Electronic system for a field device that is fed by an external electric energy supply

Abstract

The system has two voltage controllers providing constantly controlled internal useful voltages at a preset voltage level. A third voltage controller is provided, through which partial current of supply current flows for setting and maintaining an internal input voltage of the system at the voltage level. The useful currents that are driven respectively by the useful voltages flow through an operating and evaluation circuit (50). : An independent claim is also included for a field device comprising an electronic system. USE : Used for a field device that is utilized as a measuring device for measuring physical and / or chemical parameter e.g. flow rate, density, viscosity, liquid level, pressure, temperature and pH value in a pipe and / or a container. ADVANTAGE : The useful currents driven by useful voltages flow via the operating and evaluation circuit, thus keeping the operating and evaluation circuit in normal operation of the field device and supplying individual selected functional units with current. DESCRIPTION OF DRAWINGS : The drawing shows a block diagram of field device electronics in a field device. 17, 18 : Sensors 20 : Field device electronics 50 : Operating and evaluation circuit 60 : Control unit.

Description

technical field [0001] The invention relates to a field device electronics system for a field device powered by an external power source and to a field device with the field device electronics system. Background technique [0002] In industrial process measurement technology, in particular also in connection with chemical or process technology process automation and / or the control of industrial plants, for the local generation of analog or digital measured value signals of process parameters, a process-installed Measuring instruments, known as field devices. Likewise, the field device can be designed as one or more regulating devices that change process parameters and thus influence the process. For example, the process parameters to be detected and to be adjusted can be derived from the prior art, and can be liquid, powdery, vaporous or gaseous media introduced into or loaded into corresponding containers, such as conduits or grain silos The mass flow rate, density, visco...

AI Technical Summary

Problems solved by technology

However, the aforementioned field device electronics have the disadvantage that practically all internal loads are supplied by one and the same internal effective voltage and that a collapse of this single effective voltage in any case, for example as a consequence of a low current, would cause the field device to malfunction operation or even directly lead to a sudden temporary total failure of the electronic system of the field device

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