摘要 |
<p>An electro-hydraulic servo valve of two-stage type including a beam mounted for swinging movement with respect to the casing of the valve. One portion of the beam is engaged with the second-stage displaceable element of the valve and another portion of the beam carries an electrical sensor through which an electrical current is caused to pass. Magnet means are housed in the casing adjacent the other portion of the beam. As, on controlled movement of the displaceable element, the beam swings, the positional relationship of the sensor with respect to the magnetic fields of the magnet means changes, thus to so vary the electrical potential across the sensor that an electrical feedback signal is emitted by the sensor which is proportional to the displacement of said displaceable element.</p> |