This TTL circuit is from a Radio Electronics magazine from November 1983. The circuit drives a set of LEDs. The integrated circuit used is a BCD to decimal decoder.
The presented circuit monitors a line indicating if it is busy if there is an extension. The...
This high-powered megaphone circuit is from a Radio Electronics from December 1964. Note the use...
This linear circuit was found in a 1965 Electronic Design. The transistors are from that time....