This circuit is intended for detecting 3 levels power grid voltage, and it can be adapted to operate with the most diverse voltages. The circuit uses neon indicator lamps.
This circuit causes an LED to flash at a frequency determined by the capacitor. The circuit has an...
Found in American documentation from the 90s, this circuit can measure frequencies on a linear...
This frequency modulated light transmitter is from a 1990s documentation. The circuit may use...