This circuit was found in a 1977 documentation. It limits the voltage from a source using zener diodes on the rectifier bridge. It is an unusual configuration today.
This circuit triggers a load that depends on the characteristics of the transistor when we touch...
This circuit was obtained from Popular Electronics of the 1990s. It makes use of a mercury switch that...
This circuit was obtained from Linear Technology documentation from the 90s. The circuit uses...