Power saving method and power saving circuit thereof

• US 9,318,288 B2
• Filed: 01/02/2013
• Issued: 04/19/2016
• Est. Priority Date: 05/11/2012
• Status: Active Grant

• Current Assignee: Wistron Corporation
• Original Assignee: Wistron Corporation
• Inventors: Chen, Chien-Liang, Liu, Chin-Min
• Primary Examiner(s): Kaplan, Hal
• Application Number:
  US13/732,446
• Publication Number:
  US 20130300216A1
• Time in Patent Office: 1,203 Days
• Field of Search: 307/82, 307/131
• US Class Current: 1/1
• CPC Class Codes: H01H 47/00 Circuit arrangements not adapted to a particular application of the relay and designed to obtain desired operating characteristics or to provide energising current
• CPC Class Codes: H02M 1/0032 Control circuits allowing low power mode operation, e.g. in standby mode
• CPC Class Codes: H02M 1/0045 Converters combining the concepts of switch-mode regulation and linear regulation, e.g. linear pre-regulator to switching converter, linear and switching converter in parallel, same converter or same transistor operating either in linear or switching mode
• CPC Class Codes: H02M 3/00 Conversion of dc power input into dc power output
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

A power saving circuit for an electronic device is disclosed. The power saving circuit includes a direct-current (DC) power supply, a sensing unit, and a control unit. The DC power supply is used for providing a DC current. The sensing unit, coupled to the DC power supply, is used for detecting the DC current and operating to generate a voltage signal according to the DC current. The control unit, coupled to the sensing unit, is used for determining whether a system circuit of the electronic device has a light load or a heavy load and generating an enable signal.

Claims

1. A power saving circuit for an electronic device, comprising:

a direct-current (DC) power supply, for providing a direct-current power;

a sensing unit, coupled to the direct-current power supply, for detecting the direct-current power and operating to generate a voltage signal according to the direct-current power;

a control unit, coupled to the sensing unit, for determining whether a system circuit of the electronic device has a light load or a heavy load according to the voltage signal and generating an enable signal;

a heavy load high efficiency module, coupled to the control unit, for providing a first voltage to the system circuit of the electronic device according to the enable signal when the system circuit of the electronic device has the heavy load; and

a light load high efficiency module, coupled to the control unit, for providing a second voltage to the system circuit of the electronic device according to the enable signal when the system circuit of the electronic device has the light load;

wherein the first voltage is greater than the second voltage.

2. The power saving circuit of claim 1, wherein the control unit further compares the voltage signal with a predefined value to determine whether the system circuit of the electronic device has the light load or the heavy load.

3. The power saving circuit of claim 2, wherein the control unit determines the system circuit of the electronic device has the heavy load when the voltage signal is greater than the predefined value, and determines the system circuit of the electronic device has the light load when the voltage signal is less than the predefined value.

4. The power saving circuit of claim 1, wherein the sensing unit comprises:

a resistor, coupled to the direct-current power supply, for detecting the direct-current power when a load of the system circuit of the electronic device varies; and

a chip module, coupled to the resistor, for operating to generate the voltage signal according to the direct-current power.

5. The power saving circuit of claim 1, wherein the control unit is a general purpose input/output (GPIO) unit or an embedded controller.

6. A power saving method for an electronic device, the power saving method comprising:

detecting a direct-current (DC) power;

operating to generate a voltage signal according to the direct-current power;

determining whether a system circuit of the electronic device has a light load or a heavy load according to the voltage signal and generating an enable signal; and

enabling different direct-current switching modules according to the enable signal when a load of the system circuit varies;

wherein enabling the different direct-current switching modules according to the enable signal when the load of the system circuit varies comprises enabling a heavy load high efficiency module which provides a first voltage according to the enable signal when the system circuit of the electronic device has the heavy load, and enabling a light load high efficiency module which provides a second voltage according to the enable signal when the system circuit of the electronic device has the light load;

wherein the first voltage is greater than the second voltage.

7. The power saving method of claim 6, wherein determining whether the system circuit of the electronic device has the light load or the heavy load according to the voltage signal comprises comparing the voltage signal with a predefined value to determine whether the system circuit of the electronic device has the light load or the heavy load.

8. The power saving method of claim 7, wherein comparing the voltage signal with a predefined value to determine whether the system circuit of the electronic device has the light load or the heavy load comprises determining the system circuit of the electronic device has the heavy load when the voltage signal is greater than the predefined value, and determining the system circuit of the electronic device has the light load when the voltage signal is less than the predefined value.