Method and apparatus for determining external power supply type

• US 5,506,490 A
• Filed: 11/09/1993
• Issued: 04/09/1996
• Est. Priority Date: 11/09/1993
• Status: Expired due to Term

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: DeMuro, David M.
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): LAW, PATRICK B
• Application Number:
  US08/149,686
• Time in Patent Office: 882 Days
• Field of Search: 320/2, 320/15, 320/22, 320/23, 320/24, 320/39, 320/40, 320/56, 363/142, 363/143
• US Class Current: 320/106
• 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: H01R 13/6616 with resistor
• CPC Class Codes: H01R 31/065 with built-in electric apparatus
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/0032 disconnection of loads if battery is not under charge, e.g. in vehicle if engine is not running
• CPC Class Codes: H02J 7/0036 using connection detecting circuits H02J7/0034 takes precedence
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence
• 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

In summary, the present invention provides a method and apparatus for determining an external power supply type and modifying the charging of the internal battery (14) based upon the external power supply type and battery information. The device has an external power adapter (12) used to provide power to the device (10), as well as charging current for the battery which is regulated by the internal battery charger. A microcontroller (20) in the device (10) regulates the charging current to the battery (14). The microcontroller (20) preferably contains an A/D converter (21) which is connected to a pull-up resistor (32) internal to the device, and to a pull-down resistor (34) in the external power adapter (12). The voltage generated by the resistor divider network including the pull-up resistor (32) and the pull-down resistor (34) in the external power adapter is used to identify the external power adapter type. By changing the value of the pull-down resistor (34) in the external power supply to identify the external power supply, the microcontroller ( 20) in the apparatus may determine the optimum charging profile to use for the battery based upon the charger type and other information relating to the battery.

Claims

1. An apparatus for identifying an external power adapter attached to an electronic device, said external power adapter for receiving a source of primary power and providing a power input to said electronic device, the apparatus comprising:

a resistor network having a first resistor and a second resistor, said first resistor being disposed within said external power adapter and operatively coupled to said second resistor disposed within said device, said resistor network generating a sense voltage associated with said external power adapter; and

a control circuit disposed within said electronic device adapted to receive said sense voltage to identify said external power adapter.

2. The apparatus for identifying an external power adapter according to claim 1 wherein said external power adapter is a regulated power adapter receiving said source of primary power from an alternating current line.

3. The apparatus for identifying an external power adapter according to claim 1 wherein said external power adapter is a regulated power supply receiving said source of primary power from a direct current source.

4. The apparatus for identifying an external power adapter according to claim 1 further including a battery integrally connected to said device.

5. The apparatus for identifying an external power adapter according to claim 4 further including a battery charger disposed within said device for receiving a power input from said external power adapter to charge said battery.

6. The apparatus for identifying an external power adapter according to claim 5 further including a sense line from said battery providing a signal identifying the battery type of said battery.

7. The apparatus for identifying an external power adapter according to claim 6 wherein said control circuit regulates said charger circuit to charge said battery based upon said external power adapter type and said battery type.

8. An apparatus comprising:

an external power adapter adapted to receive a power input from a primary source of power;

a portable device adapted to receive said power input from said external power adapter and generate a regulated voltage;

a resistor network having a first resistor and a second resistor, said first resistor being disposed within said external power adapter and operatively coupled to said second resistor disposed within said portable device and coupled to said regulated voltage, said resistor network generating a sense voltage for identifying the type of said external power adapter; and

a microcontroller disposed within said portable device adapted to receive said sense voltage identifying said type of said external power adapter.

9. The apparatus according to claim 8 wherein said microcontroller further includes an analog to digital converter to convert said sense voltage to a digital signal.

10. The apparatus according to claim 8 further including a battery integrally connected to said portable device.

11. The apparatus according to claim 10 further including a charger circuit disposed within said device, said charger circuit for receiving said power input from said external power adapter to charge said battery.

12. The apparatus according to claim 11 further including a sense line from said battery providing a signal identifying the battery type of said battery.

13. The apparatus according to claim 12 wherein said control circuit regulates said charger circuit to charge said battery based upon a charger type and said battery type.

14. A method for identifying an external power adapter coupled to a device, said method comprising the steps of:

coupling a first resistive element positioned within the external power adapter to a second resistive element positioned within the device to create a resistor divider network;

generate an external power adapter sense voltage based upon a reference voltage; and

identify the external power adapter by the external power adapter sense voltage.

15. The method for identifying an external power adapter according to claim 14 further including a step of recharging a battery based upon the identity of an external power adapter type.

16. A portable electronic device for identifying a type of an external power adapter attached thereto for receiving a source of primary power and providing power input to said electronic device, the portable electronic device comprising:

a resistor being disposed within said portable electronic device, said resistor corresponding to one of a plurality of components forming a network generating a sense voltage associated with said external power adapter; and

a control circuit disposed within said portable electronic device adapted to receive said sense voltage to identify said external power adapter.

17. The portable electronic device for identifying an external power adapter according to claim 16 further including a battery integrally connected to said portable electronic device.

18. The portable electronic device for identifying an external power adapter according to claim 17 further including a battery charger disposed within said portable electronic device for receiving power from said external power adapter to charge said battery.

19. The portable electronic device for identifying an external power adapter according to claim 18 further including a sense line from said battery providing a signal identifying the type of said battery.

20. The portable electronic device for identifying an external power adapter according to claim 19 wherein said control circuit regulates said charger circuit to charge said battery based upon said external power adapter type and the type of said battery.