Valve position control

A system for redundant valve positioning, comprising:

• a mechanical valve positioner connected to a turbine valve to open and close the turbine valve, the mechanical valve positioner comprising a first coil and a second coil to control or sense movement of the mechanical valve positioner;
• a first valve positioner comprising a first drive circuit and a second drive circuit, the first drive circuit comprising a first driver and a first switch, and the second drive circuit comprising a second driver and a second switch, the first drive circuit being in communication the first coil and the second drive circuit being in communication with the second coil;
• a second valve positioner comprising a third drive circuit and a fourth drive circuit, the third drive circuit comprising a third driver and a third switch, and the fourth drive circuit comprising a fourth driver and a fourth switch, the third drive circuit being in communication the first coil and the fourth drive circuit being in communication with the second coil;
• wherein only one of the first switch and the third switch is closed at a time, the first driver and the third driver thereby being alternately connected to the first coil at different times such that the first driver and the third driver do not drive the first coil at a same time;
• and
• wherein only one of the second switch and the fourth switch is closed at a time, the second driver and the fourth driver thereby being alternately connected to the second coil at different times such that the second driver and the fourth driver do not drive the second coil at a same time.