Voltage Indicator with Continuity Check

• US 20160313386A1
• Filed: 12/16/2014
• Published: 10/27/2016
• Est. Priority Date: 12/20/2013
• Status: Active Grant

• Current Assignee: Panduit Corporation
• Original Assignee: Panduit Corporation
• Inventors: Bugaris, Rachel M., Hoeppner, Craig T., Fabiszak, James E., Gajjar, Nakheel S., Senese, John C., Rago, Richard A., Bolouri-Saransar, Masud, Nordin, Ronald A.
• Granted Patent: US 9,921,260 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01R 19/155 Indicating the presence of voltage
• CPC Class Codes: G01R 31/52 Testing for short-circuits, leakage current or ground faults
• CPC Class Codes: G01R 31/54 Testing for continuity
• CPC Class Codes: G01R 31/58 Testing of lines, cables or conductors testing of electric windings G01R31/72
• CPC Class Codes: H04B 3/46 Monitoring; Testing

Abstract

A system for testing electrical continuity of a device to a source wherein there is at least one conductor connecting the device to the source can include a reference capacitive load, an oscillator, and a microprocessor. The oscillator is selectively connected to the reference capacitive load and each conductor connecting the device to the source such that the frequency output of the oscillator is a function of the selected capacitive load of the oscillator. Each conductor connecting the device to the source is connected to the oscillator such that when each one is selectively connected, the output of the oscillator is a function of that conductor'"'"'s parasitic self-capacitance. The microprocessor can then compare the frequency of the signal generated when each conductor is connected to the oscillator with the frequency of the signal generated when the reference capacitive load is connected.

Claims

1. A system for testing the electrical continuity of a device to a source through a cable containing at least one conductor connecting the device to the source comprising:

a reference capacitive load;

an oscillator selectively connected to the reference capacitive load and to the at least one conductor, the oscillator configured such that a frequency output of the oscillator is a function of a selected capacitive load connected to the oscillator, the at least one conductor connected to the oscillator such that a frequency output of the oscillator when the at least one conductor is connected is a function of a parasitic self-capacitance of the at least one conductor; and

a microprocessor connected to the oscillator, the microcontroller configured to compare a frequency output of a signal generated when the at least one conductor is selectively connected with a frequency output of a signal generated when the reference capacitive load is selectively connected.

2. The system of claim 1, wherein the cable further contains a reference conductor in addition to the at least one conductor and further wherein the reference conductor is not connected to the source and a parasitic self-capacitance of the reference conductor is used for the reference capacitive load.

3. The system of claim 2 wherein the at least one conductor and the reference capacitive load is selectively connected to the oscillator via a multiplexer.

4. The system of claim 3 wherein the source is a power source.

5. The system of claim 3 wherein the source is a three-phase power-source.

6. The system of claim 5 wherein the at least one conductor comprises three conductors, each conductor of the three conductors connected to a different line of the three phase power source and each conductor of the three conductors selectively connected to the oscillator via the multiplexer.

7. A method for determining the electrical continuity of a device to a source through a cable containing at least one conductor connecting the device to the source comprising:

providing an oscillator with a frequency output that is a function of a capacitive load connected to the oscillator;

selectively connecting a reference capacitive load to the oscillator;

selectively connecting a first conductor of the at least one conductor of the cable to the oscillator such that a frequency output of the oscillator is a function of a parasitic self-capacitance of the first conductor; and

comparing a frequency output of a signal generated by the connection of the reference capacitive load with a frequency output of a signal generated by the connection of the first conductor.

8. The method of claim 7 further comprising selectively connecting a second conductor of the at least one conductor of the cable to the oscillator such that a frequency output of the oscillator is a function of a parasitic self-capacitance of the second conductor and comparing a frequency of a signal generated by the connection of the second conductor with the frequency output of the signal generated by the connection of the reference capacitance and with the frequency output of the signal generated by the connection of the first conductor.

9. The method of claim 8 further comprising selectively connecting a third conductor of the at least one conductor of the cable to the oscillator such that a frequency output of the oscillator is a function of a parasitic self-capacitance of the third conductor and comparing a frequency output of a signal generated by the connection of the third conductor with the frequency output of the signal generated by the connection of the reference capacitance, the frequency output of the signal generated by the connection of the second conductor, and the frequency output of the signal generated by the connection of the first conductor.

10. The method of claim 7 wherein the reference capacitive load is provided by a reference conductor contained with the cable, the reference conductor not being connected to the source.

11. The method of claim 7 wherein the selective connection of the reference capacitive load and the selective connection of the first conductor to the oscillator is performed via a multiplexer.