| 摘要 |
Field-device electronics including an electric current adjuster, through which a supply current flows. The electric current adjuster adjusts and/or modulates the supply current. The supply current is driven by a supply voltage provided by the external energy supply. Additionally, the field-device electronics has an internal operating and evaluating circuit for controlling the field device, as well as an internal supply circuit lying at a field-device electronics, internal input voltage derived from the supply voltage and feeding the internal operating and evaluating circuit. Provided in the supply circuit is a useful-voltage controller flowed-through, at least at times, by a first component of the supply current. The useful-voltage controller provides in the field-device electronics a first internal, useful voltage controlled to be essentially constant at a predetermined, first voltage level. Moreover, the supply circuit has a second useful-voltage controller flowed through, at least at times, by a second current component of the supply current. The second voltage controller provides in the field-device electronics a second internal, useful voltage, which is variable over a predetermined voltage range. Also contained in the supply circuit is a voltage adjuster flowed-through, at least at times, by a third current component of the supply current. The voltage adjuster serves to set and maintain the internal input voltage of the field-device electronics at a predetermined voltage level. In accordance with the invention, the operating and evaluating circuit is flowed-through, at least at times, both by a first useful current driven by the first useful voltage, and by a second useful current driven by the second useful voltage. Further, the two useful-voltage controllers are galvanically separated from one another.
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