The working principle of electric valve positioner
- - - - - - - - - - - - : electrical valve positioner is designed according to the principle of force balance of work and its working principle is based on the pneumatic valve positioner development of current signal control valve locator. When current signal from electric regulator, the input to the torque motor coil components, in the air gap torque motor to produce a magnetic field, the effects of the magnetic field together with magnet, make the armature produces a force to the left, the main lever ( Armature) Turn around the pivot ⒂, dampers near the nozzle, the nozzle back pressure after the amplifier amplification, into thin film actuator air chamber, the valve lever down _, drive feedback pole around the pivot and turn, feedback CAM of connection on the same shaft turn counterclockwise to the Lord, make through roller pay lever fulcrum around the rotation, and the feedback spring ⑾ stretching, spring tension on the lever and the torque motor function in the main lever on torque is equal, machinery rod system balance. At this point, the signal current with corresponding to the valve position. Spring is adjusted by zero. Above action is positive effect, if you want to change the way we work, as long as will turn CAM, to become A to B, etc. , can. The so-called positive locator, is the signal current is added, the output pressure also increased; So-called reaction locator, signal current is increased, the output pressure is reduced. A positive role in executing agency as long as the mount reaction locator, can realize reaction actuator movement; Instead, a backlash actuators as long as the mount reaction locator, can achieve positive action of the actuator.