This circuit for frequencies of 20 to 2 kHz was obtained in English documentation from 1966. The transistor can be any general purpose and powered by batteries.
We can use high value electrolytic capacitors in alternating current circuits with the...
This negative voltage source was found in a Popular Electronics from the 90's. The transformer has 120V...
Found in an old Popular Electronics, the sparker is driven by a motor being adapted to the...