This circuit reproduces the dial noise in a small speaker. The transistor can be a general-purpose type. We found it in an 80's Electronic Design.
This circuit generates very high voltages using an old TV flyback. The transformer has a secondary of...
This fraction watt amplifier uses transistors that are still quite common in our market. The power...
This circuit was obtained in documentation on medical applications from 1966. The circuit is used in...