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.

Among semiconductors, the muting transistor and its audio application is perhaps the most obscure and poorly understood of all. There is extremely little information on this subject available on the ...

A very simple but highly efficient combination lock circuit is shown in the figure. Any type of on/off switches can be used, varying from commercially available inexpensive types to more sophisticated ...

[Kevin Darrah] wanted to make a simple 3.3V regulator without using an integrated circuit. He wound up using two common NPN transistors and 4 1K resistors. The circuit isn’t going to beat out a cheap ...

Working on an embedded project? An 8-bit microcontroller with a pulsewidthmodulation (PWM) peripheral can provide a low-cost and easy solution to adding natural voice to your next embedded endeavor.