Security Circuit

A simple security circuit that prevents a single person from entering an area. AND gates S1 and S2 are the front enterance of the door(LED1). S3 and S4 are the back of that same door. Only one side can go through at a time. as at least one side has to be holding the keys(S switches) to the on position. This is because of the XOR gate(U4)A single override switch(overrideS) is required to be on to operate the door.