Controlled positioning of record player pick=up - uses control disc with cam and follower to direct pick up to start position

摘要

The control unit for a record player turntable is used to ensure that the pick up needle is brought to the correct start position automatically. The pick up arm (11) together with counterbalance weight (15) and needle (13) is supported on a spindle (9). A metal disc (17) passes between the armature and yoke of a solenoid (33) and can be used to control rotation of the spindle. A projection carries a follower (37) that runs in a profiled track on a control disc (47) that is rotated by belt drive from the main drive unit. As the needle swings to the start position, the follower moves vertically to cause lowering of the needle to the playing position.