Method for controlling the excitation energy in a coil arrangement of a flow meter, which is designed as a two-wire field device

摘要

A method for controlling the excitation energy in a coil assembly of a flow meter with an energy buffer system for storing energy, which is designed as a two-wire field device, for generating a magnetic field passing through a magnetic field B as a function of the excitation energy, wherein the flow meter has a plurality of operating states, between them it changes, which describe a clocked in a time interval excitation current, wherein at least a first operating state is operated with a first power in which the coil assembly excites in a first clock an excitation current having a first maximum current, the clock also having a first pulse pause. characterized by the steps of: A) storing a surplus power supplied beyond a minimum power for operating the apparatus to operate the coil assembly during a clock in response to the supplied power in the energy buffer system; wherein at least partial charging of the energy buffer system takes place in the first pulse pause and at least partial discharging of the energy buffer system takes place during the excitation of the current intensity; and B) changing over to a second operating state, in which the coil arrangement is energized in a second clock, an excitation current, wherein the clock has a second pulse pause, which is shorter than the first pulse pause.