Testing operation of electric energy meter optics system

• US 5,113,130 A
• Filed: 04/22/1991
• Issued: 05/12/1992
• Est. Priority Date: 04/05/1990
• Status: Expired due to Fees

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Balch, Richard A.
• Primary Examiner(s): Wieder, Kenneth A.
• Assistant Examiner(s): BURNS, WILLIAM
• Application Number:
  US07/687,788
• Time in Patent Office: 386 Days
• Field of Search: 324/74, 324/110, 340/870.02, 364/483, 364/464.04, 364/492, 250/231.14
• US Class Current: 324/74
• CPC Class Codes: G01R 35/04 of instruments for measuring time integral of power or current

Abstract

A method and apparatus for testing the proper operation of the optical elements in the optical detection circuit of an electronic register in an energy meter. The light emitter circuit is periodically pulsed adequately to turn the emitters to the on condition, and a comparison circuit is provided in which the voltage across a monitor point in circuit with the light emitters and a switching circuit is monitored both before and after each pulse. The absence of a voltage change upon pulsing the light emitter circuitry is used to generate a first error or failure signal. The light detector is read prior to each pulse to determine if unprogrammed light is being received prior to the pulsing of the light emitter as an indication of tampering with the accurate reading of the energy meter, and a second error signal is generated in response to unprogrammed light. The first error signal is displayed at the energy meter to the meter reader, while the second error tampering signal is stored and downloaded through an optical link for analysis at the power company.

Claims

1. Apparatus for monitoring operation of a meter, the meter including signaling means and signal receiving means for providing an indication of a quantum of energy consumption, the signaling means comprising means for emitting a first light signal and the signal receiving means comprising means for detecting the presence of the first light signal, said apparatus comprising:

means for determining that said signal receiving means is receiving a light signal other than the first light signal from said signaling means; and

means for generating an error signal in response to said determining.

2. An apparatus in accordance with claim 1 wherein said signaling means and said signal receiving means, respectively, comprise a light emitting diode and light detecting means, respectively.

3. An apparatus in accordance with claim 1 further comprising means for storing the error signal generated by said generating means.

4. Apparatus for monitoring operation of a meter, the meter including at least one emitter/detector pair means for generating electrical pulses indicative of a quantum of energy consumption, the emitter means comprising means for emitting a first light signal and the detector means comprising means for detecting the presence of the first light signal, said apparatus comprising:

means for energizing the emitter means, the emitter means having an on condition and an off condition, the emitter means transitioning from the off condition to the on condition when energized, the emitter means emitting a first signal when in the on condition;

means for checking the status of the detector means when the emitter means is in the off condition to determine whether the detector means is detecting a second signal, the second signal being a second light signal; and

means for generating an error signal when the emitter means is in the off condition and the second signal is received by the detector means.

5. An apparatus in accordance with claim 4 wherein the emitter means comprises a light emitting diode.

6. An apparatus in accordance with claim 4 wherein said energizing means comprises switching means and energy supply means.

7. An apparatus in accordance with claim 4 further comprising storage means for storing the error signal.

8. An apparatus for metering means, said apparatus comprising:

light emitting means having an on condition and an off condition, said light emitting means emitting a first light signal when in the on condition;

light detecting means disposed to intercept at least a portion of the first light signal output from said light emitting means when said light emitting means is in the on condition; and

means for generating an error message when said light emitting means is in the off condition and said light detecting means intercepts a second light signal.

9. An apparatus in accordance with claim 8 wherein said light emitting means comprises a light emitting diode.

10. An apparatus in accordance with claim 8 wherein said light emitting means and said light detecting means are also utilized to generate electrical pulses indicative of a quantum of energy consumption.

11. In an electronic register for an electric energy meter in which energy demand is detected through a toothed shutter rotating between one or more light emitters and light detector pairs, a method of checking for errors in the optical system comprising the steps of:

periodically energizing said one or more light emitters to the on condition from the off condition for purposes of detecting energy demand through the rate of interruption of the light transmission between said light emitter and light detector pairs during said on condition, said interruption of light transmission being detected by the one or more light detectors;

checking for light reception by said one or more light detectors during the off condition periods between the periodic energization of said one or more light emitters to determine if light is being received by said one or more light detectors;

generating a tamper error signal when light is received by said one or more light detectors during said off condition periods;

storing said tamper error signal; and

displaying said tamper error signal upon presentation of a proper signal for display of said tamper error signal.

12. A method for checking the proper operation of an optical electronics system in an energy meter of claim 11 wherein said tamper error signal is not displayed at said energy meter, and the additional step of downloading said tamper error signal to means for display of said error signal.

13. A method for checking the proper operation of an optical electronics system in an energy meter of claim 12 wherein each of said one or more light detectors are checked for light reception during said off condition periods for said one or more light emitters.

14. A method for checking the proper operation of an optical electronics system in an energy meter of claim 13 wherein each of said one or more light detectors are separately checked for light reception during said off condition periods.

15. A method for checking the proper operation of an optical electronics system in an energy meter of claim 14 wherein said tamper error signal is used as an indication of possible light tampering with the readings of energy demand in said electric energy meter, and one or more other error signals are displayed at said energy meter while said tamper error signal is displayed after downloading to an external device.

16. A method for checking the proper operation of an optical electronics system in an energy meter of claim 15 wherein said one or more other error signals include a light emitter error signal indicating the failure of one or more of said one or more light emitters.

17. In an electronic register for an electric energy meter in which energy demand is detected through a toothed shutter rotating between one or more light emitter and light detector pairs, a method for checking for errors in the optical electronic system comprising the steps of:

periodically energizing said one or more emitters to the on condition from the off condition for purposes of detecting energy demand through the rate of interruption of the light transmission between said light emitter and light detector pairs during said on condition, said interruption of light transmission being detected by the one or more light detectors;

checking said optical light transmission for proper operation;

generating one or more error signals in response to improper operation of said optical electronic system;

displaying one or more preselected types of error signals at said electric energy meter;

storing one or more other types of error signals in said electric energy meter; and

providing means to download said other types of error signals to an external device for subsequent reading;

wherein checking for errors in said optical electronic system includes checking said light emitters for errors which would affect light transmission, and displaying the signals indicating those errors at said electric energy meter;

wherein checking for errors in said optical electronic system includes checking said light detectors for light tampering, and including a tamper error signal as one of said one or more other types of error signals; and

wherein each of said one or more light detectors are checked for light reception during the off condition periods for said one or more light emitters.

18. A method for checking and selectively displaying errors in the operation of an optical electronic system in an energy meter of claim 17 wherein each of said one or more light detectors are separately checked for light reception during said of condition periods.

19. A method for checking and selectively displaying errors in the operation of an optical electronic system in an energy meter of claim 18 wherein said errors which would indicate possible light tampering with the energy demand readings in said electric energy meter are displayed only after downloading to an external computer, while other errors are displayed at said energy meter.

20. A method for checking and selectively displaying errors in the operation of an optical electronic system in an energy meter of claim 19 wherein said one or more error signals includes the failure of said light emitters.

21. In an electric energy meter with an opto-electronics energy sensor utilizing the rate of interruption of a light beam between a light emitter and a light detector by a shutter as an indication of rate of use of energy, a method of determining the presence of a bright light error on the light detector comprising the steps of:

turning off the energization of the light emitter for brief intervals on a repetitive basis;

testing the output of the light detector during said brief off intervals for the presence of light;

providing a tamper error signal when said light detector output indicates the presence of light during the period when the light emitter is turned off;

storing said tamper error signal; and

upon the presentation of a command signal, displaying said tamper error signal.

22. The method of testing for the presence of light tampering in an electro-optic energy meter of claim 21 wherein a light detector is spaced from a light emitter and causing a toothed shutter to rotate between said light emitter and light detector in response to the rate of energy consumption being metered to provide a pulse when a tooth of said shutter passes between said light emitter and light detector.

23. The method of testing for the presence of light tampering in an electro-optic energy meter of claim 22 wherein an optical communications link is provided between said energy meter and the outside of said energy meter through said cover, and downloading the tamper error signal to an external reader through said optical communications link.

24. The method of testing for the presence of light tampering in an electro-optic energy meter of claim 23 wherein storage means are provided in said energy meter for storing said tamper error signal and other signals.

25. The method of testing for the presence of light tampering in an electro-optic energy meter of claim 24 wherein said tamper error signal is provided to said external reader upon receipt of a command signal from said external reader by said microprocessor.

26. The method of testing for the presence of light tampering in an electro-optic energy meter of claim 25 comprising the additional step of downloading said other types of error signals through said external reader to an external computer for consideration of whether bright light tampering has occurred.