Circuit for detecting state of electromagnetic type gas emergency cut-off valve

Abstract

The utility model discloses a circuit for detecting the state of an electromagnetic gas emergency cut-off valve. The circuit comprises an LC parallel resonant circuit, a passive low-pass filter circuit and a hysteresis voltage comparison circuit, the LC parallel resonant circuit comprises a coil Lx, a first capacitor C1, a second capacitor C2, a third capacitor C3, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5 and a first comparator U1B, and the passive low-pass filter circuit comprises a sixth resistor R6 and a fourth capacitor C4. The hysteresis voltage comparator circuit comprises a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10 and a second comparator U1A.

Description

Technical Field

[0001] The utility model belongs to the field of gas valve detection, and in particular relates to a detection circuit for the state of an electromagnetic gas emergency cut-off valve. Background Art

[0002] Electromagnetic gas emergency shut-off valve, also known as solenoid valve, is a safety emergency shut-off device for gas pipelines. It can be connected to the gas leak alarm system, or to the fire protection and other intelligent alarm controller terminal modules, etc., to achieve on-site or remote automatic or manual shut-off of the gas source.

[0003] Electromagnetic gas emergency shut-off valves are generally divided into industrial and commercial use and household use according to their uses. Real-time online detection of the valve's open or shut-off state or open circuit or short circuit state has always been a potential demand. Gas emergency shut-off valves for industrial and commercial use are generally large in size and high in cost. Reed switches or other physical switching devices can be installed on the valve body for detection of the state. Gas emergency shut-off valves for household use are limited by cost and size, and it is difficult to install detection components. However, since gas emergency shut-off valves for household use are difficult to achieve the same comprehensive daily maintenance and detection as industrial and commercial gas emergency shut-off valves, the demand for real-time online status detection is more urgent. It is understood that no related products on the market have yet achieved this function. Utility Model Content

[0004] In order to overcome the shortcomings of the prior art, in summary, to solve this defect, the utility model patent provides a detection circuit for the state of an electromagnetic gas emergency shut-off valve, including an LC resonant circuit and a waveform shaping circuit.

[0005] In order to solve the above problems existing in the prior art, the technical solution adopted by the utility model is:

[0006] A detection circuit for the state of an electromagnetic gas emergency shut-off valve comprises an LC parallel resonant circuit, a passive low-pass filter circuit and a hysteresis voltage comparison circuit.

[0007] The LC parallel resonant circuit includes a coil Lx, a first capacitor C1, a second capacitor C2, a third capacitor C3, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5 and a first comparator U1B. The coil Lx is connected in parallel with the first capacitor C1, a fifth pin of the first comparator U1B is grounded through the third resistor R3, a sixth pin of the first comparator U1B is grounded through the third capacitor C3, a seventh pin of the first comparator U1B is connected to the positive electrode of the power supply through the fourth resistor R4, and one end of the second capacitor C2 is connected to the positive electrode of the power supply. The first resistor R1 is connected to the fifth pin of the first comparator U1B, the other end of the second capacitor R2 is grounded through the first capacitor C1, one end of the first resistor R1 is connected to the positive electrode of the power supply, the other end of the first resistor R1 is connected to the fifth pin of the first comparator U1B, one end of the second resistor R2 is connected to the fifth pin of the first comparator U1B, the other end of the second resistor R2 is connected to the seventh pin of the first comparator U1B, one end of the fifth resistor is connected to the sixth pin of the first comparator U1B, and the other end of the fifth resistor is connected to the seventh pin of the first comparator U1B.

[0008] The passive low-pass filter circuit includes a sixth resistor R6 and a fourth capacitor C4. One end of the sixth resistor R6 is connected to the seventh pin of the first comparator U1B, and the other end of the sixth resistor R6 is grounded through the fourth capacitor C4.

[0009] The hysteresis voltage comparison circuit includes a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10 and a second comparator U1A, wherein a first pin of the second comparator U1A is connected to the positive electrode of the power supply through the first resistor R7, a second pin of the second comparator U1A is grounded through a fourth capacitor C4, a third pin of the second comparator U1A is connected to the positive electrode of the power supply through an eighth capacitor R8, a third pin of the second comparator U1A is grounded through a ninth resistor R9, a fourth pin of the second comparator U1A is grounded, an eighth pin of the second comparator U1A is connected to the positive electrode of the power supply, one end of the tenth resistor R10 is connected to the third pin of the second comparator U1A, and the other end of the tenth resistor R10 is connected to the first pin of the second comparator U1A.

[0010] The beneficial effects of the utility model are:

[0011] The utility model is applied to household combustible gas detectors to realize real-time online monitoring of the status of the electromagnetic gas emergency shut-off valve, timely discover abnormal valve status or line faults, and send out reminder signals or upload to the supervision platform through the network to eliminate abnormalities or faults in time, so as to more effectively protect the lives and property of the people. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a circuit diagram of the utility model. DETAILED DESCRIPTION

[0013] The utility model will be further described below in conjunction with the accompanying drawings and the accompanying drawings.

[0014] In order to more clearly understand the above-mentioned purpose, features and advantages of the utility model, the utility model is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0015] The terms “first”, “second”, “third”, etc. are merely used for distinguishing descriptions and should not be understood as indicating or implying relative importance.

[0016] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0017] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0018] Embodiment 1:

[0019] like Figure 1 As shown, a detection circuit for the state of an electromagnetic gas emergency shut-off valve includes an LC parallel resonant circuit, a passive low-pass filter circuit and a hysteresis voltage comparison circuit.

[0020] The LC parallel resonant circuit includes a coil Lx, a first capacitor C1, a second capacitor C2, a third capacitor C3, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5 and a first comparator U1B. The coil Lx is connected in parallel with the first capacitor C1, a fifth pin of the first comparator U1B is grounded through the third resistor R3, a sixth pin of the first comparator U1B is grounded through the third capacitor C3, a seventh pin of the first comparator U1B is connected to the positive electrode of the power supply through the fourth resistor R4, and one end of the second capacitor C2 is connected to the positive electrode of the power supply. The LC parallel resonant circuit is connected to the fifth pin of the first comparator U1B, the other end of the second capacitor R2 is grounded through the first capacitor C1, one end of the first resistor R1 is connected to the positive electrode of the power supply, the other end of the first resistor R1 is connected to the fifth pin of the first comparator U1B, one end of the second resistor R2 is connected to the fifth pin of the first comparator U1B, the other end of the second resistor R2 is connected to the seventh pin of the first comparator U1B, one end of the fifth resistor is connected to the sixth pin of the first comparator U1B, and the other end of the fifth resistor is connected to the seventh pin of the first comparator U1B. The LC parallel resonant circuit converts the change of inductance (i.e., coil Lx) in the electromagnetic gas emergency shut-off valve into a change of frequency for measurement.

[0021] The resonant frequency of the LC parallel resonant circuit is determined by Lx and C1, and the calculation formula is:

[0022]

[0023] C1 is a fixed value and the resonant frequency is determined by Lx.

[0024] The passive low-pass filter circuit includes a sixth resistor R6 and a fourth capacitor C4, one end of the sixth resistor R6 is connected to the seventh pin of the first comparator U1B, and the other end of the sixth resistor R6 is grounded through the fourth capacitor C4. The passive low-pass filter circuit can improve the accuracy of frequency measurement. The passive low-pass filter circuit is used to filter out high-frequency signals that enter the circuit. These signals are useless interference signals, which will cause deviations in the measurement results and affect the determination of the results.

[0025] To filter out the high-frequency burr signal output by the oscillation circuit, the low-pass filter cutoff frequency is:

[0026]

[0027] The hysteresis voltage comparison circuit includes a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10 and a second comparator U1A, wherein a first pin of the second comparator U1A is connected to the positive electrode of the power supply through the first resistor R7, a second pin of the second comparator U1A is grounded through a fourth capacitor C4, a third pin of the second comparator U1A is connected to the positive electrode of the power supply through an eighth capacitor R8, a third pin of the second comparator U1A is grounded through a ninth resistor R9, a fourth pin of the second comparator U1A is grounded, an eighth pin of the second comparator U1A is connected to the positive electrode of the power supply, one end of the tenth resistor R10 is connected to the third pin of the second comparator U1A, and the other end of the tenth resistor R10 is connected to the first pin of the second comparator U1A.

[0028] The hysteresis voltage comparison circuit is used to shape the waveform after low-pass filtering into a rectangular wave with steep rising and falling edges. The hysteresis voltage is calculated as follows:

[0029]

[0030] Note: “ / / ” indicates resistor parallel operation

[0031] The shaped waveform enters the single-chip microcomputer for frequency measurement, and then realizes the valve opening and closing state and the open circuit and short circuit fault state. The model of the single-chip microcomputer is CS32L010.

[0032] Specific working principle:

[0033] According to the different relative positions of the iron core inside the solenoid valve gas emergency shut-off valve, the inductance in the open valve state and the closed valve state are different. After passing through the above detection circuit, the measured frequencies are different. The frequency values ​​in the open valve state and the closed valve state are recorded. When the frequency value is within a certain range of the recorded open valve state frequency value, it is judged as an open valve state. When the frequency value is within a certain range of the recorded closed valve state frequency value, it is judged as a closed valve state. When the line is open-circuited, the resonance condition is destroyed, and the measured frequency is close to or equal to zero Hz, which is judged as an open-circuit fault. When the line is short-circuited, it is equivalent to Lx being extremely small. It can be seen from the formula that the resonant frequency will be much higher than the normal working frequency range, which can be judged as a short-circuit fault.

[0034] The present utility model is not limited to the above-mentioned optional implementation modes. Anyone can derive other various forms of products under the inspiration of the present utility model. However, no matter what changes are made in the shape or structure, all technical solutions that fall within the scope defined by the claims of the present utility model fall within the protection scope of the present utility model.

Claims

1. A detection circuit for the state of an electromagnetic gas emergency shut-off valve, characterized in that: It includes an LC parallel resonant circuit, a passive low-pass filter circuit and a hysteresis voltage comparison circuit; The LC parallel resonant circuit includes a coil Lx, a first capacitor C1, a second capacitor C2, a third capacitor C3, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5 and a first comparator U1B. The coil Lx is connected in parallel with the first capacitor C1, a fifth pin of the first comparator U1B is grounded through the third resistor R3, a sixth pin of the first comparator U1B is grounded through the third capacitor C3, a seventh pin of the first comparator U1B is connected to the positive electrode of the power supply through the fourth resistor R4, and one end of the second capacitor C2 is connected to the positive electrode of the power supply. The fifth pin of the first comparator U1B is connected, the other end of the second capacitor R2 is grounded through the first capacitor C1, one end of the first resistor R1 is connected to the positive electrode of the power supply, the other end of the first resistor R1 is connected to the fifth pin of the first comparator U1B, one end of the second resistor R2 is connected to the fifth pin of the first comparator U1B, the other end of the second resistor R2 is connected to the seventh pin of the first comparator U1B, one end of the fifth resistor R5 is connected to the sixth pin of the first comparator U1B, and the other end of the fifth resistor is connected to the seventh pin of the first comparator U1B; The passive low-pass filter circuit includes a sixth resistor R6 and a fourth capacitor C4, one end of the sixth resistor R6 is connected to the seventh pin of the first comparator U1B, and the other end of the sixth resistor R6 is grounded through the fourth capacitor C4; The hysteresis voltage comparison circuit includes a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10 and a second comparator U1A, wherein a first pin of the second comparator U1A is connected to the positive electrode of the power supply through the first resistor R7, a second pin of the second comparator U1A is grounded through a fourth capacitor C4, a third pin of the second comparator U1A is connected to the positive electrode of the power supply through an eighth capacitor R8, a third pin of the second comparator U1A is grounded through a ninth resistor R9, a fourth pin of the second comparator U1A is grounded, an eighth pin of the second comparator U1A is connected to the positive electrode of the power supply, one end of the tenth resistor R10 is connected to the third pin of the second comparator U1A, and the other end of the tenth resistor R10 is connected to the first pin of the second comparator U1A.

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