Patent ID: 7200503

Claim:
Field device electronics for a field device, fed by an external, electric energy supply, wherein the external electric energy supply provides a supply voltage (U V ), especially a unipolar one, and delivers a variable supply current (I) driven thereby, especially a unipolar and/or binary supply current, which field-device electronics comprises: an electric current controller which a supply current (I) flows for adjusting and/or modulating, especially clocking, the supply current (I); an internal operating and evaluating circuit for controlling the field device; and an internal supply circuit feeding said internal operating and evaluating circuit and lying at an internal input voltage (U e ) of the field-device electronics derived from the supply voltage (U V ), said internal supply circuit including: a first voltage controller (UR 1 ) through which, at least at times, an especially variable, first current component (I 1 ) of the supply current (I) flows for providing in the field-device electronics a first internal, useful voltage (U N1 ) essentially controlled to be constant at a predeterminable, first voltage level (U N1 — desired ), a second voltage controller through which, at least at times, an especially variable, second current component (I 2 ) of the supply current (I) flows for providing in the field-device electronics a second internal, useful voltage (U N2 ) variable over a predeterminable voltage range, and a voltage stabilizer through which, at least at times, an especially variable, third current component (I 3 ) of the supply current flows for adjusting and maintaining the internal input voltage (U e ) of the field-device electronics at a predeterminable voltage level, wherein: said operating and evaluating circuit has flowing there through, at least at times, both by an especially variable, first useful current (I N1 ) driven by the first useful voltage (U N1 ) and by an especially variable, second useful current (I N2 ) driven by the second useful voltage (U N2 ).