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.
This double-T sine wave oscillator uses a CA39035, an integrated circuit released by RCA at the...
The integrated circuit MC1408 / MC1508, consists of an 8-bit digital / analog converter from...
This circuit, which can act as a shield, was found in an American documentation from the 90s. The...