A liquid crystal apparatus includes a liquid crystal device having a group of scanning electrodes and a group of signal electrodes intersecting each other to form an electrode matrix, and a chiral smectic liquid crystal having a threshold voltage varying depending on a voltage pulse width disposed so as to form a picture element at each intersection of the scanning electrodes and the signal electrodes. The electrodes are driven by (a) applying a scanning selection signal and a scanning non-selection signal to the scanning electrodes, (b) applying data signals to the signal electrodes so as to apply a voltage to a selected picture element at an intersection of a selected scanning electrode receiving the scanning selection signal and a selected signal electrode, the voltage applied to the selected picture element being at least two times a voltage applied to a non-selected picture element at an intersection of a non-selected scanning electrode receiving the scanning non-selection signal and a selected or non-selected signal electrode, (c) periodically applying the scanning selection signal to the scanning electrodes, and (d) setting a voltage level of the voltage according to a local environmental temperature.

Method of driving optical modulation device

A contact device for an electrical current supply of an electrode wire operating in an electro-erosion machine having an electrical conducting part, mounted in free rotation and solidly attached to a shaft extending perpendicularly to the plane of rotation. The shaft is, preferably, also conducting and extends through a leakproof cavity, containing a conductive fluid, such as mercury for example. The conducting part is preferably a steel roller, provided either with a V-shaped groove on its periphery, or animated with a back and forth movement parallel at its axis of rotation.

Contact member for supplying electrical current to an electro-erosion wire electrode

A device for conducting a machining current to a traveling wire-electrode tool in a wire-cutting electroerosion machine comprises a rotary brush block (e.g. of cylindrical shape) having a planar current-conducting surface disposed in a wire-travel path for making sliding electrical contact with the moving wire-electrode tool. A motor rotates the brush block about the rotary axis thereof to rotationally move the current-conducting surface in tangential sliding electrical contact with the moving wire-electrode tool. A scraper is provided downstream of the workpiece machining zone and upstream of the brush block to remove abrasive particles and machining chips and other products (e.g. tar) adherent on the wire tool fed from the machining zone, thus to prevent them from being carried onto the brush surface.

Method of and device for conducting machining current to a wire-electrode tool in a wire-cutting electroerosion machine

A current collector disc assembly and method preferably generally comprising a rotor segment, a rotor electrode, a stator segment, a stator electrode, a return channel, a current conduction block, a circulation control magnet, electrode supports, a passage, flow ports and a magnetically-polarized stabilizer insert.

Current collector assembly and method

A drive device for a motor vehicle includes at least one electric machine and at least one shaft, which shaft is rotatably mounted on a housing element of the drive device and can be driven by the electric machine. At least one discharge ring is provided by which the shaft is brought into electrical contact with the housing element in order to dissipate electrical charges from the shaft to the housing element via the discharge ring. The discharge ring is formed from an electrically conductive fluid.

Drive device for a motor vehicle

An electrical contact device for high currents and high current pickup speeds comprises a ring-shaped rotating metallic contact element, with the inner circumference of which a roller-shaped contact element that is made of solid material and rotates about an axis, is in electrical contact. The speed on the circumference of the roller-shaped contact element fully or almost fully coincides with the speed on the inner circumference of the ringshaped contact element. The ring-shaped contact element consists of an highly electrically conductive contact liquid which is held in an open groove by centrifugal force. The contact resistance and the friction losses of the contact device are very small.

Klaudy Peter

Papers

High speed electrical contact device including a rotating liquid contact element