| 摘要 |
<p>The camera adjusting system for medical X-ray equipment includes a motor which drives a cable system to raise and lower the camera. The motor is controlled by a tachogenerator which in turn is connected to a bridge circuit (10). This circuit includes a differential amplifier and a thyristor control unit. The control handle (6) used by the operator is interconnected with the bridge circuit. The handle has a spindle (16) through it, connected to the camera housing, enclosed in a sliding sleeve (19) with its travel limited by end stops (17, 18). Between each end stop and a shouldered part (20) of the sleeve is a ring (26, 27) of pressure dependent resistive material forming part of the bridge circuit. Each ring is mounted between two contact discs (22, 23 and 24, 25).</p> |
