# What is An Encoder?

What is An Encoder, Type and How It Works? - In an industrial equipment, an encoder is widely used to process the precision of a motion. But what exactly is an Encoder?

An encoder is a device or component capable of detecting mechanical changes into digital signals.

## A. How The Encoder Works?

Based on the type of encoder in general, inside an encoder there is a disc with small holes on the edges and an optical transmitter & optical receiver.

The perforated dish is placed between the transmitter and receiver.

When the disk rotates, there will be a pulse change process.

If the beam hits the dish and the receiver does not receive the beam, the receiver will output LOW logic.

When the emitting beam passes through the dish hole and the receiver receives the light, it will output HIGH logic.

Look at the following picture:

## B. What is the Function of the Encoder?

After we know how the encoder works, then we must know the function of the encoder on an equipment.

At least, there are 4 functions of the Encoder are:

1. Determining Position
2. Determine the Direction
3. Determining Speed
4. As a calculation

Examples:
1. Determining Position
For example, you are using a stepper motor. On the microcontroller you set the stepper to move as much as 50 steps or 90 °.

When the stepper motor has rotated in the 50 steps position and at that time you give a slightly heavy load, and the stepper motor is reduced by 1 step due to this load, the stepper motor is no longer precise to move next.

To solve this, we use an encoder. As the steps of the stepper decrease, the Encoder value also decreases. So, the microcontroller can find out the step error of the stepper motor.

2. Determine the Direction
The microcontroller can determine the movement of the dish by reading the logic data from the encoder.

Under these circumstances, the encoder can be used in conveyor control systems.

3. Determining Speed
By reading the pulse speed or voltage change from 0-5V and vice versa, the microcontroller can find out how fast a motor rotates.

4. As a calculation
Because the encoder generates logic pulses of 0 and 1 (0 and 5v), the microcontroller can count the number of times the change occurs, so that it can make work decisions by the microcontroller itself.

## C. Encoder Type Based on Manufacturing Technology

Encoders have long been used in the industrial world and up to now there are several technologies in the operation process.

There are at least 4 categories of encoders based on their operating technology:
• Magnetic
• Mechanic
• Resistive
• Optics
Based on the list above, Optical Encoder technology is the most widely used today.

Then encoders are divided into two types:
1. Absolute Encoder
2. Incremental Encoder