Standard test circuit: Vc: 5v ±0.1v, Vh(high): 5v ±0.1v, Vh(low): 1.5v ±0.1v
Good sensitivity to Combustible gas in wide range High sensitivity to Natural gas Long life and low cost Simple drive circuit MQ-7 gas sensor has high sensitivity to Carbon Monoxide.
This is a simple to use Carbon Monoxide (CO) sensor, suitable for sensing CO concentrations in the air. The MQ-7 can detect CO-gas concentrations anywhere from 20 to 2000ppm.
This sensor has a high sensitivity and fast response time. The sensor’s output is an analog resistance. The drive circuit is very simple; all you need to do is power the heater coil with 5V, add a load resistance, and connect the output to an ADC.
The main chips: the LM393, the MQ-7 CO sensor
The working voltage: DC 5 V
Dual signal output (analog output, and TTL level output)
The effective signal of TTL output is low level . (when Output low level ,the signal light on.can directly connected to the MCU)
Analog output 0 to 5V voltage, the higher the concentration ,the higher the voltage.
Has a high sensitivity and good selectivity to carbon monoxide .
