| 摘要 |
<p>An arrangement for adjusting the value of an electrical component, for example a potentiometer, by means of rotatable shaft (10) comprising first (1) and second (2) pulleys and a cord (4) passed round the pulleys in a figure of eight configuration. A control lever (3) is movable through a first angle, typically 60°, and is effective to rotate the shaft (10) of a potentiometer (11) through 300°. The first and second pulleys (1,2) are arranged with their rims in contact at point (6) so that side thrust on the potentiometer spindle (10) caused by the tension in the cord (4) is resisted by the contact between the pulleys. In order to prevent slip between the cord (4) and the pulleys (1, 2) the cord is clamped (42, 44) on each pulley and the ratio of the rim radii of the pulleys is made equal to the ratio of the core radii of the pulleys.</p><p>The arrangement may be used in television studio and outside broadcast equipment such as video tape recorders, special effects generators and remote controllers.</p> |
