Found in RCA documentation from the 1970s, this circuit is intended for firing thyristors in inverter circuits. The components are from the era and the operating frequency is 10 kHz.
This circuit was found in a 90’s 303 Circuits. The components are from the period and the heating...
Found on Popular Electronics this circuit has variations found throughout this site and section....
The transistors in this circuit from a 1994 technical publication may be BC548 and the 12 V supply...