Incremental encoder

Incremental encoder shaft rotates, have corresponding phase output. The direction of rotation of discrimination and pulse number of increase and decrease, need to use the sentence at the back of the circuit and the counter. It can be set arbitrary starting point count and infinite accumulation and can realize the circle and measurement. Can also turn each signal a pulse Z, mechanical zero as a reference. When the pulse has been fixed, but need to improve resolution, available with 90 degree phase A, B two road signals, frequency doubling on the original pulse number.

The absolute value encoder

Rotator, absolute value encoder shaft position and one-to-one code output (binary, BCD code, etc.), from the size of a code change can distinguish positive and negative position, direction and displacement without sentenced to the circuit. It has an absolute zero code, when a power outage or shutdown after the boot to measure, can still be accurately read a power outage or shutdown location code, and accurately find the zero code. The general case of absolute encoder measuring range of 0 ~ 360 degrees, but special model also can realize more circle measurement.

Sine wave encoder

Sine wave encoder also belong to the incremental encoder, the main difference is that the output signal is a sine wave analog signals, rather than a digital signal. It is mainly in order to meet the needs of the electric field - used as the feedback of the motor testing device. On the basis of compared with other systems, can be used when people need to improve the dynamic characteristics of the encoder.

In order to guarantee the performance of motor control, the encoder feedback signal must be able to provide a large number of pulses, especially at very low speed, the traditional incremental encoder to generate a large number of pulses, in many ways all have a problem, when the motor at high speed (6000 RPM), transmission and processing of digital signal is difficult. In this case, the bandwidth needed for processing to the signal of the servo motor (such as encoder turn each pulse of 10000) will easily exceed MHz threshold; On the other hand the analog signal greatly reduce the trouble, and have the ability to simulate a large number of pulse encoder. Thanks to the sine and cosine signal interpolation method, it provides a method to calculate the rotation Angle. This method can obtain the fundamental sinusoidal high increase, for example, to transfer from every 1024 encoder sine wave, each turn more than 1000000 pulse. Accept this as long as a little more than 100 KHZ or the bandwidth required of the signal is enough. Interpolation frequency multiplication must be completed by the secondary system.