This circuit makes use of unusual components today. We found it in General Electric documentation from the 1980s. The circuit operates with modulated optical signals.
I found this circuit in a Popular Electronics from November 1999. The magazine is no longer...
This circuit of a 1991 PE Hobbyst Handbook allows the brightness of the incandescent lamp to be...
This simple operational amplifier tester was published in the November 1987 issue of Radio...