TECHNICAL FIELD

The present disclosure relates to a gas sensor module.

BACKGROUND

In the context of incandescent lamps used in CO2gas sensors, a known drive method of a light source for a CO2gas sensor controls the voltage of the incandescent lamp so that the filament resistance is constant while the lamp is lit.

In recent years, development of a non-dispersive infrared (NDIR) gas sensor has also begun. This gas sensor includes a light emitter configured to emit infrared light and a light detector configured to detect infrared light that passes through a detection target gas (for example, CO2gas). The gas sensor uses the absorption characteristics of the infrared light in the gas to detect the concentration of the gas.

CITATION LIST

Patent Literature

PTL 1: JP 2000-215990 A

SUMMARY

NDIR gas sensors have an extremely large drive current (peak current) as compared to other environmental sensors such as temperature/humidity sensors or pressure sensors. Therefore, in a known gas sensor module100A that includes a light emitter10A such as a tungsten lamp (incandescent lamp) or micro electro mechanical systems (MEMS) heater and a light detector20A such as a pyroelectric sensor or thermopile, as illustrated inFIG. 7, an excessive load is placed on a power source60A.

It would be helpful to provide a gas sensor module that can reduce the load on the power source.

A gas sensor module according to an embodiment includes an infrared light emitting diode configured to emit infrared light in accordance with a drive current, a quantum infrared sensor configured to detect infrared light that passes through a detection target gas, a drive circuit configured to output the drive current to the infrared light emitting diode, a charging circuit to be connected to a power source and configured to output a charge current having a smaller current amount than the drive current, and a capacitor configured to charge by the charge current being supplied from the charging circuit and discharge by supplying the drive current to the drive circuit.

According to the present disclosure, a gas sensor module that can reduce the load on the power source can be provided.

