If you need to provide the end user with a means of adjusting values in a way that’s tactile and intuitive, then an encoder might be a suitable fit. These are devices which translate a physical motion into a digital system. They’re used in a wide range of applications, from drum machines to laboratory equipment to game consoles.
Encoders come in various types and suit various purposes. Let’s take a tour through some of the more common ones and try and establish how they might fit your needs.
An incremental encoder works by calculating changes in the position since the last movement. So, you might imagine a synthesiser whose pitch is being adjusted by a knob. The system might remember the value of a certain sound and then recall that value. Any subsequent adjustment to the encoder would then shift the value up or down.
Encoders of this kind come in various resolutions. In practice, this means that they emit more pulses per revolution. With a high-resolution encoder, precise gradations are possible.
In an absolute encoder, every possible position of the device comes with a unique value. This means that we can determine the precise position of the encoder, whatever is happening elsewhere in the circuit. Absolute encoders can return their position after a power failure, which makes them ideal for situations where power interruptions are likely.
When it comes to human interfaces, encoders are rotary, since knobs tend to be more space-efficient and intuitive than sliders. But linear encoders, which move along a straight line rather than round and round, still have their place. You might see them on mixing consoles and equalisers. They’re also used to measure the distance travelled along fixed axes, such as in a 3d printer or CNC machine.
An optical encoder does its work through light. A disc is imprinted with a coded sequence of holes, which block and permit light from an LED through to a receiver. This method allows for incredible precision, with some models allowing for millions of counts per revolution. You’ll find them in high-end medical equipment. The only downsides here are cost and fragility – optical encoders are rarely used in high-temperature settings.
Where Are They Used In The Industry?
Encoders are used just about everywhere. In the now-booming robotics industry, where consistent and accurate motion is required, they’re used to measure the movement of robotic limbs and adjust control signals to compensate. In medicine, they’re used in MRI and CT scanning machinery. In CNC machinery, they’re used to measure the distance travelled by machine tools, too. In fact, without them, such tools probably wouldn’t be possible!