This interesting reflex receiver used a different component, which at the time was showing up. The receiver is from a 1924 documentation and used a sodion tube.
This timer for a few minutes was originally indicated for photographic applications. We found it...
This circuit was found in documentation from the 50's. The circuit uses transistors of the time...
This shield circuit was found in an American publication from the 80's. The triac is of low...