This circuit delivers at its output a voltage that proportional to the amplitude of the input signal in a range of 36 dB. We found it in an American documentation from 1966.
This alarm, found in a 2002 documentation, uses several sensors and has a 12 V supply, not...
This circuit uses a special 1950's RCA strobe tube. It can be built with equivalent components for the rest...
This circuit, which can act as a shield, was found in a 1970s American documentation. The...