The closed-loop servomechanism that uses position feedback in order to control its motion and final position is called a servo motor. A servo motor is essentially an electronic amplifier which operates in conjunction with an electric motor. Often times, the two are integrated but that’s not always the case. The servo motor allows the motor to self-correct by adjusting properly to error responses as opposed to automatic settings or human input.
The term servo is believed to have originated from the French word “servomoteur” which translates as “a slave motor”. The servomechanism dates back to the 1860s when it was used on ships. The predecessor of the servo is the governor, which was a device automatically regulating the supply of steam, fuel and water to a machine, ensuring a uniform motion and limited speed. The governor had all the essentials of the modern servo motor, including response output, energy input, a way to manipulate error signal in order to minimize it and a way to display errors.
Since then, servo motors have been applied widely in many industries. You can find servo motors Australia wide in hardware shops or online. Most entry-level servos can be found with relative ease, however, there are servo motors Australia factories demand that won’t be as easily found in hobby hardware stores for example, so you’ll have to look elsewhere.
Most basic servos consist of a small motor, a small circuit and reduction gears inside of a housing. They depend on an outside source for power and a variable resistor or potentiometer to establish control. In more simple terms, the potentiometer instructs the servo motor to limit or set a certain speed. The person in control sets the potentiometer and the servo will strive to remain at that setting regardless of outside forces.
Nowadays, servo motors are used on many things that consist of an electric motor. Servos can be found in robotics, aircraft control surfaces, disc drives, camera auto focusing, toy cars, navigation systems, etc. Manufacturers used different methods to categorize the servo motor types based on weight, size and durability. There are 4 subdivisions.
- Micro servos – Relatively inexpensive and small, these can be found easier in hardware shops. They develop a little torque but enough to operate a small hobby craft and toys. Micros offer the advantage of being low weight and cost, which is often times perfect for these applications.
- Standard servos – Typically used in larger hobby planes, small robots and remote control vehicles.
- Heavy servos – Found in small to medium robotics, these are relatively more durable than the aforementioned two types. This level has generally evolved into stronger housings, axles and metal gears. They’re widely used for light aircraft, automobiles as well as law enforcement and military applications.
- Robotics servos – This type of servo motors are top shelf, they’re used for the production of large size robotics, cruise ships, commercial aircraft, off-road vehicles and spacecraft. They’re often times constructed of titanium, which allows them to be watertight and far more durable and expensive.