CN210608948U

CN210608948U - Rectifying circuit

Info

Publication number: CN210608948U
Application number: CN201921763728.4U
Authority: CN
Inventors: 曹鸿; 吴韬
Original assignee: Delta Electronics Shanghai Co Ltd
Current assignee: Delta Electronics Shanghai Co Ltd
Priority date: 2019-10-18
Filing date: 2019-10-18
Publication date: 2020-05-22
Anticipated expiration: 2029-10-18

Abstract

The present disclosure provides a rectifier circuit, including: the first bridge arm comprises a first diode and a third diode which are connected in series, wherein the anode of the first diode is connected with the cathode of the third diode and is coupled to the first end of an alternating current power supply; the second bridge arm is connected with the first bridge arm in parallel and comprises a second diode and a fourth diode which are connected in series, and the anode of the second diode is connected with the cathode of the fourth diode and is coupled to the second end of the alternating current power supply; and at least one branch circuit, which comprises a switch tube and a resistor connected in series, wherein the branch circuit is connected in parallel with at least one of the first diode, the second diode, the third diode and the fourth diode. The voltage drop generated by the surge current on the resistor and the conduction voltage drop of the body diode in the switch tube are larger than the conduction voltage drop of the rectifier diode, so that the rectifier diode becomes a main release path of the surge current, and the switch tube is prevented from being broken down by the surge current.

Description

Rectifying circuit

Technical Field

The present disclosure relates to the field of power electronics technologies, and in particular, to a rectifier circuit.

Background

With the development of miniaturization of the switching power supply, the efficiency requirement of the switching power supply is increasingly increased. The traditional preceding stage rectifying circuit of the switching power supply adopts a plurality of diodes to form a rectifying bridge, but the loss of the diode rectifying bridge is high, so that how to reduce the loss of the rectifying bridge part is one of key points for improving the efficiency of the switching power supply. For this reason, a method for reducing the loss of the rectifier bridge by using MOSFET synchronous rectification is developed in the industry, but the method is limited by the problem of surge current. Due to the existence of the MOS body diode, a path is provided for surge current, so that the surge current flows through the MOS body diode when the switching power supply is electrified for the first time, and the traditional MOS transistor has no capability of bearing the surge current, so that the risk of breaking down the MOS transistor exists. Therefore, a series resistance Rz will generally reduce the inrush current in the AC input path, as shown in fig. 1. Taking the voltage positive direction of the L end of the AC power supply as an example, at the moment of AC power-on, no driving waveform exists in the MOS transistors Q1, Q2, Q3 and Q4, and the current flows along the current-limiting resistor Rz, the body diode of the MOS transistor Q1 to the post-stage circuit and finally returns to the N end of the AC power supply through the body diode of the MOS transistor Q4 to form a loop. Because the latter circuit usually has a large capacitance, the impedance of the capacitance is low under the condition that the capacitance is not fully charged in the first time of electrification, and therefore, a large surge current is generated. And the current limiting resistor Rz connected in series in the main circuit increases the line impedance, so that the surge current is greatly reduced. The current limiting resistor Rz is generally selected to be several ohms or even larger, and great loss is generated when the circuit works in a steady state.

Even if the MOS transistor is additionally connected in parallel with a diode, as shown in fig. 2, the surge current is shared by the MOS body diode and the parallel diode. However, since the conduction voltage drop of the body diode of the MOS transistor is usually lower than that of the parallel diode, a large surge current inevitably flows through the body diode of the MOS transistor, and the surge current bearing capacity of the MOS transistor is much lower than that of the diode, so that the MOS transistor still has a risk of breakdown.

Therefore, how to develop a rectifier circuit that can improve the above prior art is a urgent need.

SUMMERY OF THE UTILITY MODEL

In view of this, an object of the present disclosure is to provide a rectifier circuit, which can effectively solve one or more defects in the prior art, and avoid the problem that a MOS transistor is broken down by a surge current.

To achieve the above object, the present disclosure provides a rectifier circuit, including: the first bridge arm comprises a first diode and a third diode which are connected in series, wherein the anode of the first diode is connected with the cathode of the third diode and is coupled to the first end of an alternating current power supply; the second bridge arm is connected with the first bridge arm in parallel and comprises a second diode and a fourth diode which are connected in series, and the anode of the second diode is connected with the cathode of the fourth diode and is coupled to the second end of the alternating current power supply; and at least one branch circuit comprising a switch tube and a resistor which are connected in series, wherein the branch circuit is connected in parallel with at least one of the first diode, the second diode, the third diode and the fourth diode.

In some embodiments, the branch circuit is connected in parallel between the anode and the cathode of the first diode.

In some embodiments, the rectifying circuit includes two of the branch circuits connected in parallel to any two of the first diode, the second diode, the third diode, and the fourth diode, respectively.

In some embodiments, the two branch circuits are connected in parallel between the anode and the cathode of the first diode and between the anode and the cathode of the second diode, respectively.

In some embodiments, the two branch circuits are connected in parallel between the anode and the cathode of the first diode and between the anode and the cathode of the third diode, respectively.

In some embodiments, the two branch circuits are connected in parallel between the anode and the cathode of the second diode and between the anode and the cathode of the third diode, respectively.

In some embodiments, the rectifying circuit includes three of the branch circuits connected in parallel to any three of the first diode, the second diode, the third diode, and the fourth diode, respectively.

In some embodiments, the three branch circuits are connected in parallel between the anode and cathode of the first diode, between the anode and cathode of the second diode, and between the anode and cathode of the third diode, respectively.

In some embodiments, the plurality of branch circuits are connected in parallel between the anode and the cathode of the first diode, between the anode and the cathode of the third diode, and between the anode and the cathode of the fourth diode, respectively.

In some embodiments, the rectifying circuit includes four of the branch circuits connected in parallel between the anode and the cathode of the first diode, between the anode and the cathode of the second diode, between the anode and the cathode of the third diode, and between the anode and the cathode of the fourth diode, respectively.

The utility model also provides a rectifier circuit, include: the first bridge arm comprises a first diode and a third diode which are connected in series, wherein the anode of the first diode is connected with the cathode of the third diode and is coupled to the first end of an alternating current power supply; the second bridge arm is connected with the first bridge arm in parallel and comprises a second diode and a fourth diode which are connected in series, and the anode of the second diode is connected with the cathode of the fourth diode and is coupled to the second end of the alternating current power supply; and the first branch circuit comprises a first switch tube, a second switch tube and a first resistor, wherein the first end of the first switch tube is connected to the first end of the alternating current power supply, the first end of the second switch tube is connected to the second end of the alternating current power supply, the second end of the first switch tube, the second end of the second switch tube and the first end of the first resistor are connected, and the second end of the first resistor is electrically connected to the cathode of the first diode and the cathode of the second diode.

In some embodiments, the rectifier circuit further includes a second branch circuit including a third switching tube and a second resistor connected in series, and the second branch circuit is connected in parallel between an anode and a cathode of the third diode or between an anode and a cathode of the fourth diode.

In some embodiments, the rectifier circuit further includes a second branch circuit, the second branch circuit includes a third switching tube, a fourth switching tube and a second resistor, the second end of the third switching tube is connected to the first end of the ac power source, the second end of the fourth switching tube is connected to the second end of the ac power source, the first end of the third switching tube, the first end of the fourth switching tube and the first end of the second resistor are connected, and the second end of the second resistor is electrically connected to the anode of the third diode and the anode of the fourth diode.

The utility model also provides a rectifier circuit, include: the first bridge arm comprises a first diode and a third diode which are connected in series, wherein the anode of the first diode is connected with the cathode of the third diode and is coupled to the first end of an alternating current power supply; the second bridge arm is connected with the first bridge arm in parallel and comprises a second diode and a fourth diode which are connected in series, and the anode of the second diode is connected with the cathode of the fourth diode and is coupled to the second end of the alternating current power supply; and the first branch circuit comprises a first switch tube, a second switch tube and a first resistor, wherein the second end of the first switch tube is connected to the first end of the alternating current power supply, the second end of the second switch tube is connected to the second end of the alternating current power supply, the first end of the first switch tube, the first end of the second switch tube and the first end of the first resistor are connected, and the second end of the first resistor is electrically connected to the anode of the third diode and the anode of the fourth diode.

In some embodiments, the rectifier circuit further includes a second branch circuit including a third switching tube and a second resistor connected in series, and the second branch circuit is connected in parallel between the anode and the cathode of the first diode or between the anode and the cathode of the second diode.

In some embodiments, the rectifier circuit further includes a second branch circuit including a third switching tube, a fourth switching tube and a second resistor, a first end of the third switching tube is connected to the first end of the ac power source, a first end of the fourth switching tube is connected to the second end of the ac power source, a second end of the third switching tube, a second end of the fourth switching tube and a first end of the second resistor are connected, and a second end of the second resistor is electrically connected to the cathode of the first diode and the cathode of the second diode.

The utility model also provides a rectifier circuit, include: the first bridge arm comprises a first diode and a third diode which are connected in series, wherein the anode of the first diode is connected with the cathode of the third diode and is coupled to the first end of an alternating current power supply; the second bridge arm is connected with the first bridge arm in parallel and comprises a second diode and a fourth diode which are connected in series, and the anode of the second diode is connected with the cathode of the fourth diode and is coupled to the second end of the alternating current power supply; and at least one branch circuit, including a switch tube and a resistor, the resistor is connected in series with the body diode of the switch tube and then connected in parallel with the switch tube, wherein the branch circuit is connected in parallel with at least one of the first diode, the second diode, the third diode and the fourth diode.

In some embodiments, the switching tube is a MOS transistor.

In some embodiments, the switch tube is an N-channel MOS transistor.

In some embodiments, the first diode, the second diode, the third diode, and the fourth diode are independently packaged diodes.

In some embodiments, the first diode, the second diode, the third diode, and the fourth diode are packaged to form a rectifier bridge structure.

The utility model discloses, realize synchronous rectification function through the rectifier bridge that diode and parallelly connected MOS transistor constitute, series resistance on MOS transistor route simultaneously guarantees to go up the electricity and does not have too big surge current to flow through the MOS transistor in the twinkling of an eye. At the moment of electrifying, the MOS transistor does not obtain a driving signal, and surge current can flow through the body diodes of the MOS transistor, but because of the existence of the resistor, the surge current can generate voltage drop on the resistor, and the voltage drop plus the conduction voltage drop of the body diode of the MOS transistor is larger than the conduction voltage drop of the rectifier diode, so that the diode becomes a main release path of the surge current, and the problem that the MOS transistor is broken down by the surge current is avoided. Because the difference of conduction voltage drops of a body diode and a rectifier diode of the MOS transistor is about hundreds of millivolts, and surge current is usually hundreds of amperes, the resistance of the resistor can compensate the voltage difference by only taking a small value, so that the loss of the resistor in steady-state operation is also small.

The above description will be described in detail by embodiments, and further explanation will be provided for the technical solution of the present invention.

Drawings

FIG. 1 is a schematic diagram of a rectifier circuit according to the prior art;

FIG. 2 is a schematic diagram of a rectifier circuit according to the prior art;

fig. 3 is a schematic structural diagram of a first embodiment of the rectifying circuit of the present invention;

fig. 4 is a schematic structural diagram of a second embodiment of the rectifier circuit of the present invention;

fig. 5 is a schematic structural diagram of a third embodiment of the rectifier circuit of the present invention;

fig. 6 is a schematic structural diagram of a fourth embodiment of the rectifier circuit of the present invention;

fig. 7 is a schematic structural diagram of a fifth embodiment of the rectifier circuit of the present invention;

fig. 8 is a schematic structural diagram of a sixth embodiment of the rectifier circuit of the present invention;

fig. 9 is a schematic structural diagram of a seventh embodiment of the rectifier circuit of the present invention;

fig. 10 is a schematic structural diagram of an eighth embodiment of the rectifier circuit of the present invention;

fig. 11 is a schematic structural diagram of a ninth embodiment of the rectifier circuit of the present invention;

fig. 12 is a schematic structural diagram of a tenth embodiment of the rectifier circuit of the present invention;

fig. 13 is a schematic structural diagram of an eleventh embodiment of the rectifier circuit of the present invention;

fig. 14 is a schematic structural diagram of a twelfth embodiment of the rectifier circuit of the present invention;

fig. 15 is a schematic structural diagram of a thirteenth embodiment of the rectifier circuit of the present invention;

fig. 16 is a schematic structural diagram of a fourteenth embodiment of the rectifier circuit of the present invention.

Description of reference numerals:

first diode D1

Second diode D2

Third diode D3

Fourth diode D4

Switching tubes Q1, Q2, Q3 and Q4

Resistors R1, R1 ', R2 and R2'

AC power supply AC

First terminal L of AC power supply

Second end N of AC power supply

Current limiting resistor Rz

Detailed Description

Some exemplary embodiments that incorporate the features and advantages of the present disclosure will be described in detail in the specification which follows. It is to be understood that the disclosure is capable of various modifications in various embodiments without departing from the scope of the disclosure, and that the description and drawings are to be regarded as illustrative in nature, and not as restrictive.

Referring to fig. 3, fig. 3 is a schematic structural diagram of a first embodiment of a rectification circuit according to the present invention. As shown in fig. 3, the rectifier circuit of the present invention includes a first bridge arm and a second bridge arm connected in parallel with the first bridge arm. Wherein the first leg comprises a first diode D1 and a third diode D3 connected in series with each other, an anode of the first diode D1 is connected with a cathode of the third diode D3 and is coupled to a first terminal L of the alternating current power source AC; and a second bridge arm including a second diode D2 and a fourth diode D4 connected in series with each other, wherein an anode of the second diode D2 is connected to a cathode of the fourth diode D4 and is coupled to a second terminal N of the alternating current power source AC. The first diode D1, the second diode D2, the third diode D3 and the fourth diode D4 may be independently packaged diodes. In some embodiments, the first diode D1, the second diode D2, the third diode D3, and the fourth diode D4 may also be packaged to form a rectifier bridge structure. Further, the rectifier circuit further includes at least one branch circuit including a switch Q1 and a resistor R1 connected in series, wherein the branch circuit may be connected in parallel to at least one of the first diode D1, the second diode D2, the third diode D3 and the fourth diode D4. Specifically, as shown in fig. 3, a first terminal of the resistor R1 is connected to the cathode of the first diode D1, a second terminal of the resistor R1 is connected to the second terminal of the switch Q1, and a first terminal of the switch Q1 is connected to the anode of the first diode D1. The present invention does not limit the positional relationship between the switching tube Q1 and the resistor R1. For example, the second terminal of the switch Q1 may be connected to the cathode of the first diode D1, the first terminal of the switch Q1 is connected to the first terminal of the resistor R1, and the second terminal of the resistor R1 is connected to the anode of the first diode D1. The switching tube Q1 is a MOS transistor. Further, the switching transistor Q1 is an N-channel MOS transistor. The first terminal of the switching transistor Q1 is the source of the MOS transistor, and the second terminal of the switching transistor Q1 is the drain of the MOS transistor.

At the moment of power-up, when no driving voltage is applied to the switching tube Q1, assuming that a forward voltage is applied between the first end L and the second end N of the AC power supply AC, the surge current flowing out from the first end L of the AC power supply will pass through the first diode D1 branch and the first resistor R1, and the switching tube Q1 is connected in series with the branch, assuming that the conduction voltage drop across the first diode D1 is VD1, the conduction voltage drop across the diode Q1 is VQ1, and the voltage drop across the resistor R1 is VR1, where VD1 is VR1+ VQ1, and the larger the resistance of R1 is, the smaller the surge current flowing through the switching tube Q1 is, so that most of the surge current flows away from the first diode D1. The surge current passes through the rear-stage line and the fourth diode D4 and then returns to the second end N of the ac power supply.

It should be noted that, in fig. 3, the branch circuit is connected in parallel between the anode and the cathode of the first diode D1, but the present invention is not limited thereto, and in other embodiments, the branch circuit may also be connected in parallel between the anode and the cathode of any other diode, for example, the branch circuit may be connected in parallel between the anode and the cathode of the second diode D2, or the branch circuit is connected in parallel between the anode and the cathode of the third diode D3, or the branch circuit is connected in parallel between the anode and the cathode of the fourth diode D4.

Further, the rectifier circuit may further include two branch circuits connected in parallel to any two of the first diode D1, the second diode D2, the third diode D3, and the fourth diode D4, respectively. Fig. 4-6 are schematic structural diagrams of second to fourth embodiments of the rectifying circuit of the present invention. As shown in fig. 4, the first branch circuit includes a first switch Q1 and a first resistor R1 connected in parallel between the anode and the cathode of the first diode D1, and the second branch circuit includes a second switch Q2 and a second resistor R1' connected in parallel between the anode and the cathode of the second diode D2. Specifically, a first end of the first resistor R1 is connected to the cathode of the first diode D1, a second end of the resistor R1 is connected to the second end of the first switch Q1, and a first end of the first switch Q1 is connected to the anode of the first diode D1; a first end of the second resistor R1 'is connected to the cathode of the second diode D2, a second end of the second resistor R1' is connected to the second end of the second switch Q2, and a first end of the second switch Q2 is connected to the anode of the second diode D2. At the moment of power-on, when no driving voltage is applied to the first switch tube Q1 and the second switch tube Q2, the conduction voltage drop of the body diode and the voltage drop of the resistor in the switch tubes are greater than the conduction voltage drop of the diode, so that the first diode D1 and the second diode D2 become main leakage paths of surge current. When a forward voltage is applied between the first end L and the second end N of the AC power source AC, a main release loop is formed by a surge current generated by starting the AC power source AC through the first diode D1, the post-stage line and the fourth diode D4 in sequence; when a negative voltage is applied between the first terminal L and the second terminal N of the ac power source, the surge current sequentially passes through the second diode D2, the post-stage line, and the third diode D3 to form a main release loop. Therefore, the switching tubes Q1 and Q2 bear smaller surge current, and the risk of breakdown of the switching tubes is avoided.

In other embodiments, as shown in fig. 5, the first branch circuit includes a first switch Q1 and a first resistor R1 connected in parallel between the anode and the cathode of the first diode D1, and the second branch circuit includes a third switch Q3 and a third resistor R2 connected in parallel between the anode and the cathode of the third diode D3. Specifically, a first end of the resistor R1 is connected to the cathode of the first diode D1, a second end of the resistor R1 is connected to the second end of the first switch Q1, and a first end of the first switch Q1 is connected to the anode of the first diode D1; a second terminal of the third switching tube Q3 is connected to the cathode of the third diode D3, a first terminal of the third switching tube Q3 is connected to a first terminal of a third resistor R2, and a second terminal of the third resistor R2 is connected to the anode of the third diode D3.

In other embodiments, as shown in fig. 6, the first branch circuit includes a second switching transistor Q2 and a second resistor R1' connected in parallel between the anode and the cathode of the second diode D2, and the second branch circuit includes a third switching transistor Q3 and a third resistor R2 connected in parallel between the anode and the cathode of the third diode D3. It should be understood that the two branch circuits may also be connected in parallel between the anode and the cathode of any other two diodes. For example, the two branch circuits may also be connected in parallel between the anodes and cathodes of the third and fourth diodes D3 and D4, respectively, or between the anodes and cathodes of the second and fourth diodes D2 and D4, respectively, or between the anodes and cathodes of the first and fourth diodes D1 and D4, respectively.

Further, the rectifier circuit may further include three branch circuits connected in parallel to any three of the first diode D1, the second diode D2, the third diode D3, and the fourth diode D4, respectively. As shown in fig. 7, the first branch circuit includes a first switch Q1 and a first resistor R1 connected in parallel between the anode and the cathode of a first diode D1; the second branch circuit comprises a second switch tube Q2 and a second resistor R1', and is connected between the anode and the cathode of the second diode D2 in parallel; the third branch circuit includes a third switching tube Q3 and a third resistor R2, and is connected in parallel between the anode and the cathode of the third diode D3. As shown in fig. 8, the three branch circuits are connected in parallel between the anodes and cathodes of the first diode D1, the third diode D3, and the fourth diode D4, respectively. It should be understood that the branch circuit may also be connected in parallel between the anodes and cathodes of any other three diodes. For example, three branch circuits are connected in parallel to the first diode D1, the second diode D2, and the fourth diode D4, respectively, or three branch circuits are connected in parallel to the second diode D2, the third diode D3, and the fourth diode D4, respectively.

Further, as shown in fig. 9, the rectifying circuit includes four branch circuits connected in parallel between the anode and the cathode of the first diode D1, between the anode and the cathode of the second diode D2, between the anode and the cathode of the third diode D3, and between the anode and the cathode of the fourth diode D4, respectively. When a forward voltage is applied between the first end L and the second end N of the AC power source AC, a main release loop is formed by a surge current generated by starting the AC power source AC through the first diode D1, the post-stage line and the fourth diode D4 in sequence; when a negative voltage is applied between the first terminal L and the second terminal N of the ac power source, the surge current sequentially passes through the second diode D2, the post-stage line, and the third diode D3 to form a main release loop. Therefore, the switching tubes Q1-Q4 bear smaller surge current, and the risk of breakdown of the switching tubes is avoided.

Fig. 10 is a schematic structural diagram of another embodiment of the rectifying circuit of the present invention, wherein the branch circuit includes a first switch Q1, a second switch Q2 and a first resistor R1, a first end of the first switch Q1 is connected to a first end L of an AC power source AC, a first end of the second switch Q2 is connected to a second end N of the AC power source AC, a second end of the first switch Q1, a second end of the second switch Q2 and a first end of the first resistor R1 are connected, and a second end of the first resistor R1 is electrically connected to a cathode of the first diode D1 and a cathode of the second diode D2. In comparison with fig. 4, fig. 10 combines two resistors in fig. 4 into one resistor, and the number of elements can be reduced and the circuit configuration can be simplified by sharing the resistors.

Further, as shown in fig. 11, the rectifier circuit further includes a second branch circuit including a third switching tube Q3 and a resistor R2 connected in series, and the second branch circuit is connected in parallel between the anode and the cathode of the third diode D3. It will be appreciated that the second branch circuit may also be connected in parallel between the anode and the cathode of the fourth diode D4. Furthermore, a second branch circuit is connected in parallel between the anode and the cathode of the third diode D3 and the fourth diode D4, respectively.

Fig. 12 is a schematic structural diagram of another embodiment of the rectifying circuit of the present invention, wherein the branch circuit includes a third switching tube Q3, a fourth switching tube Q4 and a resistor R2, the second end of the third switching tube Q3 is connected to the first end L of the AC power source AC, the second end of the fourth switching tube Q4 is connected to the second end N of the AC power source AC, the first end of the third switching tube Q3, the first end of the fourth switching tube Q4 and the first end of the resistor R2 are connected, and the second end of the resistor R2 is electrically connected to the anode of the third diode D3 and the anode of the fourth diode D4.

Further, as shown in fig. 13, the rectifier circuit further includes a second branch circuit including a first switching tube Q1 and a resistor R1 connected in series, and the second branch circuit is connected in parallel between the anode and the cathode of the first diode D1. It will be appreciated that the second branch circuit may also be connected in parallel between the anode and the cathode of the second diode D2. Even more, a second branch circuit is connected in parallel between the anodes and cathodes of the first and second diodes D1 and D2, respectively.

Fig. 14 is a schematic structural diagram of another embodiment of the rectifying circuit of the present invention, wherein the first branch circuit includes a first switch Q1, a second switch Q2 and a resistor R1, a first end of the first switch Q1 is connected to a first end L of an AC power source AC, a first end of the second switch Q2 is connected to a second end N of the AC power source AC, a second end of the first switch Q1, a second end of the second switch Q2 and a first end of the resistor R1 are connected, and a second end of the resistor R1 is electrically connected to a cathode of the first diode D1 and a cathode of the second diode D2. The second branch circuit comprises a third switching tube Q3, a fourth switching tube Q4 and a resistor R2, the second end of the third switching tube Q3 is connected to the first end L of the alternating current power supply AC, the second end of the fourth switching tube Q4 is connected to the second end N of the alternating current power supply AC, the first end of the third switching tube Q3, the first end of the fourth switching tube Q4 and the first end of the resistor R2 are connected, and the second end of the resistor R2 is electrically connected to the anode of the third diode D3 and the anode of the fourth diode D4.

At the moment of power supply, a forward voltage is applied between L and N, the surge current flowing from the first end L of the AC power supply AC passes through the first diode D1 branch and the resistor R1, and the branch of the first switch Q1 assumes that the conduction voltage drop across the first diode D1 is VD1, the conduction voltage drop across the body diode of the first switch Q1 is VQ1, and the voltage drop across the resistor R1 is VR1, where VD1 is VR1+ VQ1, and the larger R1 is, the smaller the surge current flowing through the first switch Q1 is, and most of the surge current flows away from the first diode D1. The surge current passes through the rear-stage line, the fourth diode D4 and the resistor R2 and Q4 which are connected in series, and then returns to the second end N of the alternating current power supply AC. In principle, the surge current flowing through the fourth switching tube Q4 will be small. When the first terminal L of the AC power source AC is negative and the second terminal N of the AC power source AC is positive, at the moment of powering up, the inrush current flowing from the second terminal N of the AC power source AC passes through the branch of the second diode D2, the branch of the resistor R1 and the branch of the second switching tube Q2. Similarly, the conduction voltage drop across the second diode D2 is VD2, the conduction voltage drop across the body diode of the second switching tube Q2 is VQ2, and the voltage drop across the resistor R1 is VR1, which should be VD2 equal to VR1+ VQ2, and the larger R1 is, the smaller the surge current flowing through the second switching tube Q2 is, so that most of the surge current flows away from the second diode D2. The surge current passes through the post-stage line, then passes through the third diode D3, the resistor R2, and the branch of the third switching tube Q3, and then returns to the second end N of the AC power supply AC. In principle, the surge current flowing through the third switching tube Q3 is also small.

When the voltage waveform of the alternating current power supply AC is in a positive half cycle during normal operation, a forward voltage is between L and N, and current forms a loop through the first switch tube Q1, the resistor R1, a subsequent line, the resistor R2 and the fourth switch tube Q4. Similarly, when there is a negative voltage between L and N, current flows through the second transistor Q2, the resistor R1, the subsequent circuit, the resistor R2, and the third transistor Q3 to form a loop.

Fig. 15 is a schematic structural diagram of another embodiment of the rectifying circuit of the present invention, wherein the branch circuit includes a switch Q1 and a resistor R1, and the resistor R1 is connected in series with the body diode of the switch Q1 and then connected in parallel with the switch Q1. Wherein the branch circuit may be connected in parallel to at least one of the first diode D1, the second diode D2, the third diode D3, and the fourth diode D4. As shown in fig. 15, the branch circuit is connected in parallel to both ends of the first diode D1. It is understood that the branch circuit may be connected in parallel with two ends of any other diode, such as two ends of the second diode D2, two ends of the third diode D3, or two ends of the fourth diode D4. The branch circuit may be connected in parallel to both ends of any two diodes, or the branch circuit may be connected in parallel to both ends of three diodes. As shown in fig. 16, four branch circuits are included, each of which is connected in parallel to both ends of the first diode D1, both ends of the second diode D2, both ends of the third diode D3, and both ends of the fourth diode D4. In some embodiments, the resistor is integrated in the switching tube, and can be realized by a semiconductor manufacturing process in the production and manufacturing process of the switching tube.

To sum up, the utility model discloses a constitute the rectifier bridge with rectifier diode and MOS transistor and realize the synchronous rectification function to series resistance on the conduction path of MOS transistor, when surge current appears in the circuit start, because the voltage drop of the body diode in the MOS transistor is greater than rectifier diode's conduction voltage drop in addition the voltage drop of resistance, make most surge current flow through rectifier diode, make rectifier diode become surge current's main route of releasing, thereby ensure that less surge current flows through the MOS transistor, the problem of MOS transistor by surge current breakdown has been avoided. When the circuit works normally, the current only flows through the MOS transistor to reduce the loss by controlling the on and off of the MOS transistor, thereby improving the efficiency of the circuit. Because the difference of conduction voltage drops of a body diode and a rectifier diode of the MOS transistor is about hundreds of millivolts, and surge current is usually hundreds of amperes, the resistance of the resistor can compensate the voltage difference by only taking a small value, so that the loss of the resistor is small when the current normally works.

It should be noted that the above-mentioned embodiments illustrate only preferred embodiments of the disclosure, and the disclosure is not limited to the described embodiments, as the scope of the disclosure is determined by the claims. And that this disclosure will be modified by those skilled in the art as deemed to be within the scope and spirit of the appended claims.

Claims

1. A rectifier circuit, comprising:

the first bridge arm comprises a first diode and a third diode which are connected in series, wherein the anode of the first diode is connected with the cathode of the third diode and is coupled to the first end of an alternating current power supply;

the second bridge arm is connected with the first bridge arm in parallel and comprises a second diode and a fourth diode which are connected in series, and the anode of the second diode is connected with the cathode of the fourth diode and is coupled to the second end of the alternating current power supply; and

at least one branch circuit comprising a switch tube and a resistor connected in series, wherein the branch circuit is connected in parallel to at least one of the first diode, the second diode, the third diode and the fourth diode.

2. The rectifier circuit according to claim 1, wherein said branch circuit is connected in parallel between an anode and a cathode of said first diode.

3. The rectifier circuit according to claim 1, wherein said rectifier circuit includes two of said branch circuits connected in parallel to any two of said first diode, said second diode, said third diode, and said fourth diode, respectively.

4. The rectifier circuit according to claim 3, wherein the two branch circuits are connected in parallel between an anode and a cathode of the first diode and between an anode and a cathode of the second diode, respectively.

5. The rectifier circuit according to claim 3, wherein the two branch circuits are connected in parallel between the anode and the cathode of the first diode and between the anode and the cathode of the third diode, respectively.

6. The rectifier circuit according to claim 3, wherein the two branch circuits are connected in parallel between the anode and the cathode of the second diode and between the anode and the cathode of the third diode, respectively.

7. The rectifier circuit according to claim 1, wherein said rectifier circuit includes three of said branch circuits connected in parallel to any three of said first diode, said second diode, said third diode, and said fourth diode, respectively.

8. The rectifier circuit according to claim 7, wherein the three branch circuits are connected in parallel between the anode and the cathode of the first diode, between the anode and the cathode of the second diode, and between the anode and the cathode of the third diode, respectively.

9. The rectifier circuit according to claim 7, wherein the plurality of branch circuits are connected in parallel between an anode and a cathode of the first diode, between an anode and a cathode of the third diode, and between an anode and a cathode of the fourth diode, respectively.

10. The rectifier circuit according to claim 1, wherein said rectifier circuit includes four said branch circuits connected in parallel between an anode and a cathode of said first diode, between an anode and a cathode of said second diode, between an anode and a cathode of said third diode, and between an anode and a cathode of said fourth diode, respectively.

11. A rectifier circuit, comprising:

the first branch circuit comprises a first switch tube, a second switch tube and a first resistor, wherein the first end of the first switch tube is connected to the first end of the alternating current power supply, the first end of the second switch tube is connected to the second end of the alternating current power supply, the second end of the first switch tube, the second end of the second switch tube and the first end of the first resistor are connected, and the second end of the first resistor is electrically connected to the cathode of the first diode and the cathode of the second diode.

12. The rectifier circuit according to claim 11, wherein said rectifier circuit further comprises a second branch circuit including a third switching tube and a second resistor connected in series, said second branch circuit being connected in parallel between an anode and a cathode of said third diode or between an anode and a cathode of said fourth diode.

13. The rectifier circuit according to claim 11, further comprising a second branch circuit, wherein the second branch circuit comprises a third switching tube, a fourth switching tube and a second resistor, a second end of the third switching tube is connected to the first end of the ac power source, a second end of the fourth switching tube is connected to the second end of the ac power source, the first end of the third switching tube, the first end of the fourth switching tube and the first end of the second resistor are connected, and a second end of the second resistor is electrically connected to an anode of the third diode and an anode of the fourth diode.

14. A rectifier circuit, comprising:

the first branch circuit comprises a first switch tube, a second switch tube and a first resistor, wherein the second end of the first switch tube is connected to the first end of the alternating current power supply, the second end of the second switch tube is connected to the second end of the alternating current power supply, the first end of the first switch tube, the first end of the second switch tube and the first end of the first resistor are connected, and the second end of the first resistor is electrically connected to the anode of the third diode and the anode of the fourth diode.

15. The rectifier circuit according to claim 14, wherein said rectifier circuit further comprises a second branch circuit including a third switching tube and a second resistor connected in series, said second branch circuit being connected in parallel between an anode and a cathode of said first diode or between an anode and a cathode of said second diode.

16. The rectifier circuit according to claim 14, wherein the rectifier circuit further comprises a second branch circuit including a third switching tube, a fourth switching tube and a second resistor, a first terminal of the third switching tube is connected to the first terminal of the ac power source, a first terminal of the fourth switching tube is connected to the second terminal of the ac power source, a second terminal of the third switching tube, a second terminal of the fourth switching tube and a first terminal of the second resistor are connected, and a second terminal of the second resistor is electrically connected to the cathode of the first diode and the cathode of the second diode.

17. A rectifier circuit, comprising:

and the branch circuit comprises a switch tube and a resistor, the resistor is connected with the body diode of the switch tube in series and then connected with the switch tube in parallel, and the branch circuit is connected with at least one of the first diode, the second diode, the third diode and the fourth diode in parallel.

18. The rectifier circuit according to claim 1 or 11 or 14 or 17, wherein said switching tube is a MOS transistor.

19. The rectifier circuit according to claim 18, wherein said switching transistor is an N-channel MOS transistor.

20. The rectifier circuit according to claim 1 or 11 or 14 or 17, wherein said first diode, said second diode, said third diode, said fourth diode are independently packaged diodes.

21. The rectifier circuit according to claim 1, 11, 14 or 17, wherein said first diode, said second diode, said third diode and said fourth diode are packaged to form a rectifier bridge structure.