CN204461543U - A kind of liquid level detection device - Google Patents
A kind of liquid level detection device Download PDFInfo
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- CN204461543U CN204461543U CN201420870694.XU CN201420870694U CN204461543U CN 204461543 U CN204461543 U CN 204461543U CN 201420870694 U CN201420870694 U CN 201420870694U CN 204461543 U CN204461543 U CN 204461543U
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- liquid level
- detection device
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- level detection
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Abstract
The utility model discloses a kind of liquid level detection device.Described liquid level detection device comprises: for exporting the signal generator of pulsed DC signal; Electric capacity, the first end of described electric capacity is connected to the signal output part of described signal generator; First diode, the signal input part of described first diode is connected to the second end of described electric capacity; Digital to analog converter, the signal input part of described digital to analog converter is connected to the signal output part of described first diode; Stylus module, the signal input part of described stylus module is connected between described electric capacity and described first diode, the signal output part of described stylus module is connected between described first diode and described digital to analog converter, and the signal output part ground connection of described stylus module.Liquid level detection device provided by the utility model can prevent the generation of contact pilotage electrode polarization phenomenon effectively, thus avoids the phenomenon of surface scale to occur, and improves the degree of accuracy of level sensing, extends the serviceable life of contact pilotage, reduces costs.
Description
Technical field
The utility model relates to a kind of liquid level detection device, especially relates to a kind of liquid level detection device preventing contact pilotage electrode polarization and fouling.
Background technology
Liquid level detection device is used for the height value of the liquid level detecting testing liquid in real time, thus reflects the volume change situation of testing liquid in real time.At present, traditional liquid level detection device is the contact pilotage by arranging multiple differing heights in the position of testing liquid, and contact pilotage is connected in corresponding DC circuit, the change of the liquid level of testing liquid can touch the contact pilotage of relevant position, thus the current value in change circuit, by the curtage value in testing circuit in real time, and convert the liquid level value that corresponding standard output signals reflects testing liquid in real time to.But, there is following defect in traditional liquid level emasuring device: owing to adopting direct supply as signal source, the power supply be added between different contact pilotage is also direct current, can polarization phenomena be there are between different contact pilotages, in long-term use procedure, fouling can be formed on the surface of contact pilotage, not only can affect the degree of accuracy of detection, but also affect the serviceable life of contact pilotage, need often to change contact pilotage, add cost.
Therefore, be necessary very much to design a kind of liquid level detection device that can prevent contact pilotage electrode polarization and fouling, thus ensure the degree of accuracy of detection, extend the serviceable life of contact pilotage, reduce costs.
Utility model content
In view of this, the utility model provides a kind of liquid level detection device that can prevent contact pilotage electrode polarization and fouling, is intended to the defect overcoming prior art, thus ensures the degree of accuracy of level sensing, extends the serviceable life of contact pilotage, reduces costs.
Liquid level detection device provided by the utility model comprises:
For exporting the signal generator of pulsed DC signal.
Electric capacity, the first end of described electric capacity is connected to the signal output part of described signal generator.
First diode, the signal input part of described first diode is connected to the second end of described electric capacity.
Digital to analog converter, the signal input part of described digital to analog converter is connected to the signal output part of described first diode.
Stylus module, the signal input part of described stylus module is connected between described electric capacity and described first diode, the signal output part of described stylus module is connected between described first diode and described digital to analog converter, and the signal output part ground connection of described stylus module.
Liquid level detection device as above, preferably, described liquid level detection device also comprises resistance, described resistant series is between described electric capacity and described first diode, and the first end of described resistance is connected to the second end of described electric capacity, the second end of described resistance is connected with the signal input part of described stylus module.
Liquid level detection device as above, preferably, described liquid level detection device also comprises the second diode, and described second Diode series is between the signal output part and the signal input part of described digital to analog converter of described stylus module.
Liquid level detection device as above, preferably, described liquid level detection device also comprises water level information process and controls assembly, and the signal input part of described water level information process and control assembly is connected to the signal output part of described digital to analog converter.
Liquid level detection device as above, preferably, described stylus module comprises the contact pilotage of multiple different length.
Liquid level detection device as above, preferably, described electric capacity and described stylus module form differentiating circuit.
Adopt liquid level detection device provided by the utility model, by electric capacity and signal generator with the use of, filtering process has been carried out to the signal that signal generator exports, only remain alternating component wherein, because the signal be applied in stylus module is AC signal, therefore long polarization phenomena can not be produced to contact pilotage, thus the phenomenon that effectively prevent contact pilotage surface scale occurs, not only increase the degree of accuracy of level sensing, and the serviceable life of contact pilotage can also be extended, significantly reduce cost.
Accompanying drawing explanation
Preferred embodiment in the utility model will be described in detail by accompanying drawing below, will contribute to understanding the purpose of this utility model and advantage, wherein:
Fig. 1 is a kind of preferred embodiment of liquid level detection device of the present utility model.
Fig. 2 is the preferred arrangement of contact pilotage in testing process.
Fig. 3 is the output waveform under different liquid level.
Embodiment
Below in conjunction with embodiment, the utility model is described in detail.The identical Reference numeral of wherein identical parts represents.It should be noted that, the word "front", "rear" of use is described below, "left", "right", "up" and "down" refer to direction in accompanying drawing, word " interior " and " outward " refer to the direction towards or away from particular elements geometric center respectively.
Fig. 1 is a kind of preferred embodiment of liquid level detection device of the present utility model.As shown in Figure 1, in a preferred embodiment, liquid level detection device provided by the utility model comprises: signal generator 10, electric capacity 60, first diode D1, digital to analog converter 20 and stylus module 40.
Described signal generator 10 for exporting pulsed DC signal, for described liquid level detection device provides required signal source.One of ordinary skill in the art will appreciate that described signal generator 10 can be realized by the various generator that can export pulsed DC signal, such as: pulse dc power.
The first end of described electric capacity 60 is connected to the signal output part of described signal generator 10, the signal input part of described first diode D1 is connected to the second end of described electric capacity 60, and the signal input part of described digital to analog converter 20 is connected to the signal output part of described first diode D1.The pulsed DC signal produced in described signal generator 10, after described electric capacity 60, carries out filtering process by described electric capacity 60, only retains AC signal wherein.
The signal input part of described stylus module 40 is connected between described electric capacity 60 and described first diode D1, the signal output part of described stylus module 40 is connected between described first diode D1 and described digital to analog converter 20, and the signal output part ground connection of described stylus module 40.Preferably, described liquid level detection device also comprises resistance 50, described resistance 50 is connected between described electric capacity 60 and described first diode D1, and the first end of described resistance 50 is connected to the second end of described electric capacity 60, the second end of described resistance 50 is connected with the signal input part of described stylus module 40.Particularly, as shown in Figure 1, described second diode D2 is connected between earth point on the signal output part of described stylus module 40 and the signal input part of described digital to analog converter 20.Preferably, described liquid level detection device also comprises the second diode D2, between the signal output part that described second diode D2 is connected on described stylus module 40 and the signal input part of described digital to analog converter 20.Because the power supply being added in described stylus module 40 two ends is AC power, therefore, described stylus module 40 can not produce polarization phenomena, and the phenomenon of surface scale also can not occur.It should be noted that, add described second diode D2 just a kind of preferred scheme in the present embodiment, described second diode D2 can omit under many circumstances, such as: when analog to digital conversion port is with clamping circuit, just can omit described second diode D2.
Fig. 2 is the preferred arrangement of contact pilotage in testing process.Preferably, described stylus module 40 comprises the contact pilotage of multiple different length, such as shown in Fig. 2, described stylus module 40 comprises three contact pilotages, the first contact pilotage 1, second contact pilotage 2 and the 3rd contact pilotage 3 respectively, wherein, described first contact pilotage 1 in Fig. 2, described second contact pilotage 2 and described 3rd contact pilotage 3 are corresponding with the contact pilotage of three in Fig. 1 respectively.Liquid 90 in Fig. 2 is contained in water tank 80, and described first contact pilotage 1, described second contact pilotage 2 and described 3rd contact pilotage 3 all insert in described water tank 80, and its end at various height.Shown in composition graphs 1 and Fig. 2, described electric capacity 60 forms differentiating circuit with described stylus module 40, and according to Kirchhoff's law, the input voltage U of the signal input part of described digital to analog converter 20 meets following expression formula:
Wherein, U
0represent the voltage that the signal output part of described signal generator 10 exports, τ represents the time constant of differentiating circuit, and R represents the resistance value of described stylus module 40, and C represents capacitance.
Resistance value R changes along with the change of liquid level.Particularly, shown in composition graphs 1 and Fig. 2, when the lower end of liquid level lower than described 3rd contact pilotage 3, liquid level does not all contact with three contact pilotages, now the resistance value R=R1 of described stylus module 40; When liquid level is higher than the lower end of described 3rd contact pilotage 3, and during lower end lower than described second contact pilotage 2, the resistance value R=R2 of described stylus module 40; When liquid level is higher than the lower end of described second contact pilotage 2, and during lower end lower than described first contact pilotage 1, the resistance value R=R3 of described stylus module 40; When the lower end of liquid level higher than described first contact pilotage 1, the resistance value R=R4 of described stylus module 40; Above-mentioned four resistance values meet the following conditions: R1>R2>R3>R4.Along with the rising of liquid level, the resistance value R of described stylus module 40 reduces, timeconstantτ (τ=RC) in differentiating circuit reduces, the input voltage U of described digital to analog converter 20 is also along with reduction, after pulse is risen after some fixed delays, by detecting the input voltage U of described digital to analog converter 20, the elevation information of liquid level can be reflected in real time.Particularly, when liquid level is in lower liquid level, the resistance value of described stylus module 40 is comparatively large, and timeconstantτ is comparatively large, and the input voltage of described digital to analog converter 20 is larger; When liquid level is in higher liquid level, the resistance value of described stylus module 40 is less, and timeconstantτ is less, and the input voltage of described digital to analog converter 20 is less.Wherein, one of ordinary skill in the art will appreciate that described stylus module 40 can be realized, as long as can produce the change of the resistance value of rule when liquid level contacts different contact pilotages by various existing contact pin type liquid level sensor.
Fig. 3 is the output waveform under different liquid level.As shown in Figure 3, waveform X represents the waveform of the DC pulse signal that described signal generator 10 exports, and when liquid level is lower, the waveform inputting the signal of described digital to analog converter 20 becomes waveform Y, along with the continuation of liquid level raises, the waveform inputting described digital to analog converter 20 becomes waveform Z.Preferably, described liquid level detection device also comprises water level information process and controls assembly 30, the signal input part of described water level information process and control assembly 30 is connected to the signal output part of described digital to analog converter 20, the signal of input is converted to digital signal by described digital to analog converter 20, and undertaken showing and controlling by water level information process and control assembly 30, operating personnel can read the quantity information of liquid level easily by described water level information process and control assembly 30.
Adopt liquid level detection device provided by the utility model, by electric capacity and signal generator with the use of, filtering process has been carried out to the signal that signal generator exports, only remain alternating component wherein, because the signal be applied in stylus module is AC signal, therefore long polarization phenomena can not be produced to contact pilotage, thus the phenomenon that effectively prevent contact pilotage surface scale occurs, not only increase the degree of accuracy of level sensing, and the serviceable life of contact pilotage can also be extended, significantly reduce cost.
Last it is noted that above embodiment is only in order to illustrate the technical solution of the utility model, be not intended to limit; Although be described in detail the utility model with reference to previous embodiment, those of ordinary skill in the art is to be understood that: it still can be modified to the technical scheme described in foregoing embodiments, or carries out equivalent replacement to wherein portion of techniques feature; And these amendments or replacement, do not make the essence of appropriate technical solution depart from the scope of each embodiment technical scheme of the utility model.
Claims (6)
1. a liquid level detection device, is characterized in that, described liquid level detection device comprises:
For exporting the signal generator of pulsed DC signal;
Electric capacity, the first end of described electric capacity is connected to the signal output part of described signal generator;
First diode, the signal input part of described first diode is connected to the second end of described electric capacity;
Digital to analog converter, the signal input part of described digital to analog converter is connected to the signal output part of described first diode;
Stylus module, the signal input part of described stylus module is connected between described electric capacity and described first diode, the signal output part of described stylus module is connected between described first diode and described digital to analog converter, and the signal output part ground connection of described stylus module.
2. liquid level detection device according to claim 1, it is characterized in that, described liquid level detection device also comprises resistance, described resistant series is between described electric capacity and described first diode, and the first end of described resistance is connected to the second end of described electric capacity, the second end of described resistance is connected with the signal input part of described stylus module.
3. liquid level detection device according to claim 1, is characterized in that, described liquid level detection device also comprises the second diode, and described second Diode series is between the signal output part and the signal input part of described digital to analog converter of described stylus module.
4. liquid level detection device according to claim 1, it is characterized in that, described liquid level detection device also comprises water level information process and controls assembly, and the signal input part of described water level information process and control assembly is connected to the signal output part of described digital to analog converter.
5. liquid level detection device according to claim 1, is characterized in that, described stylus module comprises the contact pilotage of multiple different length.
6. liquid level detection device according to claim 1, is characterized in that, described electric capacity and described stylus module form differentiating circuit.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420870694.XU CN204461543U (en) | 2014-12-31 | 2014-12-31 | A kind of liquid level detection device |
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| CN201420870694.XU CN204461543U (en) | 2014-12-31 | 2014-12-31 | A kind of liquid level detection device |
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| CN204461543U true CN204461543U (en) | 2015-07-08 |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108775856A (en) * | 2018-05-14 | 2018-11-09 | 兰州天启基因生物科技有限公司 | Liquid detecting device, liquid detecting method and liquid detection system |
| CN110736519A (en) * | 2019-11-28 | 2020-01-31 | 珠海格力电器股份有限公司 | Liquid level detection method, liquid level detection device and household appliance |
-
2014
- 2014-12-31 CN CN201420870694.XU patent/CN204461543U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108775856A (en) * | 2018-05-14 | 2018-11-09 | 兰州天启基因生物科技有限公司 | Liquid detecting device, liquid detecting method and liquid detection system |
| CN110736519A (en) * | 2019-11-28 | 2020-01-31 | 珠海格力电器股份有限公司 | Liquid level detection method, liquid level detection device and household appliance |
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