Found in a 90s Popular Electronics, this circuit uses a simple 9 V source. The power can be used from the circuit with which it works.
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...