CN201838147U - Household intelligent gas alarm device - Google Patents

Abstract

The utility model discloses a household intelligent gas alarm device, which consists of a gas sensor circuit, a main control circuit, a memory circuit, a keyboard input circuit, an LED display circuit, a power supply control circuit and an alarm circuit; and a main circuit control part adopts a 2051 singlechip, and an A/D sampling part adopts a multi-path single integral type switching circuit of a capacitor, so as to realize the 12-bit switching accuracy by the software calibration and the proper scale conversion. The household intelligent gas alarm device has simple structure, low cost and long service life and is reliable to operate; the device can realize the special functions of one-key zero calibration, 24-hour circulating memory, password protection and the like; the service life of a gas sensor can be maximally prolonged due to the intelligent and self-adjusting pulsed mode; the device can work by utilizing three dry batteries or the AC power supply and can work on a wall of a kitchen or on a table in a bedroom; moreover, the device can effectively prevent the accidents of personnel suffocation or explosion caused by gas leakage.

Description

Domestic intelligent gas alarm device

Technical field

The utility model relates to a kind of domestic gas concentration and reveals displaying alarm.

Background technology

Domestic gas mainly is rock gas, manufactured gas, manufactured fuel gas and liquefied petroleum gas (LPG) etc., and the combustion gas that causes is for various reasons revealed will very likely can lead to very big family disaster.And the combustion gas leak detection apparatus that is installed at present on the smoke exhaust ventilator usually can will not lose function for a long time because of the greasy dirt effect, moreover the amount of leakage that this pick-up unit can not the detection by quantitative combustion gas.Therefore press for a kind of long-acting, cheap, directly perceived and have intelligent combustion gas displaying alarm to solve the safety problem in family's combustion gas use.

The utility model content

The purpose of this utility model provides a kind of domestic intelligent gas alarm device, can show concentration and overload alarm that combustion gas is revealed in real time.

The technical solution of the utility model is as follows:

A kind of domestic intelligent gas alarm device, form by gas security circuit, governor circuit, memory circuitry, keyboard input circuit, LED display circuit, power control circuit and warning circuit, it is characterized in that: described gas security circuit is made up of heat catalytic element HB1, resistance R 9, R17, R18, R19 and amplifier U8B, wherein resistance R 9 and R19 are in parallel with resistance R 18 by the lead back of connecting, and meet amplifier U8B behind heat catalytic element HB1 and resistance R 9, R17, R18, the R19 formation Wheatstone bridge;

Described governor circuit is made up of single-chip microcomputer U1 and peripheral circuit, constant current source charging and discharging circuit and plurality of voltages change-over circuit and voltage detecting circuit, described constant current source charging and discharging circuit is made up of 2.5V direct supply, resistance R 22, R23, R24, R36, triode N5, N6 and capacitor C 3, and wherein resistance R 24 inserts the P3.7 end of single-chip microcomputer U1 by lead; Described plurality of voltages change-over circuit is made up of traffic pilot U7, and the output terminal X of traffic pilot U7 holds by the P1.1 that lead inserts single-chip microcomputer U1, and the input end of traffic pilot U7 links to each other with the output terminal of amplifier U8B in the described gas security circuit; Described voltage detecting circuit is made up of amplifier U9A and a plurality of standard DC power supply, and described voltage detecting circuit inserts the input end of traffic pilot U7 by lead;

Described memory circuitry is made up of storer U2, and wherein the SDA of storer U2, SCL end inserts P1.6, the P1.7 end of single-chip microcomputer U1 respectively by lead;

Described keyboard input circuit is made up of button S1, S2, S3, S4, constitute to go up respectively, mode switch, down and confirm button, and button S1, S2, S3, S4 insert the P3.2～P3.5 end of single-chip microcomputer U1 in the described governor circuit respectively by lead;

Described LED display circuit is four display circuits of serial of being made up of deserializer U3～U6 and charactron LED1～LED4;

Described power control circuit is made up of triode N1, N2, N3, resistance R 1, R2, diode D1, capacitor C 8, and described power control circuit inserts the 3.6V direct supply, and resistance R 2 inserts the P1.5 end of single-chip microcomputer U1 in the described governor circuit by lead;

Described warning circuit is made up of triode N7, hummer FM, resistance R 35 and capacitor C 1, and wherein resistance R 35 inserts the P1.4 end of single-chip microcomputer U1 in the described governor circuit by lead.

The beneficial effects of the utility model:

This device has that real-time working mode, pulse are interrupted working method and working method etc. is available automatically, has not only fully taken into account domestic gas to reveal the serviceable life that can reach safety detection but also take into account gas security; The utlity model has a key Protection Counter Functions, do not need repeatedly repeat key to eliminate the value at zero point one by one zero point drift; Except combustion gas amount of leakage overload alarm function, also has the low-voltage warning function in addition.

Description of drawings

Fig. 1 is a hardware block diagram of the present utility model.

Fig. 2 is a gas security circuit of the present utility model.

Fig. 3 is governor circuit of the present utility model, memory circuitry and keyboard input circuit figure.

Fig. 4 is LED display circuit figure of the present utility model.

Fig. 5 is power control circuit figure of the present utility model.

Fig. 6 is warning circuit figure of the present utility model.

Embodiment

Referring to Fig. 1,2,3,4,5,6, a kind of domestic intelligent gas alarm device, form by gas security circuit, governor circuit, memory circuitry, keyboard input circuit, LED display circuit, power control circuit and warning circuit, it is characterized in that: the gas security circuit is made up of heat catalytic element HB1, resistance R 9, R17, R18, R19 and amplifier U8B, wherein resistance R 9 and R19 are in parallel with resistance R 18 by the lead back of connecting, and meet amplifier U8B behind heat catalytic element HB1 and resistance R 9, R17, R18, the R19 formation Wheatstone bridge;

Governor circuit is made up of single-chip microcomputer U1 and peripheral circuit, constant current source charging and discharging circuit and plurality of voltages change-over circuit and voltage detecting circuit, the constant current source charging and discharging circuit is made up of 2.5V direct supply, resistance R 22, R23, R24, R36, triode N5, N6 and capacitor C 3, and wherein resistance R 24 inserts the P3.7 end of single-chip microcomputer U1 by lead; The plurality of voltages change-over circuit is made up of traffic pilot U7, and the output terminal X of traffic pilot U7 holds by the P1.1 that lead inserts single-chip microcomputer U1, and the input end of traffic pilot U7 links to each other with the output terminal of amplifier U8B in the gas security circuit; Voltage detecting circuit is made up of amplifier U9A and a plurality of standard DC power supply, and voltage detecting circuit inserts the input end of traffic pilot U7 by lead;

Memory circuitry is made up of storer U2, and wherein the SDA of storer U2, SCL end inserts P1.6, the P1.7 end of single-chip microcomputer U1 respectively by lead;

The keyboard input circuit is made up of button S1, S2, S3, S4, constitute to go up respectively, mode switch, down and confirm button, and button S1, S2, S3, S4 insert the P3.2～P3.5 end of single-chip microcomputer U1 in the governor circuit respectively by lead;

The LED display circuit is four display circuits of serial of being made up of deserializer U3～U6 and charactron LED1～LED4;

Power control circuit is made up of triode N1, N2, N3, resistance R 1, R2, diode D1, capacitor C 8, and power control circuit inserts the 3.6V direct supply, and resistance R 2 inserts the P1.5 end of single-chip microcomputer U1 in the governor circuit by lead;

Warning circuit is made up of triode N7, hummer FM, resistance R 35 and capacitor C 1, and wherein resistance R 35 inserts the P1.4 end of single-chip microcomputer U1 in the governor circuit by lead.

The utility model is described in further detail below in conjunction with concrete principle of work:

1, gas security circuit

Referring to Fig. 2, heat catalytic element HB1 is the probe that detects as combustion gas, can be continuously or the concentration of discontinuity detection domestic gas.Certainly to select the detection probe of dissimilar gases according to the kind of domestic gas.

The catalysis element principle of work is: this product comprises an operation element and a compensating element,, two elements are contained in the air chamber, be attempted by (as the resistance R among Fig. 2 17, R18//(R9+R19) operation element and the addition item with catalysis element constitutes electric bridge) on the Wheatstone bridge.Apply operating voltage, then in fresh air with the electric bridge balancing.After element runs into combustion gas, airborne oxygen and combustion gas generation catalyst combustion reaction, the operation element temperature rises, and resistance value increases, make electric bridge produce an output signal that is directly proportional with the methane volumetric concentration, deliver to by resistance R 20 and carry out processing and amplifying among the amplifier LM358.The size of measuring this signal is just known the concentration of methane, and compensating element, can comprise that voltage, temperature, humidity, wind speed, air pressure etc. compensate to the working environment of catalysis element.

2, governor circuit:

Referring to Fig. 3, adopt power supply control, data processing, information stores, the A/D change-over circuit of the conduct control core of AT89C2051 single-chip microcomputer.Main circuit is described below:

The A/D conversion:

In order to reduce circuit cost, the design does not adopt special-purpose A/D converter spare, but simulation double integration A/D transfer principle adopts constant current source that electric capacity is charged, and the calculating duration of charging realizes.As shown in Figure 2, standard 2.5V power supply, resistance R 22, R23, R24, R36, triode N5, N6, capacitor C 3 common formation constant current source charging and discharging circuit.If charging current is I ₀Then:

U _c＝I ₀×T ₁/C ..............(1)

Because of I ₀With C be definite value, so U _cWith duration of charging T ₁Be directly proportional.Voltage on the capacitor C 3 makes AB=by the input end in the same way that P1.0 send internal comparator " 01 " time, the X1 pin that switches integrated circuit MC14051 by multichannel is introduced the voltage signal U that represents combustion gas to reveal _cSwitch to P1.1, send the reverse input end of the internal comparator of 89C2051, when the charging voltage on the capacitor C 3 was higher than P1.1, (P3.6 uprised the upset of 89C2051 internal comparator, this pin outside is invisible, software can detect), at this moment software leaves P3.7 uprises, the N6 conducting, capacitor C 3 is discharged rapidly, finishes once to the integration of input voltage and for integration next time and prepares; Make AB=again " 00 ", normal voltage is transferred to P1.1, and makes the P3.7 step-down, cut off the discharge loop of C3, normal voltage is carried out integration again get:

U ₀＝I ₀×T ₀/C ..............(2)

Relatively (1), (2) have: U _c=U ₀* (T _c/ T ₀), so go forward side by side after the row operation by twice integration, the detected value of gas concentration has just had nothing to do with the capacity of charging resistor and electric capacity, because U ₀And the time T of twice integration _c, T ₀Known, be easy to obtain the detected value of gas concentration, guaranteed the precision and stability of A/D conversion again.

Power supply control:

Referring to Fig. 2,5, this circuit has three stage power source ,+3.6 volts ,+3.3 volts and+2.5 volts.3.6 volt through N1, N2 constitute controlled output+3.3 volts power supplys, offer all circuit uses except 89C2051 and display circuit.P1.5 pin by 89C2051 can control+the opening and turn-offing of 3.3 volts of power supplys, because the normal serviceable life of the sensor of domestic gas leak detection only one year, and the also unnecessary generally speaking real-time online of domestic gas leak detection detects, so can work in the mode of being interrupted by the control detection element, detected 1 minute every 5 minutes, the life-span that so just can prolong detecting element has greatly been taken into account the safety that combustion gas is used again, can certainly be arranged on and use the period of combustion gas to detect in real time, discontinuity detection when not using combustion gas just adopts real-time detecting pattern immediately as long as detected any combustion gas leakage certainly.+ 2.5 volts of power supplys are made of resistance R 4 and constant-current source device DW1, provide the reference power source of standard for detecting loop, A/D change-over circuit etc.

Information stores:

By based on I ²The Serial E of C bus ²POM 24C04 finishes.Parameter such as Time of Day initial value, gas concentration alarming threshold value, zeroing value etc. are set will be stored in advance among the storer 24C04 of this device can also be stored and per hour be detected the gas concentration maximal value so that online or off-line is consulted etc.A major advantage of the present utility model is can a key zero clearing, the reasons such as imbalance that have zero point drift characteristic and an electric bridge parameter owing to amplifier can cause alarm combustion gas reveal actual have trace output to make when being zero to show non-vanishing, can carry out system's setting in this case, can only just eliminate this zero point drift phenomenon by one-touch, a promptly so-called key zero clearing characteristic.

Warning circuit:

Referring to Fig. 6, warning circuit is by triode N7, hummer FM, resistance R 35 capacitor C 1 formation such as grade.When surpassing a certain threshold values, the combustion gas amount of leakage have the P1.4 pin output pulse signal driving hummer of 89C2051 to send alerting signal, except combustion gas excess warning function, when supply voltage drops to a certain setting value, start warning too, when using battery as the user so that the prompting changing battery.

3, keyboard input circuit and LED display circuit:

Referring to Fig. 3,4, the facial mask button is set button for input, is divided into upper and lower button, confirms button, mode switch button etc.; The LED display circuit is four LED display circuits of serial, can show gas leakage value and the various parameter that is provided with in real time.

Claims (1)

1. domestic intelligent gas alarm device, form by gas security circuit, governor circuit, memory circuitry, keyboard input circuit, LED display circuit, power control circuit and warning circuit, it is characterized in that: described gas security circuit is made up of heat catalytic element HB1, resistance R 9, R17, R18, R19 and amplifier U8B, wherein resistance R 9 and R19 are in parallel with resistance R 18 by the lead back of connecting, and meet amplifier U8B behind heat catalytic element HB1 and resistance R 9, R17, R18, the R19 formation Wheatstone bridge;

Described governor circuit is made up of single-chip microcomputer U1 and peripheral circuit, constant current source charging and discharging circuit and plurality of voltages change-over circuit and voltage detecting circuit, described constant current source charging and discharging circuit is made up of 2.5V direct supply, resistance R 22, R23, R24, R36, triode N5, N6 and capacitor C 3, and wherein resistance R 24 inserts the P3.7 end of single-chip microcomputer U1 by lead; Described plurality of voltages change-over circuit is made up of traffic pilot U7, and the output terminal X of traffic pilot U7 holds by the P1.1 that lead inserts single-chip microcomputer U1, and the input end of traffic pilot U7 links to each other with the output terminal of amplifier U8B in the described gas security circuit; Described voltage detecting circuit is made up of amplifier U9A and a plurality of standard DC power supply, and described voltage detecting circuit inserts the input end of traffic pilot U7 by lead;

Described memory circuitry is made up of storer U2, and wherein the SDA of storer U2, SCL end inserts P1.6, the P1.7 end of single-chip microcomputer U1 respectively by lead;

Described keyboard input circuit is made up of button S1, S2, S3, S4, constitute to go up respectively, mode switch, down and confirm button, and button S1, S2, S3, S4 insert the P3.2～P3.5 end of single-chip microcomputer U1 in the described governor circuit respectively by lead;

Described LED display circuit is four display circuits of serial of being made up of deserializer U3～U6 and charactron LED1～LED4;

Described power control circuit is made up of triode N1, N2, N3, resistance R 1, R2, diode D1, capacitor C 8, and described power control circuit inserts the 3.6V direct supply, and resistance R 2 inserts the P1.5 end of single-chip microcomputer U1 in the described governor circuit by lead;

Described warning circuit is made up of triode N7, hummer FM, resistance R 35 and capacitor C 1, and wherein resistance R 35 inserts the P1.4 end of single-chip microcomputer U1 in the described governor circuit by lead.

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