Improvements in Apparatus for Tension Control of Flexible Materials During Winding or Unwinding Processes

摘要

1,194,771. Control of D.C. motors. BETA INSTRUMENT CO. Ltd. 31 Jan., 1969 [2 Feb., 1968], No. 5500/68. Heading H2J. [Also in Division G3] Tension in flexible material being wound or unwound is controlled by adjustment of the speed of a reversible reel motor 1 which is energized by one or the other of identical thyristor circuits according to the direction of the required torque, the thyristors being controlled by the halves R1, R1a of a dual potentiometer actuated differentially by a tension sensing device (comprising a spring loaded jockey arm and pulley). The thyristors regulate the field or the armature current (or both) by firing angle control, triggering being effected when the charge on a capacitor C1 is enough to cause conduction of transistors Q1 and Q2 which then discharge C1 into the trigger electrode. R3 and C2 provide damping. Reverse energization provides reverse rotation or dynamic braking in the forward direction.