An actuator is a
piece of equipment that produces movement when given a signal. Actuators
are used in the computer control of an environment, industrial automation
and in robotics or , more generally, actuators are the machines used for
output in control applications. For example take the situation in a
computer controlled greenhouse...
When the temperature in the greenhouse is too high, the control
program makes a decision to open a ventilator, reduce the heating or turn
on a fan. A signal is sent to an actuator or motor to open the ventilator.
A valve in the greenhouse may be closed to restrict the flow of hot water
through radiators and pipes and another motor or actuator will lower
blinds to reduce the amount of direct sunlight. Environmental
control is not a major problem in small greenhouse but large commercial
glasshouses covering several acres, could not be monitored and controlled
manually. These glasshouses are very likely to be computer controlled.
Put simply, actuators drive motions in mechanical systems.
Most often this is by converting electrical energy into some form of
mechanical motion. Follow the menu links on the left for a description of
the principles of the most common types of actuators.