Liquid leakage detection device with photoelectric alarm output

Abstract

The utility model relates to sensor technical field, concretely is a kind of liquid leakage detection device with photoelectric alarm output, the detection device is equipped with power module, liquid leakage detection module, signal processing module and photoelectric alarm module, the liquid leakage detection module is equipped with acquisition circuit, the acquisition circuit is used to contact the liquid of the area to be detected and exports liquid leakage detection signal;Signal processing module is equipped with comparison circuit, and the input end of comparison circuit is electrically connected with the output end of acquisition circuit;By setting multiple electrostatic protection circuit including TVS protection tube and diode in power module, and setting clamping protection circuit consisting of protection diode and stabilivolt in signal acquisition module, effectively inhibit the external static electricity and overvoltage interference from power end and signal input end, ensure that core comparison circuit can obtain stable, clean input signal, to greatly reduce the false alarm rate and failure rate of device, make it applicable to complex industrial environment.

Description

Technical Field

[0001] This utility model relates to the field of sensor technology, and in particular to a leak detection device with photoelectric alarm output. Background Technology

[0002] Liquid leaks are a significant safety hazard that must be strictly prevented in industrial production, data centers, precision instrument rooms, and water / liquid supply systems in large buildings. If a leak is not detected and addressed promptly, it can lead to equipment short circuits, product failure, data loss, or even fires and other safety incidents.

[0003] Existing leak detection devices typically use sensor probes to detect liquid and output detection signals through circuitry. However, these devices still have some shortcomings in practical applications. First, their detection circuits, especially the front-end signal acquisition section, are weakly resistant to interference from environmental factors such as static electricity and voltage fluctuations, easily leading to false alarms or missed alarms, thus requiring improved reliability. Second, many devices have a limited alarm output format, possibly only providing simple level signals with limited driving capabilities. This makes it difficult to directly drive actuators requiring large currents, such as relays and solenoid valves, and also fails to provide intuitive on-site status indications, limiting their integration and application in complex automation systems.

[0004] Therefore, this application aims to provide a leakage detection device with strong anti-interference ability, high output driving capability and on-site photoelectric alarm function, so as to solve the problems of insufficient reliability and single output function in the prior art. Utility Model Content

[0005] The main objective of this invention is to provide a leak detection device with photoelectric alarm output to solve the problems raised in related technologies.

[0006] To achieve the above objectives, according to one aspect of this utility model, a leak detection device with photoelectric alarm output is provided. The detection device includes a power supply module, a leak detection module, a signal processing module, and a photoelectric alarm module. The leak detection module includes a data acquisition circuit, which contacts the liquid in the area to be detected and outputs a leak detection signal. The signal processing module includes a comparison circuit, the input of which is electrically connected to the output of the data acquisition circuit, for receiving the leak detection signal from the data acquisition circuit and performing signal conversion processing. The photoelectric alarm module includes a signal output circuit, the input of which is electrically connected to the output of the comparison circuit, for receiving the signal processed by the comparison circuit and issuing a photoelectric alarm prompt. The power supply module includes a power supply circuit, which is electrically connected to the data acquisition circuit, the comparison circuit, and the signal output circuit, providing operating voltage to each circuit.

[0007] Furthermore, the power supply circuit includes an input socket P2, two diodes, two voltage regulators, a power chip LDO1, several capacitors, and several resistors. The diodes are used for electrostatic protection, and the power chip LDO1 is used for voltage regulation.

[0008] Furthermore, the acquisition circuit includes an input terminal P1, a Zener diode D7, a TVS protection diode U4, a diode D6, and multiple resistors. The Zener diode D7 is connected in reverse series in the circuit to stabilize the voltage. Pin 1 of the input terminal P1 is connected to the IN signal, and pin 2 is grounded and connected to the leakage sensor to input the signal from the external device into the acquisition circuit. When the probe of the leakage sensor comes into contact with the liquid, it generates an electrical signal and inputs it into the circuit through the "IN" terminal of P1.

[0009] Furthermore, the multiple resistors in the acquisition circuit are resistors R7, R19, R15, and R20. Resistor R7 is a pull-up resistor, with one end connected to the +5V power supply and the other end connected to the IN signal, used to pull the voltage of the IN signal up to +5V. Resistor R19 is a current-limiting resistor, connected in series in the transmission path of the IN signal, used to limit the current. Resistors R15 and R20 are both 0Ω resistors, acting as wires to lead out the processed IN signal and connect it to the comparator circuit.

[0010] Furthermore, the comparison circuit includes comparator D5 and multiple resistors. The comparator D5 is a dual-channel voltage comparator, which internally contains two independent comparators D5A and D5B, used to compare the voltage of the input signal and output a digital level.

[0011] Furthermore, the multiple resistors in the comparator circuit are resistors R4, R5, R21, R22, R6, R12, and R20. The non-inverting input of comparator D5A is connected to the reference voltage divided by resistors R4 and R5, and the inverting input is connected to the signal composed of resistor R6 and +5V. Pin VCC is connected to the +5V power supply; pin 4 is grounded, and pin 1 is the output terminal. The non-inverting input of comparator D5B is connected to the signal divided by resistors R21 and R22, and the inverting input is connected to the signal composed of resistor R20 and +5V. Pin 7 is the output terminal.

[0012] Furthermore, the signal output circuit includes five transistors, an LED, and several resistors, namely resistors R2, R3, R8, R9, R10, R11, R13, R14, R16, R17, R18, and R26, and the transistors are transistors Q1, Q2, Q3, Q4, and Q5.

[0013] Furthermore, one end of the LED is connected to "OUT", and the other end is grounded through resistor R13. The gate of transistor Q5 is connected to the junction of resistors R13 and R16, the source is grounded, the drain is connected to the base of transistor Q2, the base of transistor Q2 is connected to the drain of transistor Q5, the collector is connected to the positive terminal of the LED through resistor R9, and the emitter is grounded through resistor R10. At the same time, the collector is also connected to a +5V power supply, forming an LED driving circuit. The gate of transistor Q3 is connected to the emitter of transistor Q2, the source is grounded, and the drain outputs an "OUT" signal through resistor R11. The gate of transistor Q4 is connected to the junction of resistors R2 and R3, the source is grounded, and the drain is connected to the base of transistor Q1. The base of transistor Q1 is connected to the drain of transistor Q4, and the collector outputs "NPN OUT" through the junction of resistors R17 and R18. The emitter is grounded.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1. By setting up a multi-electrostatic protection circuit including a TVS protection tube and a diode in the power supply module, and a clamping protection circuit consisting of a protection diode and a Zener diode in the signal acquisition module, external electrostatic and overvoltage interference from the power supply terminal and the signal input terminal is effectively suppressed, ensuring that the core comparator circuit can obtain a stable and clean input signal, thereby greatly reducing the false alarm rate and failure rate of the device, making it suitable for complex industrial environments.

[0016] 2. The signal output module employs a composite driver circuit composed of multiple transistors. This circuit amplifies the weak electrical signal output from the comparator circuit, generating a strong electrical control signal with sufficient driving capability. This signal can directly drive external actuators such as relays and solenoid valves, enabling automatic valve closure or activation of audible and visual alarms. Simultaneously, the integrated LEDs provide intuitive on-site photoelectric alarm prompts, facilitating rapid personnel location and response, thus enhancing the overall system's automation level and emergency response efficiency. Attached Figure Description

[0017] Figure 1 This is the overall circuit diagram of this utility model;

[0018] Figure 2 This is the power supply circuit diagram of this utility model;

[0019] Figure 3 This is the circuit diagram for the data acquisition of this utility model;

[0020] Figure 4 This is a comparison circuit diagram of the present invention;

[0021] Figure 5 This is the signal output circuit diagram of this utility model;

[0022] Figure 6 This is a flowchart of the present invention. Detailed Implementation

[0023] To further illustrate the technical means and effects adopted by this utility model in order to achieve the intended utility model purpose, the following detailed description of the specific implementation methods, structure, features and effects of this utility model is provided in conjunction with the accompanying drawings and preferred embodiments.

[0024] This embodiment provides a leak detection device with photoelectric alarm output, such as... Figure 1 As shown, the detection device includes a power supply module, a leak detection module, a signal processing module, and a photoelectric alarm module. The leak detection module contains a data acquisition circuit that contacts the liquid in the detection area and outputs a leak detection signal. The signal processing module contains a comparison circuit whose input is electrically connected to the output of the data acquisition circuit. This circuit receives the leak detection signal from the data acquisition circuit and performs signal conversion processing. The photoelectric alarm module contains a signal output circuit whose input is electrically connected to the output of the comparison circuit. This circuit receives the processed signal from the comparison circuit and issues a photoelectric alarm. The power supply module contains a power supply circuit that is electrically connected to the data acquisition circuit, comparison circuit, and signal output circuit. The power supply circuit provides operating voltage to each circuit. The working process of this leak detection device is as follows: Figure 6 As shown.

[0025] like Figure 2 As shown, the power supply circuit includes an input socket P2, two diodes, two voltage regulators, a power supply chip LDO1, several capacitors, and several resistors. The diodes are used for electrostatic discharge (ESD) protection, and the power supply chip LDO1 is used for voltage regulation. The two diodes in the power supply circuit are diodes D1 and D2, and the two voltage regulators are TVS diodes U1 and U2. The input socket P2 is a 3-pin connector, with pins 1, 2, and 3 connected to the corresponding pins of TVS diode U2, and pin 4 connected to the +24V power supply. The anode of diode D1 is grounded, and the cathode is connected to +24V. The anode of diode D2 is grounded, and the cathode is connected to the pin of TVS diode U2 to suppress ESD and protect the circuit. The NPN OUT pin of TVS diode U2 is the output terminal, connected to resistor R1. The other end of resistor R1 is connected to the anode of capacitor C1 and capacitor C2. The cathodes of capacitors C1 and C2 are both grounded. The GND pin of the power chip LDO1 is grounded, and the OUT pin outputs a +5V voltage, which is connected to the positive terminals of capacitors C3 and C4. The negative terminals of capacitors C3 and C4 are both grounded.

[0026] The working principle of the power supply circuit is as follows:

[0027] Input socket P2 connects to a +24V external power supply. After initial electrostatic discharge (ESD) protection by diodes D1 and D2, the voltage is filtered by resistors R1, capacitors C1 and C2, and then regulated to +5V by the LDO1 power supply chip, ultimately powering the subsequent circuits. This end-to-end ESD protection and power filtering / regulation design ensures the circuit's reliability in complex environments, representing a typical functional module of "power supply + ESD protection" in electronic equipment.

[0028] like Figure 3 As shown, the acquisition circuit includes input terminal P1, Zener diode D7, TVS protection diode U4, diode D6, and multiple resistors. Zener diode D7 is connected in reverse series in the circuit to stabilize the voltage, keeping the signal voltage near its regulated value, further suppressing overvoltage interference, and ensuring the input voltage of subsequent circuits is within a safe range. Input terminal P1 is an external interface, model WF-1A200A2P, with two pins. Pin 1 of input terminal P1 is connected to the IN signal, and pin 2 is grounded and connected to the leak sensor, used to input signals from external devices into the acquisition circuit. When the leak sensor probe comes into contact with liquid, it generates an electrical signal and inputs it to the circuit through the "IN" terminal of P1. Diode D6 is a protection diode, connected in parallel between the IN signal and GND. When an external input signal experiences an overvoltage higher than the power supply or lower than ground, the diode conducts, clamping the IN voltage within a safe range, thereby protecting subsequent circuits from voltage surges.

[0029] The acquisition circuit contains resistors R7, R19, R15, and R20. Resistor R7 is a pull-up resistor, with one end connected to the +5V power supply and the other end connected to the IN signal. It is used to pull the voltage of the IN signal up to +5V to ensure signal stability and avoid misjudgments caused by floating levels. Resistor R19 is a current-limiting resistor, connected in series in the transmission path of the IN signal to limit the current and prevent excessive current from damaging the device. Resistors R15 and R20 are both 0Ω resistors, acting as wires to lead out the processed IN signal and connect it to the comparator circuit.

[0030] like Figure 4 As shown, the comparison circuit includes comparator D5 and multiple resistors. Comparator D5 is a dual-channel voltage comparator, which contains two independent comparators D5A and D5B, used to compare the voltage of the input signal and output a digital level.

[0031] The comparator circuit uses resistors R4, R5, R21, R22, R6, R12, and R20. Resistor R12 is a pull-up resistor connected between +5V and OUT. Since comparator D5A has an open-collector output, a pull-up resistor is required to output a high level. Therefore, the output signals of comparators D5A and D5B are integrated and led out from the OUT terminal for transmission to the subsequent circuit. The non-inverting input of comparator D5A is connected to a reference voltage divided by resistors R4 and R5, and the inverting input is connected to a signal composed of resistor R6 and +5V. Pin VCC is connected to the +5V power supply; pin 4 is grounded; and pin 1 is the output terminal. The output level is determined by the comparison result of the voltages IN+ and IN-. If IN+ > IN-, the output level is determined by the voltage comparison result. N- indicates a high output level; conversely, a low output level. The non-inverting input of comparator D5B is connected to a signal divided by resistors R21 and R22 (both 20KΩ), resulting in a reference voltage of approximately +2.5V. The inverting input is connected to a signal composed of resistor R20 and +5V (51Ω), which acts as a current limiter / voltage divider. Pin 7 is the output, and the output level is determined by the voltage comparison between IN+ and IN-. If IN+ > IN-, the output is high; otherwise, it is low. The comparator circuit is a dual-channel voltage comparison and signal integration circuit. It uses two internal comparators, D5A and D5B, to compare the voltages of different input signals. The comparison results are then integrated through pull-up resistor R12 and output from the OUT terminal, enabling level detection and logic output for multiple signals.

[0032] like Figure 5 As shown, the signal output circuit includes five transistors, LEDs, and several resistors: R2, R3, R8, R9, R10, R11, R13, R14, R16, R17, R18, and R26. The transistors are Q1, Q2, Q3, Q4, and Q5.

[0033] One end of the LED is connected to "OUT", and the other end is grounded through resistor R13. The gate of transistor Q5 is connected to the junction of resistors R13 and R16, the source is grounded, the drain is connected to the base of transistor Q2, the base of transistor Q2 is connected to the drain of transistor Q5, the collector is connected to the positive terminal of the LED through resistor R9, and the emitter is grounded through resistor R10. The collector is also connected to a +5V power supply, forming the LED driver circuit. The gate of transistor Q3 is connected to the emitter of transistor Q2, the source is grounded, and the drain outputs the "OUT" signal through resistor R11. The gate of transistor Q4 is connected to the junction of resistors R2 and R3, the source is grounded, and the drain is connected to the base of transistor Q1. The base of transistor Q1 is connected to the drain of transistor Q4, and the collector outputs "NPN OUT" through the junction of resistors R17 and R18. The emitter is grounded.

[0034] The LED and resistor R13 form a status indicator circuit. Resistors R9 and R10 are current-limiting resistors for the LED. When there is an "OUT" signal, the LED lights up, clearly displaying the circuit's operating status. Transistors Q2 and Q5 form a composite driver circuit. Transistor Q5 acts as a switch, controlling the conduction of transistor Q2; after transistor Q2 is turned on, it drives the LED and simultaneously participates in signal amplification and transmission. Transistor Q3 acts as a power switch, controlling the "OUT" signal output. Resistor R11 is a current-limiting resistor, and resistor R14 is a gate pull-down resistor for transistor Q3, ensuring reliable cutoff when there is no signal. Resistors R17 and R18 are pull-up resistors, providing different voltage range driving capabilities for "OUT," adaptable to +5V or +24V subsequent circuits. Resistor R2 is a current-limiting resistor, and resistor R3 is a gate pull-down resistor for transistor Q4. Transistor Q4 acts as a switch, receiving the "OUT" signal and amplifying the current to provide drive capability for subsequent circuits. Transistors Q1 and Q4 form a composite drive circuit. Transistor Q4 controls the conduction of transistor Q1, and after transistor Q1 is turned on, it outputs a signal from "NPN OUT". Resistor R26 is a base pull-up resistor for transistor Q1, ensuring a stable base level for transistor Q1; simultaneously, resistors R17 and R18 provide a +5V or +24V pull-up option for "NPN OUT".

[0035] When leakage occurs:

[0036] When the leak sensor probe contacts the liquid, a conductive path is formed, generating an electrical signal that is input to the comparator circuit via the IN pin. Diodes D4 and D6 clamp the signal to prevent overvoltage, while Zener diode D7 further suppresses interference, ensuring a stable input signal. Resistor R7 is a pull-up resistor, pulling the IN level to +5V when there is no leak, ensuring a signal reference. Resistor R19 is a current-limiting resistor, limiting the signal current and protecting subsequent stages. Comparator D5 compares the acquired leak signal with a reference voltage and outputs a digital level to determine if a leak has occurred. Comparator D5A is connected to the reference voltage obtained by the voltage divider between resistors R4 and R5. The IN pin of comparator D5A is connected to the leak acquisition signal. If the acquired signal voltage is greater than the reference voltage, comparator D5A outputs a high level; otherwise, it outputs a low level. Comparator D5B is connected to the reference voltage obtained by the voltage divider between resistors R21 and R22. The IN pin of comparator D5B is connected to the leak acquisition signal. If the acquired signal voltage is greater than the reference voltage, comparator D5B outputs a high level; otherwise, it outputs a low level, achieving dual-channel redundancy judgment and improving reliability. When the comparator circuit outputs a leakage signal, transistors Q5 and Q2 conduct, and the LED lights up to visually indicate the leakage. At the same time, transistors Q1 and Q4 amplify the weak signal from the comparator circuit and output strong control signals from OUT and NPN OUT, which can drive relays, solenoid valves, etc., to realize actions such as valve closure and audible and visual alarms after leakage.

[0037] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A leakage detection device with photoelectric alarm output, wherein the detection device comprises a power supply module, a leakage detection module, a signal processing module, and a photoelectric alarm module, characterized in that, The leakage detection module includes a data acquisition circuit that contacts the liquid in the detection area and outputs a leakage detection signal. The signal processing module includes a comparison circuit whose input is electrically connected to the output of the data acquisition circuit. This comparison circuit receives the leakage detection signal from the data acquisition circuit and performs signal conversion processing. The photoelectric alarm module includes a signal output circuit whose input is electrically connected to the output of the comparison circuit. This signal output circuit receives the processed signal from the comparison circuit and issues a photoelectric alarm. The power supply module includes a power supply circuit that is electrically connected to the data acquisition circuit, the comparison circuit, and the signal output circuit. This power supply circuit provides operating voltage to each circuit.

2. The leakage detection device with photoelectric alarm output according to claim 1, characterized in that, The power supply circuit includes an input socket P2, two diodes, two voltage regulators, a power chip LDO1, several capacitors, and several resistors. The diodes are used for electrostatic protection, and the power chip LDO1 is used for voltage regulation.

3. The leakage detection device with photoelectric alarm output according to claim 1, characterized in that, The acquisition circuit includes an input terminal P1, a Zener diode D7, a TVS protection diode U4, a diode D6, and multiple resistors. The Zener diode D7 is connected in reverse series in the circuit to stabilize the voltage. Pin 1 of the input terminal P1 is connected to the IN signal, and pin 2 is grounded and connected to the leakage sensor. This is used to input signals from external devices into the acquisition circuit. When the probe of the leakage sensor comes into contact with liquid, it generates an electrical signal and inputs it into the circuit through the "IN" terminal of P1.

4. The leakage detection device with photoelectric alarm output according to claim 3, characterized in that, The acquisition circuit contains resistors R7, R19, R15, and R20. Resistor R7 is a pull-up resistor, with one end connected to the +5V power supply and the other end connected to the IN signal, used to pull the voltage of the IN signal up to +5V. Resistor R19 is a current-limiting resistor, connected in series in the transmission path of the IN signal, used to limit the current. Resistors R15 and R20 are both 0Ω resistors, acting as wires to lead out the processed IN signal and connect it to the comparator circuit.

5. The leakage detection device with photoelectric alarm output according to claim 1, characterized in that, The comparison circuit includes comparator D5 and multiple resistors. Comparator D5 is a dual-channel voltage comparator, which contains two independent comparators D5A and D5B, used to compare the voltage of the input signal and output a digital level.

6. The leakage detection device with photoelectric alarm output according to claim 5, characterized in that, The comparator circuit has multiple resistors R4, R5, R21, R22, R6, R12, and R20. The non-inverting input of comparator D5A is connected to a reference voltage divided by resistors R4 and R5, and the inverting input is connected to a signal composed of resistor R6 and +5V. Pin VCC is connected to the +5V power supply; pin 4 is grounded, and pin 1 is the output. The non-inverting input of comparator D5B is connected to a signal divided by resistors R21 and R22, and the inverting input is connected to a signal composed of resistor R20 and +5V. Pin 7 is the output.

7. The leakage detection device with photoelectric alarm output according to claim 1, characterized in that, The signal output circuit includes five transistors, an LED, and several resistors, namely resistors R2, R3, R8, R9, R10, R11, R13, R14, R16, R17, R18, and R26. The transistors are Q1, Q2, Q3, Q4, and Q5.

8. The leakage detection device with photoelectric alarm output according to claim 7, characterized in that, One end of the LED is connected to "OUT", and the other end is grounded through resistor R13. The gate of transistor Q5 is connected to the junction of resistors R13 and R16, the source is grounded, the drain is connected to the base of transistor Q2, the base of transistor Q2 is connected to the drain of transistor Q5, the collector is connected to the positive terminal of the LED through resistor R9, and the emitter is grounded through resistor R10. The collector is also connected to a +5V power supply, forming an LED driver circuit. The gate of transistor Q3 is connected to the emitter of transistor Q2, the source is grounded, and the drain outputs an "OUT" signal through resistor R11. The gate of transistor Q4 is connected to the junction of resistors R2 and R3, the source is grounded, and the drain is connected to the base of transistor Q1. The base of transistor Q1 is connected to the drain of transistor Q4, and the collector outputs "NPN OUT" through the junction of resistors R17 and R18. The emitter is grounded.

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