This small audio amplifier was found in an American publication in 1975, The integrated circuit used is rare today. The circuit was used in portable receivers of the time and other applications.
This circuit generates the busy tone of ordinary telephones. The transistors can be the BC548 and...
This small 1 W amplifier uses a Motorola integrated circuit from the 1970s. The integrated circuit...
This is a configuration widely used for oscillators with crystal from 1 to 20 MHz typically. The...