Adapting the Basic Concepts of Power Supplies for Communication Systems to the Circuit Technologies used in these Systems

The technologies in use in communication systems have undergone several radical changes since such systems were first introduced on a world-wide basis. By illustrating three stages in the development, this paper shows how these technological advances have affected system-specific power-supply design principles - particularly with respect to the system-specific operating-voltage requirements. The original communication systems employed analog modulators and amplifiers with thermionic tubes. These were gradually replaced by systems employing transistors. The last important development was the replacement of analog systems by digital systems. Each of these technological epochs: thermionic tubes, transistors and integrated circuits, the latter being the preferred type of circuitry for digital systems, placed special requirements on the system-specific power supply. This system-specific power supply - referred to simply as power supply in the following - is it-self fed from the installation supply voltage, which is normally a no-break supply. The power supply uses this supply voltage to generate the operating voltage required by the particular communication systems.