This two-tone alarm siren was found in the January 1975 issue of Radio Electronics magazine. The power transistor can be changed and with it, Rx has values from 10 to 47-ohm.
This circuit was found in the July 1990 Radio Electronics magazine. It is based on the 3-digit...
This circuit can be used on sound mixers to obtain effects. We found the circuit in a 1997...
This oscillator uses a ceramic resonator to determine the frequency. This kind of element is found...