Improvements relating to reeling and unreeling equipment

摘要

817,725. Automatic control systems for winders. BRITISH THOMSON-HOUSTON CO. Ltd. April 12, 1957 [April 20, 1956], No. 12173/56. Class 38 (4). [Also in Group XXXVII] In an arrangement in which a motor or motors M1, M2 energized by a generator G and driving a roller or rollers is or are connected in a loop with an electric machine RG (a motor during reeling and a generator during unreeling) coupled to the reel, and a booster B the excitation of which is controlled in accordance with the current in the loop, a proportion of the IR drop in the loop is compared with a similar proportion of the booster output and the difference is applied to adjust through a motor RhM and a rheostat Rh1 the strength of the field RGX of the machine RG in order to maintain a substantially constant voltage output, and a substantially constant booster voltage. The booster is controlled to maintain a substantially constant loop current and hence tension in the element being reeled, by an amplidyne A1 having a field due to winding AIX energized in proportion to the loop current opposing a field due to a reference winding AIY the energization of which may be predetermined by a tension selecting potentiometer VR. Inertia compensation is provided by a further winding AIZ which is energized by an amplidyne A2 in accordance with the current through the main generator G as measured by the voltage drop across compoles CG. The compensation is modified as the mass varies during reeling or unreeling by a potentiometer Rh2 also driven by the motor RhM. A unidirectional coupling may be included to prevent back driving of potentiometer Rh1, Rh2 during a breakage, or alternatively the circuit of motor RhM may include a rectifier. The amplidynes could be replaced by magnetic amplifiers. Specification 817,726 is referred to.