Operating principle and characteristics of absolute encoders

Absolute encoder performance is not easily affected by dust and condensation; its structure is simple and compact, no contact, long life, high and low temperature resistance, vibration resistance, fast response speed. Therefore, they are generally used in the fields of robotics, automated production lines, automatic assembly machines, elevators, textile machines, sewing machines, packaging and printing machines, CNC machine tools, plotters and goniometers. It can be used as a high-speed signal input element in PLC applications, enabling PLCs to implement closed-loop control more quickly and accurately.

Absolute encoder is a non-contact rotational speed measuring instrument that utilizes magnetic induction to measure the rotational speed of an object. Absolute encoder code value" and the measured "position" correspondence is unique, with "power failure memory" function, no rotational measurement of the accumulation of error, in "a cycle of" in the field of measurement and control than incremental encoder superior. "It is superior to incremental encoders in the field of measurement and control, and the range can be adjusted by adding a front reduction gearbox. Magnetoelectric speed sensor can be used for the surface of the object with a gap in the speed measurement, has good anti-interference performance, mostly used in engines and other equipment speed monitoring, there are more applications in industrial production.

Principle of operation of magneto-electric encoders (basic laws)

Magnetoelectric speed sensors use magnetic induction as the basic principle for speed measurement. Incremental encoders convert displacement into a periodic electrical signal, and then convert this electrical signal into counting pulses, indicating the size of the displacement by the number of pulses. Magneto-electric speed sensor is composed of iron core, magnet, induction coil and other components. When the measuring object rotates, the coil of the speed sensor generates magnetic lines of force, the gear rotation cuts the magnetic lines of force, and the magnetic circuit generates an electromotive force inside the induction coil due to the change of magnetoresistance.

Absolute encoder induced potential generated by the size of the voltage, and the speed of the object to be measured, the faster the speed of the object to be measured output voltage is also greater, that is to say, the output voltage and speed is proportional to. The signal output of the rope displacement sensor is divided into digital signal output and analog signal output, digital output type can choose incremental rotary encoder, absolute encoder, etc., the output signal is a square wave ABZ signal or Gray code signal, the maximum stroke can be done to 10000 mm, linear accuracy of 0.01%, according to the different configurations of the maximum resolving power of 0.001 mm / pulse. However, when the speed of the measured object exceeds the measuring range of the magnetoelectric speed sensor, the magnetic circuit loss will be too large, making the output potential saturated or even sharply reduced.

Characteristics of absolute encoders

The working method of absolute encoder determines that it has strong anti-interference, and can work in the environment of smoke, oil gas, water vapor and so on. The magnetoelectric speed sensor outputs a strong signal and has a wide measuring range. Parts such as gears, crankshafts, spokes, and rotating bodies with surface gaps can be measured.

Absolute encoders have low working and maintenance costs, no power supply is needed for the operation process, and the measurement is realized entirely by magnetic induction. Meanwhile, the operation of magnetoelectric speed sensors does not need mechanical action and lubrication is not required. Magnetoelectric speed sensors have a compact structure, small size, easy to install and use, and can be used with a variety of secondary instruments.