We found this circuit in an American documentation from 1947. The circuit uses 5 tubes and has a feature to keep the tube filaments preheated.
This circuit is from an Electronics World of 1967. The circuit slows down the activation of a...
This circuit was obtained from a Popular Electronics of the 90's. Any power MOSFET can be used as...
The integrated circuit used in this project is uncommon and so are the transistors, but they can...