POWER SUPPLY FOR FIELD MOUNTED TRANSMITTER

摘要

A field mounted transmitter (10) for use in a two-wire process control loop (16a/16b) includes a sensor (12), measurement circuitry (18) and a power supply (20). The sensor (12) senses a process variable of a process which is transmitted over the control loop (16a/16b) by the measurement circuitry (18). The power supply (20) is powered by a current flowing through the control loop (16a/16b) and powers the measurement circuitry (18). The power supply (20) includes an inductive element (70) coupled to the measurement circuitry (18) and a switch (64) which selectively couples the inductive element (70) to the control loop (16a/16b).