This circuit was found in February 1976, Radio Electronics magazine. The components are from the time and are based on the 555. The power supply must be provided with the indicated voltages.
With the coded activation of the relays, it is possible to control which of the 16 outputs...
The integrated circuit used in this application is not very common. Transistors and resistors...
This simple circuit makes use of neon lamps to indicate the voltage of a power grid. The lamps are...