This circuit was found in General Electric documentation from the 1980s. The circuit is intended to receive 50 kHz modulated optical signals. The components support modern equivalents.
This circuit of a voice-controlled switch, Vox or sonic switch was obtained in a Popular...
This circuit appeared in the July 1969 issue of Radio Electronics magazine. The sensor is an LDR....
This circuit of two transistors was found in a Japanese magazine in 1967. The transistors are made...