THIS WAS A PC BOARD I DESIGNED TO DETECT THE ROTATION OF A SHAFT AND INTERFACE WITH A PLC TO GIVE DIRECTION (CW/CCW, AND STUCK SHAFT SIGNALS). IT INCOPORATES STANDARD DIP IC'S, LEDS, DIODES, PCB HEADERS, A T9 TRANSISTOR. THIS IS FUN IFYOU JUST WANT TO SEE IF SW CAN DO A SIMPLE PCB. NOT REALLY USEFUL ELECTRONICALLY. MANY TIMES I NEED TO MODEL A CUSTOM CONTROL BOARD TO SEE HOW IT WILL FIT IN THE EQUIPMENT.