This simple circuit makes use of neon lamps to indicate the voltage of a power grid. The lamps are common neon and the circuit indicates whether the voltage is 110 V or 220 V.
This high-performance circuit was found in the 1982 SGS Linear Integrated Circuits Manual. The...
This circuit for audio applications was found in an English magazine from the 80's. The circuit...
The circuit presented uses an integrated circuit Sanyo, not very common in our day. This amplifier provides...