Found in a 90s documentation, this circuit makes use of D1, a switching diode that is uncommon today. D3 is an LED. The circuit monitors 12 V batteries.
The rectangular oscillator shown in the figure makes use of one of the four NAND ports of an...
Found in a Popular Electronics from the 90s, this circuit can act as a transmitter for an audio...
Using the LM3914 this unusual digital clock uses a Bargraph LED indicator. The LEDs are the...