The purpose of this heat detector is to find hot spots on a board or other locations. The sensor is an integrated circuit from the period. The circuit is from Radio Electronics from May 1985.
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....