CN-224231678-U - Digital processing circuit of catalytic combustion sensor

Abstract

The application relates to a digital processing circuit of a catalytic combustion sensor, which comprises a first detection resistor R1, a second detection resistor R2, a compensation element C, a microprocessor IC1, a wiring plug-in JP1, a linear stabilized voltage supply IC2 and a linear stabilized voltage supply IC2, wherein one end of the first detection resistor R1 is connected with one end of a compensation element C in the catalytic sensor CG1, the other end of the second detection resistor R2 is connected with one end of a detection element D in the catalytic sensor CG1, the other ends of the compensation element C and the detection element D are connected with a first input end of the microprocessor IC1, the other end of the second detection resistor R2 is connected with a second input end of the microprocessor IC1, the wiring plug-in JP1 is used for serial communication with the microprocessor IC1 and the outside, and the linear stabilized voltage supply IC2 is used for converting a power supply of the wiring plug-in JP1 into a stabilized voltage supply so as to supply the catalytic sensor CG 1.

Inventors

• YU LEZHONG
• CAO SHUDONG
• XU BAOBIAO

Assignees

• 济南本安科技发展有限公司

Dates

Publication Date

20260512

Application Date

20250414

Claims (6)

1. 1. A digital processing circuit of a catalytic combustion sensor, comprising: catalytic sensor CG1; One end of the first detection resistor R1 is connected with one end of the compensation element C in the catalytic sensor CG 1; One end of the second detection resistor R2 is connected with one end of a detection element D in the catalytic sensor CG1, the other end of the first detection resistor R1 is connected with the other end of the second detection resistor R2, and the other end of the compensation element C is connected with the other end of the detection element D; the microprocessor IC1 is connected with the first input end and the connecting end of the compensating element C and the other end of the detecting element D, and the second input end and the connecting end of the first detecting resistor R1 and the other end of the second detecting resistor R2; The wiring plug-in JP1 is connected with the microprocessor IC1 and is used for carrying out serial port communication with the outside and providing a power supply from the outside; and a linear stabilized power supply IC2 connected with the wiring plug-in JP1 and used for converting the power supply into a stabilized power supply, wherein the power output end of the linear stabilized power supply IC2 is used for supplying power to the catalytic sensor CG 1.
2. 2. The digital processing circuit of a catalytic combustion sensor of claim 1, wherein the digital processing circuit further comprises: The third resistor is connected in series between the first input end of the microprocessor IC1 and the connecting end of the compensating element C and the other end of the detecting element D; And the fourth resistor is connected in series with the second input end of the microprocessor IC1 and the connecting end of the other ends of the first detection resistor R1 and the second detection resistor R2.
3. 3. A catalytic combustion sensor digitizing circuit according to claim 2, the digital processing circuit is characterized in that the digital processing circuit further comprises: And one end of a fifth resistor R5 is connected with the control output end of the microprocessor IC1, the other end of the fifth resistor R5 is connected with the control input end of the linear voltage-stabilized power supply IC2, and the microprocessor IC1 is used for controlling the on-off of the linear voltage-stabilized power supply IC 2.
4. 4. A digital processing circuit of a catalytic combustion sensor according to claim 3, wherein the wiring plug-in JP1 comprises a RXD terminal, a TXD terminal, a GND terminal and a V33 terminal, wherein the RXD terminal, the TXD terminal, the GND terminal and the V33 terminal are all connected to the microprocessor IC1, the RXD terminal and the TXD terminal are used for outputting digital signals outwards, and the V33 terminal is used for being connected to an external power supply.
5. 5. The digital processing circuit of a catalytic combustion sensor according to claim 4, wherein the linear stabilized power supply IC2 comprises a Vin terminal, a Vout terminal, a GND terminal, and an EN terminal, the Vin terminal is connected to the V33 terminal of the wiring plug-in JP1, the GND terminal is connected to the GND terminal of the wiring plug-in JP1 and is grounded, the Vout terminal is a power supply output terminal, and the EN terminal is a control input terminal.
6. 6. The digital processing circuit of a catalytic combustion sensor according to claim 5, wherein the Vout end of the linear regulated power supply IC2 is further connected to a capacitor C1, and a negative electrode of the capacitor C1 is grounded.

Description

Digital processing circuit of catalytic combustion sensor Technical Field The application relates to the technical field of catalytic combustion sensors, in particular to a digital processing circuit of a catalytic combustion sensor. Background Catalytic combustion sensors are common gas detection sensors, typically consisting of a detection element and a compensation element. The basic principle is that flameless combustion occurs when the combustible gas contacts the catalyst on the detection element, so that the temperature of the carrier is increased, the temperature change can cause the increase of the resistance of the platinum wire in the detection element, the change can be detected through a circuit, and the measurement of the gas concentration is further realized. Referring to fig. 1, in order to facilitate the measurement of the variation of the detecting element, a conventional application circuit is to connect the detecting element D with the compensating element C in series, and further add a pair of auxiliary detecting resistors R1 and R2, wherein one end of the first detecting resistor R1 is connected in series with the detecting element D, the other end is connected in series with a potentiometer W, one end of the second detecting resistor R2 is connected in series with the compensating element C, the adjusting end of the potentiometer W is connected in series with the midpoint of the detecting element D and the compensating element C as an output bridge to form a wheatstone bridge circuit, and output an electric signal proportional to the concentration of the combustible gas, and one end of the first detecting resistor R1 and the other end of the second detecting resistor R2 are connected with a test voltage. Because the output signal of the catalytic combustion sensor is smaller, an amplifying circuit is generally needed in the related art to accurately measure, and an operational amplifier is needed, and secondly, because the catalytic combustion sensor has zero drift and inconsistent sensitivity, a potentiometer W is needed to be used for zero adjustment and amplification factor adjustment in the circuit. This results in a complex processing circuit for the catalytic combustion sensor, and in a production process, the potentiometer W needs to be adjusted back and forth, which is inconvenient for mass production. Because the catalytic combustion sensor consumes catalyst in the gas reaction, its lifetime is relatively short, typically about 3 years, which faces the need to replace the sensor in the field. The gas alarm used in industrial places is of an explosion-proof structure, the inside of the gas alarm is formed by combining a plurality of circuit boards, and the sensor corresponds to the circuit boards in the inside, so that the sensor is inconvenient to replace independently and gas calibration work is inconvenient in the field. Disclosure of utility model In order to facilitate independent replacement of the sensor, the application provides a digital processing circuit of a catalytic combustion sensor, which is used for directly outputting a digital gas concentration value, wherein the digital processing circuit is integrated on a circuit board and adopts the following technical scheme: a digital processing circuit of a catalytic combustion sensor, comprising: catalytic sensor CG1; One end of the first detection resistor R1 is connected with one end of the compensation element C in the catalytic sensor CG 1; One end of the second detection resistor R2 is connected with one end of a detection element D in the catalytic sensor CG1, the other end of the first detection resistor R1 is connected with the other end of the second detection resistor R2, and the other end of the compensation element C is connected with the other end of the detection element D; the microprocessor IC1 is connected with the first input end and the connecting end of the compensating element C and the other end of the detecting element D, and the second input end and the connecting end of the first detecting resistor R1 and the other end of the second detecting resistor R2; The wiring plug-in JP1 is connected with the microprocessor IC1 and is used for carrying out serial port communication with the outside and providing a power supply from the outside; and a linear stabilized power supply IC2 connected with the wiring plug-in JP1 and used for converting the power supply into a stabilized power supply, wherein the power output end of the linear stabilized power supply IC2 is used for supplying power to the catalytic sensor CG 1. By adopting the technical scheme, the inside of the microprocessor IC1 is provided with the 16-bit high-precision AD, the internal standard and the differential operational amplifier OPA function, the microprocessor IC1, the linear stabilized power supply IC2 and the wiring plug-in JP1 are utilized, so that the electric signal processing of the catalytic sensor CG1 can be realized, all