This balance control for the channels of a stereo system was found in a 1969 Mullard documentation. The transistors may be the modern BC548 equivalents.
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...