Current measuring device using hall sensors

• US 7,327,133 B2
• Filed: 05/04/2006
• Issued: 02/05/2008
• Est. Priority Date: 09/21/2005
• Status: Expired due to Fees

• Current Assignee: Universal Enterprises, Incorporated
• Original Assignee: Universal Enterprises, Incorporated
• Inventors: Baker, Robert Bruce, Wheaton, David Lauren
• Primary Examiner(s): PATEL, PARESH H
• Application Number:
  US11/429,099
• Publication Number:
  US 20070063689A1
• Time in Patent Office: 642 Days
• Field of Search: None
• US Class Current: 324/117.00H
• CPC Class Codes: G01R 1/06788 Hand-held or hand-manipulated probes, e.g. for oscilloscopes or for portable test instruments end pieces terminating in a probe H01R11/18
• CPC Class Codes: G01R 1/22 Tong testers acting as secondary windings of current transformers
• CPC Class Codes: G01R 15/125 for digital multimeters
• CPC Class Codes: G01R 15/202 using Hall-effect devices Hall elements in arrangements for measuring electrical power G01R21/08

Abstract

The present invention provides a current measuring device including a probe body having an elongated portion extending outward to a hook-shaped end wherein the hook-shaped end useful for isolating a conductor under test, a U-shaped magnetic core positioned upside down within the probe body and forming the hook-shaped end of the probe body wherein the U-shaped magnetic core has an interior surface extending between a first end and a second end and defines a current sensing zone therebetween, a first Hall sensor disposed upon the first end of the interior surface of the U-shaped magnetic core, and a second Hall sensor disposed upon the second end of the interior surface of the U-shaped magnetic core wherein the Hall sensors are capable of detecting a magnetic flux generated by an electric current passing through the conductor under test positioned within the current sensing zone. The device may further include amplifier circuitry electrically interconnected with the Hall sensors for amplifying electrical signals therefrom, an output board interconnected with the amplifier circuitry for receiving an amplified output signal from the amplifier circuitry and for providing power to the amplifier circuitry, and a digital multimeter extending rearward from the probe body opposite the hook-shaped end and electrically coupled to the output board.

Claims

1. A current measuring device comprising:

(a) a probe body having an elongated portion extending outward to a hook-shaped end, said hook-shaped end useful for isolating a conductor under test;

(b) a U-shaped magnetic core positioned upside down within said probe body and forming said hook-shaped end of said probe body, said U-shaped magnetic core having an interior surface extending between a first end and a second end and defining a current sensing zone therebetween;

(c) a first Hall sensor disposed upon said first end of said interior surface of said U-shaped magnetic core; and

(d) a second Hall sensor disposed upon said second end of said interior surface of said U-shaped magnetic core,

wherein said Hall sensors are capable of detecting a magnetic flux generated by an electric current passing through said conductor under test positioned within said current sensing zone.

2. The current measuring device of claim 1, further comprising amplifier circuitry electrically interconnected with said Hall sensors for amplifying electrical signals therefrom.

3. The current measuring device of claim 2, further comprising a flexible printed circuit board electrically coupling said Hall sensors with said amplifier circuitry.

4. The current measuring device of claim 2, further comprising an output board interconnected with said amplifier circuitry for receiving an amplified output signal from said amplifier circuitry and for providing power to said amplifier circuitry.

5. The current measuring device of claim 4, further comprising a digital multimeter extending rearward from said probe body opposite said hook-shaped end and electrically coupled to said output board, said digital multimeter having electrical circuitry for at least one of providing power to said amplifier circuitry, receiving said amplified output signal from said amplifier circuitry, receiving said amplified output signal from said amplifier circuitry and converting said amplified output signal from an analog signal to a digital signal, and displaying a current measurement on a display associated with said digital multimeter.

6. The current measuring device of claim 1, wherein each of said Hall sensors comprises a Hall element that outputs a voltage substantially proportional to said magnetic flux generated by said electric current passing through said conductor under test.

7. The current measuring device of claim 1, wherein said magnetic core comprises a non-grain oriented silicon steel material.

8. The current measuring device of claim 1, wherein said current measurement device is capable of measuring said electric current passing through said conductor under test when said electrical current is at least 0.3 amperes.

9. The current measuring device of claim 1, wherein said current measurement device is capable of selectively measuring alternating current and direct current passing through said conductor under test.

10. The current measuring device of claim 1, wherein said hook-shaped end is tapered to ease manipulation of said hook-shaped end within tight spaces for isolating said conductor under test.

11. The current measuring device of claim 1, wherein said hook-shaped end comprises a crochet hook shaped end.

12. The current measuring device of claim 11, wherein said crochet hook shaped end includes a ledge substantially perpendicular to said elongated portion and positioned inward from said current sensing zone and adjacent to the open side of said crochet hook shaped end, whereby said ledge is useful for pushing said conductor under test in an outward direction substantially parallel to said elongated portion of said measurement device and toward said crochet hook shaped end of said measuring device.

13. A handheld current measurement device comprising:

(a) a probe body having an elongated portion extending outward to a hook-shaped end, said hook-shaped end useful for isolating a conductor under test;

(b) a U-shaped magnetic core positioned upside down within said probe body and forming said hook-shaped end of said probe body, said U-shaped magnetic core having an interior surface extending between a first end and a second end and defining a current sensing zone therebetween;

(c) a first Hall sensor disposed upon said first end of said interior surface of said U-shaped magnetic core; and

(d) a second Hall sensor disposed upon said second end of said interior surface of said U-shaped magnetic core, said Hall sensors capable of detecting a magnetic flux generated by an electric current passing through said conductor under test positioned within said current sensing zone;

(e) amplifier circuitry electrically interconnected with said Hall sensors for amplifying electrical signals therefrom;

(f) a main body extending rearward from said probe body opposite said hook-shaped end;

(f) a display disposed within said main body;

(g) display circuitry electrically coupling said display with said amplifier circuitry and conditioning said electrical signals for said display; and

(f) power supply circuitry electrically interconnected with said display circuitry, said display, and said amplifier circuitry for providing power to said handheld current measuring device.

14. The handheld current measuring device of claim 13, wherein each of said Hall sensors comprises a Hall element that outputs a voltage substantially proportional to said magnetic flux generated by said electric current passing through said conductor under test.

15. The handheld current measuring device of claim 13, wherein said magnetic core comprises a non-grain oriented silicon steel material.

16. The handheld current measuring device of claim 13, wherein said handheld current measuring device is capable of measuring said electric current passing through said conductor under test when said electrical current is at least 0.3 amperes.

17. The handheld current measuring device of claim 13, wherein said handheld current measuring device is capable of selectively measuring alternating current and direct current passing through said conductor under test.

18. The handheld current measuring device of claim 13, wherein said hook-shaped end is tapered to ease manipulation of said hook-shaped end within tight spaces for isolating said conductor under test.

19. The handheld current measuring device of claim 13, wherein said hook-shaped end comprises a crochet hook shaped end.

20. The handheld current measuring device of claim 19, wherein said crochet hook shaped end includes a ledge substantially perpendicular to said elongated portion and positioned inward from said current sensing zone and adjacent to the open side of said crochet hook shaped end, whereby said ledge is useful for pushing said conductor under test in an outward direction substantially parallel to said elongated portion of said measurement device and toward said crochet hook shaped end of said handheld current measuring device.

21. A method of measuring current using a hook-shaped current measuring device, the hook-shaped current measuring device comprising a probe body having an elongated portion extending outward to a hook-shaped end useful for isolating a conductor under test, a U-shaped magnetic core positioned upside down within said probe body forming said hook-shaped end of said probe body and having an interior surface extending between a first end and a second end and defining a current sensing zone therebetween, a first Hall sensor disposed upon said first end of said interior surface of said U-shaped magnetic core, and a second Hall sensor disposed upon said second end of said interior surface of said U-shaped magnetic core, the method comprising:

(a) manipulating said hook-shaped end of said probe body to isolate said conductor under test within said current sensing zone of said hook-shaped end;

(b) holding said conductor under test within said current sensing zone; and

(c) detecting with said Hall sensors a magnetic flux generated by an electric current passing through said conductor under test positioned within said sensing zone,

wherein each of said Hall sensors comprises a Hall element that outputs a voltage substantially proportional to said magnetic flux generated by said electric current passing through said conductor under test.