The inductosyn and its application

The inductosyn is a new control element manufactured in rotary and linear forms. In its rotary form it is capable of indicating angular position to an accuracy of 5 seconds of arc with a repeatability of 1 second of arc whilst in its linear form it is capable of a positional accuracy better than 0.0001 in. with a repeatability of 25 microinches. This paper describes both forms in some detail, together with digital to analogue converters suitable for use primarily with the linear inductosyn when used as a position control device. A generalized description of the associated electronic circuits is given enabling the linear inductosyn to be used for machine tool control. Particular reference is made to a programmed co-ordinate table measuring 10 in. by 8 in. which may be positioned in one plane in the x, y co-ordinates to an accuracy of ±0 0002 in. Co-ordinate information is given in the form of punched cards and any number of co-ordinates may be specified and programmed. This is illustrated by considering a typical machining problem, that of placing hole centres in a small gearbox casting to the accuracy specified.