COUPLING UNIT TO COUPLE CARRIER FREQUENCIES FROM HIGH VOLTAGE TRANSMISSION LINES

• US 3,771,069 A
• Filed: 05/26/1972
• Issued: 11/06/1973
• Est. Priority Date: 06/01/1971
• Status: Expired due to Term

• Current Assignee: Friedrich Levacher, Hans-Joachim Kirch, Helmut Frielingsdorf, Karl Dornseifer, Karl-Heinz Nolting
• Original Assignee: Friedrich Levacher, Hans-Joachim Kirch, Helmut Frielingsdorf, Karl Dornseifer, Karl-Heinz Nolting
• Inventors: Levacher, Friedrich, Dornseifer, Karl, Nolting, Karl-Heinz, Frielingsdorf, Helmut, Kirch, Hans-Joachim
• Primary Examiner(s): Gensler, Paul L.
• Application Number:
  US05/257,328
• Time in Patent Office: 529 Days
• Field of Search: 333/8,24R,24C,32
• US Class Current: 333/24.00C
• CPC Class Codes: H04B 2203/5425 improving S/N by matching impedance, noise reduction, gain control
• CPC Class Codes: H04B 2203/5483 using coupling circuits
• CPC Class Codes: H04B 2203/5491 using filtering and bypassing
• CPC Class Codes: H04B 3/56 Circuits for coupling, blocking, or by-passing of signals

Abstract

An elongated, oil-filled isolating body has two metal caps. Each metal cap encloses one end of the elongated oil-filled body. An auto-transformer is enclosed inside each metal cap, the terminals of each of the auto-transformers connected across all the turns are connected to coupling capacitors located inside the oilfilled body. The terminals of one auto-transformer connected across part of the turns is connectable to the high frequency leads of the transmission line, which also carries high voltage phase cables, while the terminals of the other auto-transformer connected across part of the turns is connectable to a user device.

Claims

1. A coupling unit for coupling carrier frequencies from a transmission cable carrying the carrier frequencies and high voltages on respective first and second conductor means to a user device, said coupling unit comprising an elongated hollow oilfilled insulating body having opposite ends;

coupling capacitor means in the interior of said insulating body;

first input matching means adapted to be connected to the first conductor means and positioned in the region of one of said opposite ends for matching the characteristic impedance of the first conductor means with the impedance of said capacitor means;

second matching means connectable to the user device and positioned in the region of the other of said opposite ends for matching the characteristic impedance of the user device wIth the impedance of said capacitor means, said capacitor means being connected between said first and second matching means and being operative for passing the carrier frequencies to the user device while blocking transmission to the user device of the high voltages; and

further comprising first and second metal caps, said first metal cap enclosing one of said opposite ends and said first matching means and being electrically connected to the second conducting means, and said second metal cap enclosing the other of said opposite ends and said second matching means, and wherein said first matching means comprises a matching transformer having a center tap connected to said first metal cap.

2. Coupling unit as defined in claim 1, wherein said second metal cap is connected to the circuit ground.

3. Coupling unit as defined in claim 2, wherein said second matching means comprises a matching transformer having a center tap, said center tap being connected to said second metal cap.

4. Coupling unit as defined in claim 1, wherein said first conductor means comprises two leads and said coupling capacitor means comprises a separate coupling capacitor for each of the two leads.

5. Coupling unit as defined in claim 4, wherein each of the coupling capacitors has one terminal connected to said second matching means;

and further comprising an equalizing capacitor between each of said coupling capacitor terminals and said second metal cap.

6. Coupling unit as defined in claim 1, wherein said first and second matching means comprise first and second auto-transformers each having first and second sets of terminals, said first set of terminals being connected across part of the auto-transformer windings and said second set of terminals being connected across all the auto-transformer windings, said first set of terminals of said first auto-transformer is connected to said first conductor means, said second set of terminals of said first auto-transformer is connected to said coupling capacitor means;

said second set of terminals of said second auto-transformer is connected to said coupling capacitor means; and

said first set of terminals of said second auto-transformer is connectable to the user device.

7. Coupling unit as defined in claim 6, wherein said second set of terminals are arranged to be connected to a characteristic impedance of approximately 5,000 ohms, and said first set of terminals are arranged to be connected to a characteristic impedance of approximately 150 ohms.

8. Coupling unit as defined in claim 7, wherein said coupling capacitors have a capacitance of approximately 1,000 pF.

9. A coupling unit for coupling carrier frequencies from a transmission cable carrying the carrier frequencies and high voltages on respective first and second conductor means to a user device, said coupling unit comprising an elongated hollow oil-filled insulating body having opposite ends;

coupling capacitor means in the interior of said insulating body;

first input matching means adapted to be connected to the first conductor means and positioned in the region of one of said opposite ends for matching the characteristic impedance of the first conductor means with the impedance of said capacitor means;

second matching means connectable to the user device and positioned in the region of the other of said opposite ends for matching the characteristic impedance of the user device with the impedance of said capacitor means, said capacitor means being connected between said first and second matching means and being operative for passing the carrier frequencies to the user device while blocking transmission to the user device of the high voltages; and

further comprising first and second metal caps, said first metal cap enclosing one of said opposite ends and said first matching means, and said second metal cap enclosing the other of said opposite ends and said second matching means and being electrically connected to the circuit ground, said second matching means comprising a matching transformer having a center tap electrically connected to said second metal cap.

10. Coupling unit as defined in claim 9, wherein said second conductor means is connected to said first metal cap.

11. Coupling unit as defined in claim 9, wherein said first matching means comprises a matching transformer having a center tap, said center tap being connected to said first metal cap.

12. A coupling unit for coupling carrier frequencies to a user device from a transmission cable carrying the carrier frequencies on first conductor means including at least two electrical conductors and carrying high voltages on second conductor means, said coupling unit comprising an elongated hollow insulating body having opposite ends;

coupling capacitor means in the interior of said insulating body and including a separate coupling capacitor for each of said two electrical conductors;

first input matching means adapted to be connected to the first conductor means and positioned in the region of one of said opposite ends for matching the characteristic impedance of the first conductor means with the impedance of said capacitor means;

second matching means connected to one terminal of each of said coupling capacitors and connectable to the user device and positioned in the region of the other of said opposite ends for matching the characteristic impedance of the user device with the impedance of said capacitor means, said capacitor means being connected between said first and second matching means and being operative for passing the carrier frequencies to the user device while blocking transmission to the user device of the high voltages; and

further including a pair of equalizing capacitors, each electrically connected between the other terminal of a respective one of said coupling capacitors and ground potential.

13. Coupling unit as defined in claim 12, wherein said elongated hollow insulating body comprises a hollow, oil-filled body.

14. Coupling unit as defined in claim 13, further comprising first and second metal caps, said first metal cap enclosing one of said opposite ends and said first matching means, and said second metal cap enclosing the other of said opposite ends and said second matching means.