Power management circuit and electronic device using the same

• US 8,552,680 B2
• Filed: 08/31/2010
• Issued: 10/08/2013
• Est. Priority Date: 01/29/2010
• Status: Expired due to Fees

• Current Assignee: Hong Fu Jin Precision Industry (Shenzhen) Co., Ltd. (Hon Hai Precision Industry Co., Ltd.), Hon Hai Precision Industry Co., Ltd.
• Original Assignee: Hong Fu Jin Precision Industry (Shenzhen) Co., Ltd. (Hon Hai Precision Industry Co., Ltd.), Hon Hai Precision Industry Co., Ltd.
• Inventors: Zhao, Xin, Cheng, Hua-Dong, You, Ruey-Shyang, Wang, Han-Che, Li, Xiao-Guang, Hsieh, Kuan-Hong
• Primary Examiner(s): Fantu, Yalkew
• Application Number:
  US12/873,232
• Publication Number:
  US 20110187311A1
• Time in Patent Office: 1,134 Days
• Field of Search: 320/101
• US Class Current: 320/101
• 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: H01M 10/46 Accumulators structurally combined with charging apparatus circuits for charging H02J7/00
• CPC Class Codes: H01M 10/465 with solar battery as charging system
• CPC Class Codes: H02J 7/35 with light sensitive cells
• CPC Class Codes: Y02B 10/70 Hybrid systems, e.g. uninterruptible or back-up power supplies integrating renewable energies
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

An electronic device includes a first rechargeable battery, a solar cell mounted on the electronic device, a second rechargeable battery and a power management circuit. The power management circuit includes a control module, a DC/DC module, a switch and a power supply switching module. The DC/DC module is configured for converting the DC power generated by the solar cell from one voltage level to another, and activating and maintaining the activation of the control module. The switch is turned on by the control module when the control module is activated, causing the DC power from the DC/DC module to charge the second rechargeable battery. The power supply switching module is controlled by the control module to select the second rechargeable battery to power the electronic device if the voltage level of the rechargeable battery is lower than that of the second rechargeable battery.

Claims

1. An electronic device, comprising:

a first rechargeable battery;

a solar cell mounted on the electronic device and configured for receiving ambient light beams and transform received light beams into DC voltage;

a second rechargeable battery charged by the solar cell; and

a power management circuit, comprising;

a control module;

a direct current/direct current (DC/DC) module connected between the solar cell and the control module, and configured for converting the DC power generated by the solar cell from one voltage level to another, and activating the control module when the electronic device runs out of power to turn off, and maintaining the activation of the control module when the electronic device is powered by the first rechargeable battery or the second rechargeable battery;

a switch controlled by the control module and connected between the second rechargeable battery and the DC/DC module, wherein the switch is turned on by the control module after the control module is activated, causing the DC power from the DC/DC module to charge the second rechargeable battery; and

a power supply switching module controlled by the control module to select the second rechargeable battery to power the electronic device if the voltage level of the first rechargeable battery is lower than that of the second rechargeable battery.

2. The electronic device as recited in claim 1, wherein the power management circuit further comprising:

a battery detecting module, configured for detecting the voltage level of the first rechargeable battery; and

a solar power detecting module, configured for detecting the voltage level of the second rechargeable battery;

wherein the control module is further configured for comparing the voltage level of the first rechargeable battery and the voltage level of the second rechargeable battery, and controlling the power supply switching module to select the first rechargeable battery to power the electronic device if the voltage level of the first rechargeable battery is not lower than that of the second rechargeable battery.

3. A power management circuit applied in an electronic device, the electronic device comprising a first rechargeable battery, a solar cell, and a second rechargeable battery, the power management circuit comprising:

a control module;

a direct current/direct current (DC/DC) module connected between the solar cell and the control module, and configured for converting the DC power generated by the solar cell from one voltage level to another, and activating the control module when the electronic device runs out of power to turn off, and maintaining the activation of the control module when the electronic device is powered by the first rechargeable battery or the second rechargeable battery;

a switch controlled by the control module and connected between the second rechargeable battery and the control module, the switch is turned on by the control module when the control module is activated, causing the DC power from the DC/DC module to charge the second rechargeable battery; and

a power supply switching module controlled by the control module to select the second rechargeable battery to power the electronic device if the voltage level of the first rechargeable battery is lower than that of the second rechargeable battery.

4. The circuit as recited in claim 3, further comprising:

a battery detecting module, configured for detecting the voltage level of the first rechargeable battery; and

a solar power detecting module, configured for detecting the voltage level of the second rechargeable battery;

wherein the control module is further configured for comparing the voltage level of the first rechargeable battery and the voltage level of the second rechargeable battery, and controlling the power supply switching module to select the first rechargeable battery to power the electronic device if the voltage level of the first rechargeable battery is not lower than that of the second rechargeable battery.