We found this circuit in a Japanese 1968’s documentation. The circuit makes use of transistors from that country common at the time of publication. Observe the symmetrical power supply for the circuit.
This interesting shield circuit was obtained from a Poptronics of February 2001. The American...
This remote control receiver via the power grid appears elsewhere on this site from other sources....
This 555 IC circuit was found in the November 1994 issue of Radio Electronics magazine. The...