This is a very common circuit in the days of xenon flashes for cameras. This is from a Radio Electronics magazine from November 1965. It uses an SCR and has manual triggering.
This amplifier was found in a Japanese publication in 1972. Transistors are uncommon today, and...
The current of this source is 200 mA at the most, and the output depends on the zener that may...
Found in Mallory documentation from 1968 this circuit uses an integrated circuit from that time. The...