Operated directly from the power grid, this detector was found in an 80's RCA documentation. The sensor is an ionization chamber. The SCR triggers a warning siren.
We found this anti-theft circuit in a 90's English publication. The circuit uses common components...
We found this circuit in an Electronic Design from the 80's. The generated tone can be changed as well...
This astable multivibrator, well known to all, was found in the Raytheon transistor application manual of...