CURRENT TO PRESSURE CONVERTER

摘要

An electropneumatic motor includes an electrically energizable magnetic circuit with an armature resiliently suspended in the air gap defined between two opposed pole pieces of differing dimensions. One of pole pieces includes an axially adjustable member of magnetic material. A fluid nozzle is carried by the other pole piece. Axial adjustment of the pole piece member affects the strength of the magnetic field. In one embodiment, the pole piece member includes a permanent magnet, which is axially movable relative to the armature, centered in the face of the pole piece. The combination of the fixed field from the permanent magnet and the electromagnetically induced variable field helps more nearly linearize the current to armature force relationship and increases the force on the armature. To determine the operating point of the motor, the suspension for the armature can be prestressed to force it as close as possible to the nozzle, and the magnet can be advanced until the armature is pulled off of the nozzle.