This high quality circuit with complementary symmetry was found in an Electronics World of 1966. It can be made with modern transistors like the BD or TIP series.
This 2009 circuit is a bilateral call warning. Easy to build, using light communication between two...
The oscillator illustrated in the figure can be used to generate signals ranging from 100 kHz to a...
This circuit was used to reinforce radio signals for listening on the phone, making it possible to listen...