This circuit was found in the 1967 RCA SCR manual. The circuit generates approximately 300 V at a frequency of 1 kHz. The components are from the era.
This interesting adjustable power supply uses the transistors themselves as controllers and...
This alarm from an old 1978 publication uses PNP transistors and driver and output transformers that are...
This is a typical source of the time (1989) using the well-known regulator integrated circuit 723....