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.
We found this interesting bistable photoelectric control circuit in a 1988 documentation. The...
The integrated circuit used in this oscillator is no longer common in our market, as the...
This circuit was found in a 1970s documentation. The integrated circuit used is uncommon today....