What is a Programmable Unijunction Transistor (PUT)? Simple – it is a three-lead electronic semiconductor device, similar to a unijunction transistor (UJT), except that its behaviour can be controlled ...
A Planet Analog article, “2N3904: Why use a 60-year-old transistor?” by Bill Schweber, inspired some interest in this old transistor and how it’s commonly used, and if any uncommon uses might exist.