US Patent 7421938 Positioner for a fluid actuator

A positioner for a fluid actuator comprising an electronics assembly designed for setpoint/actual value comparison and for outputting a feedback control signal includes a current/pressure transducer receiving the feedback control signal for controlling the actuator, an analog power supply, particularly in a range 4 to 20 mA, for powering the electronics assembly, and an additional voltage input, particularly in a range of up to 24 V, wherein said voltage input is configured as a further power supply for powering the current/pressure transducer separate from the analog power supply.