This circuit is from an old Popular Electronics, but it can be easily implemented nowadays, even adapted to act as a shield. The circuit has the frequency given by C1 and adjusted in R1.
This circuit was found in a National Semiconductor manual from the 1970s, appearing in articles and on...
Found in 1965s General Electric documentation, this circuit is intended for the control of servos...
We found in this American documentation this circuit for activating common cathode displays. In it we...