A distinction is made between electronic and electromechanical devices. An example of
an electronic device is an environmental controller with one or more temperature
sensors and one or more relays that are used to activate equipment. An example of an
electromechanical device is a conventional thermostat, which is a temperatureactivated
relay used to turn on or off equipment such as heaters or fans as air
temperature varies. Either of these example devices can be used to operate a fan. The
type of control system used will also affect the troubleshooting options and approaches
when problems arise.