This small audio amplifier uses an uncommon integrated circuit today. The circuit is from a documentation from the 70s and is indicated for portable receivers of the time.
Found in Radio Electronics this circuit uses a fotodiac to drive a triac. The circuit can use...
This circuit was found in an Electronics Now from the 90s. The frequency depends on the crystal. The...
This power supply for gas laser was obtained in an American documentation from the 90's. The...