This circuit was found in a 80's Popular Electronics. The sensor can be any phototransistor. The circuit is indicated for an audio link modulated in pulses.
This circuit was obtained in the 1977 RCA CMOS manual. The circuit has the frequencies determined by the...
We found this circuit in a 2004 documentation. The circuit consists of a standard lamp for testing...
Found in a Popular Electronics of the 90s this configuration can be seen elsewhere on our site....