Multi-gas detector

Abstract

The utility model discloses a multi-gas detector, which belongs to the technical field of gas monitoring equipment, and comprises a main control circuit, a plurality of sensor circuits and a power supply circuit, the main control circuit is connected with the plurality of sensor circuits, the power supply circuit is connected with the main control circuit and the plurality of sensor circuits, the main control circuit comprises a single chip microcomputer U35, and the single chip microcomputer U35 is connected with the power supply circuit. The model of the single-chip microcomputer U35 is STM32F103RCT7, analog-to-digital conversion can be realized through the single-chip microcomputer, an additional analog-to-digital conversion circuit does not need to be designed, and the single-chip microcomputer can directly convert analog signals acquired by the plurality of sensor circuits into digital signals, so that the gas detector realizes data acquisition and processing of a plurality of gases, and the detection efficiency is improved. The monitoring cost can be saved, and excessive use space is not occupied.

Description

Technical Field

[0001] The utility model belongs to the technical field of gas monitoring equipment, and particularly relates to a multi-gas detector. Background Art

[0002] In scenarios such as coal mines, mining, and chip manufacturing, when the concentration of harmful gases reaches a certain level, there will be life-threatening situations such as explosions or poisoning. However, the human body's perception is slow, resulting in a short reaction time and easily causing losses to personnel and property.

[0003] Currently, the monitoring of harmful gases such as hydrogen sulfide, methane, and carbon monoxide is all for single gas detectors. When it is necessary to monitor two or more harmful gases, multiple gas detectors need to be used, resulting in higher monitoring costs and larger space occupation by using multiple gas detectors.

[0004] Therefore, how to integrate multiple gas detection devices into one is a technical problem that needs to be solved by those skilled in the art currently. Summary of the Utility Model

[0005] In order to solve the problem that most existing gas detectors are for single gas monitoring, the utility model provides a multi-gas detector that can simultaneously monitor multiple gases.

[0006] The technical solution of the utility model lies in:

[0007] A multi-gas detector of the utility model includes a main control circuit, several sensor circuits, and a power supply circuit. The main control circuit is connected to several of the sensor circuits, and the power supply circuit is connected to the main control circuit and several of the sensor circuits. The main control circuit includes a single-chip microcomputer U35, and the model of the single-chip microcomputer U35 is STM32F103RCT7.

[0008] Further, the sensor circuits include a CO sensor circuit, an H2S sensor circuit, an O2 sensor circuit, and a CH4 sensor circuit. The CO sensor circuit includes a CO sensor U7, an operational amplifier U5, an operational amplifier U68, an operational amplifier U80, and several resistors. The H2S sensor circuit includes an H2S sensor U4, an operational amplifier U81, an operational amplifier U58, an operational amplifier U82, and several resistors. The O2 sensor circuit includes an O2 sensor U63, an operational amplifier U67, an operational amplifier U84, and several resistors. The CH4 sensor circuit includes a CH4 sensor U86, zener diodes D8-D9, and several resistors.

[0009] Further, the model of the CO sensor U7 is acm3000, the model of the H2S sensor U4 is ahs3000, the models of the operational amplifier U5 and the operational amplifier U81 are both OPA4330AIDR, and the models of the operational amplifier U68, the operational amplifier U80, the operational amplifier U58, the operational amplifier U82, the operational amplifier U67 and the operational amplifier U84 are all AD8552M / TR.

[0010] Further, an alarm circuit is further included, and the alarm circuit includes a buzzer, light-emitting diodes LED1-LED4 and a vibrator U9.

[0011] Further, a display circuit is further included, and the display circuit includes an LCD display screen.

[0012] Further, the power supply circuit includes a charging management module, a sensor power supply module and a charging interface module. The charging management module includes a battery management chip U16, a battery management chip U88 and an operational amplifier U62. The battery management chip U16 is electrically connected to the battery management chip U88 and the operational amplifier U62 respectively. The sensor power supply module includes a plurality of switched capacitor voltage multipliers and a linear voltage regulator U26. The switched capacitor voltage multipliers and the linear voltage regulator U26 are both connected to a 5V power supply. The charging interface module includes a USB conversion chip U2, a USB connector and an electrostatic diode D2. The USB conversion chip U2 is electrically connected to the USB connector and the electrostatic diode D2.

[0013] Further, the model of the battery management chip U16 is TP4056, the model of the battery management chip U88 is CN302, the model of the switched capacitor voltage multiplier is PW5410A, the model of the linear voltage regulator U26 is AMS1117-3.3, the model of the USB conversion chip U2 is CH340N, and the model of the electrostatic diode D2 is SRV05-4.

[0014] Further, the sensor circuit further includes a temperature sensor circuit, and the temperature sensor circuit includes an NTC thermistor, an operational amplifier U85 and a plurality of resistors. The operational amplifier U85 is electrically connected to the NTC thermistor and the resistors.

[0015] The beneficial effects of the present utility model are as follows:

[0016] Multi-gas monitoring can be achieved by setting a main control circuit, several sensor circuits and a power supply circuit in a multi-gas detector. The single-chip microcomputer model used in the main control circuit is STM32F103RCT7. Through this single-chip microcomputer, analog-to-digital conversion can be achieved without designing an additional analog-to-digital conversion circuit. The single-chip microcomputer can directly convert the analog signals collected by several sensor circuits into digital signals, so that the gas detector realizes data acquisition and processing of multiple gases, which can save monitoring costs and will not occupy too much space for use. Description of the Drawings

[0017] Figure 1 It is the circuit principle block diagram of a multi-gas detector of the present utility model;

[0018] Figure 2 It is the circuit diagram of the main control circuit of a multi-gas detector of the present utility model;

[0019] Figure 3 It is the circuit diagram of the CO sensor circuit of a multi-gas detector of the present utility model;

[0020] Figure 4 It is the circuit diagram of the H2S sensor circuit of a multi-gas detector of the present utility model;

[0021] Figure 5 It is the circuit diagram of the O2 sensor circuit of a multi-gas detector of the present utility model;

[0022] Figure 6 It is the circuit diagram of the CH4 sensor circuit of a multi-gas detector of the present utility model;

[0023] Figure 7 It is the circuit diagram of the temperature sensor circuit of a multi-gas detector of the present utility model;

[0024] Figure 8 It is the circuit diagram of the alarm circuit of a multi-gas detector of the present utility model;

[0025] Figure 9 It is the circuit diagram of the display circuit of a multi-gas detector of the present utility model;

[0026] Figure 10 It is the circuit diagram of the charging management module of a multi-gas detector of the present utility model;

[0027] Figure 11 It is the circuit diagram of the sensor power supply module of a multi-gas detector of the present utility model;

[0028] Figure 12 It is the circuit diagram of the charging interface module of a multi-gas detector of the present utility model;

[0029] Reference numerals: 1, main control circuit; 2, sensor circuit; 21, CO sensor circuit; 22, H2S sensor circuit; 23, O2 sensor circuit; 24, CH4 sensor circuit; 3, power supply circuit; 31, charging management module; 32, sensor power supply module; 33, charging interface module; 4, alarm circuit; 41, buzzer. Detailed implementation manners

[0030] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present utility model clearer and more understandable, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0031] It should be noted that when an element is referred to as being "installed on", "provided on", "covered on", "sheathed on", "clamped on" another element, it can be directly on the other element or indirectly on the other element.

[0032] It should be understood that in the description of the present utility model, the meaning of "a plurality of" is two or more, unless otherwise clearly and specifically defined.

[0033] In addition, the orientation or positional relationship indicated by terms such as "inside", "above", "between", "on both sides", "on one side", "top", "bottom", "side" and the like is the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present utility model.

[0034] It should be noted that the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first", "second", "third", etc. may explicitly or implicitly include one or more of such features.

[0035] It should be noted that the "and / or" herein is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Among them, A and B can be singular or plural respectively.

[0036] Please refer to Figures 1 - 12, the present utility model provides a multi-gas detector, which includes a main control circuit 1, several sensor circuits 2 and a power supply circuit 3. The main control circuit 1 is connected to several sensor circuits 2, and the power supply circuit 3 is connected to the main control circuit 1 and several sensor circuits 2. The main control circuit 1 includes a single-chip microcomputer U35, and the model of the single-chip microcomputer U35 is STM32F103RCT7. An analog-to-digital converter ADC is built into this single-chip microcomputer. Through this single-chip microcomputer, analog-to-digital conversion can be achieved without designing an additional analog-to-digital conversion circuit. The single-chip microcomputer can directly convert the analog signals collected by several sensor circuits 2 into digital signals. Thus, the gas detector realizes data acquisition and processing of multiple gases, can save monitoring costs and does not occupy too much usage space. In addition, the single-chip microcomputer U35 with the model of STM32F103RCT7 is a high-speed processor and can work timely, stably and reliably.

[0037] The sensor circuit 2 includes a CO sensor circuit 21, an H2S sensor circuit 22, an O2 sensor circuit 23 and a CH4 sensor circuit 24. The CO sensor circuit 21 includes a CO sensor U7, an operational amplifier U5, an operational amplifier U68, an operational amplifier U80 and several resistors. The H2S sensor circuit 22 includes an H2S sensor U4, an operational amplifier U81, an operational amplifier U58, an operational amplifier U82 and several resistors. The O2 sensor circuit 23 includes an O2 sensor U63, an operational amplifier U67, an operational amplifier U84 and several resistors. The CO sensor circuit 21, the H2S sensor circuit 22 and the O2 sensor circuit 23 are integrated as a bridge. The sensor converts the physical quantity into an analog signal. The change in the resistance values of several resistors can measure the change in external force or physical quantity. The operational amplifier amplifies, filters and analyzes the analog signal of the sensor, realizing the miniaturization, integration and facilitation of the overall circuit. It can greatly simplify the structure of the sensor system, reduce the external connection lines, lower the circuit complexity, and improve the reliability and stability of the circuit. The CH4 sensor circuit 24 includes a CH4 sensor U86, zener diodes D8 - D9 and several resistors.

[0038] The model of the CO sensor U7 is acm3000, the model of the H2S sensor U4 is ahs3000, the models of the operational amplifier U5 and the operational amplifier U81 are both OPA4330AIDR, and the models of the operational amplifier U68, the operational amplifier U80, the operational amplifier U58, the operational amplifier U82, the operational amplifier U67 and the operational amplifier U84 are all AD8552M / TR. The CO sensor U7, the H2S sensor U4 and the O2 sensor U63 are all electrochemical sensors, and their electrodes are pre-coated with a specific electrolyte solution or solid. The chemical reaction between hydrogen sulfide and the electrolyte is used to generate a current change to detect the concentration of hydrogen sulfide, the chemical reaction between carbon monoxide and the electrolyte is used to generate a current change to detect the concentration of carbon monoxide, and the redox reaction between oxygen and the electrolyte is used to generate a current change to detect the concentration of oxygen; the CH4 sensor U86 is a thermal conductivity sensor, and the heat absorbed by methane is measured to detect its concentration.

[0039] In summary, the sensor circuit 2 adopts the integration method of electrochemistry and bridge, enabling multiple gases to be sensed simultaneously, with high accuracy and strong stability.

[0040] Furthermore, a multi-gas detector of the present utility model further includes an alarm circuit 4. The alarm circuit 4 includes a buzzer 41, light-emitting diodes LED1-LED4 and a vibrator U9. The buzzer 41 emits a sound, and by observing which light-emitting diode is actually lit and flashing for reminder, and the gas detector gives a vibration reminder. With these three reminders, workers in the working state can make timely responses, avoiding personal injuries and property losses.

[0041] Furthermore, it further includes a display circuit 5. The display circuit 5 includes an LCD display screen, that is, the human-computer interaction method using an LCD screen. Through the LCD display screen, the concentration conditions of hydrogen sulfide, methane, carbon monoxide and oxygen in the current environment can be displayed. It should be noted that human-computer interaction can also be combined with buttons, and the multi-gas detector can be controlled through the buttons.

[0042] Further, the power supply circuit 3 includes a charging management module 31, a sensor power supply module 32, and a charging interface module 33. The charging management module 31 includes a battery management chip U16, a battery management chip U88, and an operational amplifier U62. The battery management chip U16 is electrically connected to the battery management chip U88 and the operational amplifier U62 respectively. The sensor power supply module 32 includes a number of switched capacitor voltage multipliers and a linear voltage regulator U26. The switched capacitor voltage multipliers and the linear voltage regulator U26 are both connected to a 5V power supply. The charging interface module 33 includes a USB conversion chip U2, a USB connector, and an electrostatic diode D2. The USB conversion chip U2 is electrically connected to the USB connector and the electrostatic diode D2. That is, the multi-gas detector adopts an internal lithium battery power supply mode. When it runs out of power, it is charged using a USB interface.

[0043] Further, the model of the battery management chip U16 is TP4056, the model of the battery management chip U88 is CN302, the model of the switched capacitor voltage multiplier is PW5410A, the model of the linear voltage regulator U26 is AMS1117-3.3, the model of the USB conversion chip U2 is CH340N, and the model of the electrostatic diode D2 is SRV05-4. Among them, the upper threshold and the lower threshold of the battery management chip U88 with the model CN302 can be set independently, which is convenient for setting hysteresis. When the battery voltage is lower than the set lower threshold, the LBO pin of CN302 outputs a low level, and the LBO pin outputs a high level. When the battery voltage is greater than the upper threshold, the LBO pin of CN302 outputs a high level, and the LBO pin outputs a low level. The voltage difference between the lower threshold and the upper threshold is the hysteresis. Hysteresis can eliminate the detection output disorder caused by the noise of the detected power supply or the instability of the battery voltage caused by sudden changes in the load.

[0044] Further, the sensor circuit 2 further includes a temperature sensor circuit 25. The temperature sensor circuit 25 includes an NTC thermistor, an operational amplifier U85, and a number of resistors. The operational amplifier U85 is electrically connected to the NTC thermistor and the resistors. That is, the multi-gas detector can also monitor the current ambient temperature and display it on the LCD display screen.

[0045] The above embodiments only represent one implementation mode of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims

1. A multi-gas detector, characterized in that: The invention comprises a main control circuit (1), a plurality of sensor circuits (2) and a power supply circuit (3), wherein the main control circuit (1) is connected to the plurality of sensor circuits (2), the power supply circuit (3) is connected to the main control circuit (1) and the plurality of sensor circuits (2), the main control circuit (1) comprises a single-chip microcomputer U35, and the model of the single-chip microcomputer U35 is STM32F103RCT7; The sensor circuit (2) comprises a CO sensor circuit (21), an H2S sensor circuit (22), an O2 sensor circuit (23) and a CH4 sensor circuit (24); the CO sensor circuit (21) comprises a CO sensor U7, an operational amplifier U5, an operational amplifier U68, an operational amplifier U80 and a plurality of resistors; the H2S sensor circuit (22) comprises an H2S sensor U4, an operational amplifier U81, an operational amplifier U58, an operational amplifier U82 and a plurality of resistors; the O2 sensor circuit (23) comprises an O2 sensor U63, an operational amplifier U67, an operational amplifier U84 and a plurality of resistors; and the CH4 sensor circuit (24) comprises a CH4 sensor U86, voltage stabilizing diodes D8-D9 and a plurality of resistors.

2. The multi-gas detector according to claim 1, characterized in that: The model of the CO sensor U7 is acm3000, the model of the H2S sensor U4 is ahs3000, the models of the operational amplifier U5 and the operational amplifier U81 are both OPA4330AIDR, and the models of the operational amplifier U68, the operational amplifier U80, the operational amplifier U58, the operational amplifier U82, the operational amplifier U67 and the operational amplifier U84 are all AD8552M / TR.

3. The multi-gas detector according to claim 1, characterized in that: It also includes an alarm circuit (4), which includes a buzzer (41), light-emitting diodes LED1-LED4 and a vibrator U9.

4. The multi-gas detector according to claim 3, characterized in that: It also comprises a display circuit (5), wherein the display circuit (5) comprises an LCD display screen.

5. The multi-gas detector according to claim 1, characterized in that: The power supply circuit (3) comprises a charging management module (31), a sensor power supply module (32) and a charging interface module (33); the charging management module (31) comprises a battery management chip U16, a battery management chip U88 and an operational amplifier U62; the battery management chip U16 is electrically connected to the battery management chip U88 and the operational amplifier U62 respectively; the sensor power supply module (32) comprises a plurality of switch capacitor voltage multipliers and a linear voltage regulator U26; the switch capacitor voltage multipliers and the linear voltage regulator U26 are both connected to a 5V power supply; the charging interface module (33) comprises a USB conversion chip U2, a USB connector and an electrostatic diode D2; the USB conversion chip U2 is electrically connected to the USB connector and the electrostatic diode D2.

6. The multi-gas detector according to claim 5, characterized in that: The model of the battery management chip U16 is TP4056, the model of the battery management chip U88 is CN302, the model of the switched capacitor voltage doubler is PW5410A, the model of the linear regulator U26 is AMS1117-3.3, the model of the USB conversion chip U2 is CH340N, and the model of the electrostatic diode D2 is SRV05-4.

7. The multi-gas detector according to claim 1, characterized in that: The sensor circuit (2) further comprises a temperature sensor circuit (25), wherein the temperature sensor circuit (25) comprises an NTC thermistor, an operational amplifier U85 and a plurality of resistors, wherein the operational amplifier U85 is electrically connected to the NTC thermistor and the resistors.

Images