Greetings,
recently bought some Grove MQ9 sensors that seem to have a DC-DC converter on the PCB. The schematic (https://files.seeedstudio.com/wiki/Grove-Gas_Sensor-MQ9/res/Gas_Sensor_Schematic.pdf) hints at ot but is incomplete. The doc and PCB label the supply Vcc and spec it at 5V, is seems to keep the suppy voltage constant as tested from ~ 4 to 6 V, any more precie information on this board would be highly appreciated?
Enjoy your projects,
Cheers,
Stephan
