For analog lines, this circuit was found in the August 1994 issue of Electronics Now magazine. The transistors are common general-purpose types.
) This variable frequency oscillator was found in an old American documentation. Transistors allow more...
Found in the September 1982 issue of Radio Electronics magazine, this circuit triggers a relay...
Using a 106 series SCR, this circuit was found in the May 1971 Radio Electronics magazine. The...