This sonic relay or vox was found in a Popular Electronics from the 90's. The power MOSFET can be of any type determining the controlled load.
This high-gain circuit uses junction FETs (JFETs) and must be powered by somewhat high voltages. The...
This circuit counts 1 per second, displaying the value in binary. The circuit is TTL and must be...
Critical components of this project are the Geiger tube and the 300V battery. The battery can be...