阅读说明：本技术 具涌浪电流抑制的电源供应器 (Power supply with surge current suppression ) 是由 方毅雄 于 2018-06-06 设计创作，主要内容包括：本发明提供一种具涌浪电流抑制的电源供应器,该电源供应器基于一启闭信号的电位进入一启动模式或一关闭模式。该电源供应器包含一功因校正单元及一连接该功因校正单元的启动控制单元,该功因校正单元具有一稳压电容,一串联该稳压电容的热敏电阻及一并联该热敏电阻的第一开关,该启动控制单元具有一于该启动模式时启动该功因校正单元并连动导通该第一开关以短路该热敏电阻的开机模式,及一于该关闭模式时关闭该功因校正单元并连动截止该第一开关令该热敏电阻得抑制流入该功因校正单元的涌浪电流的关机模式。(The invention provides a power supply with surge current suppression, which enters a starting mode or a closing mode based on the potential of an on-off signal. The power supply comprises a power factor correction unit and a start control unit connected with the power factor correction unit, wherein the power factor correction unit is provided with a voltage stabilizing capacitor, a thermistor connected with the voltage stabilizing capacitor in series and a first switch connected with the thermistor in parallel, the start control unit is provided with a start mode for starting the power factor correction unit and connecting the first switch in a linkage manner to short circuit the thermistor in the start mode and a shutdown mode for closing the power factor correction unit and connecting the first switch in a linkage manner to stop the thermistor to inhibit surge current flowing into the power factor correction unit in the shutdown mode.)

1. A kind of power supply with surge current suppression, this power supply enters a start mode or a close mode based on the electric potential of a start-stop signal that a load sends out, this power supply characterized by that to include:

The power factor correction unit is provided with a voltage stabilizing capacitor, a thermistor connected in series with the voltage stabilizing capacitor and a first switch connected in parallel with the thermistor; and

The starting control unit is connected with the power factor correction unit and is provided with a starting mode for starting the power factor correction unit and connecting the first switch in a connecting mode to short circuit the thermistor when the power supply enters the starting mode, and a shutdown mode for closing the power factor correction unit and connecting the first switch to stop the thermistor to inhibit surge current flowing into the power factor correction unit when the power supply enters the shutdown mode.

2. The power supply of claim 1, wherein the first switch has a power input terminal connected to the voltage-stabilizing capacitor, a control terminal connected to the start-up control unit, and a first ground terminal, and the thermistor has a first terminal connected to the power input terminal and a second terminal connected to the first ground terminal.

3. The power supply of claim 2, wherein the start-up control unit has a second ground terminal connected to the first ground terminal to enable the start-up control unit and the power factor correction unit to form a common ground, and a working voltage input terminal connected to the control terminal, wherein when the start-up control unit is in the power-on mode, a voltage difference is formed between the working voltage input terminal and the second ground terminal, and the voltage difference enables the first switch to be turned on.

4. The power supply of any one of claims 1-3, wherein the power supply comprises a rectifying input unit disposed at a front stage of the power factor correction unit.

5. The power supply of claim 4, wherein the power supply comprises a power conversion unit disposed at a subsequent stage of the power factor correction unit.

6. The power supply of any one of claims 1-3, wherein the first switch is a bipolar junction transistor, a field effect transistor or a MOSFET.

Technical Field

The present invention relates to a power supply, and more particularly to a power supply with surge current suppression.

Background

In the beginning of a power supply receiving an ac power source (such as a commercial power) to be started, all components (including a voltage stabilizing capacitor) in a power factor correction unit connected in series with the voltage stabilizing capacitor will be subjected to a very large inrush current (also called surge current or inrush current). To avoid the surge current from impacting the power supply circuit and damaging the power supply, manufacturers propose suppression schemes such as TW I290405, TW I474592, TWI494747, TW M268615, and TW 200934029.

The TW I290405 patent discloses a surge current control circuit, which sets a first control unit and a second control unit in a primary loop in an impedance series mode, wherein the first control unit and the second control unit both have a current limiting resistor and a controlled switch connected in parallel. The current limiting resistor of the first control unit is used for preventing a surge current generated at the moment when the alternating current power supply is switched on, the controlled switch of the first control unit is conducted according to the voltage of the energy storage capacitor so that the current crosses the first current limiting resistor, the current limiting resistor of the second control unit is used for preventing the surge current generated at the moment when the level of the alternating current power supply is switched, and the controlled switch of the second control unit is conducted according to the alternating current power supply so that the current crosses the second current limiting resistor. Accordingly, although the TW I290405 patent proposes suppressing the inrush current, the first control unit and the second control unit are implemented by additional control circuits, which makes the overall circuit layout and system control complicated and increases the circuit cost.

Further, the TW 200934029 patent discloses an inrush current suppression circuit, which is connected between a rectification circuit and a filter circuit and includes a current limiting resistor, a capacitor and an active device having three terminals, the active device being connected in parallel with the capacitor and the current limiting resistor, respectively. When the power supply is started, current firstly flows through the current-limiting resistor and charges the capacitor, when the capacitor is charged to the voltage value capable of actuating the active component, the active component is immediately conducted to short circuit the current-limiting resistor connected in parallel with the active component, and further the electric energy consumption caused by the current-limiting resistor when the power supply is supplied is reduced. In view of the above, although the TW 200934029 patent also proposes a technique for suppressing the surge current, the circuit design of the device used in TW 200934029 needs to be considered again, and the driving of the active device involves the voltage at the point connected to the active device, which makes the driving circuit of the active device difficult to implement.

disclosure of Invention

the invention mainly aims to solve the problem that the prior embodiment can lead the composition of a derivative circuit to be complicated or difficult to control.

To achieve the above objective, the present invention provides a power supply with inrush current suppression, which enters a start-up mode or a shut-down mode based on a voltage level of an on-off signal sent by a load. The power supply comprises a power factor correction unit and a starting control unit connected with the power factor correction unit, wherein the power factor correction unit is provided with a voltage-stabilizing capacitor, a thermistor connected with the voltage-stabilizing capacitor in series and a first switch connected with the thermistor in parallel. The start control unit has a start mode for starting the power factor correction unit and turning on the first switch in a linking manner to short-circuit the thermistor when the power supply enters the start mode, and a shutdown mode for turning off the power factor correction unit and turning off the first switch in a linking manner to enable the thermistor to inhibit surge current flowing into the power factor correction unit when the power supply enters the shutdown mode.

In one embodiment, the first switch has a power input terminal connected to the voltage-stabilizing capacitor, a control terminal connected to the start control unit, and a first ground terminal, and the thermistor has a first terminal connected to the power input terminal and a second terminal connected to the first ground terminal.

In one embodiment, the start control unit has a second ground terminal connected to the first ground terminal to enable the start control unit and the power factor correction unit to form a common ground, and a working voltage input terminal connected to the control terminal, wherein when the start control unit is in the power-on mode, a voltage difference is formed between the working voltage input terminal and the second ground terminal, and the voltage difference enables the first switch to be turned on.

In one embodiment, the power supply includes a rectifying input unit disposed at a front stage of the power factor correction unit.

In one embodiment, the power supply includes a power conversion unit disposed at a subsequent stage of the power factor correction unit.

In one embodiment, the first switch may be a bipolar junction transistor, a field effect transistor, or a mosfet.

Compared with the prior art, the invention has the following advantages: the invention makes the start control unit start the power factor correction unit and simultaneously conducts the first switch in a linkage way. On the other hand, the start control unit closes the power factor correction unit and simultaneously closes the first switch in a linkage manner, so that a control circuit for controlling the first switch can be omitted, the complexity of system control is simplified, the reliability of system control is improved, and the implementation cost of an additional driving circuit is not required to be increased.

Drawings

Fig. 1 is a schematic diagram of a unit composition according to an embodiment of the present invention.

Fig. 2 is a circuit diagram according to an embodiment of the invention.

Fig. 3 is a schematic diagram illustrating an implementation of a start mode according to an embodiment of the invention.

Fig. 4 is a schematic diagram of an embodiment of a shutdown mode.

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Detailed Description

The present invention is described in detail and technical content with reference to the accompanying drawings, wherein:

Referring to fig. 1, the present invention provides a power supply 100 with inrush current suppression, the power supply 100 is mainly configured in a Personal Computer (PC) or an industrial computer (IPC), and the power supply 100 is implemented based on the specification of an ATX motherboard. Accordingly, the power supply 100 is connected to a load 200, when the load 200 is operated and is to be started, the load 200 sends an on/off signal 42 to the power supply 100 to a low voltage level, and the power supply 100 enters a start mode according to the on/off signal 42 to prepare for outputting power required by operation to the load 200. On the other hand, when the load 200 is operated to stop working, the on/off signal 42 sent by the load 200 to the power supply 100 is at a high potential (or open circuit), and the power supply 100 enters an off mode according to the on/off signal 42 at that time, and stops outputting the power required for working to the load 200. Further, the ON/off signal 42 is commonly referred to as PS _ ON #, and the definition of PS _ ON # is specified by Intel corporation. The change in the voltage level of the on/off signal 42 is only an example of the disclosure, and is not intended to limit the disclosure.

In view of fig. 2, the power supply 100 at least includes a power factor correction unit 10 and a start control unit 11 connected to the power factor correction unit 10, the power factor correction unit 10 is commonly referred to as pfc (power factor correction), and the power factor correction unit 10 can be implemented by an interleaved power factor correction circuit, a bridgeless power factor correction circuit or other circuits with power factor correction function. The power factor correction unit 10 further includes a voltage stabilizing capacitor 12, a thermistor 13 connected in series with the voltage stabilizing capacitor 12, and a first switch 14 connected in parallel with the thermistor 13. The first switch 14 may be a Bipolar Junction Transistor (BJT), a Field Effect Transistor (FET), or a Metal Oxide Semiconductor Field Effect Transistor (MOSFET). In one embodiment, the first switch 14 has a power input terminal 141 connected to the voltage-stabilizing capacitor 12, a control terminal 142 connected to the start-up control unit 11, and a first ground terminal 143, and the thermistor 13 has a first terminal 131 connected to the power input terminal 141 and a second terminal 132 connected to the first ground terminal 143. Furthermore, in one embodiment, the first switch 14 may be implemented as an N-type metal oxide semiconductor field effect transistor (N-MOSFET) having a low on-resistance, which may prevent the power supply 100 from decreasing in efficiency. On the other hand, since the first switch 14 is clamped by the thermistor 13, the withstand voltage of the first switch 14 does not have to be too high. In addition, the positions of the first switch 14 and the thermistor 13 can be adjusted according to the circuit design. On the other hand, the start control unit 11 is connected to the power factor correction unit 10, and controls the operation of the power factor correction unit 10. Also, the start control unit 11 may be implemented as a Microchip (MCU) or other circuit capable of achieving the same function. Furthermore, the start control unit 11 is further connected to the first switch 14, so as to control the power factor correction unit 10 and simultaneously drive the first switch 14. Accordingly, the start control unit 11 has a power-on mode for starting the power factor correction unit 10 and turning on the first switch 14 to short-circuit the thermistor 13 when the power supply 100 enters the start mode, and a power-off mode for turning off the power factor correction unit 10 and turning off the first switch 14 to make the thermistor 13 suppress the inrush current flowing into the power factor correction unit 10 when the power supply 100 enters the off mode.

Referring to fig. 2 and fig. 3, the power-on mode is first described, in which an ac power source 300 provides power sufficient for the power supply 100 to operate, and the power supply 100 receives the on/off signal 42 sent by the load 200 and is at a low voltage level. When the power supply 100 receives the on/off signal 42 as the low level, the start-up control unit 11 may operate based on a standby power (5VSB) generated by the power supply 100 in a normal state at the initial stage of the power supply 100. When the power supply 100 is normally powered on, the start-up control unit 11 may operate based on other power generated by the power supply 100, but not limited to, the standby power (5 VSB). The start control unit 11 starts the power factor correction unit 10, causes the power factor correction unit 10 to start power factor correction of the received power, and outputs power necessary for operation to a subsequent circuit. On the other hand, the start control unit 11 starts the power factor correction unit 10 and simultaneously turns on the first switch 14 in a linking manner to short-circuit the thermistor 13, and the main path of the current is shown as 40 in fig. 3. At this time, the thermistor 13 has no function when the power supply 100 is operating normally, so as to prevent the thermistor 13 from consuming power and causing the efficiency of the power supply 100 to be reduced.

Referring to fig. 2 and fig. 4, the shutdown mode is described herein, when the ac power source 300 cannot provide sufficient power for the power supply 100 to operate, or when the power supply 100 receives the on/off signal 42 sent by the load 200 and is at a high potential (or open circuit), the start control unit 11 stops the operation of the power factor correction unit 10, and turns off the first switch 14 in a linked manner, so that the parallel branch to which the first switch 14 belongs enters an open circuit state, so that current can only pass through the thermistor 13, and a current path at this time is as indicated by 41 in fig. 4. Therefore, the thermistor 13 is not short-circuited by the first switch 14, so that the thermistor 13 can reduce the inrush current entering the power factor correction unit 10 at the initial start-up of the power supply 100, and prevent the inrush current from impacting the components of the power supply 100, which results in circuit damage.

Referring to fig. 2, in the first embodiment, the present invention is to avoid the circuit of the power supply 100 having multiple grounds, which results in complicated circuit design and reduced system reliability. In one embodiment, the start-up control unit 11 further has a second ground 111 connected to the first ground 143 for connecting the start-up control unit 11 and the power factor correction unit 10 to form a common ground, and an operating voltage input terminal 112 connected to the control terminal 142. For further example, it is assumed that the start control unit 11 is implemented by a Microchip (MCU), the second ground 111 is the ground pin (GND) of the microchip, and the operating voltage input 112 is the power pin (Vcc) of the microchip. Similarly, when the start-up control unit 11 is implemented by a general circuit, the second ground 111 is a Ground (GND) of the general circuit, and the operating voltage input terminal 112 is a power input point (Vcc) of the general circuit. Accordingly, the start-up control unit 11 will operate with the standby power in the power-on mode, the standby power causes a voltage difference to be formed between the operating voltage input terminal 112 and the second ground terminal 111, and the voltage difference can drive the first switch 14 to turn on the first switch 14. Moreover, in addition to solving the aforementioned grounding problem, the solution disclosed in this embodiment further improves the reliability of the first switch 14 in system control, and does not need to use additional peripheral circuits, thereby avoiding increasing the cost of circuit implementation.

Referring to fig. 2, when the power factor correction unit 10 is not implemented as a bridgeless power factor correction circuit, the power supply 100 may include a rectifying input unit 15 disposed at a front stage of the power factor correction unit 10, where the rectifying input unit 15 rectifies the ac power provided by the ac power source 300 and provides the rectified power to the power factor correction unit 10. On the other hand, the power supply 100 may further have a power conversion unit 16 disposed at the rear stage of the power factor correction unit 10. The power conversion unit 16 receives the power output by the power factor correction unit 10 and modulates the power to supply the power required by the load 200, where the power modulation may be a step-up or step-down. The power conversion unit 16 may be implemented as a flyback converter, a forward converter, a push-pull converter, a half-bridge converter, a full-bridge converter, or a circuit having a function of converting direct current into direct current (DC/DC).