B25 Photo Interrupter

2 layer board of 0.50x1.80 inches (12.70x45.72 mm).
B25 Photo Interrupter board combines an RPI-574 photo interrupter component and a 2N3904 NPN small signal transistor with two mounting holes for use as a sensor. By selecting appropriate values for the resistors, the board can be customized to various operating voltage levels, etc. The purpose of adding the transistor to the board is to increase the current handling capability of the sensor board.