POWER SUPPLY AND POWER CONTROL METHOD THEREOF

• US 20170126123A1
• Filed: 11/04/2015
• Published: 05/04/2017
• Est. Priority Date: 11/04/2015
• Status: Active Grant

• Current Assignee: Getac Technology Corporation
• Original Assignee: Getac Technology Corporation
• Inventors: Hsiung, Ta-Sung
• Granted Patent: US 10,312,808 B2
• Time in Patent Office: Days
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load

Abstract

A power supply and a power control method thereof are provided. The power supply is adapted to be coupled to a load. The power supply includes a battery, an amplifying circuit, and a control circuit. The amplifying circuit receives a load voltage from an output end of the power supply. The amplifying circuit receives a battery voltage from an output end of the battery. When the load is coupled to the output end of the power supply, the amplifying circuit provides a first output voltage according to a voltage difference between the load voltage and the battery voltage. The control circuit controls the battery according to the first output voltage in providing a second output voltage, such that the load is charged at the second output voltage.

Claims

1. A power supply, adapted to be coupled to a load, comprising:

a battery having an output end;

an amplifying circuit having a first input end, a second input end and an output end, with the first input end coupled to an output end of the power supply, and the second input end coupled to the output end of the battery, wherein, when the load is coupled to the output end of the power supply, the amplifying circuit generates a first output voltage according to a voltage difference between the first input end and the second input end; and

a control circuit coupled to the battery and the amplifying circuit to control the battery in providing a second output voltage according to the first output voltage, such that the load is charged at the second output voltage.

2. The power supply of claim 1, wherein the control circuit determines whether the first output voltage is larger than a voltage threshold, controls the battery in providing the second output voltage when the determination is affirmative, and stops the battery from providing the second output voltage when the determination is negative.

3. The power supply of claim 1, wherein, when the output end of the power supply is coupled to the load, the voltage difference increases in response to the connection of the load, and the first output voltage increases with the voltage difference.

4. The power supply of claim 1, wherein, when the output end of the power supply is not coupled to the load, the voltage difference equals zero.

5. The power supply of claim 2, wherein power supply further comprises:

a first resistor coupled between the output end of the battery and the first input end of the amplifying circuit to effectuate voltage division together with the load when the load is coupled to the output end of the power supply, wherein the first resistor is an adjustable resistor; and

a diode coupled between the output end of the power supply and the first input end of the amplifying circuit to prevent reversal of the second output voltage.

6. The power supply of claim 5, wherein power supply further comprises:

a voltage-regulating circuit coupled between the control circuit and the output end of the power supply to adjust the second output voltage, wherein the voltage-regulating circuit comprises;

a voltage regulator coupled to the control circuit; and

a capacitor network having a plurality of first capacitors connected in parallel and coupled between the voltage regulator and the output end of the power supply.

7. The power supply of claim 5, wherein the amplifying circuit comprises:

a differential amplifier having a first input end, a second input end and an output end, wherein the output end provides the first output voltage;

a second resistor coupled between the first input end of the amplifying circuit and the first input end of the differential amplifier;

a third resistor coupled between the second input end of the amplifying circuit and the second input end of the differential amplifier;

a fourth resistor coupled between the first input end and the output end of the differential amplifier;

a fifth resistor coupled between a ground voltage and the second input end of the differential amplifier; and

a fourth capacitor coupled between the first input end and the second input end of the differential amplifier.

8. The power supply of claim 6, wherein the control circuit comprises:

a first inductor coupled to the output end of the battery;

a control unit having an input end, a first output end and a second output end, wherein the input end of the control unit is coupled to the output end of the amplifying circuit and adapted to receive the first output voltage, wherein a first control signal is generated from the first output end of the control unit according to the first output voltage, and a second control signal is generated from the second output end of the control unit according to the first output voltage;

a first transistor having a first end, a second end and a control end, with the first end coupled to the first inductor, the second end coupled to the ground voltage, and the control end adapted to receive the first control signal, thereby allowing the first transistor to turn on and turn off according to the first control signal; and

a second transistor having a first end, a second end and a control end, with the first end coupled to the first inductor, the second end coupled to the voltage regulator, and the control end adapted to receive the second control signal, thereby allowing the second transistor to turn on and turn off according to the second control signal.

9. The power supply of claim 8, wherein

if the first output voltage is larger than the voltage threshold, the control unit provides the first control signal whereby the first transistor switches between an off state and an on state and provides the second control signal whereby the second transistor switches between an on state and an off state, and

if the first output voltage is not larger than the voltage threshold, the control unit provides the first control signal for driving the first transistor to turn off and provides the second control signal for driving the second transistor to turn off.

10. The power supply of claim 8, wherein a battery voltage generated from the battery is boosted to the second output voltage by the control unit.

11. A power control method, adapted for use with a power supply equipped with a battery, the method comprises the steps of:

receiving a load voltage from an output end of the power supply;

receiving a battery voltage from an output end of the battery;

providing a first output voltage according to a voltage difference between the load voltage and the battery voltage when a load is coupled to the output end of the power supply; and

controlling the battery in providing a second output voltage according to the first output voltage to allow the load to be charged at the second output voltage.

12. The power control method of claim 11, wherein the step of controlling the battery in providing the second output voltage according to the first output voltage to allow the load to be charged at the second output voltage further comprises:

determining whether the first output voltage is larger than a voltage threshold;

controlling the battery in providing the second output voltage if the first output voltage is larger than the voltage threshold; and

stopping the battery from providing the second output voltage if the first output voltage is not larger than the voltage threshold.

13. The power control method of claim 11, wherein, when the output end of the power supply is coupled to the load, the voltage difference increases in response to the connection of the load, and the first output voltage increases with the voltage difference.

14. The power control method of claim 11, further comprising the step of setting the voltage difference to zero when the output end of the power supply is not coupled to the load.

15. The power control method of claim 12, wherein, if the first output voltage is larger than the voltage threshold, the step of controlling the battery in providing the second output voltage further comprises boosting the battery voltage generated from the battery to the second output voltage.