Armed with a functional inverter, the next step was an OR gate. By combining NOT and OR gates, you can easily make a NAND gate, an AND gate, a NOR gate, and any other logic you can dream up.

A PWM-controlled regulator, this time using a logic gate IC, op-amp, and resistors and capacitors to buffer the PWM signal.

Digital logic circuits generally have input power ... shows him creating a number of equivalent circuits starting with an inverter and working his way up to a half adder and an RS flip-flop.

Here we report integrated chemical logic gates based on ion bipolar junction transistors. Inverters and NAND gates of both npn type and complementary type are demonstrated. We find that ...