An AC actuator is a type of mechanical switch or control arm that is activated by alternating current (AC). Actuators are common components of many mechanical systems. The uses for an AC actuator can include incorporation into automotive controls, gate and door closure mechanisms in residential or commercial settings, and connection to electrical motors for rotary and linear actuators on assembly lines in manufacturing. Since it is something of a universal mechanical machine control, an AC actuator can vary in size and power depending on the application. They can range from very small micro-controls such as those built into electronic doorbells to ring the bell, or small valve assemblies for liquid and gas flow, up to industrial-strength components in power plants and oil refineries.
The purpose of an AC actuator is generally to transform electrical power into mechanical motion. The motion can be transmitted by cable, actuator arm, screw assembly, and more. This range of uses covers such a variety of applications with machines that the devices can be found in virtually every industry that relies on complex machinery, from transportation to agriculture, marine, and construction settings.
While most types of actuators run on AC power due to the level of force that the actuator and motor system must convey, such as in medical beds or motorized furniture, direct current (DC) actuators also are fairly common. A DC actuator may be installed in instances where there is no convenient location for AC current and where machine controls don't require a lot of power to operate, such as in portable compact disc (CD) changing systems. They range from power requirements of typically 12 to 36 volts of direct current in industrial settings, and can be set up to control various types of mechanical motion from screw drives to linear arm movements. By contrast, heavy-duty DC actuators are also common and can produce a force of up to 2,000 pounds or more (907 kilograms) with 24 volts of DC current.
In many manufacturing settings prior to 2011, the type of actuator used was often powered by hydraulic force or pneumatic air compression. While many of these actuators still exist in heavy-duty settings, they are frequently being replaced by AC actuator controls. This is because AC actuator systems tend to require less maintenance than hydraulic or pneumatic systems, and are simpler to assemble and more portable, so that they can be easily repositioned to accommodate changes in a manufacturing process. Using an AC actuator also allows for the device to be built into a control system with security features and precise levels of applied force that can be monitored and adjusted by electronic digital readouts, which are often not as easily configured with hydraulic and pneumatic controls.