Found in a documentation from the 90s, this circuit limits and amplifies a voice signal in the 800 to 3000 Hz range and is intended for transmission systems.
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...