Found in na 1980’s English magazine, this circuit produces a strong modulated tone reproduced on a speaker. The power MOSFET can be of almost any type.
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...