A half-bridge resonant short circuit protection circuit
Patent Information
- Application Number
- CN202522538819.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-28
- Publication Date
- 2026-10-09
- Estimated Expiration
- 2035-11-28
AI Technical Summary
[0004]本申请实施例通过提供一种半桥谐振短路保护电路，解决了现有技术中半桥谐振电路的短路保护电路存在电路损耗大，可靠性低的技术问题，实现了半桥谐振电路的短路保护，提高半桥谐振电路的可靠性和稳定性，增强整个电路的安全性，提升整个电路的使用寿命，减少电路的损耗等技术效果
[0031]在整个半桥谐振短路保护电路正常工作状态下，控制短路保护模块的开关子电路处于闭合状态，为整个电路供电。并通过短路保护模块的判断子电路，实时监测并判断半桥谐振模块和整个电路是否存在短路情况或整个电路的电流急剧增大的情况。如果判断子电路的电阻R3识别出整个电路存在电流急剧增大的情况，和/或，整个电路或半桥谐振模块存在短路情况，则判断子电路的开关管Q3处于导通状态，使得开关子电路处于关断状态，进而使得整个电路的电流通过判断子电路和保护子电路流向接地端。如此，对整个电路和半桥谐振模块进行电路保护，提高半桥谐振模块的可靠性和稳定性，增强整个电路的安全性，提升整个电路的使用寿命。并且，短路保护模块的判断子电路的电路结构简单，使用的电子器件少，即能实现短路保护，使得整个电路、短路保护模块和判断子电路具有损耗和能耗低、可靠性高和稳定高、成本低的特点。
Smart Images
Figure CN224843111U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of electronic circuit technology, and in particular to a half-bridge resonant short-circuit protection circuit. Background Technology
[0002] Half-bridge resonant circuits are widely used in modern switching power supplies due to their high efficiency and high power density. In a half-bridge resonant circuit, the two switching transistors (such as MOSFETs) conduct alternately in a complementary manner. Ideally, there is a small "dead time" between them to prevent simultaneous conduction. However, in practical applications, the drive signal may overlap due to signal interference, device aging, or controller failure, causing a "shoot-through" short circuit between the two switching transistors. At this time, the DC bus voltage is instantaneously short-circuited, resulting in extremely low loop impedance and triggering an avalanche-like instantaneous super-large current. This current peak may far exceed the rated value of the switching transistor within microseconds or even nanoseconds, causing irreversible thermal breakdown and permanent damage to the switching transistor. It may also affect peripheral components such as the driver chip and resonant capacitor, causing the entire circuit system to burn out or even catch fire.
[0003] Currently, the short-circuit protection circuit of a half-bridge resonant circuit detects the current in real time using a sampling resistor or current transformer. Once the current exceeds a set threshold, the drive signal is immediately blocked, forcibly turning off the switching transistor. As a result, the existing short-circuit protection circuit for half-bridge resonant circuits suffers from high circuit losses and low reliability. Utility Model Content
[0004] This application provides a half-bridge resonant short-circuit protection circuit, which solves the technical problems of high circuit loss and low reliability in the short-circuit protection circuit of the existing half-bridge resonant circuit. It realizes short-circuit protection of the half-bridge resonant circuit, improves the reliability and stability of the half-bridge resonant circuit, enhances the safety of the entire circuit, extends the service life of the entire circuit, and reduces circuit loss.
[0005] In a first aspect, this utility model provides a half-bridge resonant short-circuit protection circuit, including: a short-circuit protection module and a half-bridge resonant module, wherein the short-circuit protection module is connected to the half-bridge resonant module;
[0006] The short-circuit protection module includes: a switching sub-circuit, a judgment sub-circuit, and a protection sub-circuit. The first terminal of the judgment sub-circuit is connected to the switching sub-circuit, the second terminal of the judgment sub-circuit is connected to the half-bridge resonant module, and the third terminal of the judgment sub-circuit is connected to the protection sub-circuit.
[0007] The judgment sub-circuit includes: a switch Q3, a resistor R3, and a potentiometer R4;
[0008] The emitter of the switching transistor Q3 is connected to the switching sub-circuit, the base of the switching transistor Q3 is connected to the sliding terminal of the potentiometer R4, and the collector of the switching transistor Q3 is connected to the protection sub-circuit. The emitter of the switching transistor Q3 is the first terminal of the judgment sub-circuit, and the collector of the switching transistor Q3 is the third terminal of the judgment sub-circuit.
[0009] The first end of the resistor R3 is connected to the first fixed end of the potentiometer R4 and is connected to the emitter of the switching transistor Q3. The second end of the resistor R3 is connected to the second fixed end of the potentiometer R4 and is connected to the half-bridge resonant module. The second end of the resistor R3 is the second end of the judgment sub-circuit.
[0010] Optionally, the switching sub-circuit includes: switching transistor Q1 and switching transistor Q2;
[0011] The collector of the switching transistor Q1 is connected to the collector of the switching transistor Q2 and connected to the power supply. The emitter of the switching transistor Q1 is connected to the base of the switching transistor Q2, and the emitter of the switching transistor Q2 is connected to the emitter of the switching transistor Q3.
[0012] Optionally, the protection sub-circuit includes: resistor R1 and resistor R2;
[0013] One end of the resistor R1 is connected to the collector of the switching transistor Q3, the other end of the resistor R1 is connected to the first end of the resistor R2, and the second end of the resistor R2 is grounded.
[0014] Optionally, it also includes: a buzzer; the first end of the buzzer is connected to the power supply, and the second end of the buzzer is connected to the base of the switching transistor Q1.
[0015] Optionally, it also includes: a thyristor Q4, the first end of which is connected to the second end of the buzzer, the second end of which is connected to the first end of the resistor R2, and the third end of which is connected to the second end of the resistor R2 and grounded.
[0016] Optionally, the half-bridge resonant module includes: a half-bridge sub-circuit and a resonator circuit;
[0017] One end of the half-bridge circuit is connected to the short-circuit protection module, and the other end of the half-bridge circuit is connected to the resonator circuit.
[0018] Optionally, the half-bridge circuit includes: switching transistor Q5, switching transistor Q6, capacitor C1, and capacitor C2;
[0019] The drain of the switching transistor Q5 is connected to the first terminal of the capacitor C1 and connected to the second terminal of the resistor R3.
[0020] The source of the switching transistor Q5 is connected to the drain of the switching transistor Q6, and the second terminal of the capacitor C1 is connected to the first terminal of the capacitor C2.
[0021] The source of the switching transistor Q6 is connected to the second terminal of the capacitor C2 and grounded.
[0022] Optionally, the resonator circuit includes: a transformer U1, a switching transistor Q7, a switching transistor Q8, an inductor L1, a capacitor C2, and a load U2;
[0023] The first end of the primary side of the transformer U1 is connected to the line connecting the source of the switching transistor Q5 and the drain of the switching transistor Q6, and the second end of the primary side of the transformer U1 is connected to the line connecting the second end of the capacitor C1 and the first end of the capacitor C2.
[0024] The first end of the first winding of the secondary side of the transformer U1 is connected to the drain of the switching transistor Q7, the second end of the first winding of the secondary side of the transformer U1 is connected to the first end of the second winding of the secondary side of the transformer U1 and connected at the first intersection point, and the second end of the second winding of the secondary side of the transformer U1 is connected to the drain of the switching transistor Q8.
[0025] The source of the switching transistor Q7, the source of the switching transistor Q8, and the first end of the inductor L1 intersect at a second intersection point;
[0026] The second end of the inductor L1, the first end of the capacitor C3, and the first end of the load U2 intersect at a third intersection point;
[0027] The second end of the capacitor C3 and the second end of the load U2 intersect at a fourth intersection point, and the first intersection point is connected to the fourth intersection point.
[0028] Optionally, the switching transistor Q3 is a PNP transistor.
[0029] Optionally, both the switching transistor Q1 and the switching transistor Q2 are NPN transistors.
[0030] One or more technical solutions in the embodiments of this utility model have at least the following technical effects or advantages:
[0031] Under normal operating conditions, the switching sub-circuit of the half-bridge resonant short-circuit protection circuit is closed, supplying power to the entire circuit. The judgment sub-circuit of the short-circuit protection module monitors and determines in real time whether a short circuit exists in the half-bridge resonant module or the entire circuit, or whether the current in the entire circuit increases sharply. If the resistor R3 in the judgment sub-circuit detects a sharp increase in current in the entire circuit, and / or a short circuit exists in the entire circuit or the half-bridge resonant module, then the switching transistor Q3 in the judgment sub-circuit is turned on, causing the switching sub-circuit to turn off. This allows the current in the entire circuit to flow to the ground terminal through the judgment sub-circuit and the protection sub-circuit. This provides circuit protection for the entire circuit and the half-bridge resonant module, improving the reliability and stability of the half-bridge resonant module, enhancing the safety of the entire circuit, and extending the service life of the entire circuit. Furthermore, the judgment sub-circuit of the short-circuit protection module has a simple circuit structure and uses few electronic components, yet it achieves short-circuit protection. This results in the entire circuit, short-circuit protection module, and judgment sub-circuit being characterized by low loss and energy consumption, high reliability and stability, and low cost. Attached Figure Description
[0032] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, the same reference figures denote the same parts throughout the drawings. In the drawings:
[0033] Figure 1 The circuit diagram of the half-bridge resonant short-circuit protection circuit in the embodiment of this utility model is shown;
[0034] Figure 2 The circuit diagram of the half-bridge resonant short-circuit protection circuit in normal operation of this utility model embodiment is shown;
[0035] Figure 3 The circuit diagram of the half-bridge resonant short-circuit protection circuit in this embodiment of the present invention is shown in the case of a short circuit or a sharp increase in current.
[0036] Figure 4 This diagram illustrates the circuit current flow principle of the half-bridge resonant short-circuit protection circuit in normal operation according to an embodiment of the present invention.
[0037] Figure 5 This diagram illustrates another circuit current flow principle of the half-bridge resonant short-circuit protection circuit in normal operation according to an embodiment of the present invention. Detailed Implementation
[0038] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.
[0039] Example 1
[0040] The first embodiment of this utility model provides a half-bridge resonant short-circuit protection circuit, such as... Figure 1 As shown, it includes a short-circuit protection module and a half-bridge resonant module, with the short-circuit protection module connected to the half-bridge resonant module. The short-circuit protection module is used to provide short-circuit protection for the half-bridge resonant module. The half-bridge resonant module is used to provide power to the load. The short-circuit protection module is a short-circuit protection circuit, and the half-bridge resonant module is a half-bridge resonant circuit.
[0041] The short-circuit protection module includes a switching subcircuit, a judgment subcircuit, and a protection subcircuit. The first terminal of the judgment subcircuit is connected to the switching subcircuit, the second terminal of the judgment subcircuit is connected to the half-bridge resonant module, and the third terminal of the judgment subcircuit is connected to the protection subcircuit.
[0042] The switching sub-circuit is used to control the short-circuit protection module and the entire half-bridge resonant short-circuit protection circuit (referred to as the entire circuit in this embodiment) to be in a closed state or an open state, so as to realize short-circuit protection for the half-bridge resonant module and the entire half-bridge resonant short-circuit protection circuit. The closed state refers to closing the entire circuit, making the entire circuit a closed circuit. The open state refers to disconnecting the entire circuit, preventing the entire circuit from forming a closed circuit.
[0043] The judgment sub-circuit is used to monitor and determine in real time whether there is a short circuit in the half-bridge resonant module and the entire circuit, or whether the current in the entire circuit increases sharply.
[0044] The protection sub-circuit is used to provide withstand voltage protection for the judgment sub-circuit and the entire circuit.
[0045] The judgment subcircuit includes a switch Q3, a resistor R3, and a potentiometer R4. The emitter of the switch Q3 is connected to the switch subcircuit, the base of the switch Q3 is connected to the sliding terminal of the potentiometer R4, and the collector of the switch Q3 is connected to the protection subcircuit. The emitter of the switch Q3 is the first terminal of the judgment subcircuit, and the collector of the switch Q3 is the third terminal of the judgment subcircuit. The first terminal of the resistor R3 is connected to the first fixed terminal of the potentiometer R4 and is connected to the emitter of the switch Q3. The second terminal of the resistor R3 is connected to the second fixed terminal of the potentiometer R4 and is connected to the half-bridge resonant module, so that the potentiometer R4 and the resistor R3 are connected in parallel. The second terminal of the resistor R3 is the second terminal of the judgment subcircuit.
[0046] In this embodiment, under normal operating conditions of the entire half-bridge resonant short-circuit protection circuit, the switching sub-circuit of the control short-circuit protection module is in a closed state, supplying power to the entire circuit. The judgment sub-circuit of the short-circuit protection module monitors and determines in real time whether there is a short circuit in the half-bridge resonant module and the entire circuit, or whether the current in the entire circuit is increasing sharply. If the resistor R3 of the judgment sub-circuit detects a sharp increase in current in the entire circuit, and / or a short circuit in the entire circuit or the half-bridge resonant module, then the switching transistor Q3 of the judgment sub-circuit is turned on, causing the switching sub-circuit to turn off, thereby allowing the current in the entire circuit to flow to the ground terminal through the judgment sub-circuit and the protection sub-circuit. This provides circuit protection for the entire circuit and the half-bridge resonant module, improving the reliability and stability of the half-bridge resonant module, enhancing the safety of the entire circuit, and extending the service life of the entire circuit. Furthermore, the judgment sub-circuit of the short-circuit protection module has a simple circuit structure and uses few electronic components, yet it can achieve short-circuit protection. This results in the entire circuit, short-circuit protection module, and judgment sub-circuit having the characteristics of low loss and energy consumption, high reliability and stability, and low cost.
[0047] Below, in conjunction with Figure 1 This embodiment details the circuit structure and principle of the half-bridge resonant short-circuit protection circuit:
[0048] In the judgment sub-circuit, resistor R3 uses its voltage drop to identify whether there is a short circuit or a sudden increase in current in the entire circuit and / or the half-bridge resonant module. Switch Q3 is a PNP transistor. Switch Q3 is controlled to be in the on or off state based on the voltage drop across resistor R3. The resistance value of potentiometer R4 is set according to actual requirements. By properly designing the resistance value of potentiometer R4, the bias voltage threshold of switch Q3 is controlled, thereby providing redundancy for the short-circuit voltage threshold of the entire circuit. This allows for accurate identification of short circuits or sudden increases in current in the entire circuit and / or the half-bridge resonant module through resistor R3 and switch Q3, providing short-circuit protection for the entire circuit and the half-bridge resonant module, improving the reliability and stability of the half-bridge resonant module, enhancing the safety of the entire circuit, extending the lifespan of the entire circuit, and reducing circuit losses.
[0049] like Figure 1 As shown, the switching sub-circuit includes switching transistors Q1 and Q2. The collector of switching transistor Q1 is connected to the collector of switching transistor Q2 and is connected to the power supply VCC. The emitter of switching transistor Q1 is connected to the base of switching transistor Q2, and the emitter of switching transistor Q2 is connected to the emitter of switching transistor Q3. Both switching transistors Q1 and Q2 are NPN transistors.
[0050] Switches Q1 and Q2 combine to form a switch. When switches Q1 and Q2 are in the ON state, the switch sub-circuit is closed. When switches Q1 and Q2 are in the OFF state, the switch sub-circuit is OFF. Switches Q1 and Q2 control the entire circuit to be in a closed or open state, and also control the buzzer's on or off state. The switch sub-circuit formed by switches Q1 and Q2 offers advantages such as simple circuit structure, simplified control, low on-state voltage drop, and high current gain, thereby reducing overall circuit losses, enhancing circuit reliability and stability, and improving the efficiency of power transfer to the load.
[0051] like Figure 1 As shown, the protection sub-circuit includes resistors R1 and R2. One end of resistor R1 is connected to the collector of the switching transistor Q3, the other end of resistor R1 is connected to the first end of resistor R2, and the second end of resistor R2 is grounded. In the event of a short circuit or a sudden increase in current in the entire circuit or half-bridge resonant module, the resistors R1 and R2 can withstand surge currents, acting as voltage dividers and preventing damage to the circuit and electronic components.
[0052] like Figure 1As shown, the half-bridge resonant short-circuit protection circuit of this embodiment further includes a buzzer B1. The first terminal of the buzzer B1 is connected to the power supply VCC, and the second terminal of the buzzer B1 is connected to the base of the switching transistor Q1. When the entire circuit is in a closed loop state, the buzzer B1 is in a non-operating state. When the entire circuit is in an open loop state, the buzzer B1 is in an operating state. Furthermore, in the event of a short circuit or a sudden increase in current in the entire circuit or the half-bridge resonant module, the entire circuit is in an open loop. The buzzer B1 provides a timely audible alarm to indicate a short circuit or a sudden increase in current, facilitating timely inspection and intervention by operators.
[0053] like Figure 1 As shown, the half-bridge resonant short-circuit protection circuit of this embodiment further includes a thyristor Q4. The first terminal of the thyristor Q4 is connected to the second terminal of the buzzer B1, that is, the first terminal of the thyristor Q4, the second terminal of the buzzer B1, and the base of the switching transistor Q1 are connected. The second terminal of the thyristor Q4 is connected to the first terminal of the resistor R2, that is, the second terminal of the thyristor Q4, the first terminal of the resistor R2, and the second terminal of the resistor R1 are connected. The third terminal of the thyristor Q4 is connected to the second terminal of the resistor R2 and grounded. When the buzzer B1 is in operation, the thyristor Q4 acts as a voltage regulator, protecting the buzzer B1 and preventing it from being damaged by surge current.
[0054] like Figure 1 As shown, the half-bridge resonant module includes a half-bridge sub-circuit and a resonator circuit. One end of the half-bridge sub-circuit is connected to the short-circuit protection module, and the other end of the half-bridge sub-circuit is connected to the resonator circuit. The half-bridge sub-circuit is used to realize switch control and power transmission, while the resonator circuit is used to optimize the power waveform, realize zero-voltage switching (ZVS), and improve power transmission efficiency.
[0055] Specifically, the half-bridge circuit includes: switching transistor Q5, switching transistor Q6, capacitor C1, and capacitor C2. The drain of switching transistor Q5 is connected to the first terminal of capacitor C1 and then to the second terminal of resistor R3. The source of switching transistor Q5 is connected to the drain of switching transistor Q6, and the second terminal of capacitor C1 is connected to the first terminal of capacitor C2; the source of switching transistor Q6 is connected to the second terminal of capacitor C2 and grounded.
[0056] The resonator circuit includes: transformer U1, switching transistor Q7, switching transistor Q8, inductor L1, capacitor C2, and load U2. The load can be adjusted to a resistive load, capacitive load, inductive load, nonlinear load, or a mixed load, depending on the actual requirements of the circuit.
[0057] The first end of the primary side of the transformer U1 is connected to the line connecting the source of the switching transistor Q5 and the drain of the switching transistor Q6, and the second end of the primary side of the transformer U1 is connected to the line connecting the second end of the capacitor C1 and the first end of the capacitor C2.
[0058] The first end of the first winding of the secondary side of transformer U1 is connected to the drain of the switching transistor Q7. The second end of the first winding of the secondary side of transformer U1 is connected to the first end of the second winding of the secondary side of transformer U1 and is connected at the first intersection point. The second end of the second winding of the secondary side of transformer U1 is connected to the drain of the switching transistor Q8.
[0059] The source of the switching transistor Q7, the source of the switching transistor Q8, and the first terminal of the inductor L1 intersect at a second intersection point. The second terminal of the inductor L1, the first terminal of the capacitor C3, and the first terminal of the load U2 intersect at a third intersection point. The second terminal of the capacitor C3 and the second terminal of the load U2 intersect at a fourth intersection point, and the first intersection point is connected to the fourth intersection point.
[0060] It should also be noted that the dimensions, specifications, types, and other parameters of each electronic component in the half-bridge resonant short-circuit protection circuit can be set according to actual needs. For example, the inductance value of inductor L1 can be set according to actual needs.
[0061] The working principle of the half-bridge resonant short-circuit protection circuit in this embodiment is as follows:
[0062] like Figure 2 As shown, when the entire half-bridge resonant short-circuit protection circuit is in the loop state, it indicates that the entire circuit is working normally. The bases of switching transistors Q1 and Q2 reach the turn-on threshold voltage, and switching transistors Q1 and Q2 are in the conducting state. The current flows sequentially through the power supply VCC, switching transistors Q1 and Q2, and resistor R3, reaching the half-bridge resonant module, as shown. Figure 2 As shown by the dashed line. Since the voltage drop across resistor R3 is less than 0.7V when the entire circuit is operating normally, the bias voltage at the base of switching transistor Q3 is also less than 0.7V, keeping Q3 in the off state. Consequently, thyristor Q4 cannot reach its trigger voltage, keeping it in the off state. At this time, the entire circuit operates normally, and buzzer B1 will not sound, meaning buzzer B1 is in a non-operating state.
[0063] like Figure 3 As shown, when a short circuit occurs in the entire circuit (such as a load short circuit, a short circuit caused by the shoot-through of the upper and lower bridges in the half-bridge circuit) or when the current increases sharply, resistor R3 will have a large voltage drop. At this time, there is a large bias voltage at the base of the switching transistor Q3, causing the switching transistor Q3 to be in the conducting state, as shown. Figure 3As shown by the dashed line, the power supply VCC forms a loop through the switching transistor Q3, resistors R1 and R2, and the ground terminal GND. At this time, there will be a voltage difference of approximately 3V across resistor R2, controlling the thyristor Q4 to conduct. This creates an effective loop for buzzer B1, causing it to sound an alarm. The base voltage of switching transistor Q1 is pulled down to 0V, causing switching transistors Q1 and Q2 to disconnect, thus disconnecting the entire circuit and cutting off the power supply VCC. This provides short-circuit protection for the downstream circuit, specifically the half-bridge resonant module. This circuit protection improves the reliability and stability of the half-bridge resonant module, enhances the overall circuit safety, and extends the circuit's lifespan. Furthermore, the circuit structure is simple, using few electronic components, yet it achieves short-circuit protection. This results in the entire circuit, short-circuit protection module, and half-bridge resonant module exhibiting low power consumption, high reliability and stability, and low cost.
[0064] like Figure 4 As shown, when the entire half-bridge resonant short-circuit protection circuit is in the loop state, switching transistors Q6 and Q8 are in the off state, while switching transistors Q5 and Q7 are in the on state. The current flow of the entire circuit is as follows. Figure 4 As shown by the dashed line. The voltage polarity of the primary side of transformer U1 is positive at the top and negative at the bottom, and the voltage polarity of the secondary side is also positive at the top and negative at the bottom. The current on the secondary side flows through the switching transistor Q7 and the inductor L1 to supply power to the load U2. The voltage polarity of the load U2 is positive at the top and negative at the bottom.
[0065] like Figure 5 As shown, when the entire half-bridge resonant short-circuit protection circuit is in the loop state, switching transistors Q6 and Q8 are in the conducting state, while switching transistors Q5 and Q7 are in the off state. The current flow of the entire circuit is as follows. Figure 5 As shown by the dashed line, the voltage polarity of the primary side of transformer U1 is positive at the bottom and negative at the top, while the voltage polarity of the secondary side is also negative at the top and positive at the bottom. The current on the secondary side flows sequentially through the switching transistor Q8 and the inductor L1 to supply power to the load U2. The voltage polarity of the load U2 is positive at the top and negative at the bottom. Therefore, the voltage polarity of the load U2 does not change, providing a stable voltage power to the load U2.
[0066] Therefore, by setting up the half-bridge resonant short-circuit protection circuit in this embodiment, the entire circuit and the half-bridge resonant module are protected, improving the reliability and stability of the half-bridge resonant module, enhancing the safety of the entire circuit, and extending the service life of the entire circuit. Furthermore, the entire circuit has a simple structure, uses few electronic components, and yet achieves short-circuit protection, resulting in a circuit with low loss and energy consumption, high reliability and stability, and low cost.
[0067] Those skilled in the art will understand that although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.
[0068] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.
Claims
1. A half-bridge resonant short-circuit protection circuit, characterized in that, include: A short-circuit protection module and a half-bridge resonant module, wherein the short-circuit protection module is connected to the half-bridge resonant module; The short-circuit protection module includes: a switching sub-circuit, a judgment sub-circuit, and a protection sub-circuit. The first terminal of the judgment sub-circuit is connected to the switching sub-circuit, the second terminal of the judgment sub-circuit is connected to the half-bridge resonant module, and the third terminal of the judgment sub-circuit is connected to the protection sub-circuit. The judgment sub-circuit includes: a switch Q3, a resistor R3, and a potentiometer R4; The emitter of the switching transistor Q3 is connected to the switching sub-circuit, the base of the switching transistor Q3 is connected to the sliding terminal of the potentiometer R4, and the collector of the switching transistor Q3 is connected to the protection sub-circuit. The emitter of the switching transistor Q3 is the first terminal of the judgment sub-circuit, and the collector of the switching transistor Q3 is the third terminal of the judgment sub-circuit. The first end of the resistor R3 is connected to the first fixed end of the potentiometer R4 and is connected to the emitter of the switching transistor Q3. The second end of the resistor R3 is connected to the second fixed end of the potentiometer R4 and is connected to the half-bridge resonant module. The second end of the resistor R3 is the second end of the judgment sub-circuit.
2. The half-bridge resonant short-circuit protection circuit as described in claim 1, characterized in that, The switching sub-circuit includes: switching transistor Q1 and switching transistor Q2; The collector of the switching transistor Q1 is connected to the collector of the switching transistor Q2 and connected to the power supply. The emitter of the switching transistor Q1 is connected to the base of the switching transistor Q2, and the emitter of the switching transistor Q2 is connected to the emitter of the switching transistor Q3.
3. The half-bridge resonant short-circuit protection circuit as described in claim 2, characterized in that, The protection sub-circuit includes: resistor R1 and resistor R2; One end of the resistor R1 is connected to the collector of the switching transistor Q3, the other end of the resistor R1 is connected to the first end of the resistor R2, and the second end of the resistor R2 is grounded.
4. The half-bridge resonant short-circuit protection circuit as described in claim 3, characterized in that, Also includes: A buzzer; the first end of the buzzer is connected to the power supply, and the second end of the buzzer is connected to the base of the switching transistor Q1.
5. The half-bridge resonant short-circuit protection circuit as described in claim 4, characterized in that, Also includes: The thyristor Q4 has its first terminal connected to the second terminal of the buzzer, its second terminal connected to the first terminal of the resistor R2, and its third terminal connected to the second terminal of the resistor R2 and grounded.
6. The half-bridge resonant short-circuit protection circuit as described in any one of claims 3 to 5, characterized in that, The half-bridge resonant module includes: a half-bridge sub-circuit and a resonator circuit; One end of the half-bridge circuit is connected to the short-circuit protection module, and the other end of the half-bridge circuit is connected to the resonator circuit.
7. The half-bridge resonant short-circuit protection circuit as described in claim 6, characterized in that, The half-bridge circuit includes: switching transistor Q5, switching transistor Q6, capacitor C1, and capacitor C2; The drain of the switching transistor Q5 is connected to the first terminal of the capacitor C1 and connected to the second terminal of the resistor R3. The source of the switching transistor Q5 is connected to the drain of the switching transistor Q6, and the second terminal of the capacitor C1 is connected to the first terminal of the capacitor C2. The source of the switching transistor Q6 is connected to the second terminal of the capacitor C2 and grounded.
8. The half-bridge resonant short-circuit protection circuit as described in claim 7, characterized in that, The resonator circuit includes: transformer U1, switching transistor Q7, switching transistor Q8, inductor L1, capacitor C2, and load U2; The first end of the primary side of the transformer U1 is connected to the line connecting the source of the switching transistor Q5 and the drain of the switching transistor Q6, and the second end of the primary side of the transformer U1 is connected to the line connecting the second end of the capacitor C1 and the first end of the capacitor C2. The first end of the first winding of the secondary side of the transformer U1 is connected to the drain of the switching transistor Q7, the second end of the first winding of the secondary side of the transformer U1 is connected to the first end of the second winding of the secondary side of the transformer U1 and connected at the first intersection point, and the second end of the second winding of the secondary side of the transformer U1 is connected to the drain of the switching transistor Q8. The source of the switching transistor Q7, the source of the switching transistor Q8, and the first end of the inductor L1 intersect at a second intersection point; The second end of the inductor L1, the first end of the capacitor C3, and the first end of the load U2 intersect at a third intersection point; The second end of the capacitor C3 and the second end of the load U2 intersect at a fourth intersection point, and the first intersection point is connected to the fourth intersection point.
9. The half-bridge resonant short-circuit protection circuit as described in claim 1, characterized in that, The switching transistor Q3 is a PNP transistor.
10. The half-bridge resonant short-circuit protection circuit as described in claim 2, characterized in that, Both the switching transistors Q1 and Q2 are NPN transistors.