Electrical usage display system

• US 4,106,095 A
• Filed: 05/31/1977
• Issued: 08/08/1978
• Est. Priority Date: 05/31/1977
• Status: Expired due to Term

• Current Assignee: Electronic Data Systems, Inc. (Perspecta, Inc.)
• Original Assignee: Electronic Data Systems, Inc. (Perspecta, Inc.)
• Inventors: Yarbrough, Grover A.
• Primary Examiner(s): Morrison, Malcolm A.
• Assistant Examiner(s): Krass, Errol A.
• Application Number:
  US05/801,721
• Time in Patent Office: 434 Days
• Field of Search: 235/151.3, 235/151.31, 235/151.21, 235/92 EL, 235/92 FL, 324/103 R, 324/113-116, 324/119, 340/150, 340/151, 340/152 R, 340/178, 340/248 R, 364/464, 364/480, 364/481, 364/483
• US Class Current: 705/412
• CPC Class Codes: G01R 15/18 using inductive devices, e.g. transformers
• CPC Class Codes: G01R 21/133 by using digital technique
• CPC Class Codes: G06Q 50/06 Energy or water supply

Abstract

The specification discloses a system for displaying a cumulative indication of the estimated cost of electrical usage in a dwelling wherein electricity is applied through an electrical supply main. A coil is inductively coupled to the supply main for generating a signal representative of the magnitude of current passing through the supply main into the dwelling. The signal is rectified and amplified and is applied to an analog-to-digital converter which periodically samples the signal to generate digital signals. Input switches are operable by the consumer in order to provide a rate indication representative of the cost of the electricity flowing through the supply main. A calculator circuit is responsive to the digital signals from the analog-to-digital converter and is responsive to the rate indication from the input switches in order to periodically calculate an estimated cost of electricity passing through the supply main at the time of sampling during a preceding period. Storage circuits are connected to the calculator circuit in order to accumulate the calculated estimated cost for successive periods. A display is connected to the storage circuits for displaying the accumulated estimated cost of electricity passing through the supply main in order to assist the consumer in monitoring his energy usage.

Claims

1. A system for displaying a cumulative indication of electricity usage to a consumer comprising:

inductive coil means for being disposed adjacent an electrical supply line for generating a signal representative of the current flowing through the electrical supply line;

means for periodically generating digital signals representative of the magnitude of said signal;

computing means for receiving said digital signals and for generating periodic output signals representative of a cumulative number of said digital signals; and

display means connected to said computing means for displaying to the comsumer a cumulative indication of the electricity usage.

2. The system of claim 1 wherein said means for periodically generating digital signals comprises an analog-to-digital converter.

3. The system of claim 1 and further comprising:

means for inputting an indication of the cost of electricity to said computing means.

4. The system of claim 3 wherein said cumulative indication of the electricity usage comprises the cumulative estimated cost of the electricity usage.

5. The system of claim 1 wherein said computing means comprises a microprocessor.

6. The system of claim 1 wherein said cumulative indication comprises a cumulative indication of the magnitude of electrical amperes flowing through the electrical supply line.

7. A system for displaying a cumulative indication of the cost of electrical usage to a consumer comprising:

sensing means for being disposed adjacent an electrical power line for generating a signal representative of the electrical current flowing through the power line;

means for generating an input rate indication representative of the cost of electricity;

computing means responsive to said signal and said input rate indication for periodically calculating an estimated cost of electricity used during a preceeding period;

storing means connected to said computing means for accumulating the calculated estimated costs for successive periods; and

a display coupled to said storing means for displaying to the consumer an accumulated estimated cost of electrical usage.

8. The system of claim 7 wherein said sensing means comprises an inductive coil.

9. The system of claim 7 wherein said means for generating an input rate indication representative of the cost of electricity comprises switch means operable by the consumer.

10. The system of claim 7 wherein said computing means comprises a programmable microprocessor.

11. The system of claim 10 and further comprising:

a programmable read only memory connected to said programmable microprocessor to control the operation of said microprocessor.

12. The system of claim 11 and further comprising:

a random access memory connected to said programmable microprocessor for accumulating the estimated costs.

13. The system of claim 7 and further comprising:

an analog-to-digital converter connected between said sensing means and said computing means.

14. The system of claim 13 and further comprising:

rectifying means connected between said sensing means and said analog-to-digital converter.

15. A system for displaying a cumulative indication of the cost of electrical usage in a dwelling having an electrical supply main comprising:

coil means for being inductively coupled to the electrical supply main for generating a signal representative of the magnitude of current passing through the electrical supply main to the dwelling;

an analog-to-digital converter connected to said coil means for periodically sampling said signal to convert said signal to digital signals;

input means operable to provide a rate indication representative of the cost of the electricity;

calculating means responsive to said digital signals and said rate indication for periodically calculating an estimated cost of electricity passing through the supply main at the time of sampling during a preceding period;

storage means connected to said calculating means for accumulating the estimated costs for successive periods; and

a display coupled to said storage means for displaying the accumulated estimated cost of electricity passing through the electrical supply main.

16. The system of claim 15 wherein said input means comprises switch means settable by an operator.

17. The system of claim 15 wherein said calculating means comprises a programmable digital microprocessor.

18. The system of claim 15 wherein said storage means comprises a random access memory connected to said microprocessor for accumulating the estimated costs.

19. The system of claim 18 and further comprising:

a programmable read only memory connected to said programmable digital microprocessor to control the operation of said microprocessor.

20. The system of claim 19 and further comprising:

rectifying means connected between said coil means and said analog-to-digital converter.

21. The system of claim 20 and further comprising:

a filter connected between said rectifying means and said analog-to-digital converter.

22. The system of claim 21 and further comprising:

an amplifier connected between said filter and said analog-to-digital converter.

23. The system of claim 15 wherein said display comprises an array of light emitting diodes.

24. The system of claim 15 wherein said display displays estimated costs in dollars and cents.

25. The system of claim 15 and further comprising:

means for accumulating indications of amperes of current passing through the supply main; and

means operable to display the accumulated indications of amperes on said display.

26. The system of claim 15 and further comprising:

reset means operable to reset the contents of said storage means to zero.

27. The system of claim 15 and further comprising:

an elongated wire extending from said coil means to a housing containing said analog-to-digital converter, said input means, said calculating means, said storage means and said display.

28. The system of claim 27 wherein said housing is located within the dwelling remote from said coil means.