This circuit is for old telephones with analog lines. It was found in the May 1988 Radio Electronics magazine. The circuit is powered by the line signal voltaje.
This control circuit for direct current motors uses a 741 and an operational one of unusual power...
This is the traditional voltage follower configuration with the 741 operational amplifier. The...
This type of configuration can be seen elsewhere in this section. This is from a 1965 General...