure water. Further, water purification unit can also include: a second filtering unit 60, a wastewater waterway 140, a combination valve 1401 having a wastewater ratio function and an opening and closing function, and a water pump 120. The second filtering unit 60 is a pre-filtering unit, the second filtering unit 60 may be disposed between the first intersection 40 of the first waterway 20 and the raw water inlet of the first filtering unit 10, and the first probe 12 and the second probe 22 of the second detecting device 80 are disposed between the second filtering unit 60 and the raw water inlet of the first filtering unit 10. The wastewater waterway 140 may be communicated with the wastewater outlet of the first filtering unit 10, the combination valve 1401 is provided on the wastewater waterway 140, the combination valve 1401 may include a wastewater ratio device and a first open-close valve connected in series, or the combination valve 1401 may include a wastewater ratio device and a first open-close valve connected in series, and a second open-close valve connected in parallel with the wastewater ratio device and the first open-close valve connected in series. The water pump 120 may be disposed at any position on the circulation water path formed by the first filter unit 10 and the return water path 50, and is generally disposed upstream of the first filter unit 10, for example, between the first filter unit 10 and the second filter unit 60. The water purifying device may further include: and a third filtering unit 90, wherein the third filtering unit 90 is arranged on the second water channel 30. The third filtering unit 90 may be a post-filtering unit.

The inlet of the first water path 20 may be connected to a water source through the water inlet solenoid valve 110, raw water at the water source flows in from the first water path 20, the raw water flowing into the first filtering unit 10 is filtered, the filtered purified water is discharged from the purified water outlet of the first filtering unit 10 to the second water path 30, and the purified water is discharged for a user after being processed by the third filtering unit 90. The waste water filtered by the first filtering unit 10 is discharged through the waste water ratio device on the waste water path 140.

With the above structure, the water purifying apparatus may have a first operation state in which the return water path 50 returns the purified water flowing out from the purified water outlet to the first filter unit 10 by driving of the water pump 120. For example, the combination valve 1401 is first closed, and the return water path 50 may return the purified water flowing out of the purified water outlet to the first filter unit 10 through the second filter unit 60. The water purifying apparatus may include: and one end of the third water path 130 is connected to the waste water outlet of the first filter unit 10, and the other end of the third water path 130 is communicated with the first filter unit 10 and the second filter unit 60. The third water path 130 may be provided with a second check valve 1302 and a throttling structure, which may include a small hole, for enabling the waste water outlet of the first filtering unit 10 to be communicated to the other end of the third water path 130. When the pure water flowing out from the pure water outlet of the water return waterway 50 flows back through the second filtering unit 60 and then reaches the first filtering unit 10, the wastewater generated by the first filtering unit 10 also flows back to the downstream of the second filtering unit 60 through the third waterway 130, at this time, the second filtering unit 60 can be replaced by all the pure water, then, the water inlet electromagnetic valve 110 can be opened, the combination valve 1401 is opened or is in the wastewater ratio function, the raw water of the water source pushes out the pure water in the second filtering unit 60, so that the part of the pure water replaces the water on the raw water side of the filtering membrane in the first filtering unit 10 by the part of the pure water. Thereafter, the water inlet solenoid valve 110 is closed.

After the water purifying device outputs purified water, the water purifying device enters a first working state. Under a first working state, the return water channel 50 returns the purified water formed in the process of the first filtering unit 10 to the first water channel 20 and then enters the first filtering unit 10, so that the raw water on the raw water side of the filtering membrane in the first filtering unit 10 is replaced by the purified water, and further, when the water purifying device is not used for a long time, the raw water on the raw water side of the filtering membrane permeates the filtering membrane to reach the purified water side, the TDS of the purified water just output when the water purifying device is used again is higher, meanwhile, the second detecting device 80 can be positioned in the environment of the purified water, the water immersion quality of the second detecting device is improved, and the adverse effect on the service life caused by the fact that the second detecting device 80 is immersed in the raw water for a long time is avoided.

After the first operation state is completed, the purified water generated by the first filter unit 10 is in the first water path 20 downstream of the second filter unit 60 where the second detection device 80 is located, and at this time, the TDS detection by the second detection device 80 is performed not to detect the TDS of the raw water but to detect the TDS of the purified water. Therefore, after the first operation state is finished and when the water purifying device outputs purified water next time, the second detecting device 80 performs TDS detection after delaying for at least a predetermined time. Through the mode, after postponing the predetermined time, the raw water that the water source got into can replace the water purification in first water route 20, and at this moment, second detection device 80 carries out the TDS again and detects the TDS value that is the raw water that the water source got into that is acquireed to the reliability of the TDS value that second detection device 80 detected has been guaranteed.

As a practical matter, when the first detecting device 70 employs a TDS detecting device and the second detecting device 80 employs a TDS detecting device, the resistance value of the first resistor 11 in the first detecting device 70 is greater than the resistance value of the first resistor 11 in the second detecting device 80; the resistance value of the second resistor 21 in the first detection device 70 is larger 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 of the first resistor 11 in the second sensing device 80 is equal to the resistance of the second resistor 21 in the second sensing device 80.

Because the actual TDS value of raw water itself is just great, is equivalent to that the resistance of raw water is just less, and the actual TDS value of water purification itself is just very little, is equivalent to that the resistance of water purification is very big, so through above-mentioned mode, can effectively improve the precision of the TDS value that first detection device 70 obtained to the water purification detection, the precision of the TDS value that second detection device 80 obtained to the raw water detection.

All articles and references disclosed, including patent applications and publications, are hereby incorporated by reference for all purposes. The term "consisting essentially of …" describing a combination shall include the identified elements, components, parts or steps as well as other elements, components, parts or steps that do not materially affect the basic novel characteristics of the combination. The use of the terms "comprising" or "including" to describe combinations of elements, components, or steps herein also contemplates embodiments that consist essentially of such elements, components, or steps. By using the term "may" herein, it is intended to indicate that any of the attributes described that "may" include are optional. A plurality of 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 may be divided into separate plural elements, components, parts or steps. The disclosure of "a" or "an" to describe an element, ingredient, component or step is not intended to foreclose other elements, ingredients, components or steps.

The embodiments in the present specification are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The above embodiments are merely illustrative of the technical ideas and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. A control method of TDS detection device is characterized in that,

the control method of the TDS detection device comprises the following steps,

2. The method of controlling the TDS detecting apparatus of claim 1,

the step S2 specifically includes the steps of,

3. The method of controlling the TDS detecting apparatus of claim 2,

the control method of the TDS detection apparatus further includes,

4. The method of controlling a TDS detection apparatus as claimed in claim 3, wherein the steps S1, S2, S301, S401 are performed in sequence and circularly.

5. The method of controlling the TDS detecting apparatus of claim 1,

the step S2 specifically includes the steps of,

6. The method of controlling the TDS detecting apparatus of claim 5,

the control method of the TDS detection apparatus further includes,

7. The method of controlling a TDS detection apparatus as claimed in claim 6, wherein the steps S1, S2, S302, S402 are performed in a loop in sequence.

8. The method of controlling the TDS detection apparatus of claim 6, wherein the first detection unit comprises: 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;

9. The method of controlling the TDS detection apparatus of claim 3, wherein the first detection unit comprises: 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;

10. The method of controlling the TDS detection apparatus of any of claims 1 to 9, wherein the first detection unit comprises: 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 TDS detection method specifically comprises the following steps:

acquiring a second voltage value based on a plurality of first voltage values;

11. The method of controlling the TDS detecting apparatus of claim 10, wherein the TDS detecting apparatus includes a first TDS detecting unit,

the specific process of obtaining the second voltage value based on the plurality of first voltage values is as follows:

AD＝K1×AD1+K2×AD2+K3×AD3+……+KN×ADN，

wherein AD represents the second voltage value, N represents the number of the first voltage values, AD1, AD2 … ADN represent the plurality of first voltage values, respectively, and K1, K2 … KN represent different weight coefficients given to the plurality of first voltage values, respectively.

12. The method of controlling the TDS detection apparatus as claimed in claim 11, wherein K1, K2 … KN are sequentially decreased.

13. The method of controlling the TDS detecting apparatus of claim 10, wherein the TDS detecting apparatus includes a first TDS detecting unit,

the step of obtaining the TDS value based on the second voltage value and the corresponding relationship between the voltage value and the TDS value specifically includes,

14. The method of controlling the TDS detecting apparatus of claim 13,

and correcting the second voltage value based on the temperature of the liquid to be measured, and acquiring a third voltage value in the following specific acquisition process:

AD0＝AD/(1+a(T-25))，

15. The method of controlling the TDS detecting apparatus of claim 13,

based on the third voltage value and the corresponding relationship between the voltage value and the TDS value, a specific acquiring process of acquiring the TDS value is as follows:

TDS＝k×AD0+b，

16. The method of controlling the TDS detecting apparatus of claim 15,

when the third voltage value is in a first value interval, the value of k is k1, and when the third voltage value is in a second value interval, the value of k is k2;

17. A controller characterized in that the controller is configured to perform the control method of the TDS detection apparatus of any of the claims 1 to 16.

18. The controller of claim 17, wherein the controller comprises a chip.

19. A TDS detection device, characterized in that it comprises: the controller, the first detection unit, and the second detection unit of any one of claims 17 to 18; 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 second resistor is connected in series between a second voltage output port of the controller and the second probe.

20. The TDS detection device of claim 19, characterized by the first resistor having a resistance equal to the second resistor.

21. The TDS detection device of claim 19, further comprising a sampling circuit having a sampling point electrically connected to the first probe or the second probe, wherein a third resistor is disposed on the sampling circuit.

22. A water purification apparatus, characterized in that it comprises a TDS detection device as claimed in any of claims 19 to 21.

23. The water purification unit of claim 22, comprising: first detecting means for detecting a TDS value of the filtered purified water; a second detection means for detecting a TDS value of the raw water before filtration;

24. The water purification unit of claim 23, further comprising:

a first filter unit;

25. The water purification apparatus of claim 24, wherein the first filter unit comprises at least one of: a reverse osmosis membrane filtration unit and a nanofiltration membrane filtration unit.

26. The water purification apparatus of claim 24, wherein the water purification apparatus has a first operation state in which the return water path returns the purified water flowing out of the purified water outlet to the first filter unit;

27. The water purification device of claim 25, further comprising: the second filtering unit is a front filtering unit, the second filtering unit is arranged between the first intersection point of the first water path and the raw water inlet of the first filtering unit, and the first probe and the second probe of the second detection device are arranged between the second filtering unit and the raw water inlet of the first filtering unit.

28. The water purification apparatus of claim 23, wherein when the first detection device employs the TDS detection device and the second detection device employs the TDS detection device;