An linear actuator can help convert energy into motion but it also can help control that motion and energy.
The variables in an actuator system are the type of energy, amount of input, and speed of motion. What will always be consistent is the need for some sort of energy source and the production of mechanical motion. Actuators also work using the same components although these will look different depending on the type of actuator and its function.
The power source, as discussed, can be electric, air or gas, water or another type of energy source but these are the most common in the operation of actuators.
The power converter carries power from the power source to the actuator in line with whatever units or measurements are detailed on a controller or in its design.
A hydraulic proportional valve is one example of a power converter used on water — a mechanical part to let in or shut off the water so water flow is in line with the rate of input and the desired motion output.
Electrical inverters are another example, which is often used in industry to convert direct current electricity to alternating current electricity. They can look like rectangular electronic drives or circuits.
The actuator is a physical-mechanical device that performs the conversion. It can look different depending on what type of input/output you are working with and hoping to produce.
In a door handle, the actuator is a plastic box with plungers attached to it. A hydraulic actuator, however, is made up of metal pistons. For an actuator to be effective, its design must effectively transform energy and is tailored as such.
The mechanical load is a physical stress or opposing force on the system working against the energy the actuator produces. As such, it induces the system to produce more power.
An everyday example of this interplay can be seen when a car is driving uphill. The tilt or slope is a load the engine works against, so, to move, the car must increase its speed. In mechanical engineering, a mechanical load can be worked in as part of the system design.
The controller is a device that activates the actuator and controls the output, guiding its direction, force, and its longevity. It stops the system from working on its own devices and allows limits at both ends of the conversion, which the operator can oversee.
It could be an electric, electronic, or mechanical device, and could look like a button, lever, switch, or dial. But there are many different examples when it comes to operating an actuator.