Found in an Electronic Design from the 80s, this circuit uses an unusual component today, the regulator integrated circuit. MOSFET can be almost any type.
This polarity test or indicator indicates the polarity of a power line by LEDs. The circuit is...
This is the circuit of a digital clock published in the January 1975 issue of Radio Electronics magazine....
Found in an Elektor from the 90s, this circuit can be powered directly by the power grid. The...