Other settings like this can be found on this website. This makes use of old operational amplifiers, as the publication where we obtained, but equivalents can be used.
This circuit is used to protect an amplifier from excessive power output that would cause problems for...
This circuit was found in a French magazine Toute LÉlectronique from 1978. Transistors are not...
This circuit was found in documentation from the 50's. The circuit uses transistors of the time...