Sensitive material MQ-7 gas sensors used in clean air, low conductivity tin oxide (SnO2). High-low temperature cycling detection mode (1.5V heating) carbon monoxide detector, conductivity sensor with the increasing concentration of carbon monoxide gas in the air increases,high-temperature (5.0V heating) cleaning cryoadsorption stray gases. Using a simple circuit to change the conductivity, concentration of the gas is converted to the corresponding output signal. MQ-7 gas sensor of high sensitivity for carbon monoxide, this sensor can detect a variety of gases containing carbon monoxide, is a low-cost sensors for a variety of applications
Application:
Can be used for home and factory gas leakage monitoring devices, suitable for liquefied petroleum gas, butane, propane, methane, smoke, etc.
Features:
Using high-quality dual-panel design,with power indicator and TTL signal output instructions.
The switching signal having a DO (TTL) output and analog output AO.
TTL output valid signal is low. ( Low-level signal when the output light can be directly connected to the microcontroller or relay module )
Analog output voltage with the higher concentration of higher voltage
There are four screw holes for easy positioning.
Has a long life and reliable stability
Rapid response and recovery characteristic
Input voltage : DC5V Power consumption ( current ): 150mA DO output : TTL digital 0 and 1 ( 0.1 and 5V) AO output :0.1-0 .3 V ( relative to pollution ),the maximum concentration of a voltage of about 4V Special note: After the sensor is powered,needs to warm up around 20S,measured data was stable,heat sensor is a normal phenomenon,because the internal heating wire,if hot is not normal .
Wiring:
VCC: positive power supply (5V)
GND: power supply is negative
DO: TTL switching signal output
AO: analog signal output
NOTE:
After the sensor is powered, need to warm about 20S, measured data becomes stable, heat sensor is normal
Size:
Test program:
Function: This version of the test program supporting
Use chip: AT89S52
Crystal: 11.0592MHZ
Baud rate: 9600
Compiler Environment: Keil
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