CN215726232U - Liquid level sensor system and liquid level sensor - Google Patents
Liquid level sensor system and liquid level sensor Download PDFInfo
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- CN215726232U CN215726232U CN202122034196.4U CN202122034196U CN215726232U CN 215726232 U CN215726232 U CN 215726232U CN 202122034196 U CN202122034196 U CN 202122034196U CN 215726232 U CN215726232 U CN 215726232U
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Abstract
The utility model discloses a liquid level sensor system and a liquid level sensor, wherein the liquid level sensor system comprises a signal generation module, a detection module and a signal processing module, wherein the signal generation module is used for generating and outputting a high-frequency alternating current signal; the input end of the detection module is connected with the output end of the signal generation module to input a high-frequency alternating-current signal, the detection module comprises an impedance transformation circuit, the impedance transformation circuit comprises a detection capacitor, the capacitance value of the detection capacitor changes along with the change of the liquid level and changes the impedance of the impedance transformation circuit, and the high-frequency alternating-current signal increases or decreases along with the change of the impedance; the input end of the signal processing module is connected with the detection module to acquire a high-frequency alternating current signal or a component of the high-frequency alternating current signal, and the signal processing module is used for converting the acquired alternating current signal into a direct current signal. The liquid level sensor of the liquid level sensor system is favorable for eliminating the influence of sediments on liquid level detection and improving the accuracy of the liquid level detection.
Description
Technical Field
The utility model relates to the technical field of liquid level detection, in particular to a liquid level sensor system and a liquid level sensor.
Background
The existing capacitance type liquid level sensor carries out liquid level detection on a detected substance, generally, the change of the detected substance is firstly converted into electric capacity, and then the liquid level of the detected substance is judged by judging the change time of the electric capacity. However, as the service time of the liquid level sensor increases, the sediment generated by the measured substance is accumulated on the probe of the liquid level sensor, which affects the detection of the measured substance by the probe, and thus the liquid level of the measured substance cannot be determined according to the variation time of the capacitance.
SUMMERY OF THE UTILITY MODEL
The utility model aims to provide a liquid level sensor system which is beneficial to eliminating the influence of sediment on liquid level detection and improving the accuracy of the liquid level detection.
Another object of the present invention is to provide a liquid level sensor, which is beneficial to eliminating the influence of the sediment on the liquid level detection, and improving the accuracy of the liquid level detection.
In order to achieve the above object, the present invention discloses a liquid level sensor system, which comprises a signal generating module, a detecting module and a signal processing module; the signal generating module is used for generating and outputting a high-frequency alternating current signal; the input end of the detection module is connected with the output end of the signal generation module to input the high-frequency alternating-current signal, the detection module comprises an impedance transformation circuit, the impedance transformation circuit comprises a detection capacitor, the capacitance value of the detection capacitor changes along with the change of the liquid level and changes the impedance of the impedance transformation circuit, and the high-frequency alternating-current signal increases or decreases along with the change of the impedance; the input end of the signal processing module is connected with the detection module to acquire the high-frequency alternating current signal or the component of the high-frequency alternating current signal, and the signal processing module is used for converting the acquired alternating current signal into a direct current signal.
Optionally, the impedance transformation circuit includes a first inductor, a first resistor, and the detection capacitor connected in series.
Optionally, the detection module further includes a load resistor, and the load resistor is connected in parallel with the impedance transformation circuit.
Optionally, the signal generation module includes function generator, integrating circuit, high frequency oscillation circuit and the coupling circuit that connects gradually, function generator is used for producing and exports the square wave signal of frequency adjustable, integrating circuit be used for with square wave signal converts triangular wave signal into, high frequency oscillation circuit be used for with triangular wave signal debugs for high frequency signal, coupling circuit is used for cutting off direct current signal in the high frequency signal and exports alternating current signal in the high frequency signal.
Optionally, the function generator is a single chip microcomputer, and the single chip microcomputer is connected with the output end of the signal processing module to judge the liquid level of the measured liquid according to the direct current signal.
Optionally, the coupling circuit comprises a coupling capacitor and a second resistor connected in series.
Optionally, the signal processing module includes a detector diode and a pi-type low-pass filter connected in series, where the detector diode is configured to detect a low-frequency signal in a high-frequency signal, and the pi-type low-pass filter is configured to block the high-frequency signal and output the low-frequency signal.
Optionally, the liquid level sensor system of the present invention further includes a circuit protection module, an input end of the circuit protection module is connected to the power supply, and an output end of the circuit protection module is connected to the signal generation module, the detection module, and the signal processing module, respectively.
Optionally, the circuit protection module comprises an anti-reverse diode and a low dropout regulator which are connected in sequence, wherein the anti-reverse diode is configured to open a circuit when being connected reversely to the power supply.
In order to achieve the other purpose, the utility model further discloses a liquid level sensor, which comprises the liquid level sensor system, wherein the liquid level sensor comprises a metal shell, a probe, a circuit component and an adapter, the metal shell penetrates through the metal shell, the probe penetrates through the metal shell, the circuit component is arranged in the metal shell, the adapter is electrically connected with the circuit component, the metal shell and the probe are respectively used as two electrodes of the detection capacitor, the probe is electrically connected with the circuit component, the signal generation module, the signal processing module and the detection module except for the detection capacitor are formed on the circuit component, and the adapter is used for accessing an external electric signal to the signal generation module and outputting a detection result signal outwards.
The liquid level sensor system comprises an impedance conversion circuit and a signal generation module for providing a high-frequency alternating current signal for the impedance conversion circuit, wherein the impedance conversion circuit comprises a detection capacitor arranged in a detected liquid, when the detection capacitor detects the liquid level of the detected liquid, the capacitance value of the detected liquid is changed along with the change of the liquid level due to the difference of dielectric constants of the detected liquid and air, so that the impedance of the impedance conversion circuit is changed, meanwhile, accumulated sediments can also cause the capacitance value of the detection capacitor to be different, so that the impedance of the impedance conversion circuit is changed, the change of the impedance can cause the high-frequency alternating current signal related to the impedance conversion circuit to be increased or decreased, further, the related high-frequency alternating current signal can be converted into a direct current signal by using a signal processing module, and then the signal amount changed due to the accumulated sediments can be identified by analyzing the direct current signal, the liquid level of the detected liquid can be accurately judged, the influence of sediment on liquid level detection is favorably eliminated, and the accuracy of the liquid level detection is improved.
Drawings
Fig. 1 is a schematic block diagram of a signal generation module, a detection module, and a signal processing module in an embodiment of the present invention.
Fig. 2 is a schematic structural diagram of a signal generation module, a detection module and a signal processing module in an embodiment of the present invention.
Fig. 3 is a schematic diagram of an integrator circuit in an embodiment of the present invention.
Fig. 4 is a schematic diagram of a high-frequency oscillation circuit in the embodiment of the present invention.
FIG. 5 is a schematic diagram of a fluid level sensor system according to an embodiment of the present invention.
Fig. 6 is a schematic block diagram of a circuit protection module and a power supply in an embodiment of the utility model.
FIG. 7 is a schematic structural diagram of a liquid level sensor according to an embodiment of the utility model.
FIG. 8 is an exploded view of a fluid level sensor in accordance with an embodiment of the present invention.
Detailed Description
In order to explain technical contents, structural features, and objects and effects of the present invention in detail, the following detailed description is given with reference to the accompanying drawings in conjunction with the embodiments.
Referring to fig. 1 to 8, the present invention discloses a liquid level sensor system, which includes a signal generating module 1, a detecting module 2 and a signal processing module 3; the signal generating module 1 is used for generating and outputting a high-frequency alternating current signal; the input end of the detection module 2 is connected with the output end of the signal generation module 1 to input a high-frequency alternating-current signal, the detection module 2 comprises an impedance transformation circuit 21, the impedance transformation circuit 21 comprises a detection capacitor C1, the capacitance value of the detection capacitor C1 changes along with the change of the liquid level and changes the impedance Z of the impedance transformation circuit 21, and the high-frequency alternating-current signal increases or decreases along with the change of the impedance Z; the input end of the signal processing module 3 is connected with the detection module 2 to obtain a high-frequency alternating current signal or a component of the high-frequency alternating current signal, and the signal processing module 3 is configured to convert the obtained alternating current signal into a direct current signal.
The liquid level sensor system of the utility model comprises an impedance conversion circuit 21 and a signal generating module 1 for providing high-frequency alternating current signals for the impedance conversion circuit 21, wherein the impedance conversion circuit 21 comprises a detection capacitor C1 arranged in the detected liquid, when the detected liquid is detected by the detection capacitor C1, the capacitance value of the detected liquid and the dielectric constant of air are different, the capacitance value of the detected liquid is changed along with the change of the liquid level, the impedance Z of the impedance conversion circuit 21 is changed, the capacitance value of the detection capacitor C1 is different due to the difference of the dielectric constants of the detected liquid and the air, the change of the impedance Z can increase or decrease the high-frequency alternating current signals related to the impedance conversion circuit 21, the related high-frequency alternating current signals can be converted into direct current signals by using a signal processing module 3, and then the signal amount changed due to the accumulated deposits can be identified by analyzing the direct current signals, the liquid level of the detected liquid can be accurately judged, the influence of sediment on liquid level detection is favorably eliminated, and the accuracy of the liquid level detection is improved.
After long-term deposition experiments, the amount of the sediment is not increased after the sediment on the liquid level sensor is accumulated to a certain degree, so that the signal amount changed due to the accumulated sediment can be identified by converting a high-frequency alternating current signal related to the impedance conversion circuit 21 into a direct current signal and analyzing the direct current signal.
Referring to fig. 2, in particular, the impedance transformation circuit 21 includes a first inductor L1, a first resistor R1 and a detection capacitor C1 connected in series, and the impedance Z of the impedance transformation circuit 21 is
But is not limited thereto.
Specifically, the detection module 2 further includes a load resistor R2, and the load resistor R2 is connected in parallel with the impedance transformation circuit 21. The setting of the load resistor R2 ensures that the detection module 2 always has a signal output. When the liquid level changes, the capacitance value of the detection capacitor C1 changes to cause the impedance Z to change, so that the impedance Z and the equivalent parallel impedance of the load resistor R2 are further changed
The high-frequency alternating current signal can be increased or decreased by the changed equivalent parallel impedance, and the liquid level of the liquid to be detected can be accurately judged by analyzing the direct current signal converted by the high-frequency alternating current signal.
Referring to fig. 2 to 5, the signal generating module 1 includes a function generator 11, an integrating circuit 12, a high-frequency oscillating circuit 13 and a coupling circuit 14, which are connected in sequence, the function generator 11 is configured to generate and output a square wave signal with adjustable frequency, the integrating circuit 12 is configured to convert the square wave signal into a triangular wave signal, the high-frequency oscillating circuit 13 is configured to debug the triangular wave signal into a high-frequency signal, and the coupling circuit 14 is configured to cut off a direct current signal in the high-frequency signal and output an alternating current signal in the high-frequency signal.
In this embodiment, the integration circuit 12 is formed as a programmable integration voltage source in combination with the function generator 11, the integration circuit 12 (fig. 3) comprising an operational amplifierLarge amplifier based on virtual earth
And an integral formula:
the triangular wave signal output by the integrating circuit 12 can be calculated. The high frequency oscillation circuit 13 (fig. 4) includes a precisely programmable small-package silicon oscillator, and the oscillator can use the triangular wave signal to debug the waveform of a wide range of output frequency (typical frequency error is less than or equal to 0.5%) in cooperation with the triangular wave signal input by the programmable integrating voltage source. Frequency calculation formula of the combined oscillator:
the oscillator can be adjusted according to actual requirements so that the oscillator outputs the required signal frequency.
Referring to fig. 5, in the present embodiment, the function generator 11 is a single chip microcomputer 10, and the single chip microcomputer 10 is connected to the output end of the signal processing module 3 to determine the liquid level of the measured liquid according to the direct current signal. In this embodiment, the single chip microcomputer 100 can output a square wave signal with adjustable frequency and recognize and process a direct current signal to determine the liquid level of the liquid to be measured in cooperation with software programming.
Referring to fig. 2 and 5, the coupling circuit 14 preferably includes a coupling capacitor C2 and a second resistor R3 connected in series. The coupling capacitor C2 presents a low impedance to an alternating current signal among the high-frequency signals output from the high-frequency oscillation circuit 13 and can block a direct current signal therein.
Referring to fig. 2 and 5, in the present embodiment, the signal processing module 3 includes a detector diode 31 and a pi-type low pass filter 32 connected in series, the detector diode 32 is used for detecting a low frequency signal in a high frequency signal, and the pi-type low pass filter 32 is used for cutting off the high frequency signal and outputting the low frequency signal.
Referring to fig. 6, the liquid level sensor system of the present invention further includes a circuit protection module 4, an input end of the circuit protection module 4 is connected to the power supply 5, and an output end of the circuit protection module 4 is connected to the signal generation module 1, the detection module 2, and the signal processing module 3, respectively.
Specifically, the circuit protection module 4 includes an anti-reverse diode 41 and a low dropout regulator 42 connected in series, and the anti-reverse diode 41 is configured to open the circuit when connected in reverse to the power supply 5. In the present embodiment, the low dropout linear regulator 42(low dropout regulator) can realize high-stability wide-range input and low-dropout stable output, and ensure that each circuit module stably operates.
Referring to fig. 2, 7 and 8, the present invention also discloses a liquid level sensor 100 comprising a liquid level sensor system as described above. The liquid level sensor 100 comprises a metal shell 102 penetrating from top to bottom, a probe 101 penetrating through the metal shell 102, a circuit assembly 103 arranged in the metal shell 102 and an adapter 105 electrically connected with the circuit assembly 103, wherein the metal shell 102 and the probe 101 are respectively used as two electrodes of a detection capacitor C1, the probe 101 is electrically connected with the circuit assembly 103, the signal generation module 1, the signal processing module 3 and the detection module 2 except for the detection capacitor C1 are formed on the circuit assembly 103, and the adapter 105 is used for receiving an external electric signal to the signal generation module 1 and outputting a detection result signal outwards. The probe 101 of the liquid level sensor 100 is used as one electrode of the detection capacitor C1, and the metal shell 102 of the liquid level sensor 100 is used as the other electrode of the detection capacitor C1, so that the liquid level sensor 100 of the utility model can be applied to containers made of different materials.
Specifically, an insulating sleeve 104 is sleeved on the probe 101, the upper end of the probe 101 is electrically connected with the circuit assembly 103, and the lower end of the probe 101 extends out of the metal shell 102. The metal shell 102 includes a base 1021 and a threaded portion 1022 protruding from a bottom end of the base 1021, wherein the threaded portion 1022 is used for screwing the liquid level sensor 100 to a container filled with a liquid to be measured.
The liquid level sensor 100 of the present invention is suitable for, but not limited to, the detection of the liquid levels of the cooling liquid, the engine oil, the hydraulic oil, etc. of the generator water tank.
The above disclosure is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the scope of the present invention, therefore, the present invention is not limited by the appended claims.
Claims (10)
1. A liquid level sensor system, comprising
The signal generating module is used for generating and outputting a high-frequency alternating current signal;
the input end of the detection module is connected with the output end of the signal generation module to input the high-frequency alternating-current signal, the detection module comprises an impedance transformation circuit, the impedance transformation circuit comprises a detection capacitor, the capacitance value of the detection capacitor changes along with the change of the liquid level and changes the impedance of the impedance transformation circuit, and the high-frequency alternating-current signal increases or decreases along with the change of the impedance;
the input end of the signal processing module is connected with the detection module to acquire the high-frequency alternating current signal or the component of the high-frequency alternating current signal, and the signal processing module is used for converting the acquired alternating current signal into a direct current signal.
2. The fluid level sensor system of claim 1, wherein the impedance transformation circuit comprises a first inductor, a first resistor, and the sensing capacitor in series.
3. The fluid level sensor system of claim 1, wherein the detection module further comprises a load resistor connected in parallel with the impedance transformation circuit.
4. The liquid level sensor system of claim 1, wherein the signal generating module comprises a function generator, an integrating circuit, a high-frequency oscillating circuit and a coupling circuit, which are connected in sequence, wherein the function generator is used for generating and outputting a square wave signal with adjustable frequency, the integrating circuit is used for converting the square wave signal into a triangular wave signal, the high-frequency oscillating circuit is used for debugging the triangular wave signal into a high-frequency signal, and the coupling circuit is used for cutting off a direct current signal in the high-frequency signal and outputting an alternating current signal in the high-frequency signal.
5. The liquid level sensor system of claim 4, wherein the function generator is a single chip microcomputer, and the single chip microcomputer is connected with the output end of the signal processing module to judge the liquid level of the measured liquid according to the direct current signal.
6. The fluid level sensor system of claim 4, wherein the coupling circuit comprises a coupling capacitor and a second resistor in series.
7. The fluid level sensor system of claim 1, wherein the signal processing module comprises a detector diode and a pi-type low pass filter connected in series, the detector diode being configured to detect a low frequency signal of the high frequency signal, the pi-type low pass filter being configured to block the high frequency signal and output the low frequency signal.
8. The liquid level sensor system of claim 1, further comprising a circuit protection module, wherein an input end of the circuit protection module is connected to a power supply, and an output end of the circuit protection module is connected to the signal generation module, the detection module, and the signal processing module, respectively.
9. The fluid level sensor system of claim 8, wherein the circuit protection module comprises a reverse diode and a low dropout linear regulator connected in series, the reverse diode being configured to open a circuit when reverse connected to the power supply.
10. A liquid level sensor comprising a liquid level sensor system according to any one of claims 1 to 9; level sensor includes the metal casing that runs through from top to bottom, wears to establish metal casing's probe, install circuit assembly in the metal casing and with the adapter that the circuit assembly electricity is connected, metal casing with the probe does respectively conduct the two electrodes of detection electric capacity, the probe with the circuit assembly electricity is connected, the signal generation module signal processing module and detection module except that part except that the detection electric capacity is formed circuit assembly, the adapter is used for inserting the external signal of telecommunication extremely signal generation module and outside output testing result signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202122034196.4U CN215726232U (en) | 2021-08-26 | 2021-08-26 | Liquid level sensor system and liquid level sensor |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202122034196.4U CN215726232U (en) | 2021-08-26 | 2021-08-26 | Liquid level sensor system and liquid level sensor |
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| Publication Number | Publication Date |
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| CN215726232U true CN215726232U (en) | 2022-02-01 |
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| CN202122034196.4U Active CN215726232U (en) | 2021-08-26 | 2021-08-26 | Liquid level sensor system and liquid level sensor |
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- 2021-08-26 CN CN202122034196.4U patent/CN215726232U/en active Active
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Address after: Room 101, No. 1, East Ring 3rd Street, Jitiagang, Huangjiang Town, Dongguan City, Guangdong Province, 523000 Patentee after: Guangdong Zhengyang Sensor Technology Co.,Ltd. Address before: 523000 Jitigang Village, Huangjiang Town, Dongguan City, Guangdong Province Patentee before: DONGGUAN ZHENGYANG ELECTRONIC MECHANICAL Co.,Ltd. |
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