Found in an old publication about neon lamps this circuit works directly connected to the power grid, serving as an indicator for various situations. Ordinary neon lamps can be used.
Found in documentation from the 1980s, this amplifier uses an integrated circuit from the time....
This is a one-channel application for the Texas Instruments TMP390 sensor obtained directly from...
This moisture-activated relay was obtained from an American documentation from the 1980s,...