Found in a 1970s documentation, this mini-organ toy circuit makes use of an integrated circuit from that time. This component is difficult to obtain today.
Found in a 1990 Electronics Handbook, this circuit causes an LED to flash when the phototransistor receives...
The circuit shown in the figure is recommended for applications where a visual indication is...
This circuit is a siren with manual modulation that, instead of exciting a speaker, excites...