Found in an old Elektor, this circuit uses two 7-segment displays to indicate the volume of an amplifier. The circuit uses components that are still common today.
This circuit is from the 1977 GE semiconductor manual. The components used are uncommon today....
This circuit has 4 operating modes and was found in the 1995 Encyclopedia of Electronic Circuits...
The voltage of 30 V indicated in this project, shown in the figure, depends on the diac used. It...