Bridge rectifier capable of reducing heat with low break-over voltage

Abstract

The utility model discloses a bridge rectifier capable of reducing heat with low break-over voltage, which reduces the break-over voltage through two N-channel metal oxide semiconductor (NMOS) tubes connected to a cathode output end of a direct current output end of a basic bridge rectifier. According to the bridge rectifier capable of reducing heat with low conduction voltage provided by the embodiment of the utility model, the control signal of the NMOS tube is realized through circuit design processing, and then the whole circuit is designed and packaged in a bridge rectifier packaging structure which is standard in the industry, so that a user can reduce heat with low conduction voltage by adopting the bridge rectifier capable of reducing heat with low conduction voltage provided by the embodiment of the utility model. The external dimension after packaging is the same as the packaging dimension of an original basic bridge rectifier, a mechanical structure does not need to be changed, the packaging dimension can directly replace the original basic bridge rectifier, the scheme is rapid and simple, generated heat is reduced through the NMOS tubes, the heat dissipation problem does not need to be considered, the temperature of a whole circuit is reduced, and the service life of the whole circuit is prolonged. The reliability of the bridge rectifier is improved, and the temperature of the electrolytic capacitor which needs to be connected frequently behind the bridge rectifier is also reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of rectifier electronic circuits, in particular to a bridge stack which reduces heat generation by using a low conduction voltage. Background Art

[0002] The electricity generated by the power company is delivered to the end user in the form of AC, but most electrical products require DC power, so a rectifier is needed to rectify the AC power into DC power. In the existing method, because diodes are very cheap, there are one diode, two diodes and four diodes for rectification. The most common method is to use a bridge stack composed of four diodes for rectification. This bridge stack composed of four diodes is called a full-bridge rectifier bridge stack in the industry.

[0003] Diodes are divided into silicon diodes, germanium diodes and Schottky diodes. The conduction voltage of silicon diodes is 0.6 to 0.8 volts, that of germanium diodes is 0.2 to 0.4 volts, and that of Schottky diodes is about 0.4 volts. When the power supply current is large, the current multiplied by the conduction voltage is the wattage. The wattage caused by large current is very high. It is not just the power consumption, but the bigger problem is the generation of a lot of heat. If this heat cannot be dissipated, it will cause a very high temperature, resulting in low reliability. It will not only burn the bridge stack directly, but also cause the electrolytic capacitor next to the bridge stack to fail prematurely due to long-term high temperature. In particular, many waterproof products need to conduct the internal high heat to the outside world. The design and implementation of this heat conduction system is a very difficult problem. Therefore, how to reduce the conduction voltage on the diode in the bridge stack to reduce the heat generated by large current is an issue that the industry attaches great importance to.

[0004] Another rectification method in the industry is synchronous rectification, which is to replace the diode with a MOS tube, and use the characteristics of the MOS tube's on-resistance at the milliohm level to reduce the on-voltage to reduce the on-wattage and reduce the heat generated. For example, with an input power of 220W and an input current of 1A at 220Vac, the voltage drop on a 20 milliohm MOS tube is only 0.02V, 1A*0.02V=20mW, which is 20 milliwatts. If it is a normal bridge stack, the diode's on-voltage is generally as high as 1V, which is 1W. Therefore, compared with the diode, the heat generated by the MOS tube will not get hot at all. The synchronous rectification method is to use a control signal to control the MOS tube. When the replaced diode is turned on, the MOS tube is controlled to be turned on, and when the replaced diode is turned off, the MOS tube is controlled to be turned off. However, the actual implementation of this rectification method requires circuit design, which not only detects the voltage of the AC input power supply, but also generates a signal to trigger the gate of the MOS tube. The detected zero point is used to synchronously generate the required conduction control signal or shutdown control signal. Many parts are needed to make a PCB circuit board, and the installation problem must be considered at the same time. Even for experienced electronic engineers, it still takes some time to find materials and do experiments, etc., and how to install it on the product, or how to increase the circuit area on the original PCB, it may be necessary to change the original shell of the product, at least the PCB needs to be enlarged, and the installation structure and the space that can accommodate the control circuit that generates the trigger control MOS tube need to be redesigned. In addition to adding many complex problems during the design implementation, it may be necessary to reopen the mold of the finished product, which is time-consuming and costly.

[0005] Therefore, how to allow circuit designers to simply obtain a bridge stack with a lower on-state voltage without changing the structure of the finished product to reduce the heat generated by rectification has become the goal and expectation of many circuit design engineers. Utility Model Content

[0006] The embodiment of the utility model provides a bridge stack that reduces heat generation with a low conduction voltage, which solves the problem that the existing bridge stack has a complex design and the service life of the circuit is shortened due to temperature reasons due to high heat generated by rectification.

[0007] The utility model provides a bridge stack for reducing heat generation with a low conduction voltage, including a bridge stack packaging shell and a PCB structure. The bridge stack packaging shell includes a shell structure and four pin terminals. The four pin terminals include an AC-L input terminal, an AC-N input terminal, a DC positive output terminal and a DC negative output terminal. The PCB structure includes a basic bridge stack and a control signal generating module. The basic bridge stack includes two rectifier diodes D1 and D2, and two NMOS tubes Q1 and Q2. The basic bridge stack also includes an AC power input terminal, and the AC power input terminal includes The basic bridge stack further comprises a live input terminal connected to the AC-L input terminal, and a neutral input terminal connected to the AC-N input terminal. The basic bridge stack further comprises two DC output terminals, namely a positive output terminal and a negative output terminal. The PCB structure is sealed inside the bridge stack package shell. The N poles of the two rectifier diodes are connected to the positive output terminal. The P pole of D1 of the two rectifier diodes is connected to the live input terminal. The P pole of D2 of the two rectifier diodes is connected to the neutral input terminal. The drain of Q1 of the two NMOS tubes is connected to the live input terminal. The drain of Q2 of the two NMOS tubes is connected to the neutral line input terminal, the control signal generating module is connected to the live line input terminal, the neutral line input terminal, the cathode output terminal, the gates of Q1 and Q2, and when the voltage of the live line input terminal is higher than the voltage of the neutral line input terminal in the first half cycle of the AC power input, the control signal generating module generates a high voltage signal at the gate of Q2 to control Q2 to turn on, and generates a low voltage signal at the gate of Q1 to control Q1 to turn off, so that the current flows from the AC-L input terminal through the The D1 and Q2 flow to the AC-N input terminal to complete the conduction loop of the first half cycle of the AC power input. When the voltage of the neutral line input terminal is higher than the voltage of the live line input terminal in the second half cycle of the AC power input, the control signal generating module generates a high voltage signal at the gate of Q1 to control Q1 to turn on, and generates a low voltage signal at the gate of Q2 to control Q2 to turn off, so that the current flows from the AC-N input terminal to the AC-L input terminal through the D2 and Q1 to complete the conduction loop of the second half cycle of the AC power input.

[0008] Optionally, the control signal generating module includes two resistor voltage-dividing circuits, namely, a first resistor voltage-dividing circuit connected between the live input terminal and the negative output terminal, and a second resistor voltage-dividing circuit connected between the neutral input terminal and the negative output terminal. The first resistor voltage-dividing circuit includes three first voltage-dividing resistors connected in series. Among the three first voltage-dividing resistors, the first voltage-dividing resistor connected to the negative output terminal is connected in parallel with the gate to source of Q2. When the voltage of the live input terminal is higher than the voltage of the neutral input terminal, the voltage difference between the live input terminal and the neutral input terminal is divided on the first voltage-dividing resistor connected to the negative output terminal to become the Vgs of Q2. The Vgs of Q2 is the voltage of the gate of Q2 relative to the source, so that the conduction of Q2 is controlled by this voltage division. The second resistor voltage-dividing loop includes three second voltage-dividing resistors connected in series, the second voltage-dividing resistor connected to the negative output terminal among the three second voltage-dividing resistors is connected in parallel with the gate to source of Q1, when the voltage-dividing control on the first voltage-dividing resistor controls Q2 to be turned on, the voltage-dividing control on the second voltage-dividing resistor controls Q1 to be turned off, when the voltage at the neutral line input terminal is higher than the voltage at the live line input terminal, the voltage-dividing control on the second voltage-dividing resistor connected to the negative output terminal from the voltage difference at the neutral line input terminal to the live line input terminal becomes the Vgs of Q1, and the Vgs of Q1 is the voltage of the gate of Q1 relative to the source, so that the conduction of Q1 is controlled by this voltage-dividing control, when the voltage-dividing control on the second voltage-dividing resistor controls Q1 to be turned on, the voltage-dividing control on the first voltage-dividing resistor controls Q2 to be turned off.

[0009] Optionally, the control signal generating module includes two clamping diodes, which are respectively arranged in the two resistance voltage-dividing circuits. The first clamping diode of the two clamping diodes is connected in parallel with the first voltage-dividing resistor connected to the negative output terminal in the first resistance voltage-dividing circuit. When the voltage of the live wire input terminal is higher than that of the neutral wire input terminal, the clamping protection is started to reduce the Vgs voltage value of Q2. The second clamping diode of the two clamping diodes is connected in parallel with the second voltage-dividing resistor connected to the negative output terminal in the second resistance voltage-dividing circuit. When the voltage of the neutral wire input terminal is higher than that of the live wire input terminal, the clamping protection is started to reduce the Vgs voltage value of Q1.

[0010] Optionally, it further includes a diode D3 and a diode D4, wherein the diode D3 is connected in parallel with the middle first voltage-dividing resistor among the three first voltage-dividing resistors connected in series, and the diode D4 is connected in parallel with the middle second voltage-dividing resistor among the three second voltage-dividing resistors connected in series;

[0011] When the voltage of the live input terminal is higher than the voltage of the neutral input terminal, the current will flow to the gate of Q2 through the diode D3, turning on Q2; when the voltage of the live input terminal is lower than the voltage of the neutral input terminal, the diode D3 will prevent the current from flowing from the gate of Q2 to the live input terminal to avoid reverse current;

[0012] When the voltage of the neutral line input terminal is higher than the voltage of the live line input terminal, the current will flow to the gate of Q1 through the diode D4, turning on Q1; when the voltage of the neutral line input terminal is lower than the voltage of the live line input terminal, the diode D4 will prevent the current from flowing from the gate of Q1 to the neutral line input terminal to avoid reverse current.

[0013] The utility model provides a bridge stack for reducing heat generation with a low conduction voltage, including a bridge stack packaging shell and a PCB structure. The bridge stack packaging shell includes a shell structure and four pin terminals. The four pin terminals include an AC-L input terminal, an AC-N input terminal, a DC positive output terminal and a DC negative output terminal. The PCB structure includes a basic bridge stack and a control signal generating module. The basic bridge stack includes two rectifier diodes D1 and D2, and two NMOS tubes Q1 and Q2. The basic bridge stack also includes an AC power input terminal, and the AC power input terminal includes The basic bridge stack further comprises a live input terminal connected to the AC-L input terminal, and a neutral input terminal connected to the AC-N input terminal. The basic bridge stack further comprises two DC output terminals, namely a positive output terminal and a negative output terminal. The PCB structure is sealed inside the bridge stack package shell. The N poles of the two rectifier diodes are connected to the positive output terminal. The P pole of D1 of the two rectifier diodes is connected to the live input terminal. The P pole of D2 of the two rectifier diodes is connected to the neutral input terminal. The drain of Q1 of the two NMOS tubes is connected to the live input terminal. The drain of Q2 of the two NMOS tubes is connected to the neutral line input terminal, the control signal generating module is connected to the live line input terminal, the neutral line input terminal, the cathode output terminal, the gates of Q1 and Q2, and when the voltage of the live line input terminal is higher than the voltage of the neutral line input terminal in the first half cycle of the AC power input, the control signal generating module generates a high voltage signal at the gate of Q2 to control Q2 to turn on, and generates a low voltage signal at the gate of Q1 to control Q1 to turn off, so that the current flows from the AC-L input terminal through the The D1 and Q2 flow to the AC-N input terminal to complete the conduction loop of the first half cycle of the AC power input. When the voltage of the neutral line input terminal is higher than the voltage of the live line input terminal in the second half cycle of the AC power input, the control signal generating module generates a high voltage signal at the gate of Q1 to control Q1 to conduct, and generates a low voltage signal at the gate of Q2 to control Q2 to disconnect, so that the current flows from the AC-N input terminal through the D2 and Q1 to the AC-L input terminal to complete the conduction loop of the second half cycle of the AC power input. The bridge stack provided by the utility model reduces heat generation with low conduction voltage, and reduces the conduction voltage by connecting two NMOS tubes at the negative output terminal of the DC output terminal of the basic bridge stack.The bridge stack with low on-voltage to reduce heat provided by the embodiment of the utility model does not need to provide an external control signal for turning on or off the NMOS tube, but uses the AC power input of the basic bridge stack, and is processed by circuit design to realize the control signal of the NMOS tube, and then the entire circuit design is packaged in an industry-standard bridge stack packaging structure. For users, by adopting the bridge stack with low on-voltage to reduce heat provided by the embodiment of the utility model, the packaged appearance size is the same as the packaging size of the original basic bridge stack, and there is no need to change the mechanical structure. It is a fast and simple solution that can directly replace the original basic bridge stack in terms of packaging size. The heat generated is reduced by the NMOS tube, and not only does it not need to consider the heat dissipation problem, but it also reduces the temperature of the overall circuit, which not only improves the reliability of the bridge stack itself, but also reduces the temperature of the electrolytic capacitor that often needs to be connected behind the bridge stack. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A schematic diagram of the main principle of a bridge stack for reducing heat generation with a low conduction voltage provided by an embodiment of the utility model;

[0015] Figure 2 A schematic diagram of current flow when the AC-L input in the bridge stack is higher than the AC-N input provided by an embodiment of the utility model;

[0016] Figure 3 A schematic diagram of current flow when the AC-N input is higher than the AC-L input in the bridge stack provided by an embodiment of the utility model;

[0017] Figure 4 Another schematic diagram of the principle structure of a bridge stack for reducing heat generation with a low on-voltage is provided in an embodiment of the present application. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0019] The embodiment of the utility model provides a bridge stack for reducing heat generation with low conduction voltage, including a bridge stack packaging shell and a PCB structure, wherein the bridge stack packaging shell includes a shell structure and four pin terminals, wherein the four pin terminals include an AC-L input terminal, an AC-N input terminal, a DC positive output terminal and a DC negative output terminal, wherein the PCB structure includes a basic bridge stack and a control signal generating module, wherein the basic bridge stack includes two rectifier diodes D1 and D2, and two NMOS tubes Q1 and Q2, wherein the basic bridge stack also includes an AC power input terminal, wherein the AC power input terminal includes The basic bridge stack further comprises a live input terminal connected to the AC-L input terminal, and a neutral input terminal connected to the AC-N input terminal. The basic bridge stack further comprises two DC output terminals, namely a positive output terminal and a negative output terminal. The PCB structure is sealed inside the bridge stack package shell. The N poles of the two rectifier diodes are connected to the positive output terminal. The P pole of D1 of the two rectifier diodes is connected to the live input terminal. The P pole of D2 of the two rectifier diodes is connected to the neutral input terminal. The drain of Q1 of the two NMOS tubes is connected to the live input terminal. The drain of Q2 of the two NMOS tubes is connected to the neutral line input terminal, the control signal generating module is connected to the live line input terminal, the neutral line input terminal, the cathode output terminal, the gates of Q1 and Q2, and when the voltage of the live line input terminal is higher than the voltage of the neutral line input terminal in the first half cycle of the AC power input, the control signal generating module generates a high voltage signal at the gate of Q2 to control Q2 to turn on, and generates a low voltage signal at the gate of Q1 to control Q1 to turn off, so that the current flows from the AC-L input terminal through the The D1 and Q2 flow to the AC-N input terminal to complete the conduction loop of the first half cycle of the AC power input. When the voltage of the neutral line input terminal is higher than the voltage of the live line input terminal in the second half cycle of the AC power input, the control signal generating module generates a high voltage signal at the gate of Q1 to control Q1 to turn on, and generates a low voltage signal at the gate of Q2 to control Q2 to turn off, so that the current flows from the AC-N input terminal to the AC-L input terminal through the D2 and Q1 to complete the conduction loop of the second half cycle of the AC power input.

[0020] The basic bridge stack includes an AC power input terminal (AC power input), which are a live wire input terminal (AC-L input) and a neutral wire input terminal (AC-N input), and also includes two DC output terminals (DC output), which are a positive output terminal (DC positive output) and a negative output terminal (DC negative output). The embodiment of the utility model provides a bridge stack with low conduction voltage to reduce heat generation, which is achieved by connecting two NMOS tubes at the negative output terminal of the DC output terminal of the basic bridge stack to reduce the conduction voltage. The bridge stack with low on-voltage to reduce heat provided by the embodiment of the utility model does not need to provide an external control signal for turning on or off the NMOS tube, but uses the AC power input of the basic bridge stack, and is processed by circuit design to realize the control signal of the NMOS tube, and then the entire circuit design is packaged in an industry-standard bridge stack packaging structure. For users, by adopting the bridge stack with low on-voltage to reduce heat provided by the embodiment of the utility model, the packaged appearance size is the same as the packaging size of the original basic bridge stack, and there is no need to change the mechanical structure. It is a fast and simple solution that can directly replace the original basic bridge stack in terms of packaging size. The heat generated is reduced by the NMOS tube, and not only does it not need to consider the heat dissipation problem, but it also reduces the temperature of the overall circuit, which not only improves the reliability of the bridge stack itself, but also reduces the temperature of the electrolytic capacitor that often needs to be connected behind the bridge stack. In the field of power engineering technology, the problem that power engineers are troubled by is that the life of a power supply is basically limited by the life of the electrolytic capacitor, and the life of the electrolytic capacitor is halved every time the temperature of the electrolytic capacitor rises by 10 degrees, and even very expensive high-temperature electrolytic capacitors can only last up to 105°C. Therefore, by adopting a bridge stack with low on-voltage and reduced heat provided by the utility model, the temperature of the electrolytic capacitor is reduced, the reliability of the power supply engineering can be improved, and the service life of the power supply can be extended.

[0021] Optionally, the control signal generating module includes two resistor voltage-dividing circuits, namely, a first resistor voltage-dividing circuit connected between the live input terminal and the negative output terminal, and a second resistor voltage-dividing circuit connected between the neutral input terminal and the negative output terminal, the first resistor voltage-dividing circuit includes three first voltage-dividing resistors connected in series, the first voltage-dividing resistor connected to the negative output terminal among the three first voltage-dividing resistors is connected in parallel with the gate to source of Q2, when the voltage of the live input terminal is higher than the voltage of the neutral input terminal, the voltage difference between the live input terminal and the neutral input terminal is divided on the first voltage-dividing resistor connected to the negative output terminal to become the voltage of Q 2, the Vgs of Q2 is the voltage of the gate of Q2 relative to the source, and the conduction of Q2 is controlled by voltage division. The second resistor voltage division loop includes three second voltage division resistors connected in series, and the second voltage division resistor connected to the negative output terminal among the three second voltage division resistors is connected in parallel with the gate to source of Q1. When the voltage of the neutral line input terminal is higher than the voltage of the live line input terminal, the voltage difference from the neutral line input terminal to the live line input terminal is divided on the second voltage division resistor connected to the negative output terminal to become the Vgs of Q1. The Vgs of Q1 is the voltage of the gate of Q1 relative to the source, and the conduction of Q1 is controlled by voltage division.

[0022] Optionally, the control signal generating module includes two clamping diodes, which are respectively arranged in the two resistance voltage-dividing circuits. The first clamping diode of the two clamping diodes is connected in parallel with the first voltage-dividing resistor connected to the negative output terminal in the first resistance voltage-dividing circuit. When the voltage of the live wire input terminal is higher than that of the neutral wire input terminal, the clamping protection is started to reduce the Vgs voltage value of Q2. The second clamping diode of the two clamping diodes is connected in parallel with the second voltage-dividing resistor connected to the negative output terminal in the second resistance voltage-dividing circuit. When the voltage of the neutral wire input terminal is higher than that of the live wire input terminal, the clamping protection is started to reduce the Vgs voltage value of Q1.

[0023] Optionally, it further includes a diode D3 and a diode D4, wherein the diode D3 is connected in parallel with the middle first voltage-dividing resistor among the three first voltage-dividing resistors connected in series, and the diode D4 is connected in parallel with the middle second voltage-dividing resistor among the three second voltage-dividing resistors connected in series;

[0024] When the voltage of the live input terminal is higher than the voltage of the neutral input terminal, the current will flow to the gate of Q2 through the diode D3, turning on Q2; when the voltage of the live input terminal is lower than the voltage of the neutral input terminal, the diode D3 will prevent the current from flowing from the gate of Q2 to the live input terminal to avoid reverse current;

[0025] When the voltage of the neutral line input terminal is higher than the voltage of the live line input terminal, the current will flow to the gate of Q1 through the diode D4, turning on Q1; when the voltage of the neutral line input terminal is lower than the voltage of the live line input terminal, the diode D4 will prevent the current from flowing from the gate of Q1 to the neutral line input terminal to avoid reverse current.

[0026] See also Figure 1 , Figure 1 A schematic diagram of the main principle of a bridge stack for reducing heat generation with a low conduction voltage provided by an embodiment of the utility model is shown as follows: Figure 1 As shown, specifically, it includes a rectifier diode D1 and a rectifier diode D2, an NMOS tube Q1 and an NMOS tube Q2, the N poles of the rectifier diode D1 and the rectifier diode D2 are connected to the DC positive output, the P pole of the rectifier diode D1 is connected to the AC-L input, the P pole of the rectifier diode D2 is connected to the AC-N input, the drain of the NMOS tube Q1 of the two NMOS tubes is connected to the AC-L input, and the drain of the NMOS tube Q2 of the two NMOS tubes is connected to the AC-N input.

[0027] In this embodiment, each cycle of the AC input mains power 50Hz / 220Vac is divided into an upper half cycle and an off-duty cycle. When the AC-L input is higher than the AC-N input in the upper half cycle, the current flows as follows Figure 2 As shown, when the AC-L input is higher than the AC-N input, the body diodes of D1 and Q2 are turned on, while the body diodes of D2 and Q1 are in the off state. This means that the control effect can be achieved without controlling the NMOS tubes Q1 and Q2, that is, the body diodes of the two NMOS tubes are sufficient to achieve the rectification effect. This means that even if the control signal fails or the NMOS tube is burned out and damaged, the bridge stack provided by the embodiment of the utility model that reduces heat generation with a low on-state voltage can still provide a normal bridge stack rectification function, but does not achieve the effect of reducing the on-state voltage.

[0028] To achieve the effect of reducing the on-state voltage, a control signal must be provided when the AC-L input is higher than the AC-N input. Figure 2 To control the NMOS tube current (the thick black line indicates the current flow direction) to flow in the direction of the arrow, a high potential control voltage is provided to the gate of Q2 to turn on Q2, and a low potential control voltage is provided to the gate of Q1 to turn off Q1.

[0029] When the AC-N input is higher than the AC-L input in the second half cycle, the current flows as Figure 3The thick black line and thick dotted line shown are the effects that can be achieved without additional control signals because when the AC-N input is higher than the AC-L input, the body diodes of D2 and Q1 are turned on, and the body diodes of D1 and Q2 are turned off, that is, the rectification effect is achieved by using the body diode of the NMOS tube, which means that even if the MOS tube control signal fails or the MOS tube is burned out and damaged, the bridge stack provided by the embodiment of the utility model for reducing heat with a low on-voltage can still provide normal bridge stack functions, but the effect of reducing the on-voltage is not achieved.

[0030] To achieve the effect of reducing the on-state voltage, a control signal must be provided when the AC-N input is higher than the AC-L input. Figure 3 To control the MOS tube current (the thick black line and the thick dotted line indicate the current flow direction) to flow in the direction of the arrow, a high potential control voltage is provided to the gate of Q1 to turn on Q1, and a low potential control voltage is provided to the gate of Q2 to turn off Q2.

[0031] See also Figure 4 ,like Figure 4 As shown, Figure 4 Another schematic diagram of the bridge stack principle structure for reducing heat generation with low conduction voltage provided in the embodiment of the present application is as follows: Figure 4 As shown, Figure 4 Except Figure 1 , Figure 2 and Figure 3 The D1, D2, Q1, Q2 in the bridge stack shown in the figure that uses a low on-voltage to reduce heat generation have added a control signal generating module, that is, components other than D1, D2, Q1, Q2, which are used to generate a trigger from the AC power input signal to control the two NMOS tubes to turn on or off. These added components constitute the control signal generating module.

[0032] In the specific implementation, a PCB structure is made inside the bridge stack package shell. Figure 1 The two rectifier diodes D1 and D2, the two NMOS tubes Q1 and Q2, and the control signal generating module described above are placed on this PCB structure, such as Figure 4 As shown, the N poles of the two rectifier diodes D1 and D2 are connected to the DC positive output, the P pole of D1 of the two rectifier diodes is connected to the AC-L input, the P pole of D2 of the two rectifier diodes is connected to the AC-N input, the drain of Q1 of the two NMOS tubes is connected to the AC-L input, the drain of Q2 is connected to the AC-N input, and the control signal generating module is connected to the AC-L input, AC-N input, DC negative output, and the gates of Q1 and Q2.

[0033] R1, R3, and R6 are connected in series to form a first resistor voltage-dividing circuit, wherein R6 is the first voltage-dividing resistor connected to the negative output terminal among the three first voltage-dividing resistors, and R2, R4, and R5 are connected in series to form a second resistor voltage-dividing circuit, wherein R5 is the second voltage-dividing resistor connected to the negative output terminal among the three second voltage-dividing resistors.

[0034] First, explain how the control signal generation module works when the AC-L input is higher than the AC-N input. Figure 2 The MOS tube is controlled to allow the thick black line current to flow in the direction of the arrow, which is to provide a high potential control voltage to the gate of Q2 to turn on Q2, and provide a low potential control voltage to the gate of Q1 to turn off Q1:

[0035] When AC-L is higher than AC-N, R1, R3, R6 and the body diode of Q2 become a conduction loop, and the voltage difference between AC-L and AC-N is divided by the voltage of (R1+R3), R6 and the body diode of Q2, and V_R6 (the voltage of resistor R6) becomes the Vgs of Q2 (Vgs is the voltage of the gate of NMOS tube Q2 relative to the source), thereby realizing the conduction control of Q2. D8 is the first clamping diode, which plays a clamping protection role in this process, ensuring that the Vgs voltage value of Q2 will not be too high and burn Q2, thereby providing effective protection for Q2. When Q2 is turned on, the AC-N input and the DC negative output are only Q2's Rds_on, which is a milliohm-level resistor. Usually, an NMOS tube with an Rds_on below 400 milliohms can be selected. It is best to use a gallium nitride switch tube with a higher VDS voltage. In this way, a higher surge voltage can be ensured to avoid the switch tube from being broken down. Basically, the voltages of AC-N input and DC negative output are almost the same, which greatly reduces the on-state voltage of the bridge stack. AC-N input is equivalent to directly becoming the GND of the DC power supply. At the same time, the AC-L input current is rectified by D1 and connected to the DC positive output, becoming the positive voltage of the DC power supply.

[0036] Secondly, it is explained that when the AC-N input is higher than the AC-L input, the control signal generation module follows Figure 3 The control MOS tube allows the thick black line current to flow in the direction of the arrow, provides a high potential control voltage to the gate of Q1 to turn on Q1, and provides a low potential control voltage to the gate of Q2 to turn off Q2:

[0037] When AC-N is higher than AC-L, R2, R4, R5 and the body diode of Q1 become a conduction loop, and the voltage difference between AC-N and AC-L is divided by the voltage of (R2+R4), R5 and the body diode of Q1, and V_R5 (the voltage of resistor R5) becomes the Vgs of Q1 (Vgs is the voltage of the gate of the NMOS tube relative to the source), thereby realizing the conduction control of Q1. D7 is the second clamping diode, which plays a clamping protection role in this process to ensure that the Vgs voltage value of Q1 will not be too high and burn Q1, thereby providing effective protection for Q1. When Q1 is turned on, the AC-L and DC negative outputs are only Q1's Rds_on, which is a milliohm-level resistor. Usually, an NMOS tube with an Rds_on below 400 milliohms can be selected. It is best to use a gallium nitride switch tube with a higher VDS voltage. In this way, a higher surge voltage can be ensured to prevent the switch tube from being broken down. Basically, the voltages of AC-L and DC negative output are almost the same, which greatly reduces the on-state voltage of the bridge stack. AC-L is directly equivalent to the GND of the DC power supply. At the same time, the AC-N current is connected to the DC positive output after being rectified by D2, becoming the positive voltage of the DC power supply.

[0038] When the AC-L input is higher than the AC-N input, the current will flow to the gate of Q2 through the D3 diode, turning Q2 on. When the AC-L input is lower than the AC-N input, the diode D3 will prevent the current from flowing from the gate of Q2 to the AC-L terminal, thus avoiding the generation of reverse current.

[0039] Reverse current may cause damage to the circuit, such as damaging the chip or MOS tube. By adding diode D3, the generation of reverse current can be effectively prevented, and the reliability and stability of the circuit can be improved.

[0040] In addition, diode D3 can also protect the chip. In some cases, the gate level of Q2 may be affected by electrostatic discharge or other interference, resulting in excessive voltage. Diode D3 can limit the excessive voltage to a certain range, thereby protecting it from damage.

[0041] When the AC-N input is higher than the AC-L input, the current will flow to the gate of Q1 through the diode D4, turning Q1 on. When AC-N is lower than AC-L, the D4 diode will prevent the current from flowing from the gate of Q1MOS to the AC-N terminal, thus avoiding the generation of reverse current.

[0042] Reverse current may cause damage to the circuit, such as damaging the chip or MOS tube. By adding diode D4, the generation of reverse current can be effectively prevented, and the reliability and stability of the circuit can be improved.

[0043] In addition, the diode can also protect the chip. In some cases, the gate level of Q1 may be affected by electrostatic discharge or other interference, resulting in excessive voltage. The diode can limit the excessive voltage to a certain range, thereby protecting it from damage.

[0044] The manufactured PCB can be placed in a standard bridge stack package, and the AC input pin and DC output pin of the bridge stack package are welded to the PCB, and then the outer shell is sealed by heat pressing. Therefore, the appearance and actual mechanical dimensions are exactly the same as the original traditional bridge stack. The user does not need to include a PCB structure in the bridge stack. When using it, it can be welded to the PCB according to the general plug-in component operation, and it will not affect the original structural design of the finished product at all. When it is replaced with a bridge stack that reduces heat with a low conduction voltage provided by an embodiment of the utility model, it can be directly replaced without changing the mechanical or electronic circuit design of the finished product.

[0045] Finally, it should be noted that the above description is only a preferred embodiment of the utility model and is not intended to limit the utility model. Although the utility model is described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions recorded in the above embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A bridge stack with low on-voltage to reduce heat generation, comprising a bridge stack packaging housing, characterized in that: It also includes a PCB structure. The bridge stack package shell includes a shell structure and four pin terminals. The four pin terminals include an AC-L input terminal, an AC-N input terminal, a DC positive output terminal and a DC negative output terminal. The PCB structure includes a basic bridge stack and a control signal generating module. The basic bridge stack includes two rectifier diodes D1 and D2, and two NMOS tubes Q1 and Q2. The basic bridge stack also includes an AC power input terminal, and the AC power input terminal includes a live input terminal connected to the AC-L input terminal and a neutral input terminal connected to the AC-N input terminal. The basic bridge stack also includes two DC output terminals, which are a positive output terminal and a negative output terminal. The PCB structure is sealed inside the bridge stack package shell. The N poles of the two rectifier diodes are connected to the positive output terminal, the P pole of D1 of the two rectifier diodes is connected to the live input terminal, the P pole of D2 of the two rectifier diodes is connected to the neutral input terminal, the drain of Q1 of the two NMOS tubes is connected to the live input terminal, and the drain of Q2 of the two NMOS tubes is connected to the negative output terminal. The drain of Q2 is connected to the neutral line input terminal, the control signal generating module is connected to the live line input terminal, the neutral line input terminal, the negative electrode output terminal, the gates of Q1 and Q2, and when the voltage of the live line input terminal is higher than the voltage of the neutral line input terminal in the first half cycle of the AC power input, the control signal generating module generates a high voltage signal at the gate of Q2 to control Q2 to turn on, and generates a low voltage signal at the gate of Q1 to control Q1 to turn off, so that the current flows from the AC-L input terminal through D1 and Q2. To the AC-N input terminal, the conduction loop of the first half cycle of the AC power input is completed. When the voltage of the neutral line input terminal is higher than the voltage of the live line input terminal in the second half cycle of the AC power input, the control signal generating module generates a high voltage signal at the gate of Q1 to control Q1 to turn on, and generates a low voltage signal at the gate of Q2 to control Q2 to turn off, so that the current flows from the AC-N input terminal to the AC-L input terminal through D2 and Q1, completing the conduction loop of the second half cycle of the AC power input.

2. The bridge stack with low on-voltage to reduce heat generation according to claim 1, characterized in that: The control signal generating module includes two resistor voltage-dividing circuits, which are a first resistor voltage-dividing circuit connected between the live input terminal and the negative output terminal, and a second resistor voltage-dividing circuit connected between the neutral input terminal and the negative output terminal. The first resistor voltage-dividing circuit includes three first voltage-dividing resistors connected in series. Among the three first voltage-dividing resistors, the first voltage-dividing resistor connected to the negative output terminal is connected in parallel with the gate to source of Q2. When the voltage of the live input terminal is higher than the voltage of the neutral input terminal, the voltage difference between the live input terminal and the neutral input terminal is divided on the first voltage-dividing resistor connected to the negative output terminal to become the Vgs of Q2. The Vgs of Q2 is the voltage of the gate of Q2 relative to the source. The conduction of Q2 is controlled by this voltage division. The second resistor voltage-dividing circuit includes three second voltage-dividing resistors connected in series. Among the three second voltage-dividing resistors, the second voltage-dividing resistor connected to the negative output terminal is connected in parallel with the gate to source of Q1. When the voltage division on the first voltage-dividing resistor controls Q2 to be turned on, the voltage division on the second voltage-dividing resistor controls Q1 to be turned off. When the voltage at the neutral line input terminal is higher than the voltage at the live line input terminal, the voltage division on the second voltage-dividing resistor connected to the negative output terminal from the voltage difference between the neutral line input terminal and the live line input terminal becomes the Vgs of Q1. The Vgs of Q1 is the voltage of the gate of Q1 relative to the source. The conduction of Q1 is controlled by this voltage division. When the voltage division on the second voltage-dividing resistor controls Q1 to be turned on, the voltage division on the first voltage-dividing resistor controls Q2 to be turned off.

3. The bridge stack with low on-voltage to reduce heat generation according to claim 2, characterized in that: The control signal generating module includes two clamping diodes, which are respectively arranged in the two resistance voltage-dividing loops. The first clamping diode of the two clamping diodes is connected in parallel with the first voltage-dividing resistor connected to the negative output terminal in the first resistance voltage-dividing loop. When the voltage of the live wire input terminal is higher than that of the neutral wire input terminal, the clamping protection is started to reduce the Vgs voltage value of Q2. The second clamping diode of the two clamping diodes is connected in parallel with the second voltage-dividing resistor connected to the negative output terminal in the second resistance voltage-dividing loop. When the voltage of the neutral wire input terminal is higher than that of the live wire input terminal, the clamping protection is started to reduce the Vgs voltage value of Q1.

4. The bridge stack with low on-voltage to reduce heat generation according to claim 3, characterized in that: It also includes a diode D3 and a diode D4, wherein the diode D3 is connected in parallel with the middle first voltage-dividing resistor among the three first voltage-dividing resistors connected in series, and the diode D4 is connected in parallel with the middle second voltage-dividing resistor among the three second voltage-dividing resistors connected in series; When the voltage of the live input terminal is higher than the voltage of the neutral input terminal, the current will flow to the gate of Q2 through the diode D3, turning on Q2; when the voltage of the live input terminal is lower than the voltage of the neutral input terminal, the diode D3 will prevent the current from flowing from the gate of Q2 to the live input terminal to avoid reverse current; When the voltage of the neutral line input terminal is higher than the voltage of the live line input terminal, the current will flow to the gate of Q1 through the diode D4, turning on Q1; when the voltage of the neutral line input terminal is lower than the voltage of the live line input terminal, the diode D4 will prevent the current from flowing from the gate of Q1 to the neutral line input terminal to avoid reverse current.

Images