METHOD AND APPARATUS FOR DETECTING A SHORT CIRCUIT

• US 20110221449A1
• Filed: 03/03/2011
• Published: 09/15/2011
• Est. Priority Date: 03/09/2010
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: MA, Xiang
• Granted Patent: US 8,493,072 B2
• Time in Patent Office: Days
• US Class Current: 324/537
• CPC Class Codes: G01R 31/52 Testing for short-circuits, leakage current or ground faults
• CPC Class Codes: G01R 31/58 Testing of lines, cables or conductors testing of electric windings G01R31/72

Abstract

This invention provides a method and an apparatus for detecting a short-circuit occurring between a signal line and a ground line of a lead wire. The apparatus comprises a circuit and a resistive element. The circuit has an output terminal, an input terminal and ground. One end of the ground line is connected to the ground of the circuit, and the other end of the ground line is disconnected. A first terminal of the resistive element is connected to the output terminal of the circuit. One end of the signal line is connected to a second terminal of the resistive element, and the other end of the signal line is disconnected. The circuit is configured to provide a first voltage via the output terminal and obtain a second voltage via the input terminal connected to a joint of the signal line and the resistive element, to provide a third voltage via the output terminal and obtain a fourth voltage via the input terminal, to derive an impedance of the lead wire from the first voltage, the second voltage, the third voltage, the fourth voltage and an impedance of the resistive element, and to determine whether a short-circuit occurs or not, based on the impedance of the lead wire and a predefined impedance. In this way, the shorted lead wire can be detected with high accuracy.

Claims

1. An apparatus for detecting a short-circuit occurring between a signal line (120) and a ground line (130) of a lead wire (110), comprising:

a circuit (140) having an output terminal (170), an input terminal (190) and ground, the ground (180) of the circuit (140) being connected to one end of the ground line (130), the other end of the ground line (130) being disconnected;

a resistive element (150) having a first terminal connected to the output terminal (170) of the circuit (140) and a second terminal connected to one end of the signal line (120), the other end of the signal line (120) being disconnected;

wherein the circuit (140) is configured

to provide a first voltage via the output terminal (170) and obtain a second voltage via the input terminal (190), the input terminal (190) being connected to a joint (160) of the signal line (120) and the resistive element (150),

to provide a third voltage via the output terminal (170) and obtain a fourth voltage via the input terminal (190),

to derive an impedance of the lead wire (110) from the first voltage, the second voltage, the third voltage, the fourth voltage and an impedance of the resistive element (150), and

to determine whether a short-circuit occurs or not, based on the derived impedance of the lead wire (110) and a predefined impedance.

2. An apparatus as claimed in claim 1, wherein the circuit (140) derives the impedance of the lead wire (110) by using the following equation:

3. An apparatus as claimed in claim 1, wherein the connection between the signal line (120) and the resistive element (150) is interrupted, and the circuit (140) is further configured to provide the first voltage via the output terminal (170) and obtain the first voltage via the input terminal (190), the input terminal (190) being connected to the second terminal of the resistive element (150).

4. An apparatus as claimed in claim 1, wherein the connection between the signal line (120) and the resistive element (150) is interrupted, and the circuit (140) is further configured to provide the third voltage via the output terminal (170) and obtain the third voltage via the input terminal (190), the input terminal (190) being connected to the second terminal of the resistive element (150).

5. An apparatus as claimed in claim 1, wherein the first voltage is a highest input voltage of the circuit (140) and the third voltage is a lowest input voltage of the circuit (140).

6. An apparatus as claimed in claim 1, wherein the apparatus is an electrocardiogram apparatus.

7. A method of detecting a short-circuit occurring between a signal line (120) and a ground line (130) of a lead wire (110), comprising:

providing (410) a circuit (140) having an output terminal (170), an input terminal (190) and ground, the ground (180) of the circuit (140) being connected to one end of the ground line (130), the other end of the ground line (130) being disconnected;

providing (420) a resistive element (150) having a first terminal connected to the output terminal (170) of the circuit (140) and a second terminal connected to one end of the signal line (120), the other end of the signal line (120) being disconnected;

providing (430) a first voltage via the output terminal (170) and obtaining a second voltage via the input terminal (190), the input terminal (190) being connected to a joint (160) of the signal line (120) and the resistive element (150) by the circuit (140);

providing (440) a third voltage via the output terminal (170) and obtaining a fourth voltage via the input terminal (190);

deriving (450) an impedance of the lead wire (110) from the first voltage, the second voltage, the third voltage, the fourth voltage and an impedance of the resistive element (150); and

determining (460) whether a short-circuit occurs or not, based on the impedance of the lead wire (110) and a predefined impedance.

8. A method as claimed in claim 7, wherein the step of deriving (450) is performed by using the following equation:

9. A method as claimed in claim 7, wherein, before the step of deriving (450), further comprises:

interrupting the connection between the signal line (120) and the resistive element (150); and

providing the first voltage via the output terminal (170) and obtaining the first voltage via the input terminal (190), the input terminal (190) being connected to the second terminal of the resistive element (150) by the circuit (140).

10. A method as claimed in claim 7, wherein, before the step of deriving (450), further comprises:

interrupting the connection between the signal line (120) and the resistive element (150); and

providing the third voltage via the output terminal (170) and obtaining the third voltage via the input terminal (190), the input terminal (190) being connected to the second terminal of the resistive element (150) by the circuit (140).

11. A method as claimed in claim 7, wherein the first voltage is a highest input voltage of the circuit (140) and the third voltage is a lowest input voltage of the circuit (140).