Transformer arrangement for coupling a communication signal to a three-phase power line

• US 4,254,402 A
• Filed: 08/17/1979
• Issued: 03/03/1981
• Est. Priority Date: 08/17/1979
• Status: Expired due to Term

• Current Assignee: Rockwell International Corporation
• Original Assignee: Rockwell International Corporation
• Inventors: Perkins, William C.
• Primary Examiner(s): Groody, James J.
• Application Number:
  US06/067,259
• Time in Patent Office: 564 Days
• Field of Search: 340/310 R, 340/310 A, 340/310 CA, 307/3, 307/149, 179/2.51, 323/120, 323/108, 323/128, 323/112
• US Class Current: 307/3
• CPC Class Codes: H04B 2203/5416 by adding signals to the wave form of the power source
• CPC Class Codes: H04B 2203/5458 Monitor sensor; Alarm systems
• CPC Class Codes: H04B 2203/5466 using three phases conductors
• CPC Class Codes: H04B 2203/5483 using coupling circuits
• CPC Class Codes: H04B 3/56 Circuits for coupling, blocking, or by-passing of signals

Abstract

A communication signal is coupled simultaneously to all three phases of a three-phase power line through a three-phase open delta transformer with the communication signal being applied across the low voltage pair of windings.

Claims

1. A transformer arrangement for simultaneously coupling a signal to all three phase conductors of a three-phase power line, comprising:

a pair of high voltage windings serially connected, with their commonly connected leads being connected to one phase of the power line and the uncommon lead of each winding being connected to a different one of the other two phases of the power line;

a pair of low voltage windings serially connected across which the signal is applied, and

means for magnetically coupling each winding of one pair with a different winding of the other pair so that the voltage produced across the uncommon leads of said high voltage windings as a result of the signal applied to said serially connected low voltage windings is zero.

2. Signaling apparatus for simultaneously coupling a signal to all three phase conductors of a three-phase power line, comprising:

an AC signal device;

a pair of high voltage windings serially connected, with their commonly connected leads being connected to one phase of the power line and the uncommon lead of each winding being connected to a different one of the other two phases of the power line;

a pair of low voltage windings serially connected to said signaling device, and

means for magnetically coupling each winding of one pair with a different winding of the other pair so that the voltage produced across the uncommon leads of said high voltage windings as a result of the signal applied to said serially connected low voltage windings by said signal device is zero.

3. A signaling system, comprising:

a three-phase power line comprising three phase conductors;

an AC signaling device;

a pair of high voltage windings serially connected, with their commonly connected leads being connected to one phase of the power line and the uncommon lead of each winding being connected to a different one of the other two phases of the power line;

a pair of low voltage windings serially connected to said signaling device, and

means for magnetically coupling each winding of one pair with a different winding of the other pair so that the voltage produced across the uncommon leads of said high voltage windings as a result of the signal applied to said serially connected low voltage windings by said signaling device is zero.