[Dr. Cockroach] figured out a way to create an inverting NOT gate from just one LED and two resistors (one being a photo-resistor). The Dr. has since built AND, NAND, OR, NOR, XOR and XNOR gates ...
Complex applications use numerous NOT, AND, and OR gates, along with NAND, NOR, XOR, and XNOR gates. Logic Gates and Circuit Simplifcation Tutorial Video Credit: cslearning101 NAND logic gates serve ...