This circuit is from a Popular Electronics from the 90s, consisting of a repeater relay for remote control of TV, which today can be done by Wi-Fi or other simpler resources.
Found in a magazine 73 for radio amateurs of the 90s, this circuit shows how to supply a photo...
This circuit was found in the 1991 Electronics Experimenters handbook. It can be used to display RGB...
This sinusoidal oscillator was found in Radio Electronics in 1989. It uses a 741, but other...