Potential Separation for Filling Level Radar

Abstract

Both in potential separation in the microwave path, and in potential separation directly between the two-wire loop and the output circuit, the quality of signal transmission may be negatively affected. A filling level radar device with potential separation within the electronics unit is stated, wherein potential separation does not separate analogue signals but instead separates digital signals or direct-current-free alternating signals. For example, the separation line leads through digital signal connections or alternating-voltage signal connections. As a result of this the expenditure for potential separation may be reduced and the transmission quality may be improved.

Description

BRIEF DESCRIPTION OF DRAWINGS

Below, exemplary embodiments of the present invention are described with reference to the figures.

FIG. 1A shows a diagrammatic view of a filling level radar device with potential separation in the microwave path.

FIG. 1B shows a diagrammatic view of a filling level radar device with potential separation between the two-conductor loop and the electronics unit.

FIG. 2 shows a diagrammatic view of a filling level radar device according to several exemplary embodiments of the present invention.

FIG. 3 shows a diagrammatic view of a filling level radar device according to an exemplary embodiment of the present invention.

FIG. 4A shows a diagrammatic view of a filling level radar device according to an exemplary embodiment of the present invention.

FIG. 4B shows a diagrammatic view of a filling level radar device according to a further exemplary embodiment of the present invention.

FIG. 5 shows a diagrammatic view of a filling level radar device according to a further exemplary embodiment of the present invention.

FIG. 6 shows a diagrammatic view of a filling level radar device according to a further exemplary embodiment of the present invention.

FIG. 7 shows a block diagram of the potential separation of FIG. 3.

FIG. 8 shows a block diagram of FIG. 3 according to a further exemplary embodiment of the present invention.

FIG. 9 shows a block diagram of the potential separation of FIG. 3 according to a further exemplary embodiment of the present invention.

FIG. 10 shows a further block diagram of FIG. 3 according to a further exemplary embodiment of the present invention.

FIG. 11 shows a block diagram of the potential separation of FIG. 3 according to a further exemplary embodiment of the present invention.

FIG. 12 shows a block diagram of FIG. 3 according to a further exemplary embodiment of the present invention.

FIG. 13 shows a block diagram of FIG. 3 according to a further exemplary embodiment of the present invention.

FIG. 14 shows a block diagram of the potential separation of FIG. 4 according to an exemplary embodiment of the present invention.

FIG. 15 shows a block diagram of the potential separation of FIG. 5 according to an exemplary embodiment of the present invention.

FIG. 16 shows a block diagram of the potential separation of FIG. 6 according to an exemplary embodiment of the present invention.

Claims

1. A filling level radar for measuring a filling level in a container and for connection to a two-wire loop, comprising: an electronics unit generating a transmission signal and receiving and evaluating a receiving signal, the unit generating and emitting an output signal as a function of the evaluated receiving signal; anda potential separation situated within the unit and providing a galvanic separation of first signals in a first region of the unit from second signals in a second region of the unit;wherein the unit includes an input- and output circuit which regulates and emits the output signal and which is arranged in the first region; andwherein the transmission signal is generated in the second region.

2. The filling level radar according to claim 1, wherein the input- and output circuit receives external input signals.

3. The filling level radar according to claim 1, wherein the input- and output circuit regulates an output current of the two-wire loop.

4. The filling level radar according to claim 2, wherein the output signal is a digital output signal and wherein the input- and output circuit modulates the digital output signal and demodulates a digital input signal.

5. The filling level radar according to claim 1, wherein the unit further includes a voltage supply supplying the input- and output circuit with a first operating signal and supplying a second electronics component of the electronics unit with a second operating signal and wherein the potential separation separates the first operating signal from the second operating signal within the voltage supply.

6. The filling level radar according to claim 1, wherein the potential separation includes a inductive separation within the voltage supply.

7. The filling level radar according to claim 1, wherein the unit further includes an evaluation circuit evaluating the receiving signal.

8. The filling level radar according to claim 7, wherein the receiving signal is evaluated using (i) an identification of a filling level echo and (ii) provision of a digitalised filling level value to the input- and output circuit.

9. The filling level radar according to claim 1, wherein the unit further includes a transmitter which generates the transmission signal.

10. The filling level radar according to claim 9, wherein the transmitter is a microwave transmission circuit.

11. The filling level radar according to claim 9, wherein the transmitter includes at least one of a clock pulse circuit, an oscillator, a modulation circuit and a transmission amplifier.

12. The filling level radar according to claim 1, wherein the unit further includes a receiver which receives the measuring signal.

13. The filling level radar according to claim 12, wherein the receiver is a microwave receiving circuit.

14. The filling level radar according to claim 12, wherein the receiver includes at least one of a receiving amplifier, a mixer, a clock pulse circuit, an oscillator, a filter, an intermediate frequency amplifier, a demodulator, a logarithmic device, and an analogue/digital converter.

15. The filling level radar according to claim 1, wherein the voltage supply includes at least one of a DC/DC converter, a filter, a voltage regulator and a storage capacitor.

16. The filling level radar according to claim 1, wherein the potential separation separates digital signals.

17. The filling level radar according to claim 1, wherein the potential separation separates direct-voltage-free alternating signals.

18. The filling level radar according to claim 1, wherein the potential separation is situated within the evaluation circuit.

19. The filling level radar according to claim 1, wherein the potential separation is situated between the evaluation circuit, which is arranged in the first region, and the receiver, which is arranged in the second region.

20. The filling level radar according to claim 1, wherein the potential separation is situated within the receiver.

21. The filling level radar according to claim 1, wherein the potential separation includes an optical coupler.

22. The filling level radar according to claim 1, wherein the filling level radar (i) connects to a two-wire loop to supply energy to a filling level measuring device and (ii) emits the output signals to a single line pair.

23. The filling level radar according to claim 22, wherein the two-wire loop is a 4 . . . 20 mA two-wire current loop.

24. A method for measuring a filling level, comprising: generating a transmission signal;receiving and evaluating a receiving signal;generating and emitting an output signal as a function of the evaluated receiving signal;separating first signals in a first region of an electronics unit from second signals in a second region of the electronics unit using a potential separation situated within the electronics unit; andemitting the output signal using an input- and output circuit that is arranged in the first region;wherein the transmission signal is generated in the second region.

25. The method according to claim 24, further comprising: receiving external input signals; andregulating an output current of a two-wire loop using the input- and output circuit.

26. The method according to claim 24, wherein the input- and output circuit modulates a digital output signal and demodulates a digital input signal.