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.
This circuit was found in an American publication from 1969. Transistors are from the time and can be...
We found this circuit in a 1998 documentation. The circuit makes use of CMOS logic and must be...
This 1 transistor circuit is from a Radio Electronics from December 1958… The circuit is battery...