Introduction of encoder

An encoder is a device that converts electrical pulse signals into corresponding digital signals. It is a kind of transducer device which uses photoelectric elements to detect the conduction of photosensitive semiconductor materials after illumination and convert pulses into analog signals proportional to input quantity. There are many kinds of encoders, which can be divided into absolute, incremental and mixed types according to their working principles. Absolute encoder relies on the junction capacitance of laser diode d1 and the leakage resistance of n2 to generate a current signal proportional to the input voltage, which is characterized by simple circuit structure but low resolution. Incremental encoder uses the photoelectric flow generated when the pn junction of photodiode is positively biased to get an analog output signal proportional to the original DC after shaping by a shaping circuit. Its characteristic is that it has high resolution to the weak changes to be measured, and it can also maintain sufficient sensitivity to the signals with high-speed changes; The advantages of hybrid encoder are high resolution and convenient for multiplexing and demodulation.