This circuit was found in Raytheon's 1967 documentation. The circuit uses an operating of the era, but the configuration can be applied to modern operational amplifiers.
This circuit was found in Motorola documentation from 1966. The lamps are according to power and...
This circuit, which uses components still common today, was found in a 1997 documentation. It...
This circuit is intended to apply the music signal from a stereo to a telephone line for the...