CN112398325B

CN112398325B - Power supply device

Info

Publication number: CN112398325B
Application number: CN201910739424.2A
Authority: CN
Inventors: 詹子增
Original assignee: Acer Inc
Current assignee: Acer Inc
Priority date: 2019-08-12
Filing date: 2019-08-12
Publication date: 2022-03-08
Anticipated expiration: 2039-08-12
Also published as: CN112398325A

Abstract

The invention provides a power supply device, which comprises a protection circuit and a power conversion circuit. The protection circuit comprises a control circuit, an auxiliary capacitor and a switch circuit. The control circuit receives the alternating voltage from the alternating current power supply and generates a pulsating voltage and a control signal according to the alternating voltage. The auxiliary capacitor is coupled to the control circuit to receive the pulsating voltage and provide a first voltage accordingly. The switch circuit is coupled to the auxiliary capacitor to receive the first voltage and coupled to the control circuit to receive the control signal. The switching circuit responds to the control signal to transmit the first voltage to the power conversion circuit. The power conversion circuit converts the first voltage into an output voltage. When the switch circuit is switched to a conducting state in response to a control signal, the auxiliary capacitor reduces an input inrush current from the alternating current power supply.

Description

Power supply device

Technical Field

The present invention relates to power supply technologies, and particularly to a power supply device capable of reducing input inrush current.

Background

With the progress of technology, various types of computer devices have been developed. In order to enable the computer device to be booted smoothly, the power supply device plays an important role. Generally, based on the application requirements, the existing computer devices (such as a competitive notebook computer or a desktop computer) usually have many peripheral interfaces to connect various peripheral devices. In addition, each peripheral interface is usually provided with a large capacitor to ensure that the output of each peripheral interface is stable and does not interfere with each other. Therefore, the entire computer system (including the computer device and its peripheral devices) can be considered as a very large capacitive load for the power supply device.

In particular, at the moment when the power supply device is activated to power the whole computer system, based on the characteristics of the capacitive load, the power supply device will generate an Inrush Current (Inrush Current), wherein the value of the Inrush Current is proportional to the capacitance value of the capacitive load. It will be appreciated that the larger the capacitance value of the capacitive load, the greater the value of the current of the inrush current. The excessive surge current is liable to damage the parts in the power supply device, thereby reducing the service life of the power supply device.

Disclosure of Invention

In view of the above, the present invention provides a power supply device, which can reduce the input inrush current of the power supply device at the instant when the power supply device is started.

The power supply device comprises a protection circuit and a power conversion circuit. The protection circuit comprises a control circuit, an auxiliary capacitor and a first switch circuit. The control circuit is used for receiving the alternating current voltage from the alternating current power supply and generating a pulsating voltage and a control signal according to the alternating current voltage. The first end of the auxiliary capacitor is coupled to the control circuit to receive the pulsating voltage. The second end of the auxiliary capacitor is used for providing a first voltage. The first end of the first switch circuit is coupled to the second end of the auxiliary capacitor to receive a first voltage. The control end of the first switch circuit is coupled to the control circuit to receive the control signal. The first switch circuit transmits a first voltage to a second terminal of the first switch circuit in response to a control signal. The power conversion circuit is coupled to the second end of the first switch circuit to receive the first voltage and convert the first voltage into an output voltage to supply power to the load. When the first switch circuit is switched to a conducting state in response to the control signal, the auxiliary capacitor is used for reducing input surge current from the alternating current power supply.

In an embodiment of the invention, the control circuit includes a first unidirectional conducting circuit and a control main body. The input end of the first unidirectional conduction circuit is used for receiving alternating-current voltage. The output end of the first unidirectional conduction circuit is used for providing a pulsating voltage. The control main body is used for receiving alternating voltage and is coupled with the output end of the first unidirectional conduction circuit to receive pulsating voltage. The control main body is enabled after receiving the alternating voltage and generates a control signal according to the pulsating voltage.

In an embodiment of the invention, the control main body includes a second unidirectional conducting circuit, a voltage dividing circuit and a driving circuit. The input end of the second unidirectional conduction circuit is used for receiving alternating-current voltage. The output end of the second unidirectional conduction circuit is used for providing a second voltage. The voltage dividing circuit is coupled to the output end of the second unidirectional conducting circuit to receive the second voltage and divides the second voltage to generate a third voltage. The driving circuit is coupled to the output terminal of the first unidirectional conducting circuit to receive the pulsating voltage, and coupled to the voltage dividing circuit to receive the third voltage. The driving circuit is enabled in response to the third voltage and generates a control signal according to the pulsating voltage.

In an embodiment of the invention, the driving circuit includes a second switching circuit, a third unidirectional conducting circuit, and a voltage stabilizing circuit. The first end of the second switch circuit is coupled to the output end of the first unidirectional conducting circuit to receive the pulsating voltage. The control end of the second switch circuit is coupled with the voltage division circuit to receive the third voltage. The input end of the third unidirectional conduction circuit is coupled with the second end of the second switch circuit. The voltage stabilizing circuit is coupled with the output end of the third unidirectional conducting circuit to provide a control signal.

In an embodiment of the invention, the driving circuit further includes a fourth unidirectional conducting circuit and a first current limiting circuit. The input end of the fourth unidirectional conduction circuit is coupled with the output end of the third unidirectional conduction circuit. The first current limiting circuit is coupled between the output end of the fourth unidirectional conducting circuit and the control end of the first switch circuit.

In an embodiment of the invention, the driving circuit further includes a second current limiting circuit. The second current limiting circuit is coupled between the output end of the first unidirectional conducting circuit and the first end of the second switch circuit.

In an embodiment of the invention, a ratio of a capacitance value of the auxiliary capacitor to a capacitance value of the load is less than or equal to one fifth.

In view of the above, in the power supply apparatus provided in the embodiment of the invention, when the first switch circuit is switched to the on state, the auxiliary capacitor is substantially connected in series with the load capacitor. Because the capacitance value of the equivalent capacitor formed by the series connection of the auxiliary capacitor and the load capacitor is reduced, and the current value of the input surge current flowing into the power supply device is in direct proportion to the capacitance value of the equivalent capacitor, the input surge current can be effectively reduced through the series connection of the auxiliary capacitor and the load capacitor, so that the power supply device is prevented from being damaged due to the overlarge input surge current.

In order to make the aforementioned and other features and advantages of the invention more comprehensible, embodiments accompanied with figures are described in detail below.

Drawings

FIG. 1 is a block diagram of a power supply apparatus according to an embodiment of the present invention;

FIG. 2 is a block diagram of a control circuit according to an embodiment of the present invention;

fig. 3 is a circuit block diagram of a control circuit according to another embodiment of the invention.

The reference numbers illustrate:

100: power supply device

120: protective circuit

122. 322: control circuit

1224. 3224: control body

140: power supply conversion circuit

2242. 4242: driving circuit

2426: voltage stabilizing circuit

900: load(s)

CA: auxiliary capacitor

CS: capacitor with a capacitor element

CZ: voltage stabilizing capacitor

D1: first one-way conduction circuit

D2: second unidirectional conduction circuit

D3: third unidirectional conduction circuit

D4: fourth unidirectional conducting circuit

DIV: voltage divider circuit

GND: grounding terminal

IRS: inrush current

PAC: AC power supply

R1, R2: resistor with a resistor element

RT 1: first current limiting circuit

RT 2: second current limiting circuit

ST: control signal

SW 1: first switch circuit

SW 2: second switch circuit

V1: first voltage

V2: second voltage

V3: third voltage

VAC: alternating voltage

VO: output voltage

VP: pulsating voltage

ZD: zener diode

Detailed Description

In order that the present invention may be more readily understood, the following detailed description is provided as an illustration of specific embodiments of the invention. Further, wherever possible, the same reference numbers will be used throughout the drawings and the description to refer to the same or like parts.

Fig. 1 is a block diagram of a power supply apparatus 100 according to an embodiment of the invention. Referring to fig. 1, the power supply apparatus 100 may include a protection circuit 120 and a power conversion circuit 140, but is not limited thereto. The protection circuit 120 may include a control circuit 122, an auxiliary capacitor CA, and a first switch circuit SW 1. The control circuit 122 is configured to receive an ac voltage VAC from an ac power source PAC, and generate a pulsating voltage VP and a control signal ST according to the ac voltage VAC. A first terminal of the auxiliary capacitor CA is coupled to the control circuit 122 to receive the pulsating voltage VP. The second terminal of the auxiliary capacitor CA is used to provide the first voltage V1. The first terminal of the first switch circuit SW1 is coupled to the second terminal of the auxiliary capacitor CA to receive the first voltage V1. The control terminal of the first switch circuit SW1 is coupled to the control circuit 122 for receiving the control signal ST. The first switch circuit SW1 may transmit the first voltage V1 to the second terminal of the first switch circuit SW1 in response to the control signal ST. The power conversion circuit 140 is coupled to the second terminal of the first switch circuit SW1 to receive the first voltage V1, and converts the first voltage V1 into an output voltage VO to supply power to the load 900. In addition, at the moment the power supply apparatus 100 is activated to supply power to the load 900, the load 900 may be regarded as a capacitor CS.

Specifically, when the first switch circuit SW1 is switched to the on state in response to the control signal ST, the auxiliary capacitor CA may be used to reduce the input inrush current IRS from the ac power source PAC. In detail, at the moment when the power supply apparatus 100 is activated, the control circuit 122 receives the ac voltage VAC from the ac power source PAC, and provides the pulsating voltage VP and the control signal ST accordingly. The first switch circuit SW1 may be switched to a conductive state in response to the control signal ST. When the first switch circuit SW1 is switched to the on state, the auxiliary capacitor CA is substantially considered to be connected in series with the capacitor CS through the power conversion circuit 140. The capacitance of the equivalent capacitor formed by the auxiliary capacitor CA and the capacitor CS in series will be smaller, and the current value I of the input surge current IRS is proportional to the capacitance C of the equivalent capacitor (i.e. the current value I is proportional to the capacitance C of the equivalent capacitor)

) Therefore, the series connection of the auxiliary capacitor CA and the capacitor CS can effectively reduce the input inrush current IRS, so as to prevent the power supply apparatus 100 from being damaged by the excessive input inrush current IRS.

For example, assume that the capacitance of the capacitor CS of the load 900 is 5000 microfarads (μ F), and the capacitance of the auxiliary capacitor CA in the power supply apparatus 100 is 680 microfarads, so the capacitance of the equivalent capacitor formed by the auxiliary capacitor CA and the capacitor CS connected in series is about 600 microfarads. Compared with the power supply device without the auxiliary capacitor, the power supply device 100 of the present embodiment can reduce the capacitance of the equivalent capacitor in the current loop from 5000 microfarads to 600 microfarads, so that the current value of the input inrush current IRS can be greatly reduced.

In an embodiment of the invention, a ratio of the capacitance value of the auxiliary capacitor CA to the capacitance value of the capacitor CS is less than or equal to one fifth, but the invention is not limited thereto.

In an embodiment of the present invention, the first switch circuit SW1 may be implemented by a power transistor, but the present invention is not limited thereto.

In an embodiment of the present invention, the power conversion circuit 140 can be implemented by various types of existing power conversion circuits, but the present invention is not limited thereto.

Fig. 2 is a block diagram of the control circuit 122 according to an embodiment of the invention. Referring to fig. 1 and fig. 2, the control circuit 122 includes a first unidirectional conducting circuit D1 and a control body 1224. The input terminal of the first unidirectional conducting circuit D1 is used for receiving an alternating voltage VAC. The output terminal of the first unidirectional conducting circuit D1 is used for providing the pulsating voltage VP. The control body 1224 receives the ac voltage VAC, and is coupled to an output terminal of the first unidirectional conducting circuit D1 to receive the ripple voltage VP. The control body 1224 is enabled after receiving the ac voltage VAC, and generates the control signal ST according to the ripple voltage VP.

In an embodiment of the invention, the first unidirectional conducting circuit D1 may be implemented by a diode, wherein an anode terminal of the diode is an input terminal of the first unidirectional conducting circuit D1, and a cathode terminal of the diode is an output terminal of the first unidirectional conducting circuit D1, but the invention is not limited thereto. In other embodiments of the present invention, the first unidirectional conducting circuit D1 can also be implemented by using a unidirectional power transmission circuit known to those skilled in the art.

In an embodiment of the invention, the control body 1224 may include a second unidirectional conducting circuit D2, a voltage divider circuit DIV and a driving circuit 2242. An input terminal of the second unidirectional conducting circuit D2 receives the alternating voltage VAC. The output terminal of the second unidirectional conducting circuit D2 is used for providing a second voltage V2. The voltage divider DIV is coupled to the output terminal of the second unidirectional conductive circuit D2 for receiving the second voltage V2 and dividing the second voltage V2 to generate a third voltage V3. The driving circuit 2242 is coupled to the output terminal of the first unidirectional conducting circuit D1 for receiving the pulsating voltage VP, and is coupled to the voltage divider circuit DIV for receiving the third voltage V3. The driving circuit 2242 may be enabled in response to the third voltage V3, and generate the control signal ST according to the ripple voltage VP.

In an embodiment of the invention, the voltage divider DIV may include resistors R1 and R2. A first end of the resistor R1 is coupled to the output end of the second unidirectional conducting circuit D2 to receive the second voltage V2. A second end of the resistor R1 is coupled to a first end of the resistor R2 to provide a third voltage V3. The second terminal of the resistor R2 is coupled to the ground GND.

In an embodiment of the invention, the driving circuit 2242 may include, but is not limited to, the second switch circuit SW2, the third unidirectional conducting circuit D3 and the stabilizing circuit 2426. A first terminal of the second switch circuit SW2 is coupled to the output terminal of the first unidirectional conducting circuit D1 to receive the pulsating voltage VP. The control terminal of the second switch circuit SW2 is coupled to the voltage divider circuit DIV to receive the third voltage V3. An input terminal of the third unidirectional conducting circuit D3 is coupled to the second terminal of the second switch circuit SW 2. The stabilizing circuit 2426 is coupled to the output terminal of the third unidirectional conducting circuit D3 to provide the control signal ST.

In an embodiment of the invention, the second switch circuit SW2 can be implemented by a power transistor, for example, the invention is not limited thereto.

In an embodiment of the invention, the second unidirectional conducting circuit D2 and the third unidirectional conducting circuit D3 can be implemented by using a circuit similar to the first unidirectional conducting circuit D1.

In an embodiment of the invention, the stabilizing circuit 2426 may include a zener diode ZD and a stabilizing capacitor CZ, but the invention is not limited thereto. The cathode terminal of the zener diode ZD is coupled to the output terminal of the third unidirectional conducting circuit D3. The anode terminal of the zener diode ZD is coupled to the ground GND. The zener capacitor CZ is coupled between the cathode terminal and the anode terminal of the zener diode ZD. In other embodiments of the present invention, the voltage stabilizing circuit 2426 may omit the voltage stabilizing capacitor CZ.

The detailed operation of the control circuit 122 of fig. 2 is described below. Please refer to fig. 1 and fig. 2. Before the power supply device 100 is activated, the initial states of the first switch circuit SW1 and the second switch circuit SW2 are off states. At the moment when the power supply apparatus 100 is activated, the ac power PAC provides the ac voltage VAC to the control circuit 122, such that the first unidirectional conducting circuit D1 provides the pulsating voltage VP, and the second unidirectional conducting circuit D2 provides the second voltage V2. The voltage divider circuit DIV may divide the second voltage V2 to generate a third voltage V3. When the voltage value of the third voltage V3 rises to a specific voltage value, the second switch circuit SW2 is turned on, so that the third unidirectional conductive circuit D3 is turned on. At this time, the zener diode ZD collapses in response to the ripple voltage VP and provides a stable control signal ST in cooperation with the zener capacitor CZ, wherein the voltage value of the control signal ST may be, for example, the collapse voltage value of the zener diode ZD. Then, the first switch circuit SW1 may be turned on in response to the control signal ST.

At the moment when the first switch circuit SW1 is turned on, the ac power PAC, the first unidirectional conducting circuit D1, the auxiliary capacitor CA, the first switch circuit SW1, the power conversion circuit 140, and the capacitor CS of the load 900 form a current loop, and the auxiliary capacitor CA is connected in series with the capacitor CS through the power conversion circuit 140. Since the capacitance of the equivalent capacitor formed by the auxiliary capacitor CA and the capacitor CS connected in series will be smaller, and the current value of the input inrush current IRS is proportional to the capacitance of the equivalent capacitor, the input inrush current IRS on the current loop can be reduced, so as to prevent the power supply apparatus 100 from being damaged by the excessive input inrush current IRS.

Fig. 3 is a block diagram of a control circuit 322 according to another embodiment of the invention. Referring to fig. 2 and fig. 3, the control circuit 322 includes a first unidirectional conductive circuit D1 and a control body 3224. The control body 3224 may include a second unidirectional conducting circuit D2, a voltage dividing circuit DIV, and a driving circuit 4242. The first unidirectional conducting circuit D1, the second unidirectional conducting circuit D2 and the voltage divider circuit DIV in fig. 3 are respectively similar to the first unidirectional conducting circuit D1, the second unidirectional conducting circuit D2 and the voltage divider circuit DIV in fig. 2, so that reference may be made to the above description of fig. 2, and further description is omitted here.

In addition, the driving circuit 4242 of fig. 3 is similar to the driving circuit 2242 of fig. 2, and the difference therebetween is that the driving circuit 4242 of fig. 3 further includes a fourth unidirectional conducting circuit D4, a first current limiting circuit RT1 and a second current limiting circuit RT 2. An input terminal of the fourth unidirectional conducting circuit D4 is coupled to an output terminal of the third unidirectional conducting circuit D3. The first current limiting circuit RT1 is coupled between the output terminal of the fourth unidirectional conducting circuit D4 and the control terminal of the first switch circuit SW1 to protect the first switch circuit SW 1. The second current limiting circuit RT2 is coupled between the output terminal of the first unidirectional conducting circuit D1 and the first terminal of the second switch circuit SW2 to limit the current flowing into the second switch circuit SW 2.

In an embodiment of the present invention, the fourth unidirectional conducting circuit D4 can be implemented by a circuit similar to the first unidirectional conducting circuit D1.

In an embodiment of the invention, the first current limiting circuit RT1 and the second current limiting circuit RT2 may be implemented by resistors, but the invention is not limited thereto. In other embodiments of the present invention, the first current limiting circuit RT1 and the second current limiting circuit RT2 can be implemented by current limiting circuits known to those skilled in the art.

In addition, the operation of the control circuit 322 of fig. 3 is similar to the control circuit 122 of fig. 2, so the details of the operation of the control circuit 322 can be referred to the above description of fig. 2, and are not repeated herein.

In summary, in the power supply apparatus according to the embodiment of the invention, when the first switch circuit is switched to the on state, the auxiliary capacitor is substantially connected in series with the load capacitor. Because the capacitance value of the equivalent capacitor formed by the series connection of the auxiliary capacitor and the load capacitor is reduced, and the current value of the input surge current flowing into the power supply device is in direct proportion to the capacitance value of the equivalent capacitor, the input surge current can be effectively reduced through the series connection of the auxiliary capacitor and the load capacitor, so that the power supply device is prevented from being damaged due to the overlarge input surge current.

Although the present invention has been described with reference to the above embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention.

Claims

1. A power supply device, comprising:

a protection circuit, comprising:

the control circuit is used for receiving alternating voltage from an alternating current power supply and generating a pulsating voltage and a control signal according to the alternating voltage;

the first end of the auxiliary capacitor is coupled with the control circuit to receive the pulsating voltage, and the second end of the auxiliary capacitor is used for providing a first voltage; and

a first switch circuit, a first terminal of which is coupled to the second terminal of the auxiliary capacitor to receive the first voltage, a control terminal of which is coupled to the control circuit to receive the control signal, and which transmits the first voltage to a second terminal of the first switch circuit in response to the control signal; and

a power conversion circuit coupled to the second terminal of the first switch circuit to receive the first voltage and convert the first voltage into an output voltage to power a load,

wherein the auxiliary capacitor is configured to reduce an input inrush current from the AC power source when the first switch circuit is switched to a conducting state in response to the control signal,

wherein the control circuit comprises:

the input end of the first unidirectional conduction circuit is used for receiving the alternating voltage, and the output end of the first unidirectional conduction circuit is used for providing the pulsating voltage; and

the control body is used for receiving the alternating-current voltage and is coupled to the output end of the first unidirectional conduction circuit to receive the pulsating voltage, wherein the control body is enabled after receiving the alternating-current voltage and generates the control signal according to the pulsating voltage.

2. The power supply device according to claim 1, wherein the control main body includes:

the input end of the second unidirectional conduction circuit is used for receiving the alternating voltage, and the output end of the second unidirectional conduction circuit is used for providing a second voltage;

a voltage divider circuit coupled to the output terminal of the second unidirectional conducting circuit to receive the second voltage and divide the second voltage to generate a third voltage; and

and a driving circuit coupled to the output terminal of the first unidirectional conducting circuit to receive the ripple voltage, and coupled to the voltage dividing circuit to receive the third voltage, wherein the driving circuit is enabled in response to the third voltage, and generates the control signal according to the ripple voltage.

3. The power supply device according to claim 2, wherein the drive circuit includes:

a second switch circuit, a first terminal of the second switch circuit being coupled to the output terminal of the first unidirectional conducting circuit to receive the pulsating voltage, and a control terminal of the second switch circuit being coupled to the voltage dividing circuit to receive the third voltage;

the input end of the third unidirectional conduction circuit is coupled with the second end of the second switch circuit; and

and the voltage stabilizing circuit is coupled with the output end of the third unidirectional conduction circuit to provide the control signal.

4. The power supply apparatus according to claim 3, wherein the voltage regulator circuit comprises:

a cathode terminal of the zener diode is coupled to the output terminal of the third unidirectional conducting circuit, and an anode terminal of the zener diode is coupled to a ground terminal; and

a voltage stabilizing capacitor coupled between the cathode terminal and the anode terminal of the Zener diode.

5. The power supply apparatus according to claim 4, wherein the voltage value of the control signal is a breakdown voltage value of the Zener diode.

6. The power supply device according to claim 3, wherein the drive circuit further comprises:

the input end of the fourth unidirectional conduction circuit is coupled with the output end of the third unidirectional conduction circuit; and

and the first current limiting circuit is coupled between the output end of the fourth unidirectional conducting circuit and the control end of the first switch circuit.

7. The power supply device according to claim 6, wherein the drive circuit further comprises:

a second current limiting circuit coupled between the output of the first unidirectional conducting circuit and the first end of the second switching circuit.

8. The power supply device according to claim 6, wherein each of the first unidirectional conducting circuit, the second unidirectional conducting circuit, the third unidirectional conducting circuit and the fourth unidirectional conducting circuit is a diode, wherein an anode terminal of the diode is the input terminal and a cathode terminal of the diode is the output terminal.

9. The power supply device according to claim 1, wherein a ratio of a capacitance value of the auxiliary capacitor to a capacitance value of the load is less than or equal to one fifth.