This circuit generates various types of sounds and can be used as a toy. The circuit is from Radio Electronics from January 1983. The amplifier can be replaced with a more modern type.
This circuit was found in a 90s Radio Electronics. The FM encoder or multiplexer is an uncommon...
This touch-controlled circuit was found in English documentation from the 1970s. The components...
Found in a book on transistors from 1954, this circuit can modernly be used as a relay shield. A 1k...