Used in a variety of electrical applications, ranging from zoom camera lenses to an incredible assortment of robots and industrial machines, rotary encoders are very important for controlling devices and sending digital signals to machines. Designed to send a digital signal to another part of a device, rotary encoders are used in many electronic applications to control devices and transfer important information.
There are two different types of rotary encoders that are widely used in electronics and computing. The first is absolutely rotary encoders – a type of encoder that uses a unique digital signal whenever the shaft it rotated to a certain angle. For example, an absolute rotary encoder may send a different code to a computer or device based on the level to which it is manipulated – much like a camera zoom or volume knob.
Absolute rotary encoders use two different methods to calculate the position of the rotary knob and thus send a signal. Mechanical rotary encoders calculate the knob’s position based on the amount of mechanical movement that is applied. This makes it easy to calculate the position that the rotating disc is at, and thus work out the level.
An optical rotary encoder, on the other hand, calculates the digital signal that it will send based on the amount of light that’s present on the rotary disc at any one time. An example of this would be a computer microchip that calculates a value based on the position of a rotary encoder elsewhere in the machine based on its optics.
A secondary form of rotary encoder is known as an incremental rotary encoder. As the name would suggest, these rotary encoders calculate the level of signal that is to be sent onwards to a computer based on the number of ‘counts’ of the rotary disc. A great example of a rotary encoder is a volume or gain knob on a stereo amplifier.
As you turn the volume on your stereo amplifier, the rotary encoder increases the amount of ‘counts’ and sends this information as a cyclical output to the amplifier itself. The output is then calculated as a value, which is used to determine how loud the amplifier should be – in effect, the amount of energy that goes to the speakers.
This is a simplistic example of how an incremental rotary encoder is used, but it’s one that’s very common today. The vast majority of stereo amplifiers make use of an incremental rotary encoder, often in common with a digital volume system that can be manipulated using a remote control or numerical pad.
While rotary encoder may seem like a dull part of our electrical components, they are one of the most important electrical units in the digital world. Used in a massive range of digital devices and electrical appliances, these unique yet powerful electric tools allow us to adjust output levels and commands in a much more precise way.