Potentiometer switch for vehicle dashboard lighting - has non-rotating rocking metal disc contacting resistance wire toroid and supported on central post (NL 19.6.79)

摘要

The potentiometer switch, for a motor vehicle's dashboard lighting, has a resistance path comprising a toroidal wire helix and a movable contact to select the value of the resistance. The movable contact consists of a rocking metal disc (18) pressed into contact with the wire by a sprung ball projecting from beneath a rotary part (10). The disc tilts about a fixed post (19) at the centre of the wire helix (20). The disc is prevented from rotating.