magnetic kodiergeraet with a rotating magnetisierten kodescheibe

摘要

1,086,760. Digital shaft encoders. GENERAL PRECISION Inc. Dec. 21, 1965 [Feb. 1, 1965], No. 54094/65. Heading G4H. A shaft encoder comprises a disc 24, Fig. 1, having tracks each comprising segments of raised and lowered portions, reading heads 40 being provided for each track, the disc being magnetized to produce magnetic flux perpendicular to the surface of the disc and there being an alternate flux path 54 shunting undesired flux from the read-out element. The read-out heads are energized by an A.C. signal. When they are opposite a raised portion they are saturated by the magnetic flux of the disc. When over a lowered portion they are not saturated. The inductance in the two cases is therefore different and the signals given indicate whether the head is over a raised or lowered portion. These outputs are rectified (Fig. 8, not shown) and applied to gates. There are leading and lagging heads for each track except the least significant. One of these outputs is selected according to the presence or absence of the next less significant digit. One of the gates is enabled for this purpose and the outputs pass through Or gates. The disc is coded in binary scale.