Portable electronic apparatus with a circuit for controlling discharging of a battery, and a method associated with said circuit

• US 6,114,831 A
• Filed: 09/17/1999
• Issued: 09/05/2000
• Est. Priority Date: 09/28/1998
• Status: Expired due to Term

• Current Assignee: Z124 LLC (Flexis)
• Original Assignee: Alcatel SA (Nokia Corporation)
• Inventors: Attimont, Luc, Bodin, Jannick
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): TIBBITS, PIA FLORENCE
• Application Number:
  US09/397,962
• Time in Patent Office: 354 Days
• Field of Search: 320/106, 320/122, 320/134, 320/136, 320/141, 320/161
• US Class Current: 320/106
• CPC Class Codes: H02J 7/00047 with provisions for charging different types of batteries
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence

Abstract

A portable electronic apparatus suitable for being electrically powered by various types of batteries includes a circuit which identifies the type of battery that is connected to it, and a discharge control circuit which controls discharging of the battery, the discharge control circuit including a comparator circuit which compares the output voltage of the battery with a minimum threshold voltage, a current-determining circuit which determines a value representative of the output current of the battery, an adapter circuit which adapts the minimum threshold voltage as a function of the identified battery type and of the value representative of the output current; a disconnect/stop circuit which stops the electronic apparatus from being powered when the output voltage of the battery becomes lower than the minimum threshold voltage delivered by the adapter circuit.

Claims

1. A portable electronic apparatus suitable for being electrically powered by various types of batteries, said apparatus comprising:

means for identifying a type of battery that is connected to it, and

a discharge control circuit which controls discharging of the battery, which circuit comprises;

comparator means for comparing an output voltage of the battery with a minimum threshold voltage;

current-determining means for determining a value representative of an output current of the battery;

adapter means for adapting said minimum threshold voltage as a function of an identified battery type and of a value representative of the output current; and

stop means for stopping the electronic apparatus from being powered when the output voltage of the battery becomes lower than the minimum threshold voltage delivered by the adapter means.

2. The portable electronic apparatus according to claim 1, wherein, with each battery type having a predetermined minimum internal voltage and a predetermined internal resistance, the adapter means comprises:

first means for determining the minimum internal voltage and the internal resistance of the battery as a function of the identified battery type, and

second means for determining the adapted minimum threshold voltage as a function of the output current, of the minimum internal voltage, and of the internal resistance.

3. The portable electronic apparatus according to claim 2, wherein said first means comprises a first table in which the minimum internal voltage of the battery is stored for each possible battery type, and a second table in which the internal resistance of the battery is stored for each possible battery type.

4. The portable electronic apparatus according to claim 2, wherein said first means comprises:

a first table in which the minimum internal voltage of the battery is stored for each possible battery type, and

means for estimating the internal resistance of the battery on a basis of a measurement of a relative variation between the output voltage of the battery and the output current.

5. A method of controlling discharging of a battery powering portable electronic apparatus, the method including stopping the portable electronic apparatus from being powered by a battery whenever an output voltage of the battery becomes lower than a predetermined minimum threshold voltage, said method comprising the following steps:

identifying the type of the battery;

determining a value representative of an output current of the battery;

adapting said minimum threshold voltage as a function of the battery type and of a value representative of the output current of the battery;

comparing the output voltage of the battery with said minimum threshold voltage;

performing the preceding steps so long as the output voltage is greater than said minimum threshold voltage; and

stopping the portable electronic apparatus from being powered by the battery when the output voltage of the battery becomes lower than said minimum threshold voltage.

6. The control method according to claim 5, wherein the step of determining the value is performed by measuring the output current.

7. The control method according to claim 5, wherein the step of determining the value is performed by computing the output current deduced on a basis of consumed power that is consumed by a present operating mode of the portable electronic apparatus.

8. The control method according to claim 7, wherein the value representative of the output current is a function in particular of the output voltage of the battery.

9. The control method according to claim 5, wherein the minimum threshold voltage is adapted in particular as a function of the output voltage of the battery.