This 10 A solid state relay was found in a 1980s documentation. It can work as a shield and implemented with modern equivalent transistors.
This 1995 circuit uses an audio amplifier that is no longer common today. However, other...
The tone produced by this circuit attract fishes. The circuit is installed into a small can and...
This circuit is from Mullard 1969 documentation. The circuit operates at a relatively high supply...