Battery cutoff timer

• US 6,445,163 B1
• Filed: 10/19/2000
• Issued: 09/03/2002
• Est. Priority Date: 10/19/2000
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Network Communications Incorporated (Fujitsu Limited)
• Inventors: Darlington, Douglas W., Vezeau, Marcel, Chenier, E. Glen, Luque, Ronald D.
• Primary Examiner(s): Toatley, Gregory
• Assistant Examiner(s): LUK, LAWRENCE W
• Application Number:
  US09/692,070
• Time in Patent Office: 684 Days
• Field of Search: 320/133, 320/130, 324/415, 324/418, 361/101
• US Class Current: 320/133
• CPC Class Codes: H02J 2310/54 according to a pre-established time schedule
• CPC Class Codes: H02J 2310/60 Limiting power consumption in the network or in one section of the network, e.g. load shedding or peak shaving
• CPC Class Codes: H02J 3/14 by switching loads on to, or off from, network, e.g. progressively balanced loading
• CPC Class Codes: H02J 9/00 Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
• CPC Class Codes: Y02B 70/3225 Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y04S 20/222 Demand response systems, e.g. load shedding, peak shaving

Abstract

The invention provides a method and system for managing electrical power flow among a plurality of loads or devices, which can be classified into critical loads (as to which maintaining power flow for a maximal period is a priority) and non-critical loads (as to which power flow may be cutoff when available power becomes limited). The invention is of particular use for rationing backup battery power among a plurality of data communications or telecommunications devices or services, whereby one or more less-crucial, and perhaps power-intensive, devices may be provided with a guaranteed duration of backup battery power (to perform an orderly shutdown, for instance), while a more-crucial, and perhaps less power-intensive, device is supplied with a longer duration of backup battery power, such that as the unavailability of primary power continues, crucial functions are maintained. The ability to define exactly the duration of the non-critical devices'"'"' use of backup power is important to managing limited system resources, and can also be useful for protecting the backup storage batteries from excessive drain.

Claims

1. A battery cutoff timer for regulating electrical power flow among a plurality of loads, said timer comprising:

a triggering device;

a timer for selecting and timing at least one duration; and

a power interrupter for selectably interrupting power flow to at least one of the plurality of loads upon elapsing of said at least one duration selected by said timer, wherein the plurality of loads are divided into critical loads and non-critical loads.

2. The timer of claim 1, wherein the first of the plurality of loads that is selectably interrupted is a non-critical load.

3. The timer of claim 2, wherein said triggering device is triggered by changes in logic state associated with a primary power supply input, and wherein the power flow that is interrupted by said power interrupter comprises power from a secondary power supply input.

4. The timer of claim 3, wherein the secondary power supply input comprises at least one storage battery.

5. The timer of claim 1, further comprising an automatic power restorer for restoring power flow to a load that has had power interrupted by said power interrupter.

6. The timer of claim 5, wherein:

the triggering device is triggered by detecting a first change in a logic state associated with a power input for the electrical power flow; and

the automatic power restorer restores power to the load that has had power interrupted in reaction to a second change in the logic state.

7. The timer of claim 5, wherein:

the triggering device is triggered by detecting a first change in an on/off state for electrical current flow in a power supply unit; and

the automatic power restorer restores power to the load that has had power interrupted in reaction to a second change in the on/off state.

8. The timer of claim 1, wherein the triggering device is triggered by detecting a first change in a logic state associated with a power input.

9. The timer of claim 8, wherein the power input comprises a primary power supply input.

10. The timer of claim 9, wherein the primary power supply input comprises AC power derived from a public utility power grid.

11. The timer of claim 8, wherein the power input comprises a backup power supply input.

12. The timer of claim 11, wherein the backup power supply input comprises at least one storage battery.

13. The timer of claim 1, wherein the triggering device is triggered by detecting a first change in an on/off state for electrical current flow in a power supply input.

14. A battery cutoff timer for use with a plurality of data communications devices, the communications devices being divided into critical devices and non-critical devices, all of said devices configured to be powered at least in part by storage battery power during unavailability of primary power input, said timer comprising:

(a) a monitor device for monitoring the availability of primary power input for the data communications equipment;

(b) an alarm device for sensing a failure event in primary power for the data communications equipment;

(c) a timing device for being initiated by said alarming device and for counting-down a predetermined time interval following the failure event;

(d) a cutoff device for cutting off storage battery power to at least one non-critical device upon elapsing of such predetermined time interval during continuation of unavailability of primary power input; and

;

(e) a power restoring device for restoring primary input power to the at least one non-critical device upon resumption of availability of primary power input.

15. The timer of claim 14, wherein:

the monitor device monitors a logic state associated with the primary power input; and

the failure event comprises a first change in a logic state associated with the primary power input.

16. The timer of claim 15, wherein the power restoring device restores primary power in response to a second change in the logic state.

17. The timer of claim 14, wherein the primary power input comprises AC power derived from a public utility power grid.

18. The timer of claim 14, wherein:

the monitor device monitors an on/off state for electrical current flow from the primary power input; and

the failure event comprises detecting the off state for the electrical current flow of the primary power input.

19. The timer of claim 18, wherein the power restoring device restores power in response to detecting the on state of the primary power input.

20. The timer of claim 14, wherein:

the power restoring device is operable to determine whether the primary power input has been available for a predetermined duration; and

the power restoring device is further operable to restore the primary input power to the non-critical devices in response to determining that the primary power input has been available for the predetermined duration.

21. A method of regulating electrical power flow among a plurality of loads, said method comprising:

providing a plurality of loads coupled to a primary power input source, the plurality of loads divided into critical and non-critical loads;

monitoring input of electrical power for the loads from the primary power input source;

selecting at least one duration;

triggering a timer to count down the duration upon occurrence of a change in a logic state associated with the primary power input source;

selectably interrupting power flow to at least one non-critical load upon elapsing of said at least one duration counted down by said timer.

22. The method of claim 21, further comprising the steps of:

after the power flow is interrupted, detecting a return of the logic state to an initial state; and

in response to detecting the return of the logic state to the initial state, automatically restoring power flow to the at least one non-critical load that has had power interrupted.

23. The method of claim 21, wherein:

the logic state comprises an on/off state for electrical current flow from the primary power source; and

the step of triggering comprises triggering in response to detecting the off state of the electrical current flow from the primary power source.

24. The method of claim 21, wherein the step of triggering occurs contemporaneously with supplying a secondary storage battery power supply input source for the plurality of loads and the step of selectably interrupting power flow comprises interrupting power flow from the secondary battery power supply input source.