Method for controlling excitation energy in a coil arrangement of a flow measuring device embodied as a two-conductor field device

Abstract

A method for controlling excitation energy in a coil arrangement of a flow measuring device having an energy buffer system for storing energy and embodied as a two-conductor field device is provided for producing a magnetic field B passing through a medium as a function of the excitation energy. The wherein the flow measuring device has a plurality of operating states, between which it transfers and which describe an excitation current pulsed in a time interval. At least a first operating state is operated with a first power, in which the coil arrangement in a first period is excited with an excitation current with a first maximum electrical current level, wherein the period additionally has a first pulse pause, wherein the method is characterized by steps as follows: storing a fed-in excess power, which is beyond a minimum power for operating the device, for operating the coil arrangement during a period as a function of the supplied power in an energy buffer system; wherein an at least partial charging of the energy buffer system occurs in the first pulse pause and an at least partial discharging of the energy buffer system occurs during the excitation of the electrical current level; and changing into a second operating state, in which the coil arrangement is excited in a second period with an excitation current, wherein the second period has a second pulse pause, which is shorter than the first pulse pause.