Found in a Popular Elecronics from the 90s, this circuit appears in other versions in this section and on the website. The circuit draws one of 10 LEDs and has a sound effect produced during the draw.
This circuit is from a Radio Electronics magazine from December 1958. The indicator instrument is analog...
This circuit sends signals to a shortwave radio (range 3 to 7 MHz) at a distance of a few tens of...
This circuit was found in an Electronics World of 1968. It can be applied to any modern triac and...