Methane detection circuit

Abstract

The utility model discloses a methane detection circuit, which comprises an acquisition circuit connected with a processor and used for transmitting methane data acquired by a sensor to the processor; the processor is used for controlling the on-off of a relay circuit according to the methane data; the signal output circuit is respectively connected with the processor and external equipment and is used for converting the output voltage value of the processor into current and outputting the current to the external equipment; the setting circuit is connected with the processor and is used for setting detection parameters; and the pilot loop is respectively connected with the relay circuit and external equipment and is used for controlling the on-off of a power supply of the external equipment based on the on-off of the relay circuit, so that the accuracy of methane detection under the mine can be improved, and the service life of the methane detection device can be prolonged.

Description

Technical Field

[0001] The utility model belongs to the technical field of methane detection, and in particular relates to a methane detection circuit. Background Art

[0002] Underground mine environments often contain explosive methane gas. As methane concentrations rise, the environment becomes increasingly dangerous, posing a significant threat to the lives of mine workers and equipment. Existing technologies typically detect methane using low-concentration methane sensors based on a carrier catalytic principle. These sensors consist of a methane cutoff meter host and a sensor. The sensor utilizes a thermal catalytic element to form a Whitworth bridge, a measuring arm composed of a carrier catalytic element and a pure carrier element, and an auxiliary arm composed of a metal film resistor. A voltage-stabilizing circuit provides a stable voltage for the bridge. The low-concentration methane sensors used in existing technologies are based on chemical reactions and react to similar gases, making them prone to false alarms. Furthermore, chemical reactions are sensitive to temperature, humidity, pressure, and gas. Consequently, low-concentration methane sensors often experience zero drift and require a short calibration cycle. Furthermore, the sensor and methane cutoff meter are two independent components, making the methane cutoff meter host susceptible to noise interference. The sensor's poor waterproofing results in a high frequency of damage.

[0003] Therefore, how to avoid interference from other equipment in the underground mine environment, improve the accuracy of methane detection and extend the life of the methane detection device are technical problems that need to be solved by those skilled in the art. Utility Model Content

[0004] The purpose of the present invention is to solve the technical problems in the prior art that methane detection is easily interfered with by other devices in the same environment, and has low accuracy and short lifespan. To this end, the present invention provides a methane detection circuit, which includes:

[0005] an acquisition circuit, connected to the processor, for transmitting the methane data collected by the sensor to the processor;

[0006] The processor is used to control the on and off of the relay circuit according to the methane data;

[0007] a signal output circuit, connected to the processor and an external device respectively, for converting the output voltage value of the processor into a current and outputting it to the external device;

[0008] A setting circuit, connected to the processor, for setting detection parameters;

[0009] The pilot circuit is connected to the relay circuit and the external device respectively, and is used to control the on and off of the power supply of the external device based on the on and off of the relay circuit.

[0010] Furthermore, the circuit also includes an alarm circuit, a digital tube circuit and a power supply circuit, and the power supply circuit is used to provide 3.3V power supply and 5V power supply.

[0011] Furthermore, the setting circuit specifically includes an infrared circuit and a key circuit, wherein:

[0012] The infrared circuit specifically includes: a VOUT pin of the infrared receiving circuit is connected to the VCC pin of the infrared receiver, an IN pin of the infrared receiving circuit is connected to the OUT pin of the infrared receiver, a VI N pin of the infrared receiving circuit is connected to a 3.3V power supply, an R_OUT pin of the infrared receiving circuit is connected to the PB10 pin of the processor, and a GND pin of the infrared receiver is grounded;

[0013] The key circuit specifically includes:

[0014] One end of the button S1 and one end of the resistor R3 are connected to the PC13 pin of the processor, one end of the button S2 and one end of the resistor R4 are connected to the PA11 pin of the processor, one end of the button S3 and one end of the resistor R5 are connected to the PC4 pin of the processor, one end of the button S4 and one end of the resistor R6 are connected to the PA12 pin of the processor, and the other end of the resistor R3, the other end of the resistor R4, the other end of the resistor R5 and the other end of the resistor R6 are all connected to a 5V power supply.

[0015] Furthermore, the setting circuit also includes a remote control circuit, which includes a chip MAX3485 and an RS485 signal processing circuit. The VCC pin of the chip MAX3485 is connected to the 1st pin of the RS485 signal processing circuit, the VCC pin of the MAX3485 is also grounded through a capacitor C2, the VCC pin of the MAX3485 is also connected to a 5V power supply, the B pin of the chip MAX3485 is connected to the 2nd pin of the RS485 signal processing circuit, the A pin of the MAX3485 is connected to the 3rd pin of the RS485 signal processing circuit, the GND pin of the MAX3485 is grounded, the RO pin of the MAX3485 is connected to the PA3 pin of the processor, the RE pin of the MAX3485 is connected to the PA1 pin of the processor, the DE pin of the MAX3485 is connected to the PA1 pin of the processor, the DI pin of the MAX3485 is connected to the PA2 pin of the processor, and the RS485 signal processing circuit is also connected to the RS485A communication interface and the RS485B communication interface respectively.

[0016] Furthermore, the acquisition circuit includes a sensor isolation circuit and a sensor, specifically including:

[0017] Pin 1 of the sensor isolation circuit is connected to the VCC pin of the sensor, pin 2 of the sensor isolation circuit is connected to the GND pin of the sensor, pin 3 of the sensor isolation circuit is connected to the TX pin of the sensor, pin 4 of the sensor isolation circuit is connected to the RX pin of the sensor, pin 5 of the sensor isolation circuit is connected to a 5V power supply, pin 6 of the sensor isolation circuit is connected to a 3.3V circuit, pin 7 of the sensor isolation circuit is connected to the PA9 pin of the processor, and pin 8 of the sensor circuit is connected to the PA10 pin of the processor.

[0018] Furthermore, the pilot circuit is specifically connected to a normally closed contact in the relay circuit. When the normally closed contact is disconnected, the pilot circuit controls the power supply of the external device to be disconnected.

[0019] Furthermore, the signal output circuit specifically includes:

[0020] The FB pin of the chip AD694 is connected to the -SIG pin of the chip AD694, the +SIG pin of the chip AD694 is connected to the PA4 pin of the processor through the resistor R1, the 2VFS pin and the COM pin of the chip AD694 are both grounded, the FORCE pin of the chip AD694 is connected to the SEN pin of the chip AD694, the VS pin of the chip AD694 is grounded through the capacitor C1, the VS pin of the chip AD694 is also connected to the OUT pin of the boost circuit, the VI N pin of the boost circuit is connected to the 5V power supply, the CTRL pin of the boost circuit is connected to the PB12 pin of the processor, the IOUT pin of the chip AD694 is connected to one end of the resistor R2, and the other end of the resistor R2 is connected to an external device.

[0021] Furthermore, the relay circuit includes a relay and a relay drive circuit, the VI N pin of the relay drive circuit is connected to a 5V power supply, the Re l_out pin of the relay drive circuit is connected to the PC5 / PB15 pin of the processor, the Re l+ pin of the relay drive circuit is connected to the 5th pin of the relay, the Re l- pin of the relay drive circuit is connected to the 1st pin of the relay, the 2nd pin and the 4th pin of the relay are connected to the pilot circuit, the 1st pin of the relay is the negative pole of the coil in the relay, the 5th pin of the relay is the positive pole of the coil in the relay, and the 2nd pin and the 4th pin of the relay are normally closed contacts.

[0022] Furthermore, the alarm circuit includes a buzzer alarm circuit and an indicator light alarm circuit, wherein:

[0023] The buzzer alarm circuit includes a buzzer and a buzzer drive circuit, wherein the first pin of the buzzer is connected to the VCC pin of the buzzer drive circuit, the second pin of the buzzer is connected to the V_out pin of the buzzer drive circuit, the VIN of the buzzer drive circuit is connected to a 3.3V power supply, and the V_ctr 1 pin of the buzzer drive circuit is connected to the PB1 pin of the processor;

[0024] The indicator light alarm circuit includes an LED driving circuit and a first indicator light LED1 and a second indicator light LED2. The LED2+ pin of the LED driving circuit is connected to one end of the second indicator light LED2, the LED2- pin of the LED driving circuit is connected to the other end of the second indicator light LED2, the LED1+ pin of the LED driving circuit is connected to one end of the first indicator light LED1, the LED1- pin of the LED driving circuit is connected to the other end of the first indicator light LED1, the VI N pin of the LED driving circuit is connected to a 3.3V power supply, the Red_out pin of the LED driving circuit is connected to the PB0 pin of the processor, and the gre_out pin of the LED driving circuit is connected to the PB11 pin of the processor.

[0025] Furthermore, the digital tube circuit includes a digital tube and a digital tube driving circuit, wherein the DIG_A pin of the digital tube driving circuit is connected to the A pin of the digital tube, the DIG_B pin of the digital tube driving circuit is connected to the B pin of the digital tube, the DIG_C pin of the digital tube driving circuit is connected to the C pin of the digital tube, the DIG_D pin of the digital tube driving circuit is connected to the D pin of the digital tube, the DIG_E pin of the digital tube driving circuit is connected to the E pin of the digital tube, the DIG_F pin of the digital tube driving circuit is connected to the F pin of the digital tube, the DIG_G pin of the digital tube driving circuit is connected to the G pin of the digital tube, the DIG_H pin of the digital tube driving circuit is connected to the H pin of the digital tube, the DIG_1 pin of the digital tube driving circuit is connected to the 1st pin of the digital tube, and the DIG_ The G_2 pin is connected to the 2nd pin of the digital tube, the DIG_3 pin of the digital tube driving circuit is connected to the 3rd pin of the digital tube, the DIG_4 pin of the digital tube driving circuit is connected to the 4th pin of the digital tube, the VIN pin of the digital tube driving circuit is connected to a 3.3V power supply, the DIG_sc l pin of the digital tube driving circuit is connected to the PB6 pin of the processor, and the DIG_sda pin of the digital tube driving circuit is connected to the PB7 pin of the processor.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] The utility model provides a methane detection circuit. Compared with the prior art, the utility model includes an acquisition circuit connected to a processor, for transmitting methane data collected by a sensor to the processor; the processor is used to control the on-off of a relay circuit according to the methane data; a signal output circuit is respectively connected to the processor and an external device, for converting the output voltage value of the processor into a current and outputting it to the external device; a setting circuit is connected to the processor, for setting detection parameters; a pilot circuit is respectively connected to the relay circuit and the external device, for controlling the on-off of the power supply of the external device based on the on-off of the relay circuit, which can improve the accuracy of underground methane detection and the life of the methane detection device. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of this specification, the following is a brief introduction to the drawings required for use in the embodiments. The drawings described below are only some of the embodiments recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0029] Figure 1 The figure shows the overall structure of the methane detection circuit provided in the embodiment of this specification;

[0030] Figure 2 Shown is a pin diagram of a processor in an embodiment of this specification;

[0031] Figure 3 The figure shows a schematic diagram of the structure of the infrared circuit in the embodiment of this specification;

[0032] Figure 4 The figure shows the structure of the key circuit in the embodiment of this specification;

[0033] Figure 5 The figure shows a schematic diagram of the structure of the remote control circuit in the embodiment of this specification;

[0034] Figure 6 The figure shows a schematic diagram of the structure of the acquisition circuit in the embodiment of this specification;

[0035] Figure 7 The figure shows a schematic diagram of the structure of the signal output circuit in the embodiment of this specification;

[0036] Figure 8 Shown is a schematic diagram of the structure of the relay circuit in the embodiment of this specification;

[0037] Figure 9 The figure shows the structure diagram of the buzzer alarm circuit in the embodiment of this specification;

[0038] Figure 10The figure shows the structure of the indicator light alarm circuit in the embodiment of this specification;

[0039] Figure 11 The figure shows the structure of the digital tube circuit in the embodiment of this specification. DETAILED DESCRIPTION

[0040] To help those skilled in the art better understand the technical solutions in this specification, the following will provide a clear and complete description of the technical solutions in the embodiments of this specification, in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of this specification, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments in this specification without creative work should fall within the scope of protection of this specification.

[0041] like Figure 1 The diagram shows the overall structure of the methane detection circuit provided in the embodiments of this specification. Although this specification provides the structures shown in the following embodiments or figures, the structures described may include more or fewer structures by combining parts based on routine or no creative effort. These structures are not limited to the structures shown in the embodiments or figures of this specification. When the structures described are used in actual devices or end products, they can be implemented sequentially or in parallel according to the embodiments or module structures.

[0042] The methane detection circuit provided in the embodiments of this specification is applied to various underground mines where methane is easily generated. The circuit includes:

[0043] an acquisition circuit, connected to the processor, for transmitting the methane data collected by the sensor to the processor;

[0044] The processor is used to control the on and off of the relay circuit according to the methane data;

[0045] a signal output circuit, connected to the processor and an external device respectively, for converting the output voltage value of the processor into a current and outputting it to the external device;

[0046] A setting circuit, connected to the processor, for setting detection parameters;

[0047] The pilot circuit is connected to the relay circuit and the external device respectively, and is used to control the on and off of the power supply of the external device based on the on and off of the relay circuit.

[0048] Specifically, the acquisition circuit transmits the methane data collected by the sensor to the processor, such as Figure 2The figure shows a pin diagram of the processor in the embodiment of this specification. The sensor can be but is not limited to a point laser gas probe. The processor controls the on and off of the relay circuit according to the methane data. At the same time, the relay circuit is also connected to the pilot circuit. The pilot circuit can control the opening and closing of the external device according to the on and off of the relay circuit. In addition, a setting circuit is also provided for setting various detection parameters.

[0049] In the embodiment of the present application, the circuit is configured to include an infrared circuit and a key circuit, such as Figure 3 The figure shows the structure of the infrared circuit in the embodiment of this specification. Figure 4 The figure shows the structure of the key circuit in the embodiment of this specification, wherein:

[0050] The infrared circuit specifically includes: a VOUT pin of the infrared receiving circuit is connected to the VCC pin of the infrared receiver, an IN pin of the infrared receiving circuit is connected to the OUT pin of the infrared receiver, a VIN pin of the infrared receiving circuit is connected to a 3.3V power supply, an R_OUT pin of the infrared receiving circuit is connected to the PB10 pin of the processor, and a GND pin of the infrared receiver is grounded;

[0051] The key circuit specifically includes:

[0052] One end of the button S1 and one end of the resistor R3 are connected to the PC13 pin of the processor, one end of the button S2 and one end of the resistor R4 are connected to the PA11 pin of the processor, one end of the button S3 and one end of the resistor R5 are connected to the PC4 pin of the processor, one end of the button S4 and one end of the resistor R6 are connected to the PA12 pin of the processor, and the other end of the resistor R3, the other end of the resistor R4, the other end of the resistor R5 and the other end of the resistor R6 are all connected to a 5V power supply.

[0053] Specifically, the infrared circuit enables long-range infrared communication with a remote control equipped with an infrared transmitter, enabling parameter adjustments for the circuit. The key circuit's buttons S1, S2, S3, and S4 can be configured as follows: Power / Fn; +; -; and OK / Lock, enabling power on / off, reset, calibration, and parameter setting. Parameter settings include alarm points, power-off points, power-on points, RS485 address, power-on delay, output level selection, and a 4-20mA upper concentration limit. The key circuit is designed to directly detect the status of individual buttons via the GPIO port. This product uses pins PA12, PC4, PA11, and PC13 of a processor, which can be a single-chip microcontroller, to detect key status. When a button is not pressed, the GPIO pin input state is high; when pressed, the GPIO pin input state is low. By detecting the pin input level, it is determined whether a button has been pressed. Use 10K pull-up resistors, i.e. R3-R6, to eliminate circuit noise, etc., and connect a 0.1μF capacitor in parallel with each button to eliminate jitter generated by the internal structure of the button.

[0054] The setting circuit also includes remote control circuit, such as Figure 5 The figure shows a schematic diagram of the structure of the remote control circuit in the embodiment of this specification. The remote control circuit includes a chip MAX3485 and an RS485 signal processing circuit. The VCC pin of the chip MAX3485 is connected to the 1st pin of the RS485 signal processing circuit, the VCC pin of the MAX3485 is also grounded through a capacitor C2, the VCC pin of the MAX3485 is also connected to a 5V power supply, the B pin of the chip MAX3485 is connected to the 2nd pin of the RS485 signal processing circuit, the A pin of the MAX3485 is connected to the 3rd pin of the RS485 signal processing circuit, the GND pin of the MAX3485 is grounded, the RO pin of the MAX3485 is connected to the PA3 pin of the processor, the RE pin of the MAX3485 is connected to the PA1 pin of the processor, the DE pin of the MAX3485 is connected to the PA1 pin of the processor, the DI pin of the MAX3485 is connected to the PA2 pin of the processor, and the RS485 signal processing circuit is also connected to the RS485A communication interface and the RS485B communication interface respectively.

[0055] Specifically, the RS485 interface enables data upload and remote parameter setting of the detection device. RS485 communication is implemented using the MAX3485 chip, where VCC and GND are power pins, and the RO and DI pins are connected to the processor's PA3 and PA2 pins, respectively, directly using the microcontroller's USART for data transmission and transmission. The RE and DE pins are short-circuited and then connected to the processor's PA1 pin to control data transmission and reception. A and B are two pins in RS485 communication, outputting to the RS485 signal processing circuit, which improves the RS485 communication's anti-interference capability.

[0056] In the embodiment of the present application, the acquisition circuit includes a sensor isolation circuit and a sensor, such as Figure 6 The figure shows a schematic diagram of the structure of the acquisition circuit in the embodiment of this specification, which specifically includes:

[0057] Pin 1 of the sensor isolation circuit is connected to the VCC pin of the sensor, pin 2 of the sensor isolation circuit is connected to the GND pin of the sensor, pin 3 of the sensor isolation circuit is connected to the TX pin of the sensor, pin 4 of the sensor isolation circuit is connected to the RX pin of the sensor, pin 5 of the sensor isolation circuit is connected to a 5V power supply, pin 6 of the sensor isolation circuit is connected to a 3.3V circuit, pin 7 of the sensor isolation circuit is connected to the PA9 pin of the processor, and pin 8 of the sensor circuit is connected to the PA10 pin of the processor.

[0058] Specifically, the point laser gas probe is used as a sensor, and the point laser gas probe outputs to the processor through the TTL communication interface and the sensor isolation circuit. The VCC and GND of the sensor are power supply pins, the TX and RX of the sensor are signal pins, and the sensor isolation circuit is connected to the PA9 and PA10 pins of the processor.

[0059] In the embodiments of this application, Figure 7 FIG. 1 is a schematic diagram of the structure of a signal output circuit, which specifically includes:

[0060] The FB pin of chip AD694 is connected to the -SIG pin of chip AD694, the +S IG pin of chip AD694 is connected to the PA4 pin of the processor through resistor R1, the 2VFS pin and COM pin of chip AD694 are both grounded, the FORCE pin of chip AD694 is connected to the SEN pin of chip AD694, the VS pin of chip AD694 is grounded through capacitor C1, the VS pin of chip AD694 is also connected to the OUT pin of the boost circuit, the VIN pin of the boost circuit is connected to a 5V power supply, the CTRL pin of the boost circuit is connected to the PB12 pin of the processor, the IOUT pin of chip AD694 is connected to one end of resistor R2, and the other end of resistor R2 is connected to an external device.

[0061] Specifically, the AD694 chip converts the processor's output voltage into a 4-20mA current output for an external device (such as a coal mining machine). By programming the external device, the coal cutting speed can be automatically controlled based on the gas concentration at the working face. Connect the processor's PA4 pin to the AD694's +SIG signal input port. Short the AD694's FB and -SIG pins, and ground the 2VFS and COM pins. Select a 0-2V signal input range. Short the 10V (FORCE) pin and the 2V (SEN) pin to obtain a 2V reference voltage. Connect the AD694's power supply VS pin to the boost circuit's out pin to power the module. The AD694's IOUT pin outputs a 4-20mA current signal. R1 and R2 are 0Ω resistors that match the external circuit characteristics, addressing EMC issues and effectively suppressing noise interference. C1 is a bypass capacitor to reduce the impact of high-frequency noise on the circuit.

[0062] In the embodiment of the present application, the relay circuit includes a relay and a relay driving circuit, such as Figure 8 The figure shows a schematic diagram of the structure of the relay circuit in the embodiment of this specification. The VIN pin of the relay drive circuit is connected to the 5V power supply, the Rel_out pin of the relay drive circuit is connected to the PC5 / PB15 pin of the processor, the Rel+ pin of the relay drive circuit is connected to the 5th pin of the relay, the Rel- pin of the relay drive circuit is connected to the 1st pin of the relay, the 2nd pin and the 4th pin of the relay are connected to the pilot circuit, the 1st pin of the relay is the negative pole of the coil in the relay, the 5th pin of the relay is the positive pole of the coil in the relay, and the 2nd pin and the 4th pin of the relay are normally closed contacts.

[0063] Specifically, when the methane concentration reaches or exceeds the power-off threshold, the relay contacts open, the pilot circuit is disconnected, and the external device is powered off and shut down. If the methane concentration is detected to be below the unlocking threshold, the processor restores power to the relay, causing the relay contacts to close, and the external device can be manually restored to operation. The feedback point switch of the isolation switch is normally closed because the relay coil requires a large current (80mA) to close, and the integrated circuit cannot provide such a high current. Therefore, a relay driver circuit must be used to expand the current. The processor's PC5 / PB15 pin is connected to the Rel_out pin of the relay driver circuit as the relay control signal. The Rel+ and Rel- pins of the relay driver circuit are connected to the 5th (positive) and 1st (negative) pins of the relay coil, respectively. The normally closed contacts 2 and 4 of the relay are connected in series to the pilot circuit of the external device (e.g., a coal mining machine). In other words, the pilot circuit is specifically connected to the normally closed contacts in the relay circuit. When the normally closed contacts open, the pilot circuit controls the power supply to the external device, disconnecting it.

[0064] In the embodiment of the present application, the circuit further includes an alarm circuit, a digital tube circuit and a power supply circuit. The power supply circuit is used to provide a 3.3V power supply and a 5V power supply. The alarm circuit includes a buzzer alarm circuit and an indicator light alarm circuit. Figure 9 The structure diagram of the buzzer alarm circuit in the embodiment of this specification is shown as follows. Figure 10 The figure shows the structure of the indicator light alarm circuit in the embodiment of this specification, wherein:

[0065] The buzzer alarm circuit includes a buzzer and a buzzer drive circuit, wherein the first pin of the buzzer is connected to the VCC pin of the buzzer drive circuit, the second pin of the buzzer is connected to the V_out pin of the buzzer drive circuit, the VIN of the buzzer drive circuit is connected to a 3.3V power supply, and the V_ctr 1 pin of the buzzer drive circuit is connected to the PB1 pin of the processor;

[0066] The indicator light alarm circuit includes an LED driving circuit and a first indicator light LED1 and a second indicator light LED2. The LED2+ pin of the LED driving circuit is connected to one end of the second indicator light LED2, the LED2- pin of the LED driving circuit is connected to the other end of the second indicator light LED2, the LED1+ pin of the LED driving circuit is connected to one end of the first indicator light LED1, the LED1- pin of the LED driving circuit is connected to the other end of the first indicator light LED1, the VIN pin of the LED driving circuit is connected to a 3.3V power supply, the Red_out pin of the LED driving circuit is connected to the PB0 pin of the processor, and the gre_out pin of the LED driving circuit is connected to the PB11 pin of the processor.

[0067] Specifically, when the methane concentration reaches or exceeds the set alarm value, the processor drives the buzzer to sound an alarm and the red alarm light flashes. When the methane concentration reaches or exceeds the power-off value, the red digits on the digital tube flash, the buzzer continues to sound an alarm, and the red alarm light flashes.

[0068] Use a buzzer driver circuit to avoid the problem of the processor's GPIO driving current being too low to drive the buzzer. Connect the processor's PB1 pin to the buzzer driver circuit's V_ctrl pin, which drives the buzzer when the output is high. Connect the buzzer driver circuit's VIN pin to a 3.3V power supply. Connect the buzzer driver circuit's VCC pin to the buzzer's pin 1 to power the buzzer, and connect the buzzer's V_out pin to the buzzer's pin 2 to control the buzzer's sound.

[0069] Because the processor's GPIO ports have current sink and source limits, and if the LED indicator light shorts, current will flow directly into the IO port, damaging the processor. Therefore, an LED driver circuit is introduced to drive and protect the LED indicator light. The processor's PB0 and PB11 pins are connected to the LED driver circuit's Red_out and Gre_out, respectively. U4's VIN pin is connected to a 3.3V power supply to provide power to the LED indicator light. The LED1+, LED1-, LED2+, and LED2- components of the LED driver circuit are connected to the two ends of the first indicator light, LED1, and the second indicator light, LED2, through the driver circuit.

[0070] In the embodiment of the present application, the digital tube circuit includes a digital tube and a digital tube driving circuit, such as Figure 11The figure shows a schematic diagram of the structure of the digital tube circuit in the embodiment of the present specification, wherein the DI G_A pin of the digital tube driving circuit is connected to the A pin of the digital tube, the DI G_B pin of the digital tube driving circuit is connected to the B pin of the digital tube, the DI G_C pin of the digital tube driving circuit is connected to the C pin of the digital tube, the DI G_D pin of the digital tube driving circuit is connected to the D pin of the digital tube, the DI G_E pin of the digital tube driving circuit is connected to the E pin of the digital tube, the DI G_F pin of the digital tube driving circuit is connected to the F pin of the digital tube, the DI G_G pin of the digital tube driving circuit is connected to the G pin of the digital tube, the DI G_H pin of the digital tube driving circuit is connected to the H pin of the digital tube, the DI G_1 pin of the digital tube driving circuit is connected to the 1st pin of the digital tube, the DI G_2 pin of the digital tube driving circuit is connected to the 2nd pin of the digital tube, the DI G_3 pin of the digital tube driving circuit is connected to the 3rd pin of the digital tube, and the DI G_ The G_4 pin is connected to the 4th pin of the digital tube, the VI N pin of the digital tube driving circuit is connected to the 3.3V power supply, the DI G_sc l pin of the digital tube driving circuit is connected to the PB6 pin of the processor, and the DI G_sda pin of the digital tube driving circuit is connected to the PB7 pin of the processor.

[0071] Specifically, the digital tube is used to display methane concentration and parameter setting information. The digital tube display is implemented by the processor via a digital tube driver circuit. The processor's PB6 and PB7 pins are connected to the DI G_sc1 and DI G_sda pins of the digital tube driver circuit. The VI N pin of the digital tube driver circuit is connected to a 3.3V power supply, providing power for the driver circuit and the digital tube. The DI G_A, DI G_B, DI G_C, DI G_D, DI G_E, DI G_F, DI G_G, DI G_H, DI G_1, DI G_2, DI G_3, and DI G_4 pins of the digital tube driver circuit are connected to the A, B, C, D, E, F, G, H, 1, 2, 3, and 4 pins of the digital tube, respectively, to complete the digital tube display. Using the digital tube driver circuit, digital tube driving is accomplished by communicating with the processor via only two pins, conserving processor pin resources and simplifying the complexity of the digital tube display circuit.

[0072] It should be understood that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intervening element at the same time; when an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intervening element at the same time. In addition, the "connection" used here may include wireless connection; the wording "and / or" used includes any unit and all combinations of one or more associated listed items.

[0073] It should be understood that various parts of the present application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used to implement: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0074] Those skilled in the art will understand that all or part of the steps in the method of the above embodiment can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiment.

[0075] In addition, the functional units in the various embodiments of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into a module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0076] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0077] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0078] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

[0079] The above content is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention cannot be considered to be limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, several simple deductions or substitutions can be made, which should be considered to fall within the scope of protection of the present invention.

Claims

1. A methane detection circuit, comprising: an acquisition circuit, connected to the processor, for transmitting the methane data collected by the sensor to the processor; The processor is used to control the on and off of the relay circuit according to the methane data; a signal output circuit, connected to the processor and an external device respectively, for converting the output voltage value of the processor into a current and outputting it to the external device; A setting circuit, connected to the processor, for setting detection parameters; The pilot circuit is connected to the relay circuit and the external device respectively, and is used to control the on and off of the power supply of the external device based on the on and off of the relay circuit.

2. The methane detection circuit according to claim 1, wherein: The circuit also includes an alarm circuit, a digital tube circuit and a power supply circuit, wherein the power supply circuit is used to provide a 3.3V power supply and a 5V power supply.

3. The methane detection circuit according to claim 1, wherein: The setting circuit specifically includes an infrared circuit and a key circuit, wherein: The infrared circuit specifically includes: a VOUT pin of the infrared receiving circuit is connected to the VCC pin of the infrared receiver, an IN pin of the infrared receiving circuit is connected to the OUT pin of the infrared receiver, a VIN pin of the infrared receiving circuit is connected to a 3.3V power supply, an R_OUT pin of the infrared receiving circuit is connected to the PB10 pin of the processor, and a GND pin of the infrared receiver is grounded; The key circuit specifically includes: One end of the button S1 and one end of the resistor R3 are connected to the PC13 pin of the processor, one end of the button S2 and one end of the resistor R4 are connected to the PA11 pin of the processor, one end of the button S3 and one end of the resistor R5 are connected to the PC4 pin of the processor, one end of the button S4 and one end of the resistor R6 are connected to the PA12 pin of the processor, and the other end of the resistor R3, the other end of the resistor R4, the other end of the resistor R5 and the other end of the resistor R6 are all connected to a 5V power supply.

4. The methane detection circuit according to claim 3, wherein: The setting circuit also includes a remote control circuit, which includes a chip MAX3485 and an RS485 signal processing circuit. The VCC pin of the chip MAX3485 is connected to the 1st pin of the RS485 signal processing circuit, the VCC pin of the MAX3485 is also grounded through a capacitor C2, the VCC pin of the MAX3485 is also connected to a 5V power supply, the B pin of the chip MAX3485 is connected to the 2nd pin of the RS485 signal processing circuit, the A pin of the MAX3485 is connected to the 3rd pin of the RS485 signal processing circuit, the GND pin of the MAX3485 is grounded, the RO pin of the MAX3485 is connected to the PA3 pin of the processor, the RE pin of the MAX3485 is connected to the PA1 pin of the processor, the DE pin of the MAX3485 is connected to the PA1 pin of the processor, the DI pin of the MAX3485 is connected to the PA2 pin of the processor, and the RS485 signal processing circuit is also connected to the RS485A communication interface and the RS485B communication interface respectively.

5. The methane detection circuit according to claim 1, wherein: The acquisition circuit includes a sensor isolation circuit and a sensor, specifically including: Pin 1 of the sensor isolation circuit is connected to the VCC pin of the sensor, pin 2 of the sensor isolation circuit is connected to the GND pin of the sensor, pin 3 of the sensor isolation circuit is connected to the TX pin of the sensor, pin 4 of the sensor isolation circuit is connected to the RX pin of the sensor, pin 5 of the sensor isolation circuit is connected to a 5V power supply, pin 6 of the sensor isolation circuit is connected to a 3.3V circuit, pin 7 of the sensor isolation circuit is connected to the PA9 pin of the processor, and pin 8 of the sensor circuit is connected to the PA10 pin of the processor.

6. The methane detection circuit according to claim 1, wherein: The pilot circuit is specifically connected to the normally closed contact in the relay circuit. When the normally closed contact is disconnected, the pilot circuit controls the power supply of the external device to be disconnected.

7. The methane detection circuit according to claim 1, wherein: The signal output circuit specifically includes: The FB pin of chip AD694 is connected to the -SIG pin of chip AD694, the +SIG pin of chip AD694 is connected to the PA4 pin of the processor through resistor R1, the 2VFS pin and COM pin of chip AD694 are both grounded, the FORCE pin of chip AD694 is connected to the SEN pin of chip AD694, the VS pin of chip AD694 is grounded through capacitor C1, the VS pin of chip AD694 is also connected to the OUT pin of the boost circuit, the VIN pin of the boost circuit is connected to a 5V power supply, the CTRL pin of the boost circuit is connected to the PB12 pin of the processor, the IOUT pin of chip AD694 is connected to one end of resistor R2, and the other end of resistor R2 is connected to an external device.

8. The methane detection circuit according to claim 1, wherein: The relay circuit includes a relay and a relay driving circuit, the VIN pin of the relay driving circuit is connected to a 5V power supply, the Rel_out pin of the relay driving circuit is connected to the PC5 / PB15 pin of the processor, the Rel+ pin of the relay driving circuit is connected to the 5th pin of the relay, the Rel- pin of the relay driving circuit is connected to the 1st pin of the relay, the 2nd pin and the 4th pin of the relay are connected to the pilot circuit, the 1st pin of the relay is the negative pole of the coil in the relay, the 5th pin of the relay is the positive pole of the coil in the relay, and the 2nd pin and the 4th pin of the relay are normally closed contacts.

9. The methane detection circuit according to claim 2, wherein: The alarm circuit includes a buzzer alarm circuit and an indicator light alarm circuit, wherein: The buzzer alarm circuit includes a buzzer and a buzzer drive circuit, wherein the first pin of the buzzer is connected to the VCC pin of the buzzer drive circuit, the second pin of the buzzer is connected to the V_out pin of the buzzer drive circuit, the VIN of the buzzer drive circuit is connected to a 3.3V power supply, and the V_ctrl pin of the buzzer drive circuit is connected to the PB1 pin of the processor; The indicator light alarm circuit includes an LED driving circuit and a first indicator light LED1 and a second indicator light LED2. The LED2+ pin of the LED driving circuit is connected to one end of the second indicator light LED2, the LED2- pin of the LED driving circuit is connected to the other end of the second indicator light LED2, the LED1+ pin of the LED driving circuit is connected to one end of the first indicator light LED1, the LED1- pin of the LED driving circuit is connected to the other end of the first indicator light LED1, the VIN pin of the LED driving circuit is connected to a 3.3V power supply, the Red_out pin of the LED driving circuit is connected to the PB0 pin of the processor, and the gre_out pin of the LED driving circuit is connected to the PB11 pin of the processor.

10. The methane detection circuit according to claim 2, wherein: The digital tube circuit includes a digital tube and a digital tube driving circuit, wherein the DIG_A pin of the digital tube driving circuit is connected to the A pin of the digital tube, the DIG_B pin of the digital tube driving circuit is connected to the B pin of the digital tube, the DIG_C pin of the digital tube driving circuit is connected to the C pin of the digital tube, the DIG_D pin of the digital tube driving circuit is connected to the D pin of the digital tube, the DIG_E pin of the digital tube driving circuit is connected to the E pin of the digital tube, the DIG_F pin of the digital tube driving circuit is connected to the F pin of the digital tube, the DIG_G pin of the digital tube driving circuit is connected to the G pin of the digital tube, and the digital tube driving circuit is connected to the D pin of the digital tube. The DIG_H pin of the driving circuit is connected to the H pin of the digital tube, the DIG_1 pin of the digital tube driving circuit is connected to the 1st pin of the digital tube, the DIG_2 pin of the digital tube driving circuit is connected to the 2nd pin of the digital tube, the DIG_3 pin of the digital tube driving circuit is connected to the 3rd pin of the digital tube, the DIG_4 pin of the digital tube driving circuit is connected to the 4th pin of the digital tube, the VIN pin of the digital tube driving circuit is connected to a 3.3V power supply, the DIG_scl pin of the digital tube driving circuit is connected to the PB6 pin of the processor, and the DIG_sda pin of the digital tube driving circuit is connected to the PB7 pin of the processor.

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