This circuit found in the February 1992 issue of Radio Electronics magazine is designed to adapt an audio signal for use in a computer's ADC. It can be adapted to operate with microcontrollers.
Found in a 1960 Sylvania manual, this circuit can be implemented with a modern equivalent...
We found this circuit in a 2006 publication. The circuit is simple, being powered by a 9 V...
This circuit is from a Popular Electronics from the 90s, consisting of a repeater relay for remote...