1-10pcs Rotary Encoder Module Brick Sensor Development Round Audio Rotating Potentiometer Knob Cap EC11 for Arduino Product Introduction: 1.Operating Voltage: 5V 2.Pulse Number for One Circle: 20 3.Rotary encoder can count the output pulse times by rotating positively and negatively. This counting method has no limitation, it can reset and come back to the initial status if matching with the key on the encoder (that is to say it will count from 0) 4.Operating Principle: Incremental encoder is a kind of rotary sensor which transforms the rotation displacement into a series of digital pulse signal. These pulses are used to control angular displacement. In Eltra encoder, the transformation of angular displacement adopts photoelectric scaning principle. The reading system is based on the radial dividing plate's rotation of alternative light window and non-light window, and it will be exposed to infrared light source at the same time. The light will reflect the picture of plate on the surface of receiver. The receiver is covered by a diffraction grating, and it has the same window width with the plate. The operation of receiver is to detect the change of light plate rotation, then transform the light change into electric change. Increase the low level signal into high level and generate square pulse without any interference. This process needs circuit to deal with. The reading system usually adopts differential method, that is compare two different signals who have the same waveform bu the phase difference is 180 degree so as to improve the output signal quality and stability. Reading is formed on the basis of the difference between two signals, so it eliminates the interference. _x000D_