App-Note-203 - Two Channel Optical Interrupters

Optek has two types of dual channel optical interrupters available. The OPB822 family has two side-by-side channels on 0.212” centers and the OPB826 family has two vertical channels on 0.150” centers. These standard parts may be used for determining direction of rotation, speed, and relative location of a rotating shaft. This bulletin will discuss some of the design aspects of two channel encoding along with circuit concepts and unit performance.