No. 1 ESS Circuit Packs and Connectors

The No. 1 ESS must compare favorably with existing switching systems in cost, reliability of operation, space requirements and ease of maintenance. The extent to which these basic objectives are achieved will depend to a considerable degree upon the mechanical packaging arrangement used for its electronic circuitry. The system must he packaged so that it can be mass produced economically and yet will operate with high reliability over a 40-year life.1 Space requirements dictate compact packaging, although a high degree of miniaturization is not required. Once installed, any part of the system must be readily accessible for maintenance or replacement should the necessity arise. At the present state of the packaging art, these objectives are best served with conventional printed circuit packaging techniques. The combination of a printed wiring board circuit pack and a molded wire spring connector is the basis of the packaging concept which was adopted for the No. 1 ESS. I I . CIRCUIT PACKS