We found this circuit in the September 1994 issue of Electronics Now magazine. The circuit uses off-the-shelf components and is powered by mains power.
This circuit uses a CA3140, an operational amplifier with FETs in the input stages. Equivalent can be...
Found in a Popular Electronics from the 90s, this circuit has a configuration that has been widely...
This circuit was found in an American 80s circuit manual. The components used are unusual. The...