High speed reciprocal electromagnetic actuator with cancelled retarding-flux

摘要

An electromagnetic actuator is provided by a single armature plunger that reciprocally shuttles between two magnetic paths provided by a pair of coils. Undesired retarding-flux is cancelled in overlapping linkage paths through the plunger, yielding increased net magnetic force in the intended direction of movement and faster plunger operation. When either coil is energized, a primary flux path is created around that coil through the plunger, and a secondary flux path is created around both coils through the plunger. The primary path attracts the plunger to close a magnetic air gap. The secondary path holds the plunger in place. Current to the ON coil is also supplied through a limiting resistor to the OFF coil to generate reverse polarity flux in the latter cancelling secondary flux from the ON coil.