Electronic apparatus capable of controlling electric current supply

• US 5,191,277 A
• Filed: 09/19/1990
• Issued: 03/02/1993
• Est. Priority Date: 09/20/1989
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Ishii, Takaaki, Ishikura, Akira
• Primary Examiner(s): Hickey, R. J.
• Application Number:
  US07/584,828
• Time in Patent Office: 895 Days
• Field of Search: 320/2, 320/13, 320/22-24, 455/89
• US Class Current: 320/114
• CPC Class Codes: H02J 7/00036 Charger exchanging data with battery
• CPC Class Codes: H02J 7/00047 with provisions for charging different types of batteries
• 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: Y10S 320/12 Precharging analysis, e.g. determining presence of battery

Abstract

An electronic apparatus comprising a charger and an electronic device connected removably to the charger. The electronic device comprises a rechargeable battery unit charged by the charger when the charger is connected to the electronic device, an electronic unit having a plurality of operational modes in each of which a different operating current is required, a charger connection detector for detecting the connection of the charger to the electronic device, and a first control unit for calculating an appropriate current to be supplied from the charger, on the basis of an appropriate operating current value corresponding to the operational mode of the electronic unit and a specified charging current value for the battery unit, and informing the charger of the appropriate supplying current value when the charger connection detector detects that the charger is connected to the electronic device. The charger comprises a current supplying circuit for supplying the electric current to the electronic device, and a second control unit for controlling the current to be supplied by the current supplying circuit such that the controlled current coincides with the appropriate supplying current when the first control unit informs the charger of the appropriate supplying current value.

Claims

1. An electronic apparatus capable of controlling electric current supply, comprising:

a charger; and

an electronic device removably connected to the charger,

the electronic device comprising;

a rechargeable battery unit charged by the charger when the charger is connected to the electronic device;

an electronic unit having a plurality of operational modes in each of which the electronic unit is operated by an operating current of different values, the operating current being supplied from the rechargeable battery unit;

connection detecting means for detecting the connection of the charger to the electronic device; and

first control means for generating a control signal indicative of an appropriate supplying current value to be supplied from the charger on the basis of an appropriate operating current value for each of the operational modes of the electronic unit and a specified charging current value of the battery unit, and supplying the control signal to the charger when the connection detecting means detects that the charger is connected to the electronic device, wherein the first control means comprises

an electric current table for storing the appropriate operating current value corresponding to each of the operational modes of the electronic unit;

means for detecting a present operational mode of the electronic unit;

means for retrieving an appropriate operating current value corresponding to the present operational mode from the electric current table on the basis of the present operational mode;

means for calculating the appropriate operating current value to be supplied by the charger by adding the appropriate operating current value retrieved by the retrieving means and the specified charging current of the rechargeable battery unit; and

means for informing the charger of the appropriate supplying current value calculated by the calculating means when the connection detecting means detects that the charger is connected to the electronic device,

the charger comprising;

current supply means for supplying an electric current to the electronic device; and

second control means for controlling the current supply means such that the electric current to be supplied from the current supply means to the electronic device coincides with the appropriate supplying current value when supplied with the control signal from the first control means.

2. An electronic apparatus capable of controlling electric current supply, comprising:

a charger; and

an electronic device removably connected to the charger,

the electronic device comprising;

a rechargeable battery unit charged by the charger when the charger is connected to the electronic device;

an electronic unit having a plurality of operational modes in each of which the electronic unit is operated by an operating current of different values, the operating current being supplied from the rechargeable battery unit;

connection detecting means for detecting the connection of the charger to the electronic device; and

first control means for generating a control signal indicative of an appropriate supplying current value to be supplied from the charger on the basis of an appropriate operating current value for each of the operational modes of the electronic unit and a specified charging current value of the battery unit, and supplying the control signal to the charger when the connection detecting means detects that the charger is connected to the electronic device, wherein the first control means comprises

an electric current table for storing the appropriate operating current value corresponding to each of the operational modes of the electronic unit;

means for detecting a present operational mode of the electronic unit;

means for retrieving an appropriate supplying current value corresponding to the present operational mode from the electric current table on the basis of the present operational mode; and

means for informing the charger of the appropriate supplying current value retrieved by the retrieving means,

the charger comprising;

current supply means for supplying an electric current to the electronic device; and

second control means for controlling the current supply means such that the electric current to be supplied from the current supply means to the electronic device coincides with the appropriate supplying current value when supplied with the control signal from the first control means.

3. An electronic apparatus capable of controlling electric current supply, comprising:

a charger; and

an electronic device removably connected to the charger,

the electronic device comprising;

a rechargeable battery unit charged by the charger when the charger is connected to the electronic device;

an electronic unit having a plurality of operational modes in each of which the electronic unit is operated by an operating current of different values, the operating current being supplied from the rechargeable battery unit;

connection detecting means for detecting the connection of the charger to the electronic device; and

first control means for generating a control signal indicative of an appropriate supplying current value to be supplied from the charger on the basis of an appropriate operating current value for each of the operational modes of the electronic unit and a specified charging current value of the battery unit, and supplying the control signal to the charger when the connection detecting means detects that the charger is connected to the electronic device,

the charger comprising;

current supply means for supplying an electric current to the electronic device, comprising

a PNP transistor having an emitter connected through a first resistor to a DC power source, a base connected through a second resistor to the DC power source, and a collector connected to the rechargeable battery unit mounted in the electronic device;

an NPN transistor having a collector connected to the base of the PNP transistor; and

a plurality of P-channel MOS field effect transistors each having a source connected to the emitter of the NPN transistor and a drain grounded through a resistor of different resistance; and

second control means for controlling the current supply means such that the electric current to be supplied from the current supply means to the electronic device coincides with the appropriate supplying current value when supplied with the control signal from the first control means, wherein the second control means supplies a first driving current to the base of the NPN transistor and a second drive current selectively to the gates of the plurality of the P-channel MOS field effect transistors in correspondence to the appropriate supplying current to thereby selectively turn on one or more of the plurality of the P-channel MOS field effect transistors.