The operational amplifier used is not common today, but the circuit can be implemented with modern operational ones. The gain is 1000 and the source must be symmetrical.
Found in an old Elektor, this circuit uses two 7-segment displays to indicate the volume of an...
This resistance meter has a linear scale, converting resistances to voltage. The operational...
I got this circuit from an English magazine from 1977. It can still be easily assembled, as the...