This circuit is from an Electronics Now from the 90s. The circuit uses a power integrated circuit from the time that must be equipped with a heatsink. The power supply is 18 V.
This sensitive two-transistor circuit was found in the June 1965 Radio Electronics magazine. The...
This circuit, obtained in an old publication, causes a second telephone bell to be played in a...
Found in a1969’s neon lamp documentation, this circuit uses a high voltage transistor. The output...