CN217060789U

CN217060789U - Alarm for harmful gas in vehicle

Info

Publication number: CN217060789U
Application number: CN202123420144.7U
Authority: CN
Inventors: 邱志杰
Original assignee: Xiamen Hedman Electronic Technology Co ltd
Current assignee: Xiamen Hedman Electronic Technology Co ltd
Priority date: 2021-12-31
Filing date: 2021-12-31
Publication date: 2022-07-26
Anticipated expiration: 2031-12-31

Abstract

The utility model relates to a monitoring field discloses an alarm of harmful gas in car in the car. It comprises the following steps: the voltage reduction module, the low voltage detection module, gaseous detection module, MCU control module, display module and alarm module, on-vehicle DC power supply is connected to the input of voltage reduction module, voltage reduction module parallel connection MCU control module, the low voltage detection module, display module and gaseous detection module, MCU control module connects display module, MCU control module connects the low voltage detection module, MCU control module connects alarm module, on-vehicle DC power supply is connected to the low voltage detection module, alarm module connects on-vehicle DC power supply. Through rationalizing the design to the alarm, adopt step-down module, low pressure detection module, gaseous detection module, MCU control module, display module and alarm module, can detect often and report to the police and prejudge the combustible gas in the car.

Description

Alarm for harmful gas in vehicle

Technical Field

The utility model relates to a monitoring field in the car, concretely relates to harmful gas's alarm in car.

Background

With the improvement of living standard of people, the caravan is more popular, and although facilities on the caravan are complete, the caravan is accompanied by more and more potential safety hazards. In order to avoid some safety problems, it is necessary to detect the concentration of combustible gas in real time in a motor home. The existing product can only fix an alarm point for alarming, has no visual interface, and cannot display the current combustible gas concentration and self-define the alarm point in real time.

Therefore, the existing alarm apparatus needs to be further improved in view of the above problems.

SUMMERY OF THE UTILITY MODEL

The utility model aims at overcoming current alarm and not showing combustible gas concentration in real time and warning in advance the scheduling problem, through carrying out rationalization design to the alarm, adopt step-down module, low pressure detection module, gaseous detection module, MCU control module, display module and alarm module, can detect often and report to the police and predict the combustible gas in the car. Adopt the step-down module, can realize the power supply demand of other modules, adopt MCU control module and gaseous detection module, can detect the gas state in the car often, adopt MCU control module and display module, can show the gas concentration value often, adopt MCU control module and alarm module, can in time report to the police, adopt MCU control module and low pressure detection module, include the work of other each modules when carrying out the low pressure.

The technical scheme of the utility model is specifically as follows:

an alarm for noxious gases in a vehicle, the alarm comprising: the input end of the voltage reduction module is connected with the output end of a vehicle-mounted direct-current power supply, the output end of the voltage reduction module is connected with the power input end of the MCU control module, the low-voltage input end of the low-voltage detection module, the power input end of the display module and the power input end of the gas detection module in parallel, the detection output end of the MCU control module is connected with the detection input end of the gas detection module, the display output end of the MCU control module is connected with the display input end of the display module, the enable end of the MCU control module is connected with the enable end of the low-voltage detection module, the pulse signal end of the MCU control module is connected with the pulse signal end of the alarm module, the power input end of the low-voltage detection module is connected with the output end of the vehicle-mounted direct-current power supply, and the power input end of the alarm module is connected with the output end of the vehicle-mounted direct-current power supply.

Further, the voltage reduction module includes a voltage reduction circuit, the voltage reduction circuit includes an interface CON1, a capacitor E1, a capacitor C1, a chip IC2, an inductor L1, a capacitor E2, and a capacitor C3, the input end of the interface CON1 is connected to the output end of the on-board dc power supply, the "1" terminal of the interface CON1 is grounded, the "2" terminal of the interface CON1 is connected in parallel to the anode of the capacitor E1, one end of the capacitor C1 and the "1" terminal of the chip IC2, the "2" terminal of the chip IC2 is commonly connected to the negative terminal of the capacitor E1 and the other terminal of the capacitor C1, the '5' terminal of the chip IC2 is connected with one end of the inductor L1, the other end of the inductor L1 is connected with the '4' terminal of the chip IC2, the positive electrode of the capacitor E2 and one end of the capacitor C3 in parallel, the negative electrode of the capacitor E2 and the other end of the capacitor C3 are grounded in common, and the other end of the inductor L1 is set as the output end of the voltage reduction module.

Further, the low voltage detection module includes a low voltage detection circuit, the low voltage detection circuit includes resistance R6, resistance R7, resistance R8, electric capacity C5 and diode D2, the one end of resistance R8 is connected the output of on-vehicle dc power supply, resistance R8's other end parallel connection resistance R6's one end, resistance R7's one end and diode D2's positive pole, diode D2's negative pole is connected the output of step-down module, resistance R6's other end ground connection, resistance R7's other end parallel connection the enable end of MCU control module and the one end of electric capacity C5, the other end ground connection of electric capacity C5.

Further, the gas detection module comprises a gas detection circuit, the gas detection circuit comprises a resistor R3, a resistor R4, a resistor R5 and a pre-calibration module, a terminal 1 of the pre-calibration module is connected with the output end of the voltage reduction module, a terminal 2 of the pre-calibration module is connected with one end of the resistor R3, the other end of the resistor R3 is connected with the first detection output end of the MCU control module, a terminal 3 of the pre-calibration module is connected with one end of the resistor R4, the other end of the resistor R4 is connected with the second detection output end of the MCU control module, a terminal 4 of the pre-calibration module is grounded, a terminal 5 of the pre-calibration module is connected with one end of the resistor R5, and the other end of the resistor R5 is connected with the third detection output end of the MCU control module.

Further, the MCU control module includes MCU control circuit, MCU control circuit includes chip IC1, resistance R19 and switch K1, chip IC1 '28's terminal is connected the output of step-down module, chip IC1 '1' terminal ground connection, chip IC1 '14' terminal is connected resistance R19's one end, resistance R19's the other end is connected switch K1's one end, switch K1's the other end ground connection.

Further, the display module comprises a display circuit, the display circuit comprises a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R15, a resistor R16, a resistor R17, a resistor R18, a transistor Q2, a transistor Q3 and an LED1, a "1" terminal of the LED1 is connected to one end of the resistor R18, the other end of the resistor R18 is connected to a first display output end of the MCU control module, a "2" terminal of the LED1 is connected to one end of the resistor R17, the other end of the resistor R17 is connected to a second display output end of the MCU control module, a "3" terminal of the LED1 is connected to one end of the resistor R16, the other end of the resistor R16 is connected to a third display output end of the MCU control module, a "4" terminal of the LED1 is connected to one end of the resistor R15, the other end of the resistor R15 is connected to a fourth display output end of the MCU control module, a terminal "5" of the LED1 is connected to a collector of the transistor Q3, an emitter of the transistor Q3 is connected to an output terminal of the buck module, a base of the transistor Q3 is connected to one end of the resistor R10, the other end of the resistor R10 is connected to a fifth display output terminal of the MCU control module, a terminal "6" of the LED1 is connected to one end of the resistor R11, the other end of the resistor R11 is connected to a sixth display output terminal of the MCU control module, a terminal "7" of the LED1 is connected to one end of the resistor R12, the other end of the resistor R12 is connected to a seventh display output terminal of the MCU control module, a terminal "8" of the LED1 is connected to one end of the resistor R13, the other end of the resistor R13 is connected to an eighth display output terminal of the MCU control module, a terminal "9" of the LED1 is connected to one end of the resistor R14, and the other end of the resistor R14 is connected to a ninth display output terminal of the MCU control module, the '10' terminal of the LED1 is connected with the collector of the triode Q2, the emitter of the triode Q2 is connected with the output end of the voltage reduction module, the base of the triode Q2 is connected with one end of the resistor R9, and the other end of the resistor R9 is connected with the tenth display output end of the MCU control module.

Further, the alarm module comprises an alarm circuit, the alarm circuit comprises an inductor L12, a resistor R1, a diode D1, a resistor R2, a triode Q1 and a speaker BEEP, the inductor L12 is provided with two output ends, the input end of the inductor L12 is connected with the output end of the vehicle-mounted direct current power supply, the first output end of the inductor L12 is connected with the input end of the speaker BEEP, the second output end of the inductor L12 is connected in parallel with one end of the resistor R1, the negative electrode of the diode D1 and the output end of the speaker BEEP, the other end of the resistor R1 is connected in parallel with the positive electrode of the diode D1 and the collector electrode of the triode Q1, the emitter of the triode Q1 is grounded, the base of the triode Q1 is connected with one end of the resistor R2, and the other end of the resistor R2 is connected with the pulse signal end of the MCU control module.

Furthermore, the model of the LED1 is an MJG-3261 LED device.

Furthermore, the model of the chip IC1 is HT66F 0185.

Furthermore, the model of the pre-calibration module is FSM-10H-01.

Furthermore, the model of the chip IC2 is an AP2905 chip.

Further, the diode D2 is an IN4148 diode.

Further, the diode D1 is F7.

Advantageous effects

The utility model discloses a rationalize the design to the alarm, adopt step-down module, low pressure detection module, gaseous detection module, MCU control module, display module and alarm module, can detect often and report to the police and prejudge the combustible gas in the car. Adopt the step-down module, can realize the power supply demand of other modules, adopt MCU control module and gaseous detection module, can detect the gas state in the car often, adopt MCU control module and display module, can show the gas concentration value often, adopt MCU control module and alarm module, can in time report to the police, adopt MCU control module and low pressure detection module, include the work of other each modules when carrying out the low pressure.

Drawings

Fig. 1 is a schematic structural view of the alarm for harmful gas in a vehicle of the present invention.

Reference numerals: 1. a voltage reduction module; 2. a low voltage detection module; 3. a gas detection module; 4. an MCU control module; 5. a display module; 6. and an alarm module.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts all belong to the protection scope of the present invention.

Referring to fig. 1, the utility model provides a pair of in-car harmful gas's alarm, the alarm includes: the device comprises a voltage reduction module 1, a low-voltage detection module 2, a gas detection module 3, an MCU control module 4, a display module 5 and an alarm module 6, wherein the input end of the voltage reduction module is connected with the output end of a vehicle-mounted direct-current power supply, the output end of the voltage reduction module is connected with the power input end of the MCU control module, the low-voltage input end of the low-voltage detection module, the power input end of the display module and the power input end of the gas detection module in parallel, the detection output end of the MCU control module is connected with the detection input end of the gas detection module, the display output end of the MCU control module is connected with the display input end of the display module, the enable end of the MCU control module is connected with the enable end of the low-voltage detection module, the pulse signal end of the MCU control module is connected with the pulse signal end of the alarm module, the power input end of the low-voltage detection module is connected with the output end of the vehicle-mounted direct-current power supply, and the power supply input end of the alarm module is connected with the output end of the vehicle-mounted direct-current power supply.

Wherein the voltage reduction module comprises a voltage reduction circuit, the voltage reduction circuit comprises an interface CON1, a capacitor E1, a capacitor C1, a chip IC2, an inductor L1, a capacitor E2 and a capacitor C3, the input end of the interface CON1 is connected to the output end of the on-board dc power supply, the "1" terminal of the interface CON1 is grounded, the "2" terminal of the interface CON1 is connected in parallel to the positive electrode of the capacitor E1, one end of the capacitor C1 and the "1" terminal of the chip IC2, the "2" terminal of the chip IC2 is commonly connected to the cathode of the capacitor E1 and the other end of the capacitor C1, the '5' terminal of the chip IC2 is connected with one end of the inductor L1, the other end of the inductor L1 is connected with the '4' terminal of the chip IC2, the positive electrode of the capacitor E2 and one end of the capacitor C3 in parallel, the negative electrode of the capacitor E2 and the other end of the capacitor C3 are grounded, and the other end of the inductor L1 is set as the output end of the voltage reduction module.

The low-voltage detection module comprises a low-voltage detection circuit, the low-voltage detection circuit comprises a resistor R6, a resistor R7, a resistor R8, a capacitor C5 and a diode D2, one end of the resistor R8 is connected with the output end of the vehicle-mounted direct-current power supply, the other end of the resistor R8 is connected with one end of the resistor R6, one end of the resistor R7 and the anode of the diode D2 in parallel, the cathode of the diode D2 is connected with the output end of the voltage reduction module, the other end of the resistor R6 is grounded, the other end of the resistor R7 is connected with the 27 terminal of the chip IC1 of the MCU control module and one end of the capacitor C5 in parallel, and the other end of the capacitor C5 is grounded.

The gas detection module comprises a gas detection circuit, the gas detection circuit comprises a resistor R3, a resistor R4, a resistor R5 and a pre-calibration module, wherein a 1 terminal of the pre-calibration module is connected with the output end of the voltage reduction module, a 2 terminal of the pre-calibration module is connected with one end of the resistor R3, the other end of the resistor R3 is connected with a 21 terminal of a chip IC1 of the MCU control module, a 3 terminal of the pre-calibration module is connected with one end of the resistor R4, the other end of the resistor R4 is connected with a 25 terminal of a chip IC1 of the MCU control module, a 4 terminal of the pre-calibration module is grounded, a 5 terminal of the pre-calibration module is connected with one end of the resistor R5, and the other end of the resistor R5 is connected with a 26 terminal of a chip IC1 of the MCU control module.

Wherein, MCU control module includes MCU control circuit, MCU control circuit includes chip IC1, resistance R19 and switch K1, chip IC 1's "28" terminal is connected the output of step-down module, chip IC1 "1" terminal ground connection, chip IC 1' 14 "terminal is connected resistance R19's one end, resistance R19's the other end is connected switch K1's one end, switch K1's other end ground connection.

Wherein, the display module comprises a display circuit, the display circuit comprises a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R15, a resistor R16, a resistor R17, a resistor R18, a triode Q2, a triode Q3, and an LED1, a terminal "1" of the LED1 is connected with one end of the resistor R1, the other end of the resistor R1 is connected with a terminal "20" of the chip IC1 of the MCU control module, a terminal "2" of the LED1 is connected with one end of the resistor R1, the other end of the resistor R1 is connected with a terminal "18" of the chip IC1 of the MCU control module, a terminal "4" of the LED1 is connected with one end of the resistor R1, the other end of the resistor R1 is connected with a terminal "68516" of the chip IC1 of the MCU control module, a "5" terminal of the LED1 is connected to a collector of the transistor Q3, an emitter of the transistor Q3 is connected to an output terminal of the buck module, a base of the transistor Q3 is connected to one end of the resistor R10, the other end of the resistor R10 is connected to a "2" terminal of the chip IC1 of the MCU control module, a "6" terminal of the LED1 is connected to one end of the resistor R11, the other end of the resistor R11 is connected to a "13" terminal of the chip IC1 of the MCU control module, a "7" terminal of the LED1 is connected to one end of the resistor R12, the other end of the resistor R12 is connected to a "24" terminal of the chip IC1 of the MCU control module, a "8" terminal of the LED1 is connected to one end of the resistor R13, the other end of the resistor R13 is connected to a "23" terminal of the chip IC1 of the MCU control module, and a "9" terminal of the LED1 is connected to one end of the resistor R14, the other end of the resistor R14 is connected with a '15' terminal of a chip IC1 of the MCU control module, a '10' terminal of the LED1 is connected with a collector of the triode Q2, an emitter of the triode Q2 is connected with an output end of the voltage reduction module, a base of the triode Q2 is connected with one end of the resistor R9, and the other end of the resistor R9 is connected with a '3' terminal of a chip IC1 of the MCU control module.

The alarm module comprises an alarm circuit, the alarm circuit comprises an inductor L12, a resistor R1, a diode D1, a resistor R2, a triode Q1 and a loudspeaker BEEP, the inductor L12 is provided with two output ends, the input end of the inductor L12 is connected with the output end of the vehicle-mounted direct-current power supply, the first output end of the inductor L12 is connected with the input end of the loudspeaker BEEP, the second output end of the inductor L12 is connected with one end of the resistor R1, the negative electrode of the diode D1 and the output end of the loudspeaker BEEP in parallel, the other end of the resistor R1 is connected with the positive electrode of the diode D1 and the collector electrode of the triode Q1 in parallel, the emitter electrode of the triode Q1 is grounded, the base electrode of the triode Q1 is connected with one end of the resistor R2, and the other end of the resistor R2 is connected with the '17' terminal of a chip IC1 of the MCU control module.

The LED1 is an MJG-3261 LED device, the chip IC1 is an HT66F0185 chip, the pre-calibration module is an FSM-10H-01 chip, the chip IC2 is an AP2905 chip, the diode D2 is an IN4148 diode, and the diode D1 is an F7 diode.

The utility model discloses a concrete implementation principle: the alarm converts 12VDC into 5VDC through the voltage reduction module and supplies power to other modules; the voltage of the storage battery of the motor home can be detected in real time through the low-voltage detection module, and when the voltage is lower than a set threshold value, reminding is carried out; processing the acquired information through the MCU control module, and outputting a display and alarm driving signal; the propane concentration information is collected through a gas detection module and transmitted to an MCU control module for processing; the MCU control module processes and outputs a driving signal, and the alarm module receives the driving signal and then outputs an alarm; the display module is used for displaying the acquired data in real time; the propane gas concentration in the environment can be detected in real time, visualization is achieved, numerical values can be displayed on the nixie tube in real time, an alarm point can be set, and the buzzer is driven to give an alarm when the detected concentration exceeds the alarm point. The concentration of propane in the environment is detected and displayed in real time, the detected concentration is compared with the set concentration, and an alarm is given when the detected concentration exceeds the set concentration. The alarm can detect and display the concentration value of propane in real time, and can alarm when the concentration value exceeds a set value by comparing the concentration value with the set alarm value, so that accidents caused by propane leakage are prevented.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. An alarm device for harmful gas in a vehicle, the alarm device comprising: the input end of the voltage reduction module is connected with the output end of a vehicle-mounted direct-current power supply, the output end of the voltage reduction module is connected with the power input end of the MCU control module, the low-voltage input end of the low-voltage detection module, the power input end of the display module and the power input end of the gas detection module in parallel, the detection output end of the MCU control module is connected with the detection input end of the gas detection module, the display output end of the MCU control module is connected with the display input end of the display module, the enable end of the MCU control module is connected with the enable end of the low-voltage detection module, the pulse signal end of the MCU control module is connected with the pulse signal end of the alarm module, the power input end of the low-voltage detection module is connected with the output end of the vehicle-mounted direct-current power supply, and the power input end of the alarm module is connected with the output end of the vehicle-mounted direct-current power supply.

2. The alarm for the harmful gas in the vehicle according to claim 1, wherein the voltage reduction module comprises a voltage reduction circuit, the voltage reduction circuit comprises an interface CON1, a capacitor E1, a capacitor C1, a chip IC2, an inductor L1, a capacitor E2 and a capacitor C3, an input end of the interface CON1 is connected with an output end of the vehicle-mounted DC power supply, a "1" terminal of the interface CON1 is grounded, a "2" terminal of the interface CON1 is connected in parallel with a positive electrode of the capacitor E1, one end of the capacitor C1 and a "1" terminal of the chip IC2, a "2" terminal of the chip IC2 is grounded with a negative electrode of the capacitor E1 and the other end of the capacitor C1, a "5" terminal of the chip IC2 is connected with one end of the inductor L1, the other end of the inductor L1 is connected in parallel with a "4" terminal of the chip IC2, a positive electrode of the capacitor E2 and one end of the capacitor C3, and the other end of the capacitor E3 are grounded, the other end of the inductor L1 is set as the output end of the voltage reduction module.

3. The alarm device for the harmful gases in the vehicle according to claim 1, wherein the low voltage detection module comprises a low voltage detection circuit, the low voltage detection circuit comprises a resistor R6, a resistor R7, a resistor R8, a capacitor C5 and a diode D2, one end of the resistor R8 is connected to the output end of the vehicle-mounted dc power supply, the other end of the resistor R8 is connected in parallel to one end of the resistor R6, one end of the resistor R7 and the anode of the diode D2, the cathode of the diode D2 is connected to the output end of the voltage reduction module, the other end of the resistor R6 is grounded, the other end of the resistor R7 is connected in parallel to the enable end of the MCU control module and one end of the capacitor C5, and the other end of the capacitor C5 is grounded.

4. The alarm for the harmful gas in the vehicle according to claim 1, the gas detection module includes a gas detection circuit including a resistor R3, a resistor R4, a resistor R5, and a pre-calibration module, the 1 terminal of the pre-calibration module is connected with the output end of the voltage reduction module, the 2 terminal of the pre-calibration module is connected with one end of the resistor R3, the other end of the resistor R3 is connected with a first detection output end of the MCU control module, a 3 terminal of the pre-calibration module is connected with one end of the resistor R4, the other end of the resistor R4 is connected with a second detection output end of the MCU control module, a '4' terminal of the pre-calibration module is grounded, and the '5' terminal of the pre-calibration module is connected with one end of the resistor R5, and the other end of the resistor R5 is connected with the third detection output end of the MCU control module.

5. The alarm of harmful gas in a vehicle according to claim 1, wherein the MCU control module comprises an MCU control circuit, the MCU control circuit comprises a chip IC1, a resistor R19 and a switch K1, a '28' terminal of the chip IC1 is connected with the output end of the voltage reduction module, a '1' terminal of the chip IC1 is grounded, a '14' terminal of the chip IC1 is connected with one end of the resistor R19, the other end of the resistor R19 is connected with one end of the switch K1, and the other end of the switch K1 is grounded.

6. The alarm device for harmful gases in vehicle according to claim 1, wherein said display module includes a display circuit, said display circuit includes a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R15, a resistor R16, a resistor R17, a resistor R18, a transistor Q2, a transistor Q3 and an LED1, said LED1 has a "1" terminal connected to one end of said resistor R18, said resistor R18 has another end connected to a first display output terminal of said MCU control module, said LED1 has a "2" terminal connected to one end of said resistor R17, said resistor R17 has another end connected to a second display output terminal of said MCU control module, said LED1 has a "3" terminal connected to one end of said resistor R16, said resistor R16 has another end connected to a third display output terminal of said MCU control module, said LED1 has a "4" terminal connected to one end of said resistor R15, the other end of the resistor R15 is connected with a fourth display output end of the MCU control module, a '5' terminal of the LED1 is connected with a collector of the triode Q3, an emitter of the triode Q3 is connected with an output end of the voltage reduction module, a base of the triode Q3 is connected with one end of the resistor R10, the other end of the resistor R10 is connected with a fifth display output end of the MCU control module, a '6' terminal of the LED1 is connected with one end of the resistor R11, the other end of the resistor R11 is connected with a sixth display output end of the MCU control module, a '7' terminal of the LED1 is connected with one end of the resistor R12, the other end of the resistor R12 is connected with a seventh display output end of the MCU control module, a '8' terminal of the LED1 is connected with one end of the resistor R13, and the other end of the resistor R13 is connected with an eighth display output end of the MCU control module, the "9" terminal of LED1 is connected the one end of resistance R14, the other end of resistance R14 is connected the ninth of MCU control module shows the output, LED 1's "10" terminal is connected triode Q2's collecting electrode, triode Q2's projecting pole is connected the output of step-down module, triode Q2's base is connected the one end of resistance R9, resistance R9's the other end is connected the tenth of MCU control module shows the output.

7. The alarm device for harmful gas in a vehicle according to claim 1, the alarm module comprises an alarm circuit, the alarm circuit comprises an inductor L12, a resistor R1, a diode D1, a resistor R2, a triode Q1 and a loudspeaker BEEP, the inductor L12 is provided with two output ends, the input end of the inductor L12 is connected with the output end of the vehicle-mounted direct current power supply, a first output terminal of the inductor L12 is connected to an input terminal of the speaker BEEP, a second output terminal of the inductor L12 is connected in parallel to one terminal of the resistor R1, a cathode of the diode D1 and an output terminal of the speaker BEEP, the other end of the resistor R1 is connected in parallel with the anode of the diode D1 and the collector of the triode Q1, the emitting electrode of the triode Q1 is grounded, the base electrode of the triode Q1 is connected with one end of the resistor R2, and the other end of the resistor R2 is connected with the pulse signal end of the MCU control module.

8. The alarm device for harmful gas in vehicle according to claim 6, wherein said LED1 is an LED device of MJG-3261 type.

9. The alarm of claim 5, wherein the type of the IC1 is HT66F 0185.

10. The alarm of harmful gas in a vehicle according to claim 4, wherein the type of the pre-calibration module is FSM-10H-01.