A bridgeless rectifier single-stage PFC circuit

Abstract

The present invention discloses a bridgeless rectifier single-stage PFC circuit, including a transformer T3, a transformer T4, a MOS tube Q3, a MOS tube Q4, a resistor R6, a diode D5, a diode D6, a resistor R7, a resistor R5, a resistor R8, a diode D7, a polar capacitor CE2, and a diode D8. The present invention provides a bridgeless rectifier single-stage PFC circuit, which effectively utilizes a MOS tube to replace a bridge rectifier, not only improves the efficiency of the power supply, reduces input loss, and enables the power supply to have a switch conversion function, and at the same time effectively reduces the overall operating temperature of the power supply, improves the reliability and service life of the power supply, and greatly promotes the development of the industry.

Description

Technical Field

[0001] The invention belongs to the field of electronic circuits, and in particular relates to a bridgeless rectifier single-stage PFC circuit. Background Art

[0002] With the rise of LED lighting products, high-power LED power supplies are widely used (such as 500W), and almost all power supplies have a large rectifier bridge stack inside. The loss of the bridge stack will reach about 1.4V each time it is turned on. When the AC input voltage is 100V, the current will reach about 5A, and the power loss is 1.4V*5A=7W. The loss is very large. How to better reduce the loss of the power supply has become the research direction in the industry.

[0003] The invention can directly remove the bridge stack and use two NMOS to replace the bridge stack rectification, so that the NMOS has the dual functions of rectification and voltage switch conversion, thereby improving power supply efficiency, reducing input loss of power supply products, reducing the overall temperature of power supply products, improving the reliability of power supply products, and increasing the life of power supply products. Summary of the invention

[0004] The purpose of the present invention is to overcome the above problems and provide a single-stage PFC circuit without bridge rectifier, which effectively utilizes MOS tubes instead of bridge rectifier, not only improving the efficiency of the power supply and reducing input loss, but also enabling the power supply to have the function of switching conversion, and at the same time effectively reducing the overall operating temperature of the power supply, improving the reliability and service life of the power supply, and greatly promoting the development of the industry.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] A bridgeless rectifier single-stage PFC circuit includes a transformer T3, a transformer T4, a MOS tube Q3, a MOS tube Q4, a resistor R6 connected in series between the S pole and the G pole of the MOS tube Q3, a diode D5 whose N pole is connected to the G pole of the MOS tube Q3 and whose P pole is connected to the 7th pin of the transformer T3, a diode D6 whose N pole is connected to the G pole of the MOS tube Q4 and whose P pole is connected to the 5th pin of the transformer T3, and a resistor R7 connected in series between the G pole and the S pole of the MOS tube Q4. , a resistor R5 with one end connected to the 4th pin of the transformer T3 and the other end connected to the D pole of the MOS tube Q4, a diode D7 with a P pole connected to the 10th pin of the transformer T4 and an N pole connected to the 8th pin of the transformer T4 through a resistor R8, a polar capacitor CE2 with a positive pole connected to the N pole of the diode D7 and a negative pole connected to the 8th pin of the transformer T4, and a diode D8 with a P pole connected to the 6th pin of the transformer T4 and an N pole connected to the N pole of the diode D7.

[0007] Preferably, the S pole of the MOS tube Q3 is connected to the 8th pin of the transformer T3, and the 1st pin of the transformer T4 is connected to the D pole of the MOS tube Q3.

[0008] Preferably, the 5th pin of the transformer T4 is connected to the D pole of the MOS tube Q4, the S pole of the MOS tube Q4 is connected to the 5th pin of the transformer T3, and the D pole of the MOS tube Q4 serves as the CS terminal of the circuit.

[0009] Preferably, the negative electrode of the polar capacitor CE2 is grounded.

[0010] Preferably, the S pole of the MOS tube Q4 is connected to the live wire, the 4th pin of the transformer T3 is connected to the neutral wire, and the 1st pin of the transformer T3 is connected to the PWM control signal.

[0011] Furthermore, a second circuit structure variation is also included, which includes a transformer T1, a transformer T2, a MOS tube Q1, a MOS tube Q2, a diode D3 whose P pole is connected to the 10th pin of the transformer T1 and whose N pole is connected to the 8th pin of the transformer T1 after passing through a resistor R4, a polar capacitor CE1 whose positive pole is connected to the N pole of the diode D3 and whose negative pole is connected to the 8th pin of the transformer T1, a diode D4 whose N pole is connected to the N pole of the diode D3 and whose P pole is connected to the 6th pin of the transformer T1, a resistor R2 connected in series between the G pole and the D pole of the MOS tube Q1, a resistor R3 connected in series between the G pole and the S pole of the MOS tube Q2, one end of which is connected to the D pole of the MOS tube Q2 and the other end is connected to the 4th pin of the transformer T2. The circuit is composed of a resistor R1 connected to the pin 1 of the transformer T1, a diode D1 whose N pole is connected to the G pole of the MOS tube Q and whose P pole is connected to the 7 pin of the transformer T2, and a diode D2 whose N pole is connected to the G pole of the MOS tube Q2 and whose P pole is connected to the 6 pin of the transformer T2; wherein, the 1 pin of the transformer T1 is connected to the live wire, the N pole of the transformer T2 is connected to the neutral wire, the 1 pin of the transformer T2 is connected to the PWM control signal, the negative pole of the polarity capacitor CE1 is grounded, the D pole of the MOS tube Q1 is connected to the 5 pin of the transformer T1, the S pole of the MOS tube Q1 is connected to the S pole of the MOS tube Q2, the D pole of the MOS tube Q2 is connected to the 5 pin of the transformer T2, and the D pole of the MOS tube Q2 serves as the CS end of the circuit.

[0012] Furthermore, a third circuit structure variation is also included, which includes a transformer T5, a transformer T6, a transformer T7, a MOS tube Q5, a MOS tube Q6, a control chip U1, a diode D11 whose P pole is connected to the 10th pin of the transformer T5 and whose N pole is connected to the 8th pin of the transformer T5 through a resistor R12, a polar capacitor CE3 whose positive pole is connected to the N pole of the diode D11 and whose negative pole is connected to the 8th pin of the transformer T5, whose N pole is connected to the N pole of the diode D11 and whose P pole is connected to the transformer T5. The diode D12 connected to the 6th pin of T5, the resistor R10 connected in series between the G pole and the D pole of the MOS tube Q5, the resistor R11 connected in series between the G pole and the S pole of the MOS tube Q6, the diode D9 connected to the G pole of the MOS tube Q5 and the P pole with the 7th pin of the transformer T6, the diode D10 connected to the G pole of the MOS tube Q6 and the P pole with the 6th pin of the transformer T6, one end of which is connected to the 3rd pin of the control chip U1 and the other end is connected to the control chip U1 The 4-pin resistor R9 of the transformer T5 is connected to the 4-pin of the transformer T7, the capacitor C4 is connected to the resistor R9 in parallel, the diode D14 is connected to the 4-pin of the control chip U1 by the N pole and the 4-pin of the transformer T7 by the P pole, and the diode D13 is connected to the N pole of the diode D14 and the P pole is connected to the 1-pin of the transformer T7 by the N pole; wherein the 1-pin of the transformer T5 is connected to the live wire, the 5-pin of the transformer T7 is connected to the neutral wire, the 1-pin of the transformer T6 is connected to the PWM control signal, and the control chip U Pin 3 of 1 serves as the CS terminal of Dina Road, the negative pole of polarity capacitor CE3 is grounded, the D pole of MOS tube Q5 is connected to the 5 pin of transformer T5 and the 8 pin of transformer T6 at the same time, the S pole of MOS tube Q5 is connected to the S pole of MOS tube Q6, the D pole of MOS tube Q6 is connected to the 8 pin of transformer T7 and the 5 pin of transformer T6 at the same time, the 1 pin of transformer T6 is connected to the 8 pin of control chip U1, and the 4 pin of transformer T6 is connected to the 5 pin of control chip U1.

[0013] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0014] The circuit structure of the present invention effectively utilizes MOS tubes to replace bridge rectifiers, which not only improves the efficiency of the power supply and reduces input loss, but also enables the power supply to have the function of switching conversion. At the same time, it also effectively reduces the overall operating temperature of the power supply, improves the reliability and service life of the power supply, and greatly promotes the development of the industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a circuit structure diagram of the present invention.

[0016] Figure 2 This is a second circuit structure diagram of the present invention.

[0017] Figure 3 This is a third circuit structure diagram of the present invention. DETAILED DESCRIPTION

[0018] The present invention will be further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto.

[0019] Example 1

[0020] like Figure 1 As shown, a bridgeless rectifier single-stage PFC circuit includes a transformer T3, a transformer T4, a MOS tube Q3, a MOS tube Q4, a resistor R6 connected in series between the S pole and the G pole of the MOS tube Q3, a diode D5 whose N pole is connected to the G pole of the MOS tube Q3 and whose P pole is connected to the 7th pin of the transformer T3, a diode D6 whose N pole is connected to the G pole of the MOS tube Q4 and whose P pole is connected to the 5th pin of the transformer T3, a resistor R6 connected in series between the G pole and the S pole of the MOS tube Q4, and a diode D7 connected in series between the G pole and the S pole of the MOS tube Q4. R7, a resistor R5 having one end connected to the 4th pin of the transformer T3 and the other end connected to the D pole of the MOS tube Q4, a diode D7 having a P pole connected to the 10th pin of the transformer T4 and an N pole connected to the 8th pin of the transformer T4 through a resistor R8, a polar capacitor CE2 having a positive pole connected to the N pole of the diode D7 and a negative pole connected to the 8th pin of the transformer T4, and a diode D8 having a P pole connected to the 6th pin of the transformer T4 and an N pole connected to the N pole of the diode D7.

[0021] The S pole of the MOS tube Q3 is connected to the 8 pin of the transformer T3, and the 1 pin of the transformer T4 is connected to the D pole of the MOS tube Q3. The 5 pin of the transformer T4 is connected to the D pole of the MOS tube Q4, and the S pole of the MOS tube Q4 is connected to the 5 pin of the transformer T3, and the D pole of the MOS tube Q4 serves as the CS end of the circuit. The negative pole of the polar capacitor CE2 is grounded. The S pole of the MOS tube Q4 is connected to the live wire, the 4 pin of the transformer T3 is connected to the neutral wire, and the 1 pin of the transformer T3 is connected to the PWM control signal.

[0022] The specific circuit principle is:

[0023] When the AC input is connected, the live line is in the positive half cycle and the neutral line is in the negative half cycle, and the body diode inside the MOS tube Q3 is turned on. The voltage is output to the D pole of the MOS tube Q4 through the MOS tube Q3 to the 1 pin and the 5 pin of the transformer T4. The MOS tube Q4 is controlled to be in the on state by the PWM control signal timing. When the MOS tube Q4 is turned on, the MOS tube Q3 is also in the on state due to the control of the timing control signal. The MOS tube Q3 is used as a synchronous rectifier device for the AC input due to the timing control. The transformer T4 generates a 1 positive and 5 negative voltage, and the secondary of the transformer T4 generates a 6 positive and 8 negative voltage. The diode D8 is turned on to charge the polarity capacitor CE2, and at the same time, it provides power to the rear load to complete the working state of the positive half cycle of the AC input live line and the negative half cycle of the neutral line.

[0024] When the AC input is connected, the neutral line is in the positive half cycle and the live line is in the negative half cycle, the body diode inside the MOS tube Q4 is turned on, and the voltage is output to the D pole of the MOS tube Q3 through the MOS tube Q4 to the 5 pins and 1 pins of the transformer T4. The MOS tube Q3 is controlled to be turned on by the PWM control signal timing, and the MOS tube Q3 is turned on. At the same time, the MOS tube Q4 is also turned on due to the control of the timing control signal. Q4 is used as a synchronous rectifier device for AC input due to the timing control. The transformer T4 generates 5 positive and 1 negative voltages, and the secondary of the transformer T4 generates 10 positive and 8 negative voltages. The diode D7 is turned on to charge the polar capacitor CE2, and at the same time, it provides power to the rear load to complete the working state of the positive half cycle of the AC input neutral line and the negative half cycle of the live line.

[0025] This circuit uses the relatively low conduction internal resistance of the NMOS tube and uses the dual role of the NMOS tube as an AC input rectifier and a voltage conversion device to reduce the input loss of the power supply, improve the efficiency of the power supply and simplify the use space.

[0026] Example 2

[0027] like Figure 2As shown, it also includes a second circuit structure variation, which includes a transformer T1, a transformer T2, a MOS tube Q1, a MOS tube Q2, a diode D3 whose P pole is connected to the 10th pin of the transformer T1 and whose N pole is connected to the 8th pin of the transformer T1 after passing through a resistor R4, a polar capacitor CE1 whose positive pole is connected to the N pole of the diode D3 and whose negative pole is connected to the 8th pin of the transformer T1, a diode D4 whose N pole is connected to the N pole of the diode D3 and whose P pole is connected to the 6th pin of the transformer T1, a resistor R2 connected in series between the G pole and the D pole of the MOS tube Q1, a resistor R3 connected in series between the G pole and the S pole of the MOS tube Q2, one end of which is connected to the D pole of the MOS tube Q2 and the other end of which is connected to the 4th pin of the transformer T2. The circuit is composed of a resistor R1 connected to each other, a diode D1 whose N pole is connected to the G pole of the MOS tube Q and whose P pole is connected to the 7 pin of the transformer T2, and a diode D2 whose N pole is connected to the G pole of the MOS tube Q2 and whose P pole is connected to the 6 pin of the transformer T2; wherein, the 1 pin of the transformer T1 is connected to the live wire, the N pole of the transformer T2 is connected to the neutral wire, the 1 pin of the transformer T2 is connected to the PWM control signal, the negative pole of the polarity capacitor CE1 is grounded, the D pole of the MOS tube Q1 is connected to the 5 pin of the transformer T1, the S pole of the MOS tube Q1 is connected to the S pole of the MOS tube Q2, the D pole of the MOS tube Q2 is connected to the 5 pin of the transformer T2, and the D pole of the MOS tube Q2 serves as the CS end of the circuit.

[0028] Example 3

[0029] like Figure 3As shown, the third circuit structure variation is also included, which includes a transformer T5, a transformer T6, a transformer T7, a MOS tube Q5, a MOS tube Q6, a control chip U1, a diode D11 whose P pole is connected to the 10th pin of the transformer T5 and whose N pole is connected to the 8th pin of the transformer T5 through a resistor R12, a polar capacitor CE3 whose positive pole is connected to the N pole of the diode D11 and whose negative pole is connected to the 8th pin of the transformer T5, whose N pole is connected to the N pole of the diode D11 and whose P pole is connected to the The diode D12 is connected to the 6 pin of the MOS tube Q5, the resistor R10 is connected in series between the G pole and the D pole of the MOS tube Q5, the resistor R11 is connected in series between the G pole and the S pole of the MOS tube Q6, the diode D9 is connected to the G pole of the MOS tube Q5 and the P pole is connected to the 7 pin of the transformer T6, the diode D10 is connected to the G pole of the MOS tube Q6 and the P pole is connected to the 6 pin of the transformer T6, one end is connected to the 3 pin of the control chip U1, and the other end is connected to the 4 pin of the control chip U1. The invention relates to a diode D14 having an N-pole connected to the 4-pin of the control chip U1 and a P-pole connected to the 4-pin of the transformer T7, and a diode D13 having an N-pole connected to the N-pole of the diode D14 and a P-pole connected to the 1-pin of the transformer T7; wherein the 1-pin of the transformer T5 is connected to the live wire, the 5-pin of the transformer T7 is connected to the neutral wire, the 1-pin of the transformer T6 is connected to the PWM control signal, and the control chip U1 is connected to the 4-pin of the control chip U1 and the P-pole is connected to the 4-pin of the transformer T7; Pin 3 of is used as the CS end of Dina Road, the negative pole of polarity capacitor CE3 is grounded, the D pole of MOS tube Q5 is connected to the 5 pin of transformer T5 and the 8 pin of transformer T6 at the same time, the S pole of MOS tube Q5 is connected to the S pole of MOS tube Q6, the D pole of MOS tube Q6 is connected to the 8 pin of transformer T7 and the 5 pin of transformer T6 at the same time, the 1 pin of transformer T6 is connected to the 8 pin of control chip U1, and the 4 pin of transformer T6 is connected to the 5 pin of control chip U1.

[0030] As described above, the present invention can be well implemented.

Claims

1. A bridgeless rectifier single-stage PFC circuit, characterized in that: It consists of a transformer T3, a transformer T4, a MOS tube Q3, a MOS tube Q4, a resistor R6 connected in series between the S pole and the G pole of the MOS tube Q3, a diode D5 whose N pole is connected to the G pole of the MOS tube Q3 and whose P pole is connected to the 7th pin of the transformer T3, a diode D6 whose N pole is connected to the G pole of the MOS tube Q4 and whose P pole is connected to the 5th pin of the transformer T3, a resistor R7 connected in series between the G pole and the S pole of the MOS tube Q4, a resistor R5 whose one end is connected to the 4th pin of the transformer T3 and whose other end is connected to the D pole of the MOS tube Q4, a diode D7 whose P pole is connected to the 10th pin of the transformer T4 and whose N pole is connected to the 8th pin of the transformer T4 via a resistor R8, a polar capacitor CE2 whose positive pole is connected to the N pole of the diode D7 and whose negative pole is connected to the 8th pin of the transformer T4, and a diode D8 whose P pole is connected to the 6th pin of the transformer T4 and whose N pole is connected to the N pole of the diode D7.

2. The bridgeless rectifier single-stage PFC circuit according to claim 1, characterized in that: The S pole of the MOS tube Q3 is connected to the 8th pin of the transformer T3, and the 1st pin of the transformer T4 is connected to the D pole of the MOS tube Q3.

3. The bridgeless rectifier single-stage PFC circuit according to claim 2, characterized in that: The 5th pin of the transformer T4 is connected to the D pole of the MOS tube Q4, the S pole of the MOS tube Q4 is connected to the 5th pin of the transformer T3, and the D pole of the MOS tube Q4 serves as the CS terminal of the circuit.

4. The bridgeless rectifier single-stage PFC circuit according to claim 3, characterized in that: The negative electrode of the polar capacitor CE2 is grounded.

5. The bridgeless rectifier single-stage PFC circuit according to claim 4, characterized in that: The S pole of the MOS tube Q4 is connected to the live wire, the 4th pin of the transformer T3 is connected to the neutral wire, and the 1st pin of the transformer T3 is connected to the PWM control signal.

6. The bridgeless rectifier single-stage PFC circuit according to claim 5, characterized in that: The second circuit structure variation is also included, which includes a transformer T1, a transformer T2, a MOS tube Q1, a MOS tube Q2, a diode D3 whose P pole is connected to the 10th pin of the transformer T1 and whose N pole is connected to the 8th pin of the transformer T1 after passing through a resistor R4, a polar capacitor CE1 whose positive pole is connected to the N pole of the diode D3 and whose negative pole is connected to the 8th pin of the transformer T1, a diode D4 whose N pole is connected to the N pole of the diode D3 and whose P pole is connected to the 6th pin of the transformer T1, a resistor R2 connected in series between the G pole and the D pole of the MOS tube Q1, a resistor R3 connected in series between the G pole and the S pole of the MOS tube Q2, one end of which is connected to the D pole of the MOS tube Q2 and the other end of which is connected to the 4th pin of the transformer T2. The circuit is composed of a resistor R1 connected to a MOS tube Q, a diode D1 whose N pole is connected to the G pole of the MOS tube Q and whose P pole is connected to the 7 pin of the transformer T2, and a diode D2 whose N pole is connected to the G pole of the MOS tube Q2 and whose P pole is connected to the 6 pin of the transformer T2; wherein, the 1 pin of the transformer T1 is connected to the live wire, the N pole of the transformer T2 is connected to the neutral wire, the 1 pin of the transformer T2 is connected to the PWM control signal, the negative pole of the polarity capacitor CE1 is grounded, the D pole of the MOS tube Q1 is connected to the 5 pin of the transformer T1, the S pole of the MOS tube Q1 is connected to the S pole of the MOS tube Q2, the D pole of the MOS tube Q2 is connected to the 5 pin of the transformer T2, and the D pole of the MOS tube Q2 serves as the CS end of the circuit.

7. The bridgeless rectifier single-stage PFC circuit according to claim 5, characterized in that: The third circuit structure variation is also included, which includes a transformer T5, a transformer T6, a transformer T7, a MOS tube Q5, a MOS tube Q6, a control chip U1, a diode D11 whose P pole is connected to the 10th pin of the transformer T5 and whose N pole is connected to the 8th pin of the transformer T5 through a resistor R12, a polar capacitor CE3 whose positive pole is connected to the N pole of the diode D11 and whose negative pole is connected to the 8th pin of the transformer T5, whose N pole is connected to the N pole of the diode D11 and whose P pole is connected to the 6th pin of the transformer T5. The diode D12 is connected to the G pole and the D pole of the MOS tube Q5, the resistor R10 is connected in series between the G pole and the S pole of the MOS tube Q6, the diode D9 is connected to the G pole of the MOS tube Q5 and the P pole is connected to the 7 pin of the transformer T6, the diode D10 is connected to the G pole of the MOS tube Q6 and the P pole is connected to the 6 pin of the transformer T6, one end of the diode D10 is connected to the 3 pin of the control chip U1 and the other end is connected to the 4 pin of the control chip U1. The invention comprises a resistor R9 connected to the pin 4 of the control chip U1, a capacitor C4 arranged in parallel with the resistor R9, a diode D14 whose N pole is connected to the pin 4 of the control chip U1 and whose P pole is connected to the pin 4 of the transformer T7, and a diode D13 whose N pole is connected to the N pole of the diode D14 and whose P pole is connected to the pin 1 of the transformer T7; wherein, the pin 1 of the transformer T5 is connected to the live wire, the pin 5 of the transformer T7 is connected to the neutral wire, the pin 1 of the transformer T6 is connected to the PWM control signal, and the control chip U1 Pin 3 of is used as the CS end of Dina Road, the negative pole of polarity capacitor CE3 is grounded, the D pole of MOS tube Q5 is connected to the 5 pin of transformer T5 and the 8 pin of transformer T6 at the same time, the S pole of MOS tube Q5 is connected to the S pole of MOS tube Q6, the D pole of MOS tube Q6 is connected to the 8 pin of transformer T7 and the 5 pin of transformer T6 at the same time, the 1 pin of transformer T6 is connected to the 8 pin of control chip U1, and the 4 pin of transformer T6 is connected to the 5 pin of control chip U1.

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