Digital intelligent combustible gas detection sensitive unit and detection device thereof

Abstract

The utility model discloses a digital intelligent combustible gas detection sensitive unit and a detection device thereof, which belong to the technical field of carrier catalytic elements, and comprise a control circuit module, a power supply circuit module, a Wheatstone circuit module, an amplification circuit module, an adjustable reference voltage circuit module and an MCU (Microprogrammed Control Unit) circuit module, the Wheatstone circuit module is electrically connected with the power supply circuit module, the amplification circuit module and the adjustable reference voltage circuit module; the MCU circuit module is electrically connected with the amplification circuit module and the adjustable reference voltage circuit module; through the built-in power supply circuit module, the Wheatstone circuit module, the amplification circuit module, the adjustable reference voltage circuit module and the MCU circuit module, the consistency of power supply voltages of the Wheatstone circuit module and the adjustable reference voltage circuit module is ensured, an external power supply is simplified, and the external power supply can be used in a certain range.

Description

Technical Field

[0001] This utility model belongs to the field of carrier catalytic element technology, and in particular relates to a digital intelligent combustible gas detection sensitive unit and its detection device. Background Technology

[0002] A carrier catalytic element for combustible gas detection contains a heated catalytic bead and a thermistor assembly. When combustible gas comes into contact with the catalytic bead, it undergoes a flameless combustion reaction with oxygen under the action of the catalyst, producing carbon dioxide and water, and releasing heat, causing a change in the thermistor resistance. By measuring the change in resistance, an electrical signal proportional to the concentration of combustible gas can be converted into a quantitative detection signal. The carrier catalytic element consists of a detection element and a compensation element. To achieve measurement, it is usually connected in series with two equivalent resistors to form a Wheatstone bridge structure.

[0003] Currently, carrier-based catalytic elements only encapsulate the detection and compensation elements and lack digital output transmission capabilities. Users need to build external circuits to convert the signals into digital signals and then calibrate them using software before use. In addition, the detection and compensation elements of carrier-based catalytic elements cannot achieve perfect resistance matching during encapsulation, and errors will exist between the resistors. This makes it difficult to control the voltage difference output of the resistor bridge formed by them, especially during mass production, where the dispersion increases and the consistency is very poor. It is necessary to match the resistance values ​​of the detection and compensation elements as much as possible, which increases the production difficulty and cost. Utility Model Content

[0004] The purpose of this utility model is to provide a digital intelligent combustible gas detection sensitive unit and its detection device in order to solve the above-mentioned problems.

[0005] On the one hand, in order to achieve the above objectives, this utility model adopts the following technical solution: a digital intelligent combustible gas detection sensing unit, which includes:

[0006] The control circuit module includes a power supply circuit module, a Wheatstone circuit module, an amplifier circuit module, an adjustable reference voltage circuit module, and an MCU circuit module. The Wheatstone circuit module is electrically connected to the power supply circuit module, the amplifier circuit module, and the adjustable reference voltage circuit module. The MCU circuit module is electrically connected to the amplifier circuit module and the adjustable reference voltage circuit module. The Wheatstone circuit module consists of a detection element and a compensation element connected to two resistors.

[0007] As a further description of the above technical solution:

[0008] The power supply circuit module uses a chip with the model number MT3520B.

[0009] As a further description of the above technical solution:

[0010] The input of the adjustable reference voltage circuit module is a resistor divider. After passing through a voltage follower circuit, it is connected to the reference input pin of the amplifier circuit module. The pull-up resistors at the input remain unchanged, and all the pull-down resistors form a parallel array. The other ends of all the pull-down resistors are connected to different I / O ports of the MCU circuit module.

[0011] As a further description of the above technical solution:

[0012] The amplifier circuit module uses an amplifier of model RS6334XTQC16.

[0013] As a further description of the above technical solution:

[0014] The MCU circuit module uses a chip with model number HC32L110C6UA.

[0015] As a further description of the above technical solution:

[0016] A fault detection circuit module is also connected between the Wheatstone circuit module and the MCU circuit module.

[0017] On the other hand, in order to achieve the above objectives, the present invention adopts the following technical solution: a digital intelligent combustible gas detection device, comprising:

[0018] The casing has a groove on its top;

[0019] An explosion-proof disc, which is engaged within the groove;

[0020] A first circuit board is disposed inside the housing, and an insulating gasket is connected to the first circuit board;

[0021] A bracket is mounted on the first circuit board, and a detection element and a compensation element are mounted on the bracket. The detection element and the compensation element are connected to the control circuit module.

[0022] The second circuit board blocks the bottom opening of the housing, and the second circuit board is connected to the first circuit board via pin headers;

[0023] The PCB cross pin is connected to the second circuit board.

[0024] In summary, due to the adoption of the above technical solution, the beneficial effects of this utility model are:

[0025] 1. In this utility model, by incorporating a built-in power supply circuit module, a Wheatstone circuit module, an amplifier circuit module, an adjustable reference voltage circuit module, and an MCU circuit module, the consistency of the power supply voltage of the Wheatstone circuit module and the adjustable reference voltage circuit module is ensured, simplifying the external power supply, and the external power supply can be used within a certain range.

[0026] 2. In this utility model, by adding a control circuit module to the original detection and compensation elements of the carrier catalytic element, compared with the previous simple carrier catalytic element packaging, it integrates analog and digital circuits, which can effectively reduce production difficulty and production cost, reduce the time for engineers to carry out secondary development, and improve anti-interference ability. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of a digital combustible gas detection device.

[0028] Figure 2 This is an exploded diagram of a digital combustible gas detection device.

[0029] Figure 3 This is a top view of a digital combustible gas detection device.

[0030] Figure 4 This is a system block diagram of a digital intelligent combustible gas detection sensing unit.

[0031] Figure 5 This is a circuit diagram of a digital intelligent combustible gas detection sensing unit.

[0032] Legend:

[0033] 1. Housing; 2. Explosion-proof sheet; 3. First circuit board; 4. Insulating gasket; 5. Bracket; 6. Detection element; 7. Compensation element; 8. Control circuit module; 81. Power supply circuit module; 82. Wheatstone circuit module; 83. Amplifier circuit module; 84. Adjustable reference voltage circuit module; 85. MCU circuit module; 86. Fault detection circuit module; 9. Second circuit board; 10. Pin header; 11. PCB cross pins. Detailed Implementation

[0034] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0035] Please see Figure 1-5This utility model provides a technical solution:

[0036] A digital intelligent combustible gas detection sensing unit includes:

[0037] The control circuit module 8 includes a power supply circuit module 81, a Wheatstone circuit module 82, an amplifier circuit module 83, an adjustable reference voltage circuit module 84, and an MCU circuit module 85. The Wheatstone circuit module 82 is electrically connected to the power supply circuit module 81, the amplifier circuit module 83, and the adjustable reference voltage circuit module 84. The MCU circuit module 85 is electrically connected to the amplifier circuit module 83 and the adjustable reference voltage circuit module 84. The Wheatstone circuit module 82 consists of a detection element 6 and a compensation element 7 connected to two resistors.

[0038] Specifically, the input power is regulated by the power circuit module 81 and then used to power the bridge circuit.

[0039] The amplifier circuit module 83 uses a chip of model RS6334XTQC16;

[0040] The MCU circuit module 85 uses a chip with the model number HC32L110C6UA;

[0041] The differential signal output by the Wheatstone circuit module 82 is sent to the MCU circuit module 85 after passing through the amplifier circuit module 83 and the adjustable reference voltage circuit module 84. The voltage divider signal of the detection element 6 and the compensation element 7 is connected to the MCU circuit module 85 after passing through the voltage follower.

[0042] The MCU circuit module 85 converts the two analog voltage signals into digital signals through ADC conversion. Then, the concentration value of combustible gas is calculated by the filtering, calibration, compensation and other algorithms inside the MCU circuit module 85, and sent to the host computer through the UART serial port.

[0043] The adjustable reference voltage circuit module 84 has a resistor divider at its input, which then passes through a voltage follower circuit and is connected to the reference input pin of the amplifier circuit module 83. The pull-up resistors at the input remain unchanged, and all the pull-down resistors form a parallel array. The other ends of all the pull-down resistors are connected to different I / O ports of the MCU circuit module 85 (configured as open-drain). After receiving the command to change the pull-down resistors via UART, the MCU circuit module 85 changes the switching state of the I / O connected to the pull-down resistor array, thereby achieving the purpose of adjusting the reference voltage.

[0044] The power supply circuit module 81 uses a chip with the model number MT3520B;

[0045] A fault detection circuit module 86 is also connected between the Wheatstone circuit module 82 and the MCU circuit module 85. It has a self-diagnostic function. The MCU circuit module 85 collects the voltage between the detection element 6 and the compensation element 7. When the voltage value exceeds a certain range, such as being close to 0V or the power supply voltage, it determines that the carrier element is damaged. When calibrating the gas concentration, it can also analyze the sensitivity of the detection element 6.

[0046] A digital combustible gas detection device includes:

[0047] The housing 1 has a groove on its top;

[0048] Explosion-proof disc 2, which is snapped into the groove;

[0049] A first circuit board 3 is disposed inside the housing 1, and an insulating gasket 4 is connected to the first circuit board 3;

[0050] A bracket 5 is mounted on the first circuit board 3. A detection element 6 and a compensation element 7 are mounted on the bracket 5. The detection element 6 and the compensation element 7 are connected to the control circuit module 8.

[0051] The second circuit board 9 blocks the bottom opening of the housing 1, and the second circuit board 9 is connected to the first circuit board 3 through the pin header 10;

[0052] PCB cross pin 11 is connected to the second circuit board 9.

[0053] Working Principle: First, the housing 1 is made of stainless steel, and the explosion-proof sheet 2 is made of powder metallurgy. The second circuit board 9 is encapsulated with epoxy resin between itself and the housing 1, solving the problem that the micropores in the housing due to the powder metallurgy sintering process make it susceptible to moisture penetration after long-term use, affecting the stability of the internal circuitry. Second, the differential signal output from the Wheatstone circuit module 82 is sent to the MCU circuit module 85 after passing through the amplifier circuit module 83 and the adjustable reference voltage circuit module 84. The voltage divider signals from the detection element 6 and the compensation element 7 are connected to the MCU circuit module 85 after passing through a voltage follower. The MCU circuit module 85 converts the two analog voltage signals into digital signals through ADC conversion. Then, the concentration value of the combustible gas is calculated by the filtering, calibration, and compensation algorithms inside the MCU circuit module 85, and sent to the host computer through the UART serial port. Among them, the adjustable reference... The input of voltage circuit module 84 is a resistor divider, which then passes through a voltage follower circuit and is connected to the reference input pin of amplifier circuit module 83. The pull-up resistors at the input remain unchanged, and all the pull-down resistors form a parallel array. The other ends of all the pull-down resistors are connected to different I / O ports of MCU circuit module 85 (configured as open-drain). After receiving a command to change the pull-down resistors via UART, MCU circuit module 85 changes the switching state of the I / O connected to the pull-down resistor array, thereby achieving the purpose of adjusting the reference voltage. Finally, fault detection circuit module 86 provides a self-diagnostic function. MCU circuit module 85 collects the voltage between detection element 6 and compensation element 7. When the voltage value exceeds a certain range, such as approaching 0V or the power supply voltage, it determines that the carrier element is damaged. When calibrating the gas concentration, the sensitivity of detection element 6 can also be analyzed.

[0054] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A digital intelligent combustible gas detection sensing unit, characterized in that, include: The control circuit module (8) includes a power supply circuit module (81), a Wheatstone circuit module (82), an amplifier circuit module (83), an adjustable reference voltage circuit module (84), and an MCU circuit module (85). The Wheatstone circuit module (82) is electrically connected to the power supply circuit module (81), the amplifier circuit module (83), and the adjustable reference voltage circuit module (84). The MCU circuit module (85) is electrically connected to the amplifier circuit module (83) and the adjustable reference voltage circuit module (84). The Wheatstone circuit module (82) consists of a detection element (6) and a compensation element (7) connected to two resistors.

2. The intelligent combustible gas detection sensing unit according to claim 1, characterized in that, The power supply circuit module (81) uses a chip with the model number MT3520B.

3. The intelligent combustible gas detection sensing unit according to claim 1, characterized in that, The amplifier circuit module (83) uses an amplifier of model RS6334XTQC16.

4. The intelligent combustible gas detection sensing unit according to claim 1, characterized in that, The input terminal of the adjustable reference voltage circuit module (84) is a resistor voltage divider. After passing through a voltage follower circuit, it is connected to the reference input pin of the amplifier circuit module (83). The pull-up resistors at the input terminal remain unchanged. All the pull-down resistors form a parallel array. The other end of all the pull-down resistors is connected to different IO ports of the MCU circuit module (85).

5. The intelligent combustible gas detection sensing unit according to claim 1, characterized in that, The MCU circuit module (85) uses a chip with the model number HC32L110C6UA.

6. The intelligent combustible gas detection sensing unit according to claim 1, characterized in that, A fault detection circuit module (86) is also connected between the Wheatstone circuit module (82) and the MCU circuit module (85).

7. A digital intelligent combustible gas detection device, comprising the digital intelligent combustible gas detection sensing unit as described in any one of claims 1-6, characterized in that, Also includes: The shell (1) has a groove on its top; Explosion-proof disc (2), which is snapped into the groove; A first circuit board (3) is disposed inside the housing (1), and an insulating pad (4) is connected to the first circuit board (3). A bracket (5) is mounted on the first circuit board (3), a detection element (6) and a compensation element (7) are mounted on the bracket (5), and the detection element (6) and the compensation element (7) are connected to the control circuit module (8) of the intelligent combustible gas detection sensitive unit. The second circuit board (9) blocks the bottom opening of the housing (1), and the second circuit board (9) is connected to the first circuit board (3) through pin header (10). PCB cross pin (11), which is connected to the second circuit board (9).

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