AC adaptor with power consumption reduction in unused state for a battery-operated electronic apparatus

• US 6,052,291 A
• Filed: 11/19/1998
• Issued: 04/18/2000
• Est. Priority Date: 12/08/1997
• Status: Expired due to Term

• Current Assignee: Lenovo PC International Limited (Lenovo Group Ltd.)
• Original Assignee: International Business Machines Corporation
• Inventors: Suzuki, Keiji, Horikoshi, Hideto
• Primary Examiner(s): NGUYEN, MATTHEW VAN
• Application Number:
  US09/195,815
• Time in Patent Office: 516 Days
• Field of Search: 363/20, 363/21, 307/44, 307/45, 307/46, 307/48, 307/49, 307/64, 307/66, 320/5, 320/9, 320/10, 320/20, 320/23, 320/53
• US Class Current: 363/21.12
• CPC Class Codes: H02J 9/005 using a power saving mode for copiers G03G15/5004
• CPC Class Codes: H02M 1/36 Means for starting or stopping converters
• CPC Class Codes: H02M 3/33523 with galvanic isolation between input and output of both the power stage and the feedback loop
• CPC Class Codes: Y02B 70/30 Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
• CPC Class Codes: Y04S 20/20 End-user application control systems

Abstract

An AC adaptor that can reduce power not in use state, and a battery-operated electronic apparatus that can employ such an AC adaptor. An AC adaptor includes, (a) an input line along which an external AC voltage is input, (b) a first transformer for transforming the input AC voltage into a DC voltage at a first voltage level, (c) a switch provided on the primary side of the first transformer, (d) an output line along which a DC voltage on the secondary side of the first transformer is output externally, (e) a second transformer for transforming the input AC voltage into a DC voltage at a second voltage level that is higher than the first voltage level and for outputting the resultant DC voltage to the output line, and (f) an AC adaptor operation control circuit for comparing a voltage level across the output line with a reference voltage level, which is higher than the first voltage level and which is lower than the second voltage level, and for turning on the switch when the voltage level across the output line is lower than the reference voltage level, or for turning off the switch when the voltage level across the output line exceeds the reference voltage level. When an electronic apparatus does not require supply of power, the AC adaptor is detached from the system load in the apparatus, so that the voltage across the output line of the AC adaptor exceeds the reference voltage. In response to the result of the comparison, the switch on the primary side of the first transformer is turned off, and thus the operation of the first transformer can be halted.

Claims

1. An electronic apparatus operable by either one of a DC voltage from an AC adaptor connected externally by an input line to the electronic apparatus or a DC voltage from a battery internal to the electronic apparatus, comprising:

means included as a part of the external AC adaptor for determining whether the electronic apparatus requires an external power source; and

means included as a part of the external AC adaptor for automatically terminating any generation of a voltage potential across the input line of the AC adaptor from the electronic apparatus when the electronic apparatus does not require power to operate from the AC adaptor external power source.

2. An electronic apparatus, including a battery, with an AC adaptor, which electronic apparatus is operable by either a DC voltage from a power source, including the AC adaptor, or from the battery, comprising:

an input line providing a DC voltage from the AC adaptor;

a power switch for instructing that the power source AC adaptor be turned ON and OFF;

a system load for consuming the DC voltage supplied from either the AC adaptor or the battery;

a charging controller for controlling a charged state of the battery; and

means for monitoring the ON/OFF state of the power source AC adaptor and the recharged state of the battery and for automatically stopping the generation of any voltage in AC adaptor to be provided on the input line when the AC adaptor power source is turned OFF and when the battery is not to be recharged.

3. An electronic apparatus having a load operable by a DC voltage, comprising:

an AC adaptor connected to an external AC voltage source including means for generating a DC voltage and connected to the electronic apparatus by an input line for supplying the DC voltage for operation of the load of the electronic apparatus;

means included as a part of the AC adaptor for determining whether the load of the electronic apparatus requires a DC voltage for operation of the load of the electronic apparatus; and

means included as a part of the AC adaptor for automatically disconnecting the means for generating the DC voltage of the AC adaptor from the external AC voltage source when the load of the electronic apparatus does not require power from the AC adaptor power source to operate.

4. The electronic apparatus as defined in claim 3, further including a battery for supplying a DC voltage to the load of the electronic apparatus as an alternate to a supply of the DC voltage from the AC adaptor.

5. The electronic apparatus as defined in claim 4, wherein the means for automatically disconnecting the means for generating the DC voltage of the AC adaptor from the external AC voltage source when the load of the electronic apparatus does not require power from the AC adaptor power source to operate, also provides for automatically disconnecting the means for generating the DC voltage of the AC adaptor from the external AC voltage source when the load of the electronic apparatus does not require power from the battery, the alternate source of DC voltage to the load of the electronic apparatus.

6. The electronic apparatus as defined in claim 5, wherein the means for automatically disconnecting the means for generating the DC voltage of the AC adaptor from the external AC voltage source when the load of the electronic apparatus does not require power includes comparator means for determining that the electronic apparatus does not require power.

7. The electronic apparatus as defined in claim 6, further including a charging controller for controlling a charged state of the battery;

and

wherein the means for automatically disconnecting the means for generating the DC voltage of the AC adaptor from the external AC voltage source when the load of the electronic apparatus does not require power, includes means for monitoring the connective state of the power source AC adaptor to the external AC voltage source and the recharged state of the battery and for automatically disconnecting the AC adaptor power source from the AC power source when the electronic apparatus does not require power and when the battery is not to be recharged.

8. The electronic apparatus as defined in claim 7, wherein the means for monitoring the connective state of the power source AC adaptor to the external AC voltage source and the recharged state of the battery and for automatically disconnecting the AC adaptor power source from the AC power source when the electronic apparatus does not require power and when the battery is not to be recharged, includes a connection to the AC voltage source which is independent of the AC adaptor connection to the AC voltage source which is used to generate the DC voltage for operation of the load of the electronic apparatus.

9. An electronic apparatus having a load operable by a DC voltage, comprising:

a battery for supplying the DC voltage for operation of the load of the electronic apparatus;

an AC adaptor connected to an external AC voltage source including means for generating a DC voltage and connected to the electronic apparatus by an input line for supplying the DC voltage for operation of the load of the electronic apparatus;

means included as a part of the AC adaptor for determining whether the load of the electronic apparatus requires a DC voltage for operation of the load of the electronic apparatus; and

means included as a part of the AC adaptor for automatically disconnecting the means for generating the DC voltage of the AC adaptor from the external AC voltage source when the load of the electronic apparatus does not require power from the battery or the AC adaptor power source to operate.

10. The electronic apparatus as defined in claim 9, wherein the means for automatically disconnecting the means for generating the DC voltage of the AC adaptor from the external AC voltage source when the load of the electronic apparatus does not require power includes comparator means for determining that the load of the electronic apparatus does not require power.

11. The electronic apparatus as defined in claim 10, further including a charging controller for controlling a charged state of the battery;

and

wherein the means for automatically disconnecting the means for generating the DC voltage of the AC adaptor from the external AC voltage source when the load of the electronic apparatus does not require power, includes means for monitoring the connective state of the power source AC adaptor to the external AC voltage source and the recharged state of the battery and for automatically disconnecting the AC adaptor power source from the AC power source when the electronic apparatus does not require power and when the battery is not to be recharged.

12. The electronic apparatus as defined in claim 11, further including comparator means for determining that the load of the electronic apparatus does not require power which comparator compares the DC voltage generated as an output voltage by the AC adaptor with a reference voltage, which reference voltage is set higher than the output voltage and lower than a voltage output of a separate voltage source for operating the means for automatically disconnecting the means for generating the DC voltage of the AC adaptor.

13. An electronic apparatus having a load operable by a DC voltage, comprising:

a battery for supplying the DC voltage for operation of the load of the electronic apparatus;

an AC adaptor connected to an external AC voltage source including means for generating a DC voltage and connected to the electronic apparatus by an input line for supplying the DC voltage for operation of the load of the electronic apparatus, as an alternate to the battery as a DC voltage source, and for charging of the battery;

operating means, included as a part of the AC adaptor, for automatically disconnecting the means for generating the DC voltage of the AC adaptor, including comparator means for determining whether the electronic apparatus requires a DC voltage, which comparator compares the DC voltage generated as an output voltage by the AC adaptor with a reference voltage, which reference voltage is set higher than the output voltage and lower than a voltage output of a separate voltage source for the operating means for automatically disconnecting the means for generating the DC voltage of the AC adaptor;

a charging controller for controlling a charged state of the battery; and

wherein the operating means included as a part of the AC adaptor for automatically disconnecting the means for generating the DC voltage of the AC adaptor from the external AC voltage source, includes means for monitoring the connective state of the power source AC adaptor to the external AC voltage source and the recharged state of the battery and for the automatic disconnection of the AC adaptor power source from the AC power source both when the electronic apparatus does not require power and when the battery is not to be recharged.

14. The electronic apparatus having a load operable by a DC voltage, as defined in claim 13, further including a control element for preventing the separate voltage source for the operating means for supplying power to the electronic apparatus.

15. An electronic apparatus and an AC adaptor, comprising:

a load in the electronic apparatus operable by a DC voltage;

a battery in the electronic apparatus for supplying the DC voltage for operation of the load of the electronic apparatus;

an AC adaptor connectable to an external AC voltage source to obtain AC power;

power means, in the AC adaptor, for accessing the AC power and for generating a DC voltage as an adaptor output voltage and connected to the electronic apparatus for supplying the adaptor output voltage for operation of the load of the electronic apparatus, as an alternate to the battery as a DC voltage source, and for charging of the battery;

control means, in the AC adaptor, for automatically connecting and disconnecting the power means for accessing the AC power from the AC power;

control power means, in the AC adaptor, for accessing the AC power for providing a control output voltage to operate the control means;

comparator means, in the AC adaptor, for determining whether the electronic apparatus requires a DC voltage, which comparator compares the adaptor output voltage with a reference voltage, which reference voltage is higher than the adaptor output voltage and lower than the control output voltage;

a charging controller for controlling a charged state of the battery; and

wherein the control means, includes monitoring means for monitoring the access state of the power means to the AC power and the recharge state of the battery and for the automatic connection and disconnection of the AC adaptor power means from the AC power when the electronic apparatus does not require power from the AC adaptor and when the battery is not to be recharged.

16. An electronic apparatus having a load operable by a DC voltage, comprising:

a battery for supplying the DC voltage for operation of the load of the electronic apparatus;

an AC adaptor connected to an external AC voltage source including adaptor means for generating a DC voltage and connected to the electronic apparatus by an input line for supplying the DC voltage for operation of the load of the electronic apparatus;

monitoring means included as a part of the AC adaptor for determining whether the load of the electronic apparatus requires a DC voltage for operation of the load of the electronic apparatus; and

control means included as a part of the AC adaptor for automatically precluding the generation of the DC voltage at the AC adaptor when the electronic apparatus does not require power from the AC adaptor power source.