This biestable vox circuit was found in an old documentation. The circuit makes use of components of the time (80's) and can work as a shield since the power is 5 V.
This highly sensitive circuit causes one relay to be closed when the other is open or still...
This amplifier circuit with a low power MOSFET was found in Popular Electronics from the 90s. The...
A high-frequency square wave oscillator using an LC-tuned circuit is shown here. The upper...