Capacitive power supply having charge equalization circuit

• US 5,063,340 A
• Filed: 10/25/1990
• Issued: 11/05/1991
• Est. Priority Date: 10/25/1990
• Status: Expired due to Term

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Kalenowsky, John A.
• Primary Examiner(s): Stephan, Steven L.
• Assistant Examiner(s): Dougherty, Thomas M.
• Application Number:
  US07/603,087
• Time in Patent Office: 376 Days
• Field of Search: 320/1, 320/15-18, 361/15-18, 315/241 R, 315/241 P
• US Class Current: 320/166
• CPC Class Codes: H02H 7/16 for capacitors for synchronous capacitors H02H7/06
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits

Abstract

A capacitive power supply having a charge equalization circuit. The charge equalization circuit is comprised of a shunt circuit connected in a parallel connection with capacitive elements of the capacitive power supply. Once a charging current is applied to the capacitive power supply to store charge thereupon to form thereby a potential difference across the capacitive elements of a pre-determined level, the shunt circuit forms a shunt to shunt the charging current thereto.

Claims

1. A portable, rechargeable power supply forming a power source of pre-defined characteristics for powering a load element when coupled thereto, said power supply having:

means forming a first conductive surface comprised of a conductive material for collecting and storing electrical charge responsive to application of a charging current thereto;

means forming a second conductive surface comprised of a conductive material and spaced-apart from the first conductive surface whereby a potential difference is formed between the first conductive surface and the second conductive surface when electrical charge is stored upon the first conductive surface, said first conductive surface and said second conductive surface spaced-apart therefrom together being of a low electrical resistance to minimize, thereby, resistive loss across the first and second conductive surfaces, respectively, during discharge of the electrical charge stored upon the first conductive surface to power the load element when coupled thereto;

a transistor network formed of at least one transistor having a first terminal connected to the first conductive surface and a second terminal connected to the second conductive surface; and

means for biasing the transistor to vary conductive characteristics thereof such that the transistor forms a shunt for reducing levels of the charging current applied to the first conductive surface when the potential difference formed between the first conductive surface and the second conductive surface is beyond a pre-determined value.

2. The portable, rechargeable power supply of claim 1 wherein said at least one transistor of the transistor network comprises a bipolar junction transistor.

3. The portable, rechargeable power supply of claim 2 wherein said means for biasing biases a base electrode of the bipolar junction transistor with a current of a level indicative of the potential difference formed between the first conductive surface and the second conductive surface.

4. The portable, rechargeable power supply of claim 3 wherein the transistor forms a shunt when the current supplied to the base electrode of the transistor is beyond a certain level.

5. The portable, rechargeable power supply of claim 3 wherein said means for biasing comprises a resistor having first and second sides wherein the first side of the resistor is connected to the first conductive surface and the second side of the resistor is connected to the base electrode of the transistor.

6. The portable, rechargeable power supply of claim 1 further comprising a plurality of first conductive surfaces and a plurality of second conductive surfaces wherein pairs of surfaces, each formed of a first conductive surface and a corresponding, spaced-apart, second conductive surface are connected in a series connection.

7. The portable, rechargeable power supply of claim 6 further comprising a plurality of transistor networks, each formed of at least one transistor and means for biasing the transistors of each of the transistor networks wherein each pair of surfaces has associated therewith at least one transistor network for forming a shunt circuit for shunting the charging current thereto when potential differences formed between the surfaces forming the pairs of surfaces is beyond the pre-determined value.

8. The portable, rechargeable power supply of claim 7 wherein said pairs of surfaces are stacked vertically upon one another wherein a first conductive surface of a first pair of surfaces is coupled to a second conductive surface of a pair of surfaces positioned thereabove, and wherein a second conductive surface of said first pair of surfaces is coupled to a first conductive surface of a pair of surfaces positioned therebeneath to connect the pairs of surfaces, thereby, in said series connection.

9. The portable, rechargeable power supply of claim 1 wherein said conductive material comprising the first and the second conductive surfaces, respectively, includes a conductive, ceramic material.

10. The portable, rechargeable power supply of claim 1 further comprising an aqueous, dielectric material separating the first and the second conductive surfaces, respectively.

11. The portable, rechargeable power supply of claim 1 further comprising a nonaqueous, dielectric material separating the first and the second conductive surfaces, respectively.

12. The portable, rechargeable power supply of claim 1 further comprising a solid-state, dielectric material separating the first and the second conductive surfaces, respectively.

13. The portable, rechargeable power supply of claim 1 wherein said first conductive surface is of a porous configuration.

14. The portable, rechargeable power supply of claim 1 wherein said second surface is of a porous configuration.

15. The portable, rechargeable power supply of claim 1 wherein said first conductive surface is of elongated lengthwise and widthwise dimensions relative to depthwise dimensions thereof.

16. The portable, rechargeable power supply of claim 1 wherein said second conductive surface is of elongated lengthwise and widthwise dimensions relative to depthwise dimensions thereof.

17. The portable, rechargeable power supply of claim 1 further comprising a supportive housing for supportively housing the first conductive surface, and the second conductive surface spaced-apart therefrom, therewithin.

18. A rechargeable, transceiver power supply for carriage with a transceiver to power the transceiver when suitably coupled thereto, said transceiver power supply comprised of:

means forming a first conductive surface comprised of a conductive material for collecting and storing electrical charge responsive to application of a charging current thereto;

means forming a second conductive surface comprised of a conductive material and spaced-apart from the first conductive surface whereby a potential difference is formed between the first conductive surface and the second conductive surface when electrical charge is stored upon the first conductive surface, said first conductive surface and said second conductive surface spaced-apart therefrom together being of a low electrical resistance to minimize, thereby, resistive loss across the first and second conductive surfaces, respectively, during discharge of the electrical charge stored upon the first conductive surface to power the transceiver when coupled thereto; and

a transistor network formed of at least one transistor having a first terminal connected to the first conductive surface and a second terminal connected to the second conductive surface; and

means for biasing the transistor to vary conductive characteristics thereof such that the transistor forms a shunt for reducing levels of the charging current applied to the first conductive surface when the potential difference formed between the first conductive surface and the second conductive surface is beyond a pre-determined value.

19. The transceiver power supply of claim 18 further comprising a plurality of first conductive surfaces and a plurality of second conductive surfaces wherein pairs of surfaces, each formed of a first conductive surface and a corresponding, spaced-apart second conductive surface are connected in a series connection.

20. The transceiver power supply of claim 19 further comprising a plurality of transistor networks, each formed of at least one transistor and means for biasing the transistors of each of the transistor networks wherein each pair of surfaces has associated therewith at least one transistor network for forming a shunt circuit for shunting the charging current thereto when potential differences formed between the surfaces forming the pairs of surfaces is beyond the pre-determined value.

21. The transceiver power supply of claim 20 wherein said pairs of surfaces are stacked vertically upon one another wherein a first conductive surface of a first pair of surfaces is coupled to a second conductive surface of a pair of surfaces positioned thereabove, and wherein a second conductive surface of said first pair of surfaces coupled to a first conductive surface of a pair of surfaces positioned therebeneath to connect the pairs of surfaces, thereby, in said series connection.

22. A portable, rechargeable power supply forming a power source of pre-defined characteristics for powering a load element when coupled thereto, said power supply comprising:

a plurality of conductive-surface pairs, each of said conductive-surface pairs formed of a first conductive surface comprised of a conductive material for collecting and storing electrical charge responsive to application of a charging current thereto, and a second conductive surface comprised of a conductive material and spaced-apart from the first conductive surface whereby a potential difference is formed between the first conductive surface and the second conductive surface when electrical charge is stored upon the first conductive surface, said first conductive surface and said second conductive surface spaced-apart therefrom of each conductive-surface pair together being of a low electrical resistance to minimize, thereby, resistive loss across the first and second conductive surfaces, respectively, of the conductive-surface pairs during discharge of the electrical charge stored upon the first conductive surfaces to power the load element when coupled thereto;

a plurality of transistor networks associated with each conductive-surface pair of the plurality of conductive surface pairs, each transistor network of the plurality of transistor networks formed of at least one transistor having a first terminal connected to the first conductive surface and a second terminal connected to the second conductive surface, respectively, of a conductive-surface pair associated therewith; and

means for biasing the transistors of the plurality of transistor networks such that the transistors of the transistor networks form shunts for reducing levels of the charging current applied to the first conductive surface when the potential difference formed between the first and second conductive surfaces, respectively, of the conductive-surface pairs are beyond pre-determined values.

23. The portable, rechargeable power supply of claim 22 wherein the conductive-surface pairs of the plurality of conductive-surface pairs are stacked vertically upon one another wherein a first conductive surface of a first pair of surfaces is coupled to a second conductive surface of a pair of surfaces positioned thereabove, and wherein a second conductive surface of said first pair of surfaces is coupled to a first conductive surface of a pair of surfaces positioned therebeneath to connect the conductive-surface pairs, thereby, in a series connection.

24. The portable, rechargeable power supply of claim 23 wherein the transistors of the plurality of transistor networks are comprised of bipolar junction transistors.

25. The portable, rechargeable power supply of claim 24 wherein said means for biasing biases base electrodes of the bipolar junction transistors with currents of levels indicative of the potential differences formed between the first conductive surfaces and the second conductive surfaces of the plurality of conductive-surface pairs.

26. The portable, rechargeable power supply of claim 24 wherein said means for biasing comprises resistors associated with each transistor network of the plurality of transistor networks, wherein first sides of the resistors are connected to the first conductive surfaces and the second sides of the resistors are connected to the base electrodes of the transistors of the transistor networks associated therewith.