This small tone generator was found in the November 1987 issue of Radio Electronics magazine. The phototransistor is common and controls the sounds generated. The basic frequency is given by C1.
Found in General Electric documentation from the 1980s, this high speed perforated tape reader...
This circuit indicates when the voltage of a 12 V battery is low. With changes, for example, the...
We found this signal generator circuit in the November 1978 issue of Radio Electronics magazine. The...