This incremental rotary encoders Exquisite workmanship ,Quality assurance for 1 years. If there are quality problems within 1 years, you can send us email. We will send you new ones . Product Name: incremental rotary encoders 100P/R , AB two phases.AB two -phase quadrature output rectangular pulse, the circuit output is NPN open collector output type . Encoder size ： Encoder size: 38 x 35.5mm/1.49" x 1.39" ；Shaft: 6 x 15mm/0.23" x 0.59"；Axis stopper platform: High 5mm, 20mm；Power source: DC 5-24V；Maximum mechanical speed: 6300 R / min. Connection: white = A phase, Green = B phase, red = power +, black = V0 ； Note: AB two -phase outputs must not be connected directly to VCC, otherwise, they will burn the output transistor. Package content：1 x Incremental Rotary Encoder ；Net Weight : 130g; Model: incremental rotary encoders, AB two phases, 1. It can be used to measure the rotational speed, Angle and acceleration of the object and the length measurement. 2. Suitable for a variety of intelligent control displacement measurement ,automatic fixed-length automatic guillotine paper machine, steel cut length control, civilian measured height human scale, students racing robots. Note: If the encoder is not connected to the device can not be directly connected to oscilloscope ( open collector output without pull-up resistor when there is no voltage output) If you want the oscilloscope in AB two-phase output, work with two pull-up resistors(not included).