Comparison circuit of ultrasonic liquid level sensor

Abstract

The utility model discloses a comparison circuit of an ultrasonic liquid level sensor, which comprises a current and voltage comparison unit, the current and voltage comparison unit is electrically connected with a filter and a signal output port, the filter is electrically connected with a delay sampling circuit, and the delay sampling circuit is electrically connected with a signal input port; the current and voltage comparison unit comprises a comparator U1, and a pin 1 of the comparator U1 is electrically connected with one end of a resistor R2, one end of a resistor R1 and one end of a capacitor C1. According to the utility model, time-delay sampling is carried out when an input signal is sampled, an offset of the input signal is constructed, the inherent time-delay condition is equivalently eliminated, in addition, a subsequent filter is matched to integrate electric signals, so that the electric signals input to the current and voltage comparison unit are stable electric signals, and the accuracy of sampling is improved. Therefore, the accuracy of comparison output results is improved, and use requirements are met.

Description

Technical Field

[0001] The utility model relates to the technical field of ultrasonic liquid level sensors, in particular to a comparison circuit of an ultrasonic liquid level sensor. Background Technique

[0002] As a circuit in an ultrasonic liquid level sensor, the basic principle of the comparison circuit is as follows: the input signal is compared and judged with the reference voltage in real time, quickly and accurately, and the judgment result is output for other circuits to process. For example, once the input signal changes from lower than the reference voltage to higher than the reference voltage, or from higher than the reference voltage to lower than the reference voltage, the judgment result is immediately output to the subsequent circuit for processing; when the comparison circuit in the prior art compares and judges the input signal, due to the existence of the inherent delay, there is always a certain inherent error in the comparison circuit, thus affecting its comparison result and not meeting the use requirements. Therefore, we propose a comparison circuit of an ultrasonic liquid level sensor. Content of the Utility Model

[0003] The purpose of the utility model is to solve the defects existing in the prior art, and to propose a comparison circuit of an ultrasonic liquid level sensor.

[0004] In order to achieve the above purpose, the utility model adopts the following technical scheme:

[0005] A comparison circuit of an ultrasonic liquid level sensor, including a current-voltage comparison unit, the current-voltage comparison unit is electrically connected to a filter and a signal output port, the filter is electrically connected to a delay sampling circuit, and the delay sampling circuit is electrically connected to a signal input port;

[0006] The current-voltage comparison unit includes a comparator U1. One end of a resistor R2, one end of a resistor R1, and one end of a capacitor C1 are electrically connected to pin 1 of the comparator U1. The other ends of the resistor R1 and the capacitor C1 are both grounded. The other end of the resistor R2 is electrically connected to one end of a resistor R10 and one end of a resistor R9. The other end of the resistor R10 is electrically connected to the negative electrode of a suppression diode TVS1. The positive electrode of the suppression diode TVS1 and the other end of the resistor R9 are both grounded. Pin 2 of the comparator U1 is electrically connected to one end of the resistor R2, one end of a resistor R3, one end of a resistor R4, and one end of a capacitor C2. The other end of the resistor R2, the other end of the resistor R4, the other end of the capacitor C2, and pin 3 of the comparator U1 are all grounded. Pin 5 of the comparator U1 is electrically connected to the other end of the resistor R3. Pin 5 of the comparator U1 is also electrically connected to pin 2 of a triode Q1. Pin 3 of the triode Q1 is electrically connected to one end of the resistor R4 and one end of the capacitor C2. Pin 1 of the triode Q1 is electrically connected to one end of a resistor R6, one end of a resistor R5, and one end of a resistor R7. The other end of the resistor R7 is electrically connected to a high-frequency VCC1. The other end of the resistor R5 is electrically connected to a TX2 output port. The other end of the resistor R6 is electrically connected to an RX2 output port. Pin 4 of the comparator U1 is electrically connected to one end of a resistor R8 and one end of a capacitor C3. The other end of the capacitor C3 is grounded.

[0007] Preferably, the delay sampling circuit includes an amplifier U2. One end of a resistor R12 is electrically connected to pin 1 of the amplifier U2. The other end of the resistor R12 is electrically connected to one end of a resistor R11 and one end of a resistor R13. The other end of the resistor R13 and pin 2 of the amplifier U2 are both grounded. The other end of the resistor R11 is electrically connected to one end of a delay relay KT. The other end of the delay relay KT is electrically connected to a signal input port. Pin 2 of the amplifier U2 is also electrically connected to one end of a resistor R14. One end of the resistor R14 is also grounded. The other end of the resistor R14 is electrically connected to one end of a resistor R15 and one end of a resistor R16. One end of the resistor R15 is also electrically connected to one end of the resistor R16. The other end of the resistor R16 is grounded. Pin 3 of the amplifier U2 is electrically connected to the other end of the resistor R15.

[0008] Preferably, the filter includes a filter chip Z. One end of the filter chip Z is electrically connected to pin 3 of the amplifier U2. The other end of the filter chip Z is electrically connected to the other end of the resistor R8.

[0009] Preferably, the model of the comparator U1 is MC33202DR2G.

[0010] Preferably, the suppression diode TVS1 is a transient voltage suppression diode, and the transient suppression diode has the characteristics of fast response speed, large transient power, low leakage current, and small breakdown voltage deviation.

[0011] Preferably, the model of the filter chip Z is UAS42.

[0012] Compared with the existing technology, the beneficial effects of the present utility model are as follows:

[0013] When sampling the input signal, the present utility model performs delayed sampling to construct an offset of the input signal, thereby equivalently eliminating the situation of inherent delay. In addition, in cooperation with the subsequent integration of the filter for the electrical signal, the electrical signal input to the current-voltage comparison unit is a stable electrical signal, thus improving the accuracy of the comparison output result and meeting the usage requirements. Description of the Drawings

[0014] Figure 1 It is a connection block diagram of a comparison circuit of an ultrasonic level sensor proposed by the present utility model;

[0015] Figure 2 It is a circuit diagram of the current-voltage comparison unit of a comparison circuit of an ultrasonic level sensor proposed by the present utility model;

[0016] Figure 3 It is a circuit diagram of the connection between the delayed sampling circuit and the filter of a comparison circuit of an ultrasonic level sensor proposed by the present utility model. Detailed Embodiments

[0017] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments.

[0018] Refer to Figures 1-3 , a comparison circuit of an ultrasonic level sensor, including a current-voltage comparison unit. The current-voltage comparison unit is electrically connected to a filter and a signal output port. The filter is electrically connected to a delayed sampling circuit, and the delayed sampling circuit is electrically connected to a signal input port;

[0019] The current-voltage comparison unit includes a comparator U1. The model of the comparator U1 is MC33202DR2G. One end of the pin 1 of the comparator U1 is electrically connected to one end of a resistor R2, one end of a resistor R1, and one end of a capacitor C1. The other ends of the resistor R1 and the capacitor C1 are both grounded. The other end of the resistor R2 is electrically connected to one end of a resistor R10 and one end of a resistor R9. The other end of the resistor R10 is electrically connected to the negative pole of a suppression diode TVS1. The positive pole of the suppression diode TVS1 and the other end of the resistor R9 are both grounded. The suppression diode TVS1 is a transient voltage suppression diode, and the transient suppression diode has the characteristics of fast response speed, large transient power, low leakage current, and small breakdown voltage deviation;

[0020] Pin 2 of comparator U1 is electrically connected to one end of resistor R2, one end of resistor R3, one end of resistor R4, and one end of capacitor C2. The other end of resistor R2, the other end of resistor R4, the other end of capacitor C2, and pin 3 of comparator U1 are all grounded. Pin 5 of comparator U1 is electrically connected to the other end of resistor R3. Pin 5 of comparator U1 is also electrically connected to pin 2 of triode Q1. Pin 3 of triode Q1 is electrically connected to one end of resistor R4 and one end of capacitor C2. Pin 1 of triode Q1 is electrically connected to one end of resistor R6, one end of resistor R5, and one end of resistor R7. The other end of resistor R7 is electrically connected to high-frequency VCC1. The other end of resistor R5 is electrically connected to TX2 output port. The other end of resistor R6 is electrically connected to RX2 output port. Pin 4 of comparator U1 is electrically connected to one end of resistor R8 and one end of capacitor C3. The other end of capacitor C3 is grounded;

[0021] The delay sampling circuit includes amplifier U2. Pin 1 of amplifier U2 is electrically connected to one end of resistor R12. The other end of resistor R12 is electrically connected to one end of resistor R11 and one end of resistor R13. The other end of resistor R13 and pin 2 of amplifier U2 are both grounded. The other end of resistor R11 is electrically connected to one end of delay relay KT. The other end of delay relay KT is electrically connected to the signal input port. Delay relay KT is used to delay the input signal and construct an offset of the input signal to equivalently eliminate the situation of inherent delay;

[0022] Pin 2 of amplifier U2 is also electrically connected to one end of resistor R14. One end of resistor R14 is also grounded. The other end of resistor R14 is electrically connected to one end of resistor R15 and one end of resistor R16. One end of resistor R15 is also electrically connected to one end of resistor R16. The other end of resistor R16 is grounded. Pin 3 of amplifier U2 is electrically connected to the other end of resistor R15; The filter includes filter chip Z, and the model of filter chip Z is UAS42. One end of filter chip Z is electrically connected to pin 3 of amplifier U2. The other end of filter chip Z is electrically connected to the other end of resistor R8;

[0023] The utility model performs delay sampling when sampling the input signal, constructs an offset of the input signal, and equivalently eliminates the situation of inherent delay. In addition, it cooperates with the subsequent filter to integrate the electrical signal, so that the electrical signal input to the current-voltage comparison unit is a stable electrical signal, thereby improving the accuracy of the comparison output result and meeting the use requirements.

[0024] Working principle: When in use, an electrical signal is input into the delay sampling circuit through the signal input port. The delay relay KT in the delay sampling circuit is used to control the output time of the signal, construct an offset of the input signal, and equivalently eliminate the inherent delay. At the same time, cooperate with the amplifier U2 to amplify the delayed electrical signal and input it into the filter. The filter integrates the electrical signal and inputs it into the current-voltage comparison unit. The comparator U1 in the current-voltage comparison unit compares and judges the input current and voltage, and outputs the comparison result. The electrical signal is made stable by the method of delaying and integrating before comparison, so as to improve the accuracy of the comparison output result.

[0025] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A comparison circuit for an ultrasonic level sensor, including a current-voltage comparison unit, characterized in that, The current-voltage comparison unit is electrically connected to a filter and a signal output port. The filter is electrically connected to a delay sampling circuit, and the delay sampling circuit is electrically connected to a signal input port; The current-voltage comparison unit includes a comparator U1. One end of a resistor R2, one end of a resistor R1, and one end of a capacitor C1 are electrically connected to pin 1 of the comparator U1. The other ends of the resistor R1 and the capacitor C1 are both grounded. The other end of the resistor R2 is electrically connected to one end of a resistor R10 and one end of a resistor R9. The other end of the resistor R10 is electrically connected to the negative electrode of a suppression diode TVS1. The positive electrode of the suppression diode TVS1 and the other end of the resistor R9 are both grounded. One end of a resistor R2, one end of a resistor R3, one end of a resistor R4, and one end of a capacitor C2 are electrically connected to pin 2 of the comparator U1. The other end of the resistor R2, the other end of the resistor R4, the other end of the capacitor C2, and pin 3 of the comparator U1 are all grounded. Pin 5 of the comparator U1 is electrically connected to the other end of the resistor R3. Pin 5 of the comparator U1 is also electrically connected to pin 2 of a triode Q1. Pin 3 of the triode Q1 is electrically connected to one end of the resistor R4 and one end of the capacitor C2. One end of a resistor R6, one end of a resistor R5, and one end of a resistor R7 are electrically connected to pin 1 of the triode Q1. The other end of the resistor R7 is electrically connected to a high-frequency VCC1. The other end of the resistor R5 is electrically connected to a TX2 output port. The other end of the resistor R6 is electrically connected to an RX2 output port. One end of a resistor R8 and one end of a capacitor C3 are electrically connected to pin 4 of the comparator U1. The other end of the capacitor C3 is grounded.

2. The comparison circuit of an ultrasonic level sensor according to claim 1, wherein The delay sampling circuit includes an amplifier U2. One end of a resistor R12 is electrically connected to pin 1 of the amplifier U2. The other end of the resistor R12 is electrically connected to one end of a resistor R11 and one end of a resistor R13. The other end of the resistor R13 and pin 2 of the amplifier U2 are both grounded. The other end of the resistor R11 is electrically connected to one end of a delay relay KT. The other end of the delay relay KT is electrically connected to the signal input port. One end of a resistor R14 is also electrically connected to pin 2 of the amplifier U2. One end of the resistor R14 is also grounded. The other end of the resistor R14 is electrically connected to one end of a resistor R15 and one end of a resistor R16. One end of the resistor R15 is also electrically connected to one end of the resistor R16. The other end of the resistor R16 is grounded. Pin 3 of the amplifier U2 is electrically connected to the other end of the resistor R15.

3. The comparison circuit of an ultrasonic level sensor according to claim 2, characterized in that, The filter includes a filter chip Z. One end of the filter chip Z is electrically connected to pin 3 of the amplifier U2. The other end of the filter chip Z is electrically connected to the other end of the resistor R8.

4. The comparison circuit of an ultrasonic liquid level sensor according to claim 1, characterized in that The model of the comparator U1 is MC33202DR2G.

5. The comparison circuit of an ultrasonic level sensor according to claim 1, characterized in that, The suppression diode TVS1 is a transient voltage suppression diode.

6. The comparison circuit of an ultrasonic level sensor according to claim 3, characterized in that, The model of the filter chip Z is UAS42.

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