Non-contact liquid level detector

Abstract

The utility model discloses a non-contact liquid level detector with long service life, which comprises a plurality of induction discs which are attached to the outer side wall of a container to be subjected to liquid level detection, are arranged in pairs and are arranged oppositely so as to send out alternating complementary waveforms or receive waveform signals output by the opposite induction discs; the sampling circuit is connected with the induction disc so as to sample the waveform signals received by the induction disc; the waveform signal generating circuit is connected with the induction disc so as to output a waveform signal to the induction disc; and the main control circuit is connected with the sampling circuit. According to the non-contact type liquid level detector with the long service life, alternating complementary waveforms can be generated and then sent to the induction disc through the arrangement of the waveform signal generating circuit, waveform signals are sampled through the sampling circuit, and meanwhile through the effect of the main control circuit, the non-contact type liquid level detector with the long service life can be obtained through the mode of processing and analyzing the waveform signals. And the effect of non-contact liquid level detection is achieved.

Description

Technical Field

[0001] The utility model relates to a liquid level detector, more specifically to a non-contact liquid level detector. Background Art

[0002] At present, the existing technology mainly uses liquid level detectors to detect liquid levels. However, the existing detection schemes of liquid level detectors include magnetic float type liquid level switch detection, tuning fork type liquid level detection, and ultrasonic type liquid level detection. The above three methods all require contact with liquid or placing the detection sensor in the liquid cavity to be detected, and liquid is generally highly corrosive. Therefore, after long-term use, the above-mentioned liquid level detector equipment is prone to corrosion and failure, which greatly reduces the service life of the liquid level detector. Utility Model Content

[0003] In view of the deficiencies in the prior art, the utility model aims to provide a non-contact liquid level detector with a long service life.

[0004] To achieve the above object, the utility model provides the following technical solution: a non-contact liquid level detector with a long service life, characterized in that it includes:

[0005] A plurality of sensing discs are attached to the outer wall of the liquid level container to be detected, and are arranged opposite to each other in pairs to emit alternating complementary waveforms or receive waveform signals output by the opposite sensing discs;

[0006] A sampling circuit is connected to the induction disk to sample the waveform signal received by the induction disk;

[0007] The waveform signal generating circuit is connected to the induction disk to output the waveform signal to the induction disk;

[0008] The main control circuit is connected to the sampling circuit to receive the waveform signal sampled by the sampling circuit and process and analyze the waveform signal. When the two received waveforms are greater than the calibration deviation, it is determined that there is no liquid. When the two received waveforms are less than the calibration deviation, it is determined that there is liquid.

[0009] As a further improvement of the present invention, the sampling circuit comprises:

[0010] Amplifying transistor Q4, the base of which is connected to the induction disk, the emitter of which is connected to resistor R13, which is then connected to resistor R15 and then to ground, the collector of which is connected to diode D5 and capacitor C11 and then to ground, and the node between the diode D5 and capacitor C11 is connected to resistor R17 and then to the main control circuit.

[0011] As a further improvement of the present invention, a capacitor C12 and a resistor R18 connected in parallel are connected between the resistor R17 and the main control circuit.

[0012] As a further improvement of the present invention, the waveform signal generating circuit comprises:

[0013] The waveform generating chip U4 has an output terminal, and the output terminal is connected to the induction disk to output a waveform signal of an alternating complementary waveform to the induction disk.

[0014] As a further improvement of the present utility model, the main control circuit comprises:

[0015] A main control chip U2, the main control chip U2 has an input end and an output end, the input end is connected to the end of the resistor R17, and the output end outputs a display signal;

[0016] The display circuit is connected to the output end of the main control chip U2, and receives the display signal output by the output end to display the identification and analysis results.

[0017] As a further improvement of the present invention, the display circuit includes a light-emitting diode LED1 and a resistor R1. The light-emitting diode LED1 and the resistor R1 are connected in series with each other and connected to the output end to receive a display signal output by the output end. When the display signal shows that there is liquid, the light-emitting diode LED1 is always on; when there is no liquid, the light-emitting diode LED1 flashes.

[0018] As a further improvement of the present invention, the main control chip U2 further has a calibration end, and the calibration end is connected to a calibration button K1 and then to the light emitting diode LED1.

[0019] The beneficial effect of the utility model is that, by setting up a plurality of induction disks, two by two can be set in a group and arranged relatively to each other, by sending waveform signals of alternating complementary waveforms to penetrate the container to be detected, and by the influence of the liquid on the waveform conduction, it is realized whether there is liquid in the container to be detected. Compared with the liquid level detector in the prior art, this does not contact with the liquid to be detected, so that the corrosion of the detector by the liquid can be effectively avoided, and the service life of the liquid level detector is greatly extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A circuit diagram of a waveform signal generating circuit and a sampling circuit of a non-contact liquid level detector with a long service life of the utility model;

[0021] Figure 2 The utility model discloses a circuit diagram of a main control circuit of a non-contact liquid level detector with a long service life. DETAILED DESCRIPTION

[0022] The present invention will be further described below with reference to the embodiments shown in the accompanying drawings.

[0023] Reference Figures 1 to 2 As shown, a non-contact liquid level detector with a long service life in this embodiment is characterized by comprising:

[0024] A plurality of sensing discs are attached to the outer wall of the liquid level container to be detected, and are arranged opposite to each other in pairs to emit alternating complementary waveforms or receive waveform signals output by the opposite sensing discs;

[0025] The sampling circuit 1 is connected to the induction disk to sample the waveform signal received by the induction disk;

[0026] The waveform signal generating circuit 2 is connected to the induction disk to output the waveform signal to the induction disk;

[0027] The main control circuit 3 is connected to the sampling circuit 1 to receive the waveform signal sampled by the sampling circuit 1 and process and analyze the waveform signal. When the two received waveforms are greater than the calibration deviation, it is determined that there is no liquid. When the two received waveforms are less than the calibration deviation, it is determined that there is liquid. In the process of using the non-contact liquid level detector with a long service life of this embodiment, it is only necessary to stick the two sensor disks on the outer wall of the container of the liquid to be detected oppositely without contacting the liquid. When performing liquid level detection, firstly, the waveform signal generating circuit 2 generates a waveform signal of an alternating complementary waveform and transmits it to the sensor disk. The sensor disk will emit an electromagnetic wave of the waveform. In the process of penetrating the container of the liquid to be detected, the electromagnetic wave will produce different changes due to the presence or absence of liquid. Therefore, the electromagnetic wave emitted by the target sensor disk received by the sensor disk is sampled by the sampling circuit 1, and then the waveform contained in the electromagnetic wave is processed and analyzed through the action of the main control circuit 3, and then it is determined that there is no liquid after the double waveforms are greater than the calibration deviation. When the double waveform is smaller than the calibration deviation, it is determined that there is liquid. In this way, non-contact liquid level detection can be simply and effectively realized. Compared with the liquid level detector in the prior art, it can effectively avoid the situation where liquid corrosion causes the liquid level detector to have a short service life.

[0028] As an improved specific implementation, the sampling circuit 1 includes:

[0029] The amplifier transistor Q4 has a base connected to the induction disk, an emitter connected to a resistor R13, then connected to a resistor R15 and then grounded, a collector connected to a diode D5 and a capacitor C11 and then grounded, a node between the diode D5 and the capacitor C11 is connected to a resistor R17 and then connected to the main control circuit 3. By setting the amplifier transistor Q4, an amplifier circuit can be effectively formed, and the sampled signal is amplified and input into the main control circuit 3, so that the main control circuit 3 can process and analyze it conveniently.

[0030] As a specific implementation of the improvement, a capacitor C12 and a resistor R18 connected in parallel are connected between the resistor R17 and the main control circuit 3. Through the setting of the capacitor C12 and the resistor R18, an RC filter circuit can be simply and effectively formed to filter the signal input into the main control circuit 3, thereby increasing the accuracy of the final processing and analysis of the main control circuit 3.

[0031] As an improved specific implementation, the waveform signal generating circuit 2 includes:

[0032] The waveform generating chip U4 has an output end, and the output end is connected to the induction disk to output a waveform signal of an alternating complementary waveform to the induction disk. Through the setting of the waveform generating chip U4, the modulation effect inside the chip can be effectively utilized to realize the output of an alternating complementary waveform, so that the use of a single-channel high-speed low-side gate driver to drive two induction disks is realized simply and effectively.

[0033] As an improved specific implementation, the main control circuit 3 includes:

[0034] A main control chip U2, the main control chip U2 has an input end and an output end, the input end is connected to the end of the resistor R17, and the output end outputs a display signal;

[0035] The display circuit 4 is connected to the output end of the main control chip U2, and receives the display signal output by the output end to display the identification and analysis results. Through the setting of the main control chip U2 and the display circuit 4, it is possible to simply and effectively display whether there is liquid in the container, which is convenient for people to detect whether there is liquid in the container.

[0036] As an improved specific implementation method, the display circuit 4 includes a light-emitting diode LED1 and a resistor R1. The light-emitting diode LED1 and the resistor R1 are connected in series with each other and connected to the output end to receive a display signal output by the output end. When the display signal is that there is liquid, the light-emitting diode LED1 is always on; when there is no liquid, the light-emitting diode LED1 flashes. Through the setting of the light-emitting diode LED1 and the resistor R1, it is possible to effectively remind whether there is liquid in the container by whether the light-emitting diode LED1 is emitting light.

[0037] As an improved specific implementation, the main control chip U2 also has a calibration end, which is connected to the light-emitting diode LED1 after being connected to the calibration button K1. Through the setting of the calibration end and the calibration button K1, the calibration button K1 can be pressed to achieve initialization calibration of the main control chip U2, which is used to calibrate the initialization judgment threshold.

[0038] In summary, the non-contact liquid level detector with a long service life of this embodiment can effectively drive the sensing disk to emit alternating complementary waveforms through the settings of the main control circuit 3, the waveform signal generating circuit 2 and the sampling circuit 1, and then through the processing and analysis of the waveform signal, it is simple and effective to realize the detection of whether there is liquid in the container without contacting the liquid.

[0039] The above is only a preferred embodiment of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A non-contact liquid level detector with a long service life, characterized in that: include: A plurality of sensing discs are attached to the outer wall of the liquid level container to be detected, and are arranged opposite to each other in pairs to emit alternating complementary waveforms or receive waveform signals output by the opposite sensing discs; A sampling circuit (1) is connected to the induction disk to sample the waveform signal received by the induction disk; A waveform signal generating circuit (2) is connected to the induction disk to output a waveform signal to the induction disk; The main control circuit (3) is connected to the sampling circuit (1) to receive the waveform signal sampled by the sampling circuit (1) and process and analyze the waveform signal. When the two received waveforms are greater than the calibration deviation, it is determined that there is no liquid. When the two received waveforms are less than the calibration deviation, it is determined that there is liquid.

2. The non-contact liquid level detector with a long service life according to claim 1, characterized in that: The sampling circuit (1) comprises: An amplifier transistor Q4, the base of which is connected to the induction disk, the emitter of which is connected to a resistor R13, which is then connected to a resistor R15, and then to ground; the collector of which is connected to a diode D5 and a capacitor C11, and then to ground; the node between the diode D5 and the capacitor C11 is connected to a resistor R17, and then to a main control circuit (3).

3. The non-contact liquid level detector with a long service life according to claim 2, characterized in that: A capacitor C12 and a resistor R18 are connected in parallel to each other at a position between the resistor R17 and the main control circuit (3).

4. The non-contact liquid level detector with a long service life according to claim 3, characterized in that: The waveform signal generating circuit (2) comprises: The waveform generating chip U4 has an output terminal, and the output terminal is connected to the induction disk to output a waveform signal of an alternating complementary waveform to the induction disk.

5. The non-contact liquid level detector with a long service life according to claim 4, characterized in that: The main control circuit (3) comprises: A main control chip U2, the main control chip U2 has an input end and an output end, the input end is connected to the end of the resistor R17, and the output end outputs a display signal; A display circuit (4) is connected to the output end of the main control chip U2, and receives a display signal output from the output end to display the identification and analysis result.

6. The non-contact liquid level detector with a long service life according to claim 5, characterized in that: The display circuit (4) comprises a light emitting diode LED1 and a resistor R1. The light emitting diode LED1 and the resistor R1 are connected in series to an output end to receive a display signal output by the output end. When the display signal indicates that there is liquid, the light emitting diode LED1 is always on; when there is no liquid, the light emitting diode LED1 flashes.

7. The non-contact liquid level detector with a long service life according to claim 6, characterized in that: The main control chip U2 also has a calibration end, and the calibration end is connected to a calibration button K1 and then connected to the light emitting diode LED1.

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