Found in a 1964 General Electric documentation, this circuit uses PUTs that are not currently common components. By changing the capacitors, the frequency can be changed.
Found on Popular Electronics this circuit has variations found throughout this site and section....
Found in an Electronics Now from the 1980s, this circuit uses some components that are still...
High Current Through Hole Inductors for Vishay's 5A Series IHXL-2000VZ-5A Series Power Supply are...