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 circuit allows 220 / 240V shavers to be used in the 110V network. The diodes can be general...
Used with telephones at the time, this circuit was found in Popular Electronics from the 90s. The...
This circuit was obtained from an American 80's documentation. It can be implemented with modern...