Basic knowledge of encoder: 4 detailed explanations

1. What is "phase shift" and what impact does it have on the system?

Refers to the deviation between the A and B phase signals and the ideal 90 phase difference. Excessive phase shift can affect the accuracy of direction determination and the stability of counting at high speeds.

2. In automation control systems, where are encoders usually installed?

It is usually installed at the end of the servo motor, the end of the drive screw, or the driven wheel shaft, used to directly or indirectly measure the position and speed of the final actuator.

3. What is the response frequency of the encoder?

Response frequency is the number of pulses output by the encoder per unit time, measured in Hz. Electrical maximum response speed (r/min)=maximum response frequency/single turn resolution * 60

Therefore, when the encoder rotation speed exceeds the electrical maximum response speed, it will not be able to keep up with the electrical signal; Due to the limitations of bearings, the mechanical speed of encoders is usually less than the maximum electrical response speed.

4. What are the common output forms of encoders?

The output forms of incremental encoders mainly include:

Open collector output: simple and economical, but poor anti-interference and short transmission distance.

Voltage output: There are commonly TTL levels (5V) and HTL levels (10-30V), with the latter having stronger anti-interference ability.

Push pull output: better performance than open collector, more stable signal.

Differential output: Output complementary signals (such as A+/A -), with strong resistance to common mode interference, making it the preferred choice for long-distance transmission and harsh industrial environments。