Found in Radio Electronics from the 90s, this circuit is intended for analog TV applications of the time. The transistor used as well as the module are uncommon components today.
This circuit is from a Popular Electronics from the 90s. The circuit has a tone frequency...
This solar powered circuit was found in a 1991 documentation. The transistor is a general purpose...
This circuit is based on a common cathode 7-segment display. The circuit is based on CMOS...