Inductive differential angle or path encoder - suppresses induced noise directly by using two coil parts connected in series opposition

摘要

The encoder has a U-shaped iron core with two parallel limbs (1, 2) one of which carries a coil and a short-circuiting ring that encircles at least one limb. The ring can be moved along its limb to alter the inductance of the coil. The coil is divided into two equal parts (14, 15). One part is on one limb and the other part on the other limb. The two parts are connected in series in opposite senses so that interference is reduced or eliminated. Interference may be induced in the coil because of spurious electromagnetic radiation caused by the switching processes. No extra noise suppression is required.