CN210665724U - Combustible gas detector adopting modular structure and having display function - Google Patents

Abstract

The utility model discloses a combustible gas detector with display adopting a modular structure, which comprises a sensor module, a mainboard module and a display module which are connected in sequence, wherein the sensor module is an independent module; the mainboard module comprises an amplifying circuit, a single chip microcomputer circuit, a relay output circuit, a 4-20mA output circuit, an RS485 bus circuit and a power supply circuit, wherein the amplifying circuit is connected with the single chip microcomputer circuit, and the single chip microcomputer circuit is respectively connected with the relay output circuit, the 4-20mA output circuit and the RS485 bus circuit; the display module comprises an LED display module and an LCD display module. The utility model carries out modular design of the combustible gas detector with display, can be combined and flexibly combined, and can fully meet the requirements of customers; the modules are unified, the production and debugging are convenient, and the quality control is simple; the performance is more stable and the measurement is more accurate due to the fact that the microprocessor is arranged in the whole device; the sensor module is used as an independent module, and the expansibility is strong.

Description

Combustible gas detector adopting modular structure and having display function

Technical Field

The utility model belongs to the technical field of combustible gas surveys the technique and specifically relates to an adopt modular structure have and show combustible gas detector.

Background

The combustible gas detector is used for dangerous occasions where combustible gas leakage possibly exists, is used for detecting the concentration of leaked gas, and has important function on preventing dangerous events such as explosion, combustion and the like.

The requirements of enterprises are different when the combustible gas detector is configured, the price is low, the on-site display is not needed, and the on-site display is needed; the display of the nixie tube and the display of the liquid crystal are needed; the current output of 4-20mA is needed, and the current output of a bus is needed. The common solution in the market at present is to combine different requirements, use different design schemes, and design and produce a plurality of models of detectors for the selection of customers. Several different types of detectors are commonly included: a non-display 4-20mA output gas detector (without a microprocessor), a non-display bus output detector (with a microprocessor and for setting addresses through a dial switch), an LED display gas detector (with a microprocessor and for infrared remote control operation) and an LCD display gas detector (with a microprocessor and for infrared remote control operation). But the above solution brings great inconvenience to production debugging and quality control of enterprises. Meanwhile, the detector without display usually adopts a scheme without a microprocessor, so that the detection precision is relatively low and the performance is poor.

SUMMERY OF THE UTILITY MODEL

For solving the above-mentioned problem that common solution exists on the existing market, the utility model provides an adopt modular structure have and show combustible gas detector helps the various different requirements of unified customer, uses the same module to carry out different combinations, and the production debugging method is single, convenient, and the quality is controlled easily.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

a combustible gas detector with a display and adopting a modular structure comprises a sensor module, a main board module and a display module which are sequentially connected, wherein the sensor module is an independent module; the mainboard module comprises an amplifying circuit, a single chip microcomputer circuit, a relay output circuit, a 4-20mA output circuit, an RS485 bus circuit and a power supply circuit, wherein the amplifying circuit is connected with the single chip microcomputer circuit and used for amplifying a sensor signal through the amplifying circuit and then transmitting the amplified signal to the single chip microcomputer circuit for data conversion, the single chip microcomputer circuit is respectively connected with the relay output circuit, the 4-20mA output circuit and the RS485 bus circuit and used for controlling the signal output of the relay output circuit, the 4-20mA output circuit and the RS485 bus circuit according to the measured gas concentration through the single chip microcomputer circuit, and the power supply circuit is used for realizing 24V to 5V and 2.5V conversion; the display module comprises an LED display module and an LCD display module, and the LED display module and the LCD display module are identical in appearance, size and connection mode.

Further, the sensor module includes a catalytic combustion gas sensor U1, a bit filter capacitor C1, and a terminal P1, the terminal P1 being connected to the motherboard module.

Further, the singlechip circuit comprises a singlechip STM8S005K6 and capacitors C19-C21.

Further, the relay output circuit comprises a socket J5, a relay K2, a diode D5, a triode Q3, a resistor R16 and a signal input SW3, wherein the signal input SW3 is from a pin of a single chip microcomputer STM8S005K 6.

Further, the 4-20mA output circuit comprises resistors R18-R25, capacitors C23-24, an operational amplifier IC1A-IC1B, a triode Q4, a diode D6, a signal input PWM and a 4-20mA current output OUT, wherein the signal input PWM is a pulse width modulation signal output by the singlechip STM8S005K 6.

Further, the RS485 bus circuit comprises a level conversion chip U4, resistors R7-R9, R12, R15, capacitors C12-C13, C17, a transient suppression chip U6, a socket J4 and signal inputs RXD, TXD and DIR, wherein the signal inputs RXD, TXD and DIR are connected to pins of a single chip microcomputer STM8S005K6, the TXD and RXD are serial communication signals of the single chip microcomputer, and the DIR is used for controlling the direction of data transmission.

Has the advantages that:

the utility model discloses there will be and show that combustible gas detector has carried out the modularized design, falls into three module: the sensor module, the mainboard module and the display module can be separated, combined and flexibly combined, and can fully meet the requirements of customers; the modules are unified, the production and debugging are convenient, and the quality control is simple; the performance is more stable and the measurement is more accurate due to the fact that the microprocessor is arranged in the whole device; the sensor module is used as a single module, a new sensor module can be designed to adapt to other types of gas sensors when required by customers, and expansibility is strong.

Drawings

FIG. 1 is a block diagram of a combustible gas detector with display in modular structure;

fig. 2 is a block diagram of the main board module of the present invention;

fig. 3 is a circuit diagram of the sensor module of the present invention;

fig. 4 is a circuit diagram of the amplifying circuit of the present invention;

fig. 5 is a circuit diagram of the single chip circuit of the present invention;

fig. 6 is a circuit diagram of the relay output circuit of the present invention;

FIG. 7 is a circuit diagram of the 4-20mA output circuit of the present invention;

fig. 8 is a circuit diagram of the RS485 bus circuit of the present invention;

fig. 9 is a circuit diagram of the LED display module of the present invention;

fig. 10 is a circuit diagram of the LCD display module of the present invention;

in the figure: the display device comprises a sensor module 1, a mainboard module 2, an amplifying circuit 21, a singlechip circuit 22, a relay output circuit 23, a 24-4-20mA output circuit, a 25-RS485 bus circuit, a power supply circuit 26, a display module 3, an LED display module 31 and an LCD display module 32.

Detailed Description

The present invention will be further explained with reference to the drawings and examples.

The utility model provides an adopt modular structure have and show combustible gas detector, as shown in FIG. 1, it includes consecutive sensor module 1, mainboard module 2 and display module 3, and display module 3 includes LED display module 31 and LCD display module 32.

As shown in fig. 2, the motherboard module 2 includes an amplifying circuit 21, a single chip microcomputer circuit 22, a relay output circuit 23, a 4-20mA output circuit 24, an RS485 bus circuit 25 and a power supply circuit 26, the amplifying circuit 21 is connected to the single chip microcomputer circuit 22, the single chip microcomputer circuit 22 is respectively connected to the relay output circuit 23, the 4-20mA output circuit 24 and the RS485 bus circuit 25, and the power supply circuit 26 is used for converting 24V to 5V and 2.5V, and is implemented by using a common circuit.

As shown in fig. 3, the sensor module 1 includes a catalytic combustion gas sensor U1, a bit filter capacitor C1, and a connection terminal P1, the connection terminal P1 is connected to the motherboard module 2, and the U1 employs a catalytic combustion gas sensor NAP55 from japan. The current detector is applied to combustible gas detection, temporarily only has one sensor module 1, and is suitable for catalytic combustion gas sensors. However, since the sensor module 1 is a single module, a new sensor module 1 can be designed to accommodate other types of gas sensors, such as electrochemical gas sensors, NDIR gas sensors, PID gas sensors, semiconductor gas sensors, etc., for a wider variety of, concentration gas measurements, as desired by the customer.

As shown in fig. 4, the amplifying circuit 21 includes a socket J3, connectors JP1, JP2, resistors R4-R6, R10-R11, R13-R14, R26, capacitors C14-16, operational amplifiers U5A, U5B, and J3 connected to the sensor module 1, wherein the sensor signal is filtered by the capacitors C16, and then sent to a differential amplifying circuit composed of U5A for amplification together with a follower composed of U5B and a reference signal divided by R6 and R14, and a differential pressure signal is output. The amplification factor depends on the resistors R5, R11 and R4, R13. The amplified signal is filtered by a low pass filter composed of R10 and C15 and then sent to the input terminal of an analog-to-digital conversion circuit inside the single chip circuit 22 for data conversion.

As shown in FIG. 5, the single chip microcomputer circuit 22 comprises a single chip microcomputer STM8S005K6 and capacitors C19-C21 of ST company.

As shown in fig. 6, the relay output circuit 23 includes a socket J5, a relay K2, a diode D5, a transistor Q3, a resistor R16, and a signal input SW3, and the signal input SW3 is from a pin of the single chip microcomputer STM8S005K 6. The signal output of SW3 is controlled by the one-chip microcomputer circuit 22 based on the measured gas concentration. When SW3 is at low level, Q3 is disconnected, relay K2 is not attracted, and J5 is in a normally open state; when SW3 outputs high level, Q3 is conducted, relay K2 pulls in, and J5 is in conducting state.

As shown in fig. 7, the 4-20mA output circuit 24 includes resistors R18-R25, capacitors C23-24, an operational amplifier IC1A-IC1B, a transistor Q4, a diode D6, a signal input PWM and a 4-20mA current output OUT, the signal input PWM is a pulse width modulation signal output by the single chip microcomputer STM8S005K6, a dc voltage signal proportional to a duty ratio is output after being filtered by a low pass filter composed of R19, C23, R20 and C24, and an output voltage after being filtered by a follower composed of IC1A is used as an input signal of the 4-20mA conversion circuit. The IC1B and the Q4 form a current negative feedback amplifying circuit, an input signal is compared with the voltage on the sampling resistor R25, and the difference voltage is amplified to drive the Q4. When the input signal is greater than the voltage across the sampling resistor R25, the IC1B output voltage increases, causing the Q4 output current to increase, resulting in an increase in the voltage across R25; when the input signal is less than the voltage across the sampling resistor R25, the IC1B output voltage decreases, thereby decreasing the Q4 output current, resulting in a decrease in the voltage across R25; through such a negative feedback process, the voltage on the input signal and the sampling resistor R25 are equalized, thereby ensuring that the output current is equal to the input voltage/R25. Since R22 is 180 Ω, the 4-20mA output current corresponds to an input voltage of 720 mV-3.6V.

As shown in fig. 8, the RS485 bus circuit 25 includes a level conversion chip U4, resistors R7-R9, R12, R15, capacitors C12-C13, C17, a transient suppression chip U6, a socket J4, and signal inputs RXD, TXD, and DIR, wherein the signal inputs RXD, TXD, and DIR are connected to pins of a single chip STM8S005K6, the TXD and RXD are serial communication signals of the single chip, and DIR is used for controlling the direction of data transmission, and is in a receiving state when DIR is low level and is in a transmitting state when DIR is high level. The U4 is an RS485 level conversion chip and can be replaced by a chip with the same function. In the figure, R8 and R12 are current limiting resistors; u6 is a transient suppression chip for protecting RS485 chip; c13 and C17 are filter capacitors for filtering high-frequency noise on the signal line; r7, R9, R15 are used to provide a certain bus state when there is no data transfer; c12 is a chip decoupling capacitor; the socket J4 is used for RS485 bus connection.

The LED display module 31 shown in fig. 9 and the LCD display module 32 shown in fig. 10 have the same shape, size and connection mode, and can be directly replaced. In fig. 9, D2, D3, D4 and D5 are low-alarm, high-alarm, fault and power indicator lamps, and R2, R3, R6 and R7 current-limiting resistors, respectively; u1 is infrared receiving head for realizing remote control operation, C1, C2 bit power filter capacitor, R1 bit pull-up resistor; d1 bit four-digit nixie tube, U2 is driving chip, model TM1650, I2C bus interface, R4, R5 are bus pull-up resistance. In fig. 10, D2, D3, D4 and D5 are low-alarm, high-alarm, fault and power indicator lamps respectively, and R2, R3, R6 and R7 current-limiting resistors; u2 is infrared receiving head for realizing remote control operation, C1, C2 bit power filter capacitor, R1 bit pull-up resistor; u1 bit four-bit liquid crystal, U3 is driving chip, model HT16C21, I2C bus interface, R4, R5 are bus pull-up resistors.

To the limitation of the protection scope of the present invention, it should be understood by those skilled in the art that, on the basis of the technical solution of the present invention, various modifications or deformations that can be made by those skilled in the art without creative efforts are still within the protection scope of the present invention.

Claims (6)

1. The utility model provides an adopt modular structure have and show combustible gas detector which characterized in that: the display module comprises a sensor module (1), a main board module (2) and a display module (3) which are sequentially connected, wherein the sensor module (1) is an independent module; the mainboard module (2) comprises an amplifying circuit (21), a single chip microcomputer circuit (22), a relay output circuit (23), a 4-20mA output circuit (24), an RS485 bus circuit (25) and a power supply circuit (26), the amplifying circuit (21) is connected with the single chip microcomputer circuit (22), used for transmitting the sensor signal to a single chip circuit (22) for data conversion after being amplified by an amplifying circuit (21), the single chip circuit (22) is respectively connected with a relay output circuit (23), a 4-20mA output circuit (24) and an RS485 bus circuit (25), the single chip circuit (22) is used for controlling the signal output of the relay output circuit (23), the 4-20mA output circuit (24) and the RS485 bus circuit (25) according to the measured gas concentration, and the power supply circuit (26) is used for converting 24V into 5V and 2.5V; the display module (3) comprises an LED display module (31) and an LCD display module (32), and the LED display module (31) and the LCD display module (32) are identical in appearance, size and connection mode.

2. The combustible gas detector with display adopting modular structure as claimed in claim 1, wherein: the sensor module (1) comprises a catalytic combustion gas sensor U1, a bit filter capacitor C1 and a terminal P1, the terminal P1 being connected to the main board module (2).

3. The combustible gas detector with display adopting modular structure as claimed in claim 1, wherein: the single chip microcomputer circuit (22) comprises a single chip microcomputer STM8S005K6 and capacitors C19-C21.

4. The combustible gas detector with display adopting modular structure as claimed in claim 1, wherein: the relay output circuit (23) comprises a socket J5, a relay K2, a diode D5, a triode Q3, a resistor R16 and a signal input SW3, wherein the signal input SW3 is from a pin of a single chip microcomputer STM8S005K 6.

5. The combustible gas detector with display adopting modular structure as claimed in claim 1, wherein: the 4-20mA output circuit (24) comprises resistors R18-R25, capacitors C23-24, an operational amplifier IC1A-IC1B, a triode Q4, a diode D6, a signal input PWM and a 4-20mA current output OUT, wherein the signal input PWM is a pulse width modulation signal output by the singlechip STM8S005K 6.

6. The combustible gas detector with display adopting modular structure as claimed in claim 1, wherein: the RS485 bus circuit (25) comprises a level conversion chip U4, resistors R7-R9, R12, R15, capacitors C12-C13, C17, a transient suppression chip U6, a socket J4 and signal inputs RXD, TXD and DIR, wherein the signal inputs RXD, TXD and DIR are connected to pins of a single chip microcomputer STM8S005K6, the TXD and the RXD are serial communication signals of the single chip microcomputer, and the DIR is used for controlling the direction of data transmission.

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