Apparatus and method for controlling power supply to a battery-powered electronic device

• US 6,452,362 B1
• Filed: 07/27/2000
• Issued: 09/17/2002
• Est. Priority Date: 07/27/1999
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Choo, Yeon-Chul
• Primary Examiner(s): Vu, Bao Q.
• Assistant Examiner(s): LUK, LAWRENCE W
• Application Number:
  US09/627,301
• Time in Patent Office: 782 Days
• Field of Search: 320/116, 320/118, 320/121, 320/124, 320/132, 320/136
• US Class Current: 320/116
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0025 Sequential battery discharge in systems with a plurality of batteries
• CPC Class Codes: H02J 7/32 for charging batteries from a charging set comprising a non-electric prime mover rotating at constant speed
• CPC Class Codes: Y02B 40/00 Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers

Abstract

A battery-powered electronic device having a main battery and a second battery, and method for controlling power supply to a battery-powered electronic device, are described. If the two batteries are simultaneously mounted in the electronic device, the electronic device receives power from the battery having a relatively higher voltage level in advance of receiving power from the other battery. When the voltage levels of the two batteries are substantially identical to each other, as the one battery is discharged, the other battery is also simultaneously discharged.

Claims

1. An electronic device, comprising:

a main circuit power input terminal for supplying power to a main circuit of the electronic device from any of a first battery and a second battery;

a battery control circuit, said battery control circuit responsive to an output voltage of said first battery, when said first battery is connected to said electronic device, and responsive to an output voltage of said second battery, when said second battery is connected to said electronic device, for generating a corresponding battery selection control signal dependent upon an output voltage level of said first battery and an output voltage level of said second battery; and

a battery selection circuit, said battery selection circuit for electrically connecting one of said first battery and said second battery that has a relatively higher output voltage level than the other of said first battery and said second battery to said main circuit power input terminal in response to the corresponding battery selection control signal when both of said first battery and said second battery are connected to the electronic device.

2. The electronic device of claim 1, further comprised of said battery selection circuit comprising:

a first switch circuit which is positioned for connection between said first battery and said main circuit power input terminal, and is selectively turned on and off in response to the corresponding battery selection control signal; and

a second switch circuit which is positioned for connection between said second battery and said main circuit power input terminal, and is selectively turned on and off in response to the corresponding battery selection control signal.

3. The electronic device of claim 2, further comprising an adapter detection circuit for detecting an alternating current adapter when connected to said main circuit power input terminal to generate an adapter detection signal to cut off any power supplied to the electronic device by any of said first battery and said second battery so that power is then supplied to the electronic device by said alternating current adapter.

4. The electronic device of claim 3, further comprised of said battery selection circuit further comprising a third switch circuit which is connected to said main circuit power input terminal and is connected between said first switch circuit and said second switch circuit, and said third switch circuit is selectively turned on and offin response to the adapter detection signal to selectively provide and cut off any power supplied to the electronic device by any of said first battery and said second battery.

5. The electronic device of claim 3, further comprised of said first switch circuit and said second switch circuit are turned off in response to the adapter detection signal when said alternating current adapter is connected to said main circuit power input terminal.

6. The electronic device of claim 1, further comprised of said battery control circuit comprising:

a first voltage divider for dividing the output voltage of said first battery and providing a first divided voltage;

a second voltage divider for dividing the output voltage of said second battery and providing a second divided voltage; and

a comparator for comparing the first divided voltage with the second divided voltage and generating the corresponding battery selection control signal depending upon a result of the comparison of the first divided voltage with the second divided voltage.

7. The electronic device of claim 1, further comprising a battery voltage detection circuit which is positioned for connection to said first battery and to said second battery, and said battery voltage detection circuit for generating a corresponding low voltage detection signal when the output voltage level of said first battery is lower than a predetermined value and for generating the corresponding low voltage detection signal when the output voltage level of said second battery is lower than the predetermined value, and said battery voltage detection circuit for then providing the corresponding low voltage detection signal to the main circuit to warn a user of a low battery condition.

8. The electronic device of claim 7, further comprised of said battery voltage detection circuit comprising:

a low voltage detector for outputting the corresponding low voltage detection signal when an input voltage level to said low voltage detector from any of said first battery and said second battery is lower than the predetermined value;

a first diode positioned for connection between a voltage input terminal of said low voltage detector and said first battery; and

a second diode positioned for connection between the voltage input terminal of said low voltage detector and said second battery.

9. The electronic device of claim 7, further comprised of said battery selection circuit comprising:

a first switch circuit which is positioned for connection between said first battery and said main circuit power input terminal, and said first switch circuit is selectively turned on and off in response to the corresponding battery selection control signal; and

a second switch circuit which is positioned for connection between said second battery and said main circuit power input terminal, and said second switch circuit is selectively turned on and off in response to the corresponding battery selection control signal.

10. The electronic device of claim 9, further comprised of said battery control circuit comprising:

a first voltage divider for dividing the output voltage of said first battery and providing a first divided voltage;

a second voltage divider for dividing the output voltage of said second battery and providing a second divided voltage; and

a comparator for comparing the first divided voltage with the second divided voltage and generating the corresponding battery selection control signal depending upon a result of the comparison of the first divided voltage with the second divided voltage.

11. The electronic device of claim 9, further comprised of said battery voltage detection circuit comprising:

a low voltage detector for outputting the corresponding low voltage detection signal when an input voltage level to said low voltage detector from any of said first battery and said second battery is lower than the predetermined value;

a first diode positioned for connection between a voltage input terminal of said low voltage detector and said first battery; and

a second diode positioned for connection between the voltage input terminal of said low voltage detector and said second battery.

12. The electronic device of claim 11, further comprised of said battery selection circuit further comprising a diode connected to one end and to another end of said first switch circuit, and said battery voltage detection circuit further comprises a switch circuit which is positioned for connection between said first diode and said first battery and is selectively turned on and off in response to the corresponding battery selection control signal, and with said first switch circuit of said battery selection circuit and said switch circuit of said battery voltage detection circuit being selectively turned on and off together in response to the corresponding battery selection control signal.

13. The electronic device of claim 12, further comprised of said battery control circuit comprising:

a first voltage divider for dividing the output voltage of said first battery and providing a first divided voltage;

a second voltage divider for dividing the output voltage of said second battery and providing a second divided voltage; and

a comparator for comparing the first divided voltage with the second divided voltage and generating the corresponding battery selection control signal depending upon a result of the comparison of the first divided voltage with the second divided voltage.

14. The electronic device of claim 12, further comprising an adapter detection circuit for detecting an alternating current adapter when connected to said main circuit power input terminal to generate an adapter detection signal to cut off any power supplied to the electronic device by any of said first battery and said second battery so that power is supplied to the electronic device by said alternating current adapter, and

further comprised of said battery selection circuit further comprising a third switch circuit which is connected to said main circuit power input terminal and connected between said first switch circuit and said second switch circuit, and said third switch circuit is selectively turned on and off in response to the adapter detection signal to selectively provide and cut off any power supplied to the electronic device by any of said first battery and said second battery.

15. The electronic device of claim 14, further comprised of said first switch circuit and said second switch circuit are turned off in response to the adapter detection signal when said alternating current adapter is connected to said main circuit power input terminal.

16. The electronic device of claim 14, further comprised of said battery control circuit comprising:

a first voltage divider for dividing the output voltage of said first battery and providing a first divided voltage;

s a second voltage divider for dividing the output voltage of said second battery and providing a second divided voltage; and

a comparator for comparing the first divided voltage with the second divided voltage and generating the corresponding battery selection control signal depending upon a result of the comparison of the first divided voltage with the second divided voltage.

17. The electronic device of claim 1, further comprised of said battery selection circuit for electrically connecting both of said first battery and said second battery to said main circuit power input terminal in response to the corresponding battery selection control signal when the output voltage level of said first battery is substantially identical to the output voltage level of said second battery and both of said first battery and said second battery are connected to the electronic device.

18. The electronic device of claim 1, further comprised of said battery selection circuit for electrically connecting one of said first battery and said second battery to said main circuit power input terminal in response to the corresponding battery selection control signal when only one of said first battery and said second battery is connected to the electronic device.

19. An electronic device, comprising:

a main circuit power input terminal for supplying power to a main circuit of the electronic device;

a first battery and a second battery;

a battery control circuit, said battery control circuit responsive to an output voltage of said first battery and to an output voltage of said second battery, for generating a battery selection control signal dependent upon an output voltage level of said first battery and an output voltage level of said second battery; and

a battery selection circuit, said battery selection circuit for electrically connecting one battery of said first battery and said second battery that has a relatively higher output voltage level than the other of said first battery and said second battery to said main circuit power input terminal in response to the battery selection control signal.

20. A method of controlling power supply to a battery-powered electronic device, comprising the steps of:

determining whether a first battery and a second battery are simultaneously connected to said electronic device;

supplying power to said electronic device from a connected one of said first battery and said second battery, when one of said first battery and said second battery is solely connected to said electronic device;

comparing an output voltage level of said first battery with an output voltage level of said second battery, when said first battery and said second battery are simultaneously connected to said electronic device; and

supplying power to said electronic device from one of said first battery and said second battery that has a relatively higher output voltage level that the other of said first battery and said second battery as a result of said comparing step.

21. The method of claim 20, further comprising the step of:

simultaneously supplying power to said electronic device from both of said first battery and said second battery when the output voltage level of said first battery and the output voltage level of said second battery are substantially identical as a result of said comparing step.

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

determining whether an alternating current adapter is connected to said electronic device; and

cutting off any power supplied from said first battery and said second battery to said electronic device when said alternating current adapter is connected to said electronic device.