This circuit was found in a 90s Wels' Think Tank. The frequency depends on C2 and R3. The handset or speaker must be at least 80-ohm. Observe the low supply voltage.
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...