Encoders are more durable. According to the working principle, encoders can be divided into three categories: absolute, incremental and hybrid.

1, absolute encoder: it relies on laser diode and other components to generate current signals, which is characterized by simple circuit structure but low resolution.

2. Incremental encoder: The photocurrent generated when the photodiode pn junction is positively biased is shaped by a shaping circuit to obtain an analog output signal proportional to the original DC, which is characterized by high resolution for weak changes in measurement and sufficient sensitivity for high-speed changes.

3. Advantages of hybrid encoder: high resolution and easy multiplexing and demodulation.