Uploaded with ImageShack.com Excuse the quality of that picture its the best I can do at the moment. Ok basically I'm trying to create a tachometer circuit that will ultimately interface with a PLC digital input. Only thing is for some reason I can never get 24vdc emitter of my npn transistor to ground, right now it stays at 18 volts then drops to 16 or so when I break the infrared beam between the infrared diode and infrared emitter. What I want to happen is switch the 24VDC off and on every time the infrared beam is broken. Any help would be GREATLY appreciated. Apologize if this isn't all that coherent, I've been troubleshooting this for a while and I'm getting tired.