摘要 |
An improved pilot stage includes a flapper having first and second ends, first and second nozzles in fluid communication with the first and second ends, and a magnetic torque motor having a first coil which is magnetically coupled to the first end of the flapper. An input current to the first coil creates a magnetic torque on the flapper, causing the flapper to pivot. The torque input from the magnetic circuit is reflected through the pivot to create a balancing differential pressure output at the nozzles proportional to the input electrical signal. The flapper does not require a torsion bar (or tube) pivot or a separate armature, as required by functionally similar pilot stages.
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