Operation and usage scenarios of actuators

An actuator is a device that, based on some trigger mechanism, will make something move, rotate, oscillate, or initiate some operation. Actuators can perform actions on themselves (turn water sprinklers on/off, change temperature settings in a thermostat, and so on) or on the sensors (starting/stopping a sensor or moving a sensor from one location to another, for example). Generally, actuation requires more energy than sensing; accordingly, actuators are supplied with stronger batteries or are mains-powered. However, in a typical deployment, the count of sensors would far exceed the number of actuators.

For a completely automated and/or remote operation, sensors and actuator work in a complementary fashion to monitor and change the environmental state, as shown in the following diagram:

Figure 9.6 – Sensor and actuator working in a complementary fashion

Actuators can be broadly categorized into three categories...