Power supplies for the Type-P1 carrier system

Low first cost and annual charges, good voltage regulation, high reliability, and low maintenance were major objectives guiding the choice of power supply design for the type-P1 (rural) carrier system recently developed by Bell Telephone Laboratories. A study of conventional designs revealed that new techniques would be necessary to realize these objectives. This paper describes how the use of semiconductor devices, the employment of unconventional approaches to power supply packaging, and the development of a new type of lead-acid storage battery influenced design decisions to the end that the major objectives were realized.