Using the LM3914 this unusual digital clock uses a Bargraph LED indicator. The LEDs are the segments of a 7-segment display. We found it in February 1980 Radio Electronics magazine.
Using a 4046 PLL this circuit recognizes a 1.6 to 1.8 kHz tone by driving an output LED. The...
This battery charger circuit was found in ancient American documentation. The components are...
This circuit is of great use today, when solar energy is becoming increasingly important. The...