Abstract: An electrical plug and receptacle relying on magnetic force from an electromagnet to maintain contact are disclosed. The plug and receptacle can be used as part of a power adapter for connecting an electronic device, such as a laptop computer, to a power supply. The plug includes electrical contacts, which are preferably biased toward corresponding contacts on the receptacle. The plug and receptacle each have a magnetic element. The magnetic element on one of the plug or receptacle can be a magnet or ferromagnetic material. The magnetic element on the other of the plug or receptacle is an electromagnet. When the plug and receptacle are brought into proximity, the magnetic attraction between the electromagnet magnet and its complement, whether another magnet or a ferromagnetic material, maintains the contacts in an electrically conductive relationship.

Abstract: A fiber processing machine includes an arrangement for forwarding a sliver through a space in an advancing direction; an arrangement for continuously displacing the sliver in the space transversely to the advancing direction while the sliver is forwarded in the advancing direction; and an apparatus for detecting a presence, absence, motion or standstill of a sliver. The apparatus includes a transmitter emitting a sensor beam passing through the space transversely to advancing direction for being intermittently interrupted by the sliver during displacement thereof transversely to the advancing direction; and a receiver positioned in a path of the sensor beam for receiving a light or a dark signal dependent whether or not the sensor beam is interrupted by the sliver during displacement thereof transversely to the advancing direction.

Abstract: A method of operating a sliver draw unit of a spinning preparation machine includes the following steps: applying, by incremental rotary displacement sensors, signals to an electronic control and regulating device; determining from the signals the angular position and/or the rotary direction of at least one of the roll pairs of the draw unit during operation and standstill; and rotating at least one of the roll pairs into a predetermined angular position by controlling the electric motor driving that roll pair.