This circuit was found in American documentation from the 1960s. The operational amplifier is from that time, but the configuration applies to modern equivalents.
This circuit was obtained in a Radio Shack documentation from 1977. It can be used as a multimedia...
This circuit was found in an American documentation from 1968. The configuration can be adapted to...
Equivalent transistors, such as the BC548, can be used in this circuit that we find in...