This circuit was obtained from a Philips documentation from 1970. It can be built on modern operational amplifiers.
We found this circuit in a Popular Electronics from the 80s. This circuit eventually doesn't work with...
This circuit consists of a 10 + 10 V symmetrical source that operates from a single 5V input. It is...
This circuit is from an English magazine of 1977. The circuit is still current, just using BC547...