Abstract
Digital attenuators are simple multiplying digital-to-analog converters used to replace coefficient-setting potentiome ters in modern analog/hybrid computers. This report de scribes a new digital attenuator system employing low- phase-shift miniature metal-film ladder networks. They are switched by latching reed relays which give the system a nondestructive coefficient memory even when the com puter is switched off. New digital control logic employs serial data transmission and requires only one address line per 14-bit attenuator. It permits one to set all 200 attenuators of a typical hybrid computer installation within 20 milliseconds. For maximum contact life, relay contacts are switched only when no current is flowing. The digital computer static-check routine can readily check individual relays to simplify maintenance.
Particular emphasis in this report is on a digital-attenu ator system designed for a very fast repetitive computer in the Analog/Hybrid Computing Laboratory at the Uni versity of Arizona. The same design approach is readily applied to "slow" analog computers and appears to be even more advantageous there.
Get full access to this article
View all access options for this article.