Absolute Encoder Working principle & Applications

Absolute Encoder Working principle

A turning encoder or a shaft encoder is an electro-mechanical gadget, used to change over the movement of a shaft, position of rakish, or convert the hub to simple/computerized yield signals. There are two kinds of turning encoder like outright encoder and gradual encoder. These encoders are pertinent, where checking, controlling, or both are needed For instance mechanical technology, modern controls, visual focal points, and so forth This article talks about one of the sorts of revolving encoders specifically outright encoder and its working with applications.

What is an Absolute Encoder?

An outright encoder is utilized to give a remarkable position worth of shaft or information word at each mark of upset to address the "outright" position of the encoder. These encoders are accessible in either single-turn or multi-turn. Single-turn encoders are utilized where position confirmation is required while multi-turn encoders are utilized for extended or complex situating based applications.

Outright Encoders

This encoder likewise holds the data on the current position when the power supply is segregated from the encoder. The encoder position is open quickly once the power supply is given. This encoder incorporates distinctive code rings through an assortment of paired weightings which supply an information word connoting the encoder's outright situation in a solitary upset. So this sort of encoder is oftentimes called an equal outright encoder.

Working Principle

The outright encoder working standard is, the point at which the shaft pivots, it works by creating a computerized expression of touch. There are two plates including concentric rings through offset markers. Here, one plate is associated with the focal shaft though different moves openly.

When the plate pivots, then, at that point, the markers through the way of this encoder will change the decent circle's position. Each plan with a flat out rotational encoder circle means a special twofold code. The parallel code in this encoder will decide the total situation of the article.

Outright Encoder Types

There are various sorts of outright encoders accessible which incorporate the accompanying.

Natural Solid Core Absolute Encoder

The natural strong center sort is planned with carbon brushes. Its strong resistor body is wide, so it gives a more extended mechanical life when contrasted with a twofold encoder. The primary capacity of this encoder is to change voltage and current inside exceptionally solid, high wear obstruction hardware and furthermore in AC and DC circuits.

The benefits of outright strong center mostly incorporate high unwavering quality, mechanical life is longer, heat obstruction is great, higher power though the inconveniences are dynamic clamor is high, dampness opposition is poor, exactness is poor, the temperature coefficient is enormous and producing process is muddled.

Metal Glaze Absolute Encoder

The lattice creation of this sort of encoder is earthenware, though the resistor body is planned with sintered metallic glass glaze. This encoder is made with vacuum innovation by organizing various materials like metal oxide film, metal composite film, button oxide film, metal amalgam film on a fired substrate.

The benefits of this encoder incorporate high goal, less commotion electromotive power, and so forth The burdens are resistor esteem is little that reaches from 10 ohms to 00 kilo-ohms, mechanical life is less, wear obstruction is poor, and so forth

Twisting Absolute Encoder

Winding sort can be planned by utilizing nickel-chromium amalgam wire or constantan wire like a resistor and injured on a protecting edge. This sort of encoder is utilized basically as a transformer and voltage divider.

The benefits of this encoder incorporate high accuracy, contact obstruction is little, and temperature coefficient is little. The hindrances are low obstruction, the goal is poor and high-recurrence attributes are poor.

Computerized Absolute Encoder

This encoder is a semiconductor IC, utilized chiefly for estimation in 360 levels of the unrest known as a solitary turn encoder. So it is fitting for sound encompass control, home theater framework, digital TV hardware and sound intensifier.

The benefits of this encoder chiefly incorporate little size, easy to associate, high change exactness, no commotion, programming control is simple and its life expectancy is long. The weaknesses are; it isn't appropriate for cruel and outside conditions, hard to beat the slip while estimating objects inside the circle.

Gradual Encoder

It incorporates a special code for each shaft position to address the proper situation of the encoder. It is an electro-mechanical gadget, used to change the rakish situation of the shaft into a heartbeat or computerized signal.

These encoders require power while utilizing this device. These encoders need power all through the activity of the gadget.

Its expense is high when contrasted with the steady type. Its cost is less because of less mind boggling

These encoders are utilized in various applications where controlling, checking is required like demonstrative imaging, careful mechanical technology, etc. These are utilized in applications where speed and course data is important

When the power is lost, it doesn't lose the data of position. Once the power is lost, the framework shows a mistake.

Servo Motor Control with Absolute Encoder with Arduino

In this segment, let us in on the best way to control a servo engine utilizing a flat out encoder with Arduino. The interfacing chart of servo engine control with outright encoder is displayed in the figure beneath.

In the event that this encoder is turned a clockwise way, the revolution of the servo engine is additionally a clockwise way. Essentially, in the event that this encoder is pivoted an anticlockwise way, the servo engine additionally turns the anticlockwise way. Associations are made according to the outright encoder wiring outline displayed previously. The necessary parts are,

Outright Encoder Interfacing with Arduino Board


Servo engine

Outright encoder

Power supply

The stockpile pin-like 'Vin' of the outright encoder is associated with the 5 Volts supply of the Arduino and the ground pin of the encoder is associated with the Arduino's ground pin. The information pin of this encoder is associated with the (advanced) pin 4 of the Arduino and the clock pin and switch pin of this encoder is associated with the computerized pins 3 and 4 of the Arduino.

Then, at that point, the Vin of the servo engine is associated with the 3.3volts of the Arduino. The ground of the Arduino is associated with the servo engine's ground. The sign pin of the servo engine is associated with the Arduino's computerized pin. The code to interface encoder with Arduino for servo engine control is given beneath.

#incorporate <Servo.h>

#characterize clk 3

#characterize information 4

#characterize sw 5

int counter=90;

int state;

int lstate;

Servo s;

void arrangement()




s.attach(9); (here 's' alludes to servo engine)



state= digitalRead(clk);

in the event that (state!=lstate)

if(digitalRead(data)!= state)


counter= constrain(counter,1,180);



counter= constrain(counter,1,180);




The library capacity of the servo engine is remembered for the Arduino code to run the code. Then, the clock pin, information pin, and switch are characterized with 3, 4, and 5 pins individually. The worth of the counter is set to 90. To store the information, state and Istate factors are used.

The variable 's' is characterized for servo engines. The pins CLK, SW, and information are characterized as info pins in the arrangement capacity and servo engine appended at pin 9. To screen the result work on the screen, the sequential being capacity is utilized. Peruse the condition of the put away information and clock pin in the Istate variable. While on the up and up work, the condition of the put away information is perused in the expressed variable. As far as possible the counter worth between 1-180. Then, at that point, the capacity is composed to apply the counter worth on the servo engine.

Benefits and Disadvantages

The benefits of an outright encoder incorporate the accompanying.

Battery reinforcement isn't important to keep away from information misfortune.

They have various capacities like scaling, speed, Fieldbus and preset.

Attractive or optical output estimation.

Whenever power is lost, it gives constant position checking.

The adaptability of programming.

Interface choices are different like Ethernet, Analog, Serial, Parallel and Fieldbus.

Accuracy control permits use in various applications where useful wellbeing is required.

The specific situation of a machine not really settled.

The disservices of a flat out encoder incorporate the accompanying.

Confounded to produce


Where are Absolute Encoders utilized/Applications?

These are relevant where controlling or observing of mechanical frameworks is required like the accompanying.

Careful advanced mechanics


Symptomatic imaging


Radiation treatment

Modern advanced mechanics

Satellite interchanges

ROVs and UAVs

How would you test the Absolute Encoder?

The outright encoder testing is utilized to proclaim whether that is outright or steady. Assuming the encoder needs to move to decide its position, it is known as gradual. On the off chance that the result of the encoder is in a steady situation without movement then it is known as outright.

How would you investigate an encoder?

For investigating an encoder, we want to actually look at the associations, position of the shaft, free associations, wrong voltage supply, and so forth

What is an outright point encoder?

An encoder that actions outright or genuine precise position is known as indisputably the rakish encoder.