Subtractive current measuring method

• US 7,583,075 B1
• Filed: 12/05/2006
• Issued: 09/01/2009
• Est. Priority Date: 12/05/2006
• Status: Active Grant

• Current Assignee: Vertiv Corporation (Vertiv Holdings Co.)
• Original Assignee: Aphel Ltd. (Eaton Corporation PLC.), Geist Manufacturing Inc. (Pce, Inc.)
• Inventors: Hutchison, Hugh G.
• Primary Examiner(s): PATEL, PARESH H
• Application Number:
  US11/633,753
• Time in Patent Office: 1,001 Days
• Field of Search: None
• US Class Current: 324/127
• CPC Class Codes: G01R 15/183 using transformers with a magnetic core
• CPC Class Codes: G01R 19/0092 measuring current only all subgroups of G01R19/00 take precedence
• CPC Class Codes: G01R 19/10 Measuring sum, difference or ratio

Abstract

The present invention is a subtractive current measuring system for a power receptacle. The system may comprise one or more of the following features: (a) a power receptacle; (b) a current carrying input wire; (c) a current carrying output wire; (d) a current transformer; (e) an electrical measuring device; and (f) interconnecting circuitry linking the current transformer and the electrical measuring device.

Claims

1. A method for monitoring current levels in a power receptacle,

the method comprising the steps:

connecting a current carrying input wire, a terminal of a power receptacle and a current carrying output wire in series;

routing the current carrying input wire and the current carrying output wire through a wire-wrapped, toroidal-core current transformer; and

configuring portions of the current carrying input wire and the current carrying output wire disposed within a plane defined by the current transformer such that the current carrying output wire cancels a portion of the electromagnetic field of the current carrying input wire;

passing a current through the current carrying input wire; and

measuring a current generated in the current transformer by the resultant electromagnetic field of the current carrying input wire and the current carrying output wire disposed within the free-space void in the toroidal core.

2. The method of claim 1,

further comprising the step:

connecting two or more power receptacles in series via the current carrying input wire and the current carrying output wire.

3. The method of claim 1, wherein the step of configuring the portions of the current carrying input wire and the current carrying output wire comprises the step:

physically coupling the current carrying input wire and the current carrying output wire.

4. The method of claim 3, wherein the step of physically coupling the current carrying input wire and the current carrying output wire comprises the step:

intertwining of the current carrying input wire and the current carrying output wire.

5. The method of claim 3, wherein the step of physically coupling the current carrying input wire and the current carrying output wire comprises the step:

disposing the current carrying input wire and the current carrying output wire within conjoined insulating conduits.

6. The method of claim 1, wherein the portions of the current carrying input wire and the current carrying output wire disposed within the plane are aligned along an axis perpendicular to the plane.