Central control system

A sensor device comprising:

• a sensor;
• a power switch;
• a power source switch control circuit configured to control switching of the power switch;
• and
• a voltage regulator circuit configured to regulate an input voltage through the power switch and supply a voltage to the sensor,
• wherein the power switch comprises a transistor comprising an oxide semiconductor layer comprising a channel formation region.

A sensor device comprising:

• an interface configured to connect with a central control device;
• a sensor;
• a power switch;
• a power source switch control circuit configured to control switching of the power switch in accordance with a control signal from the central control device;
• and
• a voltage regulator circuit configured to regulate an input voltage through the power switch and supply a voltage to the sensor,
• wherein the power source switch control circuit is connected to the interface, and
• wherein the power switch comprises a transistor comprising an oxide semiconductor layer comprising a channel formation region.

A device comprising:

• a micro control unit;
• a power switch;
• a power source switch control circuit configured to control switching of the power switch;
• and
• a voltage regulator circuit configured to regulate an input voltage through the power switch and supply a voltage to the micro control unit,
• wherein the power switch comprises a transistor comprising an oxide semiconductor layer comprising a channel formation region.