Portable computer/radio power management system

• US 5,638,540 A
• Filed: 02/02/1995
• Issued: 06/10/1997
• Est. Priority Date: 06/08/1993
• Status: Expired due to Term

• Current Assignee: Spinel Ektronix LLC (Intellectual Ventures LLC)
• Original Assignee: US Robotice Mobile Communications Corporation
• Inventors: Aldous, Steven C.
• Primary Examiner(s): Harvey, Jack B.
• Assistant Examiner(s): Myers, Paul R.
• Application Number:
  US08/384,357
• Time in Patent Office: 859 Days
• Field of Search: 320/5, 320/6, 320/15, 395/750, 364/707, 370/94.1
• US Class Current: 713/300
• CPC Class Codes: G06F 1/263 Arrangements for using multiple switchable power supplies, e.g. battery and AC G06F1/30 takes precedence
• CPC Class Codes: H02J 1/102 being switching converters H02J1/108, H02J1/12 take precedence
• CPC Class Codes: H02M 1/10 Arrangements incorporating converting means for enabling loads to be operated at will from different kinds of power supplies, e.g. from ac or dc

Abstract

An electrical power management system for supplying power to a computer peripheral having a relatively high intermittent power demand, such as a packet-switched data radio. A first self-contained rechargeable power supply, outputting power appropriate for the electrical appliance, stores electrical energy and supplies power to the appliance. A second self-contained rechargeable power supply stores electrical energy and supplies electrical power to intermittently recharge the first power supply. The first and the second power supplies can be such self-contained units as single or multicell batteries or capacitors. Preferably, the first power supply is a battery or a capacitor and the second power source is an internal power supply of a portable personal computer.

Claims

1. An electrical power management element comprising:

radio transmitter means for transmitting packets of data;

first power supply means, rechargeable, for storing electrical energy and supplying power to the radio transmitter means;

second power supply means, self-contained, for storing electrical energy and supplying electrical current to recharge the first power supply means;

means for switching electrical current output from the second power supply means to the first power supply means so as to recharge the first power supply means;

means for controlling the recharging of the first power supply means by performing a set of programmed steps comprising;

detecting the transmission of a packet of data by the radio transmitter means; and

activating the switch means to switch power output from the second power supply means to the first power supply means to charge the first power supply means by an amount substantially equal to the discharge occurring during the previous transmission of the packet of data, to thereby preserve the energy in the second power supply means by replacing only the energy used by the first power supply means during the previous transmission and not fully recharging the first power supply means after every transmission.

2. A system as defined in claim 1, wherein the first power supply means comprises a first rechargeable battery.

3. A system as defined in claim 1 wherein the second power supply means comprises the internal power supply of a portable computer.

4. A system as defined in claim 1 wherein the step of activating the switch means further comprises the step of recharging the first power supply means by an amount equal to the drain during an average transmission.

5. A system as defined in claim 4 wherein the switching means further comprises first means for converting the voltage of the second power supply means to the voltage of the first power supply means.

6. A system as defined in claim 5 wherein the first converting means comprises a DC-to-DC voltage converter.

7. A system as defined in claim 3 wherein the second power supply means further comprises an AC power source.

8. A system as defined in claim 7 further comprising means for converting power derived from the AC power source to 5 VDC.

9. A system as defined in claim 8 wherein the converting means comprises a DC converter and a DC voltage regulator.

10. A system as defined in claim 9 wherein the set of programmed steps further comprises:

determining whether power is being supplied to the system from the AC power source or from the personal computer power supply; and

activating the switch means to switch power output from the AC power source to the first power supply means whenever power is being supplied to the system from the AC power source, otherwise activating the switch means to switch power output from the personal computer power supply to the first power supply means whenever power is being supplied to the system by the personal computer power supply but not by the AC power source, so as to recharge the first power supply means.

11. An electrical power management system comprising:

radio transmitter means for transmitting packets of data;

first power supply means, rechargeable, for storing electrical energy and supplying power to the radio transmitter means;

second power supply means, self-contained, for storing electrical energy and supplying electrical current to recharge the first power supply means;

means for switching electrical current output from the second power supply means to the first power supply means so as to recharge the first power supply means;

processor means for controlling the recharging of the first power supply means by performing a set of programmed steps comprising;

detecting the transmission of a packet of data by the radio transmitter means;

deriving the amount of electrical energy consumed by the radio transmitter means during transmission of the packet of data;

computing a recharging time and power equal to the time and power required for the second power supply means to recharge the first power supply means so as to restore electrical energy to the first power supply means in an amount substantially equal to the amount of electrical energy consumed by the radio transmitter means during transmission of the packet of data;

activating the switch means to switch power output from the second power supply means to the first power supply means to restore said electrical energy; and

program memory means for storing machine-readable instructions utilized by said processor means to carry out said set of programmed steps.

12. A system as defined in claim 11 wherein the radio transmitter means comprises a packet-switched data radio.

13. A system as defined in claim 11, wherein the first power supply means comprises a first rechargeable battery.

14. A system as defined in claim 13 wherein the first rechargeable battery has a higher power output than the second power supply means.

15. A system as defined in claim 11 wherein the first power supply means comprises a capacitor.

16. A system as defined in claim 11 wherein the second power supply means comprises the internal power supply of a personal computer.

17. A system as defined in claim 16 wherein the personal computer power supply has a lower power capacity than that of the first power supply means.

18. A system as defined in claim 11 wherein the voltage of the first power supply means is different from the voltage of the second power supply means.

19. A system as defined in claim 18 wherein the switching means further comprises first means for converting the voltage of the second power supply means to the voltage of the first power supply means.

20. A system as defined in claim 19 wherein the first converting means comprises a DC-to-DC voltage converter.

21. A system as defined in claim 16 wherein the second power supply means further comprises an AC power source.

22. A system as defined in claim 21 further comprising means for converting power derived from the AC power source to 5 VDC.

23. A system as defined in claim 22 wherein the converting means comprises a DC converter and a DC voltage regulator.

24. A system as defined in claim 23 wherein the set of programmed steps further comprises:

determining whether power is being supplied to the system from the AC power source and from the personal computer power supply; and

activating the switch means to switch power output from the AC power source to the first power supply means whenever power is being supplied to the system from the AC power source, otherwise activating the switch means to switch power output from the personal computer power supply to the first power supply means whenever power is being supplied to the system by the personal computer power supply but not by the AC power source, so as to recharge the first power supply means.

25. A system as defined in claim 11 wherein the processor means comprises a programmable microprocessor.

26. A system as defined in claim 11 wherein the deriving step further comprises the steps of:

measuring the average rate at which the radio transmitter means consumes power during the transmission of the packet of data and the duration of the transmission of the packet of data; and

multiplying the average energy consumption rate by the duration of the transmission.

27. A system as defined in claim 11 wherein the first power supply means comprises a capacitor having a capacitor storage voltage that is higher than the operating voltage of the second power supply means.

28. A system as defined in claim 11 wherein the processor receives power from the second power supply means.

29. A system as defined in claim 11 further comprising an initializing step comprising the steps of:

detecting an electrical energy level stored in the first power supply means;

activating the switch means to switch power output from the second power supply means to said first power supply means when the energy level of the first power supply means is less than a first predetermined energy level so as to recharge the first power supply means to said energy level; and

deactivating the switch means to stop power output from the first power supply means to the second power supply means so as to stop recharging the first power supply means.

30. A system as defined in claim 29 wherein the detecting step comprises the step of placing an electrical test load on the first power supply means and measuring the voltage level on said means to compute the electrical energy level of the first power supply means.

31. A system as defined in claim 11 wherein the set of programmed steps further comprises the steps of:

monitoring the voltage level of the second power supply means; and

modifying the power drain on the second power supply by adjusting the switch means to ensure the voltage level of the second power supply means does not become less than a predetermined voltage level.

32. An electrical power management system comprising:

an electrical appliance having a predetermined power demand;

first self-contained rechargeable power supply means, having a first power capacity that is equal to or greater than the predetermined power demand, for storing electrical energy and supplying power to the appliance;

second self-contained rechargeable power supply means, having a second power capacity that is less than the predetermined power demand for storing electrical energy and supplying electrical current to intermittently recharge the first power supply means;

voltage converter switch means for switching electrical current output from the second power supply means to the first power supply means and for converting the voltage output by the second power supply means to the voltage output by the first power supply means so as to recharge the first power supply means;

processor means for controlling the recharging of the first power supply means by performing a set of programmed steps comprising;

detecting the transmission of a packet of data by radio transmitter means;

deriving the amount of electrical energy consumed by the radio transmitter means during transmission of the packet of data;

activating the voltage converter switch means to switch power output from the second power supply means to restore said electrical energy in an amount substantially equal to the amount of energy used during transmission of the packet of data; and

program memory means for storing machine-readable instructions utilized by said processor means to carry out said set of programmed steps.

33. A system as defined in claim 32 wherein the appliance comprises a packet-switched data radio.

34. A system as defined in claim 32 wherein the first power supply means comprises a first rechargeable battery.

35. A system as defined in claim 32 wherein the first power supply means comprises a capacitor.

36. A system as defined in claim 32 wherein the second power supply means comprises the internal power supply of a personal computer.

37. A system as defined in claim 32 wherein the voltage of the first power supply means is different than the voltage of the second power supply means.

38. A system as defined in claim 36 wherein the second power supply means further comprises an AC power source.

39. A system as defined in claim 38 further comprising means for converting power derived from the AC power source to 5 VDC.

40. A system as defined in claim 39 wherein the converting means comprises DC converter and a DC voltage regulator.

41. A system as defined in claim 38 wherein the set of programmed steps further comprises:

determining whether power is being supplied to the system from the AC power source and from the personal computer power supply; and

activating the switch means to switch power output from the AC power source to the first power supply means whenever power is being supplied to the system from the AC power source, otherwise activating the switch means to switch power output from the personal computer power supply to the first power supply means whenever power is being supplied to the system by the personal computer power supply but not by the AC power source, so as to recharge the first power supply means.

42. A system as defined in claim 32 wherein the processor means comprises a programmable microprocessor.

43. A system as defined in claim 42 wherein the microprocessor receives power from the second power supply means.

44. A system as defined in claim 32 wherein the deriving step further comprises the steps of:

measuring the average rate at which the radio transmitter means consumes power during the transmission of the packet of data and the duration of the transmission of the packet of data; and

multiplying the average energy consumption rate by the duration of the transmission.

45. A system as defined in claim 32 wherein the set of programmed steps further comprises the step of initializing the first power supply means each time the radio transmitter means is turned on.

46. A system as defined in claim 45 wherein the initializing step further comprises the steps of:

detecting an electrical energy level stored in the first power supply means;

activating the voltage converter switch means to switch power output from the second power supply means to said first power supply means when the energy level of the first power supply means is less than a first predetermined energy level so as to recharge the first power supply means to above said level; and

deactivating the voltage converter switch means to stop power output from the first power supply means to the second power supply means so as to stop recharging the first power supply means.

47. A system as defined in claim 46 wherein the detecting step comprises the step of placing an electrical test load on the first power supply means and measuring the voltage level on said means to compute the electrical energy level of the first power supply means.

48. A system as defined in claim 32 wherein the set of programmed steps further comprises the steps of:

monitoring the voltage level of the second power supply means; and

modifying the power drain on the second power supply by adjusting the voltage converter switch means to ensure the voltage level of the second power supply means does not become less than a first predetermined voltage level.

49. An electrical power management system for use with a portable personal computer and a computer peripheral, wherein the portable personal computer has a peripheral port powered by an internal battery powered power supply and wherein the peripheral requires power that exceeds the peak power capacity of the peripheral port supply but the average power requirements of the peripheral are less than the average power capacity of the peripheral power supply, the electrical power management system comprising:

first power supply means for storing electrical energy and supplying power to the peripheral;

means for switching electrical current output from the peripheral port supply of the personal computer to the first power supply means so as to recharge the first power supply means;

processor means for controlling the recharging of the first power supply means by performing a set of programmed steps comprising;

detecting the transmission of a packet of data by radio transmitter means;

deriving the amount of electrical energy consumed by the radio transmitter means during transmission of the packet of data; and

activating the switch means to switch power output from the internal power supply of the personal computer to the first power supply means to restore said electrical energy in an amount substantially equal to the derived amount of electrical energy consumed during transmission of the pocket of data; and

program memory means for storing machine-readable instructions utilized by said processor means to carry out said set of programmed steps.

50. A system as defined in claim 49 wherein the peripheral comprises a packet-switched data radio.

51. A system as defined in claim 49 wherein the first power supply means comprises a capacitor.

52. A system as defined in claim 49 wherein the voltage of the first power supply means is different than the voltage of the internal power supply.

53. A system as defined in claim 52 wherein the switching means further comprises first means for converting the voltage of the internal power supply to the voltage of the first power supply means.

54. A system as defined in claim 53 wherein the first converting means comprises a DC-to-DC voltage converter.

55. A system as defined in claim 49 wherein the processor means comprises a programmable microprocessor.

56. A system as defined in claim 49 wherein the deriving step comprises the steps:

measuring the average rate at which the radio transmitter means consumes power during the transmission of the packet of data and the duration of the transmission of the packet of data; and

multiplying the average energy consumption rate by the duration of the transmission.

57. A system as defined in claim 49 wherein the processor receives power from the internal power supply.

58. A system as defined in claim 51 wherein the storage voltage of the capacitor is greater than the operating voltage of the internal power supply.

59. A system as defined in claim 49 wherein the set of programmed steps further comprises the step of initializing the first power supply means each time the radio transmitter means is turned on.

60. A system as defined in claim 59 wherein the initializing step further comprises the steps of:

detecting an electrical energy level stored in the first power supply means;

activating the voltage converter switch means to switch power output from the second power supply means to said first power supply means when the energy level of the first power supply means is less than a first predetermined energy level so as to recharge the first power supply means to above said level; and

deactivating the voltage converter switch means to stop power output from the first power supply means to the second power supply means so as to stop recharging the first power supply means.

61. A system as defined in claim 60 wherein the detecting step comprises the step of placing an electrical test load on the first power supply means to compute the electrical energy level of the first power supply means.

62. A system as defined in claim 49 wherein the set of programmed steps further comprises the steps of:

monitoring the voltage level of the second power supply means; and

modifying the power drain on the second power supply by adjusting the voltage converter switch means to ensure the voltage level of the second power supply means does not become less than a first predetermined voltage level.

63. An electrical power management system comprising in combination:

a packet-switched data radio having a predetermined power demand and incorporating a first rechargeable battery having a power capacity equal to or greater than the predetermined power demand and having a first voltage rating, for storing electrical energy and supplying power to the packet-switched data radio;

a portable personal computer incorporating a peripheral port powered by an internal battery powered power supply, said port having a power capacity less than the predetermined power demand and having a second voltage rating for storing electrical energy and supplying electrical current to intermittently recharge the first power supply means;

voltage converter switch means, electrically coupled to both the first and second rechargeable batteries, for switching electrical current output from the second rechargeable battery to the first rechargeable battery and for converting the voltage output by the second rechargeable battery to the voltage output by the first rechargeable battery so as to recharge the first rechargeable battery;

a programmable microprocessor, receiving power supplied from the second rechargeable battery, for controlling the recharging of the first rechargeable battery by performing a set of programmed steps comprising;

initializing the first power supply means each time the radio transmitter means is turned on, the initializing step comprising the steps of;

detecting an electrical energy level stored in the first power supply means;

activating the voltage converter switch means to switch power output from the second power supply means to said first power supply means when the energy level of the first power supply means is less than a first predetermined energy level so as to recharge the first power supply means; and

deactivating the voltage converter switch means to stop power output from the first power supply means to the second power supply means so as to stop recharging the first power supply means;

replacing the electrical energy consumed by the radio transmitter following each transmission cycle, the replacing step comprising the steps of;

detecting the transmission of a packet of data by radio transmitter means;

deriving the amount of electrical energy consumer by the radio transmitter means during transmission of the packet of data; and

activating the voltage converter switch means to switch power output from the second power supply means to the first power supply means to restore said electrical energy;

program memory means for storing machine-readable instructions utilized by said processor means to carry out said set of programmed steps.

64. A system as defined in claim 63 wherein the set of programmed steps further comprises the steps of:

monitoring the voltage level of the second power supply means;

adjusting the voltage converter switch means to ensure the voltage level of the second power supply means does not become less than a first predetermined voltage level;

repeating the monitoring step until the voltage of the second power supply means is not less than the first predetermined voltage level; and

reenabling the voltage converter switch means.

65. An electrical power management system comprising:

radio transmitter means for transmitting packets of data;

first power supply means for storing electrical energy and supplying power to the radio transmitter means;

second power supply means for storing electrical energy and supplying electrical current to recharge the first power supply means;

means for switching electrical current output from the second power supply means to the first power supply means so as to recharge the first power supply means;

means for controlling the recharging of the first power supply means by performing a set of programmed steps comprising;

detecting the transmission of data by the radio transmitter means; and

activating the switch means to switch power output from the second power supply means to the first power supply means to charge the first power supply means by an amount substantially equal to the discharge occurring during transmission of the data packets thereby preserving the energy in the second power supply means by replacing the energy used by the first power supply means during transmission.