The rotary encoder is a sensor, the main speed detection played a mechanical movement, the role of the position, angle, distance and other parameters. The method of the encoder as a signal detection has been widely used in various industries.

Rotary encoder works like this: When the rotary encoder grating disk drive shaft rotates, the light emitted by the light emitting element is the grating disk slot cut into intermittent light receiving element and generate an initial signal. The signal processing circuit after subsequent output pulse or code signal.

The rotary encoder has the advantage of small size, light weight, variety, full-featured, high frequency response, high resolving power, torque, low power consumption, stable performance, reliability and long service life.
Common types of rotary encoder incremental encoders, absolute encoders, sine encoders, three encoders what is the difference?

1, incremental encoder
 When the incremental encoder shaft rotates, there is a corresponding phase output. Discrimination and increase or decrease the number of pulses of the rotational direction, to the rear of the circuit requires the use of judgment and counter. The count starting point can be set, and can achieve unlimited accumulation and measurement of multi-turn. It can also be issued per revolution a pulse signal Z as a reference mechanical zero position. When the pulse is fixed, while the need to improve resolution, using a band 90 degrees out of phase A, B of the two signals, the original number of pulses multiplier.

2, absolute encoder
When the absolute encoder shaft rotator have position correspondence code (binary, BCD code, etc.) output from the code changes the size of the positive and negative directions to determine the location and displacement, without judgment to the circuit. It has an absolute zero-bit code, when a power failure or power-cycle re-measure, you can still read accurately position to power failure or shutdown code, and find exactly zero code. Under normal circumstances an absolute encoder measuring range of 0 to 360 degrees, but special models can also be multi-ring measurements.

3, sine wave encoder
Sinusoidal encoders are also incremental encoder, the main difference is that the output signal is a sine wave analog signals rather than digital signals. It appears primarily to meet the needs of the electrical field - as a motor feedback detector elements. On the basis of comparison with other systems, people can use this encoder is needed to improve the dynamic characteristics.

So in practice, how to choose a rotary encoder it?

In order to ensure good performance motor control, encoder feedback signal must be able to provide a large number of pulses, especially at low speed when using the traditional incremental encoder generates a large number of pulses, in many ways has a problem when the motor rotation speed (6000rpm), the transmission and processing of digital signals is difficult. In this case, the processing to a servo motor, servo motor signals required bandwidth (for example, the encoder pulses per revolution 10000) will easily exceed MHz threshold; on the other hand analog signal greatly reduces the above-mentioned problems, and It has the ability to simulate a large pulse encoder. Thanks to the interpolation of the sine and cosine signals, it provides a method for the calculation of the angle of rotation. This method can achieve high power increase substantially sinusoidal, for example, from 1024 sine wave per revolution encoders, access to more than 1,000,000 pulses per revolution. This signal is required to accept slightly higher than 100KHz bandwidth as long as sufficient. Interpolation multiplier must be completed by the secondary system.

For the user to select the appropriate encoder performance is very important, we should understand the characteristics of various types of rotary encoder, to find a suitable encoder to use, Guangdong Granville Electronics Co., Ltd. specializes in producing rotary encoder 25, by virtue of years of research and production experience, unanimously recognized by customers and the community, is an excellent manufacturer of rotary encoder, please contact us to discuss related operations.