Output short circuit and anti-backflow protection circuit

Abstract

The utility model relates to an output short circuit and anti-backflow protection circuit, comprising an output module, a short circuit self-locking module, an anti-backflow module and an analog module, the output module is connected in parallel with an adjustable resistor, and the adjustable resistor is connected in series with a multi-position switch; the short-circuit self-locking module is electrically connected to the output module, the short-circuit self-locking module is provided with a comparison unit and a self-locking unit, and the comparison unit is connected to the adjustable resistor in series and is connected to the self-locking unit in series; the anti-backflow module is connected in parallel with the output module; the simulation module is electrically connected with the multi-position switch, and the simulation module is connected with the output module and the anti-backflow module in parallel. The utility model aims to more stably protect the equipment.

Description

Technical Field

[0001] The utility model relates to the technical field of protection circuits, in particular to an output short circuit and backflow prevention protection circuit. Background Art

[0002] With the advancement of science and technology, the electronics industry is also constantly moving forward in the wave of development. More and more electronic devices have entered all aspects of people's lives. In order to have stronger performance and occupy more market share, the internal circuits of existing electronic devices are developing in the direction of being smaller and more precise. At the same time, in order to prevent the circuit from being easily damaged when the device is working, in addition to the normal working circuit, the circuit also needs to add a protection circuit.

[0003] In related technologies, protection circuits are used to isolate external anomalies from core components on a circuit board. When a power supply component short-circuits, most use only output overcurrent protection. This approach is uncontrollable and only triggers protection when the current reaches a certain value. This single approach is extremely passive and prone to untimely protection, resulting in damage to the main switch tube after a sudden increase in current. Utility Model Content

[0004] The main purpose of the utility model is to provide an output short circuit and anti-backflow protection circuit, aiming at more stable protection equipment.

[0005] To achieve the above objectives, the present invention proposes an output short circuit and anti-backflow protection circuit, which includes an output module, a short circuit self-locking module, an anti-backflow module, and an analog module:

[0006] The output module is connected in parallel with an adjustable resistor, and the adjustable resistor is connected in series with a multi-position switch;

[0007] The short-circuit self-locking module is electrically connected to the output module, and the short-circuit self-locking module is provided with a comparison unit and a self-locking unit, wherein the comparison unit is connected in series to the adjustable resistor and in series to the self-locking unit;

[0008] The anti-backflow module is connected in parallel to the output module; and

[0009] The analog module is electrically connected to the multi-position switch, and the analog module is connected in parallel to the output module and the backflow prevention module.

[0010] In one embodiment of the present application, the anti-backflow module includes an anti-backflow MOS tube and an anti-backflow triode:

[0011] One end of the anti-backflow MOS tube is connected in series to the output module, and the other end is connected in series to the analog module; and

[0012] The anti-backflow transistors are provided in two groups, and the two anti-backflow transistors are arranged opposite to the anti-backflow MOS transistor. The emitters of the two anti-backflow transistors are electrically connected to the input section and output end of the anti-backflow MOS transistor, the bases of the two anti-backflow transistors are connected to each other, the collectors of the anti-backflow transistors are connected in series with a resistor, and the anti-backflow transistors are connected in parallel to the analog module.

[0013] In one embodiment of the present application, an anti-reverse diode is provided between the base of the anti-backflow transistor and the input and output ends of the anti-backflow MOS tube, and between the collector of the anti-backflow transistor and the gate source of the anti-backflow MOS tube. The anti-reverse diode is provided in multiple groups, and the multiple groups of anti-reverse diodes are arranged at intervals.

[0014] In one embodiment of the present application, the comparison unit includes a voltage drop detection resistor and a comparator:

[0015] The two ends of the step-down detection resistor are electrically connected to the output module and the adjustable resistor respectively; and

[0016] The positive electrode of the comparator is electrically connected to the step-down detection resistor, and a boost resistor is provided relative to the step-down detection resistor. A protection unit is connected in parallel with the step-down detection resistor and the boost resistor. The negative electrode of the comparator is provided with a comparison reference generation module, and the comparator is connected in series to the self-locking unit.

[0017] In one embodiment of the present application, the self-locking unit includes a conducting MOS tube and a self-locking circuit:

[0018] The conducting MOS transistor is connected in series with the output module and the adjustable resistor; and

[0019] The self-locking circuit is connected to the comparison unit, and the self-locking circuit is connected in parallel to the two ends of the conductive MOS tube. The self-locking circuit is configured to receive the self-locking signal sent by the comparison unit and be turned on, so as to shield the conductive MOS tube when a short circuit occurs in the output module.

[0020] In one embodiment of the present application, the self-locking unit also includes an activation unit, which is provided with a driving switch, one end of which is electrically connected to the conductive MOS tube, and the other end is electrically connected to the self-locking circuit, for reactivating the conductive MOS tube and closing the self-locking circuit.

[0021] The technical solution of the utility model is to divide the entire protection circuit into an output module, a short-circuit self-locking module, an anti-backflow module and an analog module. The output module is provided with a battery for simulating power supply components or electrical devices, etc., and an adjustable resistor is connected in parallel thereto. The adjustable resistor can be switched to 0Ω. The circuit short-circuit effect can be achieved through the adjustable resistor, thereby activating the short-circuit self-locking module. The short-circuit self-locking module is electrically connected to the output module. The module is composed of a comparison unit and a self-locking unit. The comparison unit is connected in series with the adjustable resistor and can detect the short circuit of the circuit in the first time, so that the entire circuit can handle the short circuit as quickly as possible to avoid further damage, making the circuit easy to maintain. The comparison unit is connected in series with the self-locking unit. The self-locking unit is provided with a conduction structure relative to the output module and the adjustable resistor. The self-locking unit is connected in parallel to the conduction structure. Structure, through the comparison unit to detect the short circuit, the self-locking unit will be activated, and the conduction structure will be short-circuited and shielded, so that the circuit between the output module and the adjustable resistor is broken to prevent the output module from short-circuiting. There are multiple groups of resistors connected in the short-circuit self-locking module, and the output module is protected by these resistors. The anti-backflow module is connected in parallel with the output module, and the analog module and the adjustable resistor are set at intervals and respectively connected to a gear of the multi-position switch. The analog module is connected through the multi-position switch so that the analog module can simulate circuit backflow or reverse connection accidents. The anti-backflow module is connected in parallel with the analog module, and also has a conduction structure in series with the output module and the analog module. When a backflow circuit or reverse current occurs, the circuit will be blocked or directly disconnected to achieve the purpose of protecting the circuit. The above structure can protect the circuit more stably and avoid circuit damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0023] Figure 1 This is a schematic diagram of an embodiment of the output short circuit and anti-backflow protection circuit of the utility model;

[0024] Figure 2 This is a schematic diagram of a short-circuit self-locking module of an embodiment of the output short-circuit and anti-backflow protection circuit of the utility model;

[0025] Figure 3 This is a schematic diagram of the anti-backflow module of an embodiment of the output short circuit and anti-backflow protection circuit of the utility model.

[0026] Description of Figure Numbers:

[0027] 1. Output module; 11. Adjustable resistor; 12. Multi-position switch; 2. Short-circuit self-locking module; 3. Comparison unit; 31. Step-down detection resistor; 32. Comparator; 33. Boost resistor; 34. Comparison reference generation module; 4. Self-locking unit; 41. Conducting MOS tube; 42. Self-locking circuit; 43. Activation unit; 44. Driving switch; 5. Anti-backflow module; 51. Anti-backflow MOS tube; 52. Anti-backflow transistor; 53. Anti-reverse diode; 6. Analog module.

[0028] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0030] Reference Figures 1 to 3 In one embodiment of the present invention, an output short circuit and anti-backflow protection circuit is proposed, including an output module 1, a short circuit self-locking module 2, an anti-backflow module 5 and an analog module 6. The output module 1 is connected in parallel with an adjustable resistor 11, and the adjustable resistor 11 is connected in series with a multi-position switch 12; the short circuit self-locking module 2 is electrically connected to the output module 1, and the short circuit self-locking module 2 is provided with a comparison unit 3 and a self-locking unit 4, and the comparison unit 3 is connected in series with the adjustable resistor 11 and the self-locking unit 4; the anti-backflow module 5 is connected in parallel with the output module 1; the analog module 6 is electrically connected to the multi-position switch 12, and the analog module 6 is connected in parallel with the output module 1 and the anti-backflow module 5.

[0031] In an output short circuit and anti-backflow protection circuit of the present application, the entire protection circuit is divided into an output module 1, a short circuit self-locking module 2, an anti-backflow module 5 and an analog module 6. The output module 1 is provided with a battery for simulating power supply components or electrical devices, etc., and an adjustable resistor 11 is connected in parallel thereto. The adjustable resistor 11 can be switched to 0Ω. The circuit short-circuit effect can be achieved through the adjustable resistor 11, thereby activating the short circuit self-locking module 2. The short circuit self-locking module 2 is electrically connected to the output module 1. The module is composed of a comparison unit 3 and a self-locking unit 4. The comparison unit 3 is connected in series with the adjustable resistor 11, and can detect the short circuit of the circuit in the first time, so that the entire circuit can handle the short circuit as quickly as possible to avoid further damage, making the circuit easy to maintain. The comparison unit 3 is connected in series with the self-locking unit 4. The self-locking unit 4 is provided with a conductive structure relative to the output module 1 and the adjustable resistor 11, and the self-locking unit 4 is also provided with a conductive structure relative to the output module 1 and the adjustable resistor 11. Connected to the conduction structure, the short circuit is detected by the comparison unit 3, the self-locking unit 4 will be activated, and the conduction structure will be short-circuited and shielded, so that the circuit between the output module 1 and the adjustable resistor 11 is broken to prevent the output module 1 from being short-circuited. There are multiple groups of resistors connected in the short-circuit self-locking module 2, and the effect of protecting the output module 1 is achieved through these resistors. The anti-backflow module 5 is connected in parallel to the output module 1, and the analog module 6 and the adjustable resistor 11 are arranged at intervals, and each is connected to a gear of the multi-position switch 12. The analog module 6 is connected through the multi-position switch 12 so that the analog module 6 can simulate circuit backflow or reverse connection accidents. The anti-backflow module 5 is connected in parallel to the analog module 6, and also has a conduction structure in series relative to the output module 1 and the analog module 6. When a backflow circuit or reverse current occurs, the circuit will be blocked or the circuit will be directly disconnected to achieve the purpose of protecting the circuit. The above structure can protect the circuit more stably and avoid circuit damage.

[0032] See also Figure 3 In one embodiment of the present application, the anti-backflow module 5 includes an anti-backflow MOS tube 51 and an anti-backflow triode 52. One end of the anti-backflow MOS tube 51 is connected in series to the output module 1, and the other end is connected in series to the analog module 6. There are two groups of anti-backflow triodes 52, and the two anti-backflow triodes 52 are arranged opposite to the anti-backflow MOS tube 51. The emitters of the two anti-backflow triodes 52 are electrically connected to the input section and output end of the anti-backflow MOS tube 51, the bases of the two anti-backflow triodes 52 are connected to each other, the collectors of the anti-backflow triodes 52 are connected in series with a resistor, and the anti-backflow triodes 52 are connected in parallel to the analog module 6.

[0033] In an output short circuit and anti-backflow protection circuit of the present application, the above-mentioned conduction structure is a MOS tube structure. The MOS tube has three groups of pins, which can be used to connect the circuit and can also be shielded by other control circuits to achieve the effect of blocking the circuit. In this embodiment, the anti-backflow module 5 includes an anti-backflow MOS tube 51 and an anti-backflow transistor 52. The anti-backflow transistor 52 is provided with two groups. Figure 3, can be divided into Q3 and Q4, the anti-backflow MOS tube 51 is named Q1. In this embodiment, Q3 and Q4 are both PNP transistors. The input voltage passes through the transistor, and the base of Q3 is grounded. Set V3 = 0. At this time, the voltage at Q4 is equal to the input voltage. At this time, Q3 is turned on. After turning on, the tube voltage will drop, so V3 = input voltage - fixed value, and the voltage at Q4 V4 = output voltage - fixed value. It is necessary to meet V4>V3 to make Q4 turn on, but the output voltage will be greater than the input voltage, so the transistor in the circuit will be cut off. In summary, when the circuit is working normally, Q1 and Q3 are turned on, and Q4 is not turned on. When backflow occurs, Q1 and Q3 are not turned on, and Q4 is turned on, so as to achieve the purpose of disconnecting the circuit and protecting the circuit. The resistors connected to Q3 and Q4 are R1 and R2 respectively. These resistors can be inductor structures, which can further protect components and reduce damage when backflow and reverse current occur in the circuit. Among them, a capacitor can be connected in parallel with R2 to improve protection performance.

[0034] See also Figure 3 In one embodiment of the present application, an anti-reverse polarity diode 53 is provided between the base of the anti-backflow transistor 52 and the input and output ends of the anti-backflow MOS tube 51, and between the collector of the anti-backflow transistor 52 and the gate source of the anti-backflow MOS tube 51. There are multiple groups of anti-reverse polarity diodes 53, and the multiple groups of anti-reverse polarity diodes 53 are arranged at intervals.

[0035] In an output short circuit and anti-backflow protection circuit of the present application, an anti-reverse diode 53 is provided between the base of the anti-backflow transistor 52 and the input and output terminals of the anti-backflow MOS tube 51, and between the collector of the anti-backflow transistor 52 and the gate source of the anti-backflow MOS tube 51. Figure 3 These diodes can prevent external reverse power supply and are used to improve the protection performance of the circuit.

[0036] See also Figure 2 In one embodiment of the present application, the comparison unit 3 includes a step-down detection resistor 31 and a comparator 32. The two ends of the step-down detection resistor 31 are electrically connected to the output module 1 and the adjustable resistor 11, respectively. The positive electrode of the comparator 32 is electrically connected to the step-down detection resistor 31, and a boost resistor 33 is provided relative to the step-down detection resistor 31. The step-down detection resistor 31 and the boost resistor 33 are connected in parallel with a protection unit. The negative electrode of the comparator 32 is provided with a comparison reference generation module 34. The comparator 32 is connected in series to the self-locking unit 4.

[0037] In an output short circuit and anti-backflow protection circuit of the present application, the comparison unit 3 includes a step-down detection resistor 31 and a comparator 32. In this embodiment, the step-down detection resistor 31 is R7, and its resistance value is set to 5mΩ in this embodiment. The adjustable resistor 11 is connected through the multi-position switch 12. The adjustable resistor 11 adjusts the resistance value to 0Ω, which can cause a short circuit in the circuit. At this time, a voltage drop will be generated at R7. The comparator 32 is connected to R7, and the comparator 32 is connected in parallel to the adjustable resistor 11. A boost resistor 33R21 is provided between the comparator 32 and R7, and the value of R21 is set to 1K Ω, the protection unit is a diode and capacitor connected in parallel, which can protect the two groups of resistors and prevent reverse voltage from damaging the components. R21 and R7 are connected to the positive electrode of the comparator 32. When R7 drops in voltage, R21 will increase in voltage. In order to compare this value, the negative electrode of the comparator 32 is connected to a comparison reference generation module 34. The module has R9 with a resistance value of 200KΩ and R8 with a resistance value of 5.1KΩ in parallel. In this way, when R21 increases in voltage and generates a high voltage at the diode D1, the high voltage will become a self-locking signal for activating the self-locking unit 4, so that the circuit performs self-protection.

[0038] See also Figure 2 In one embodiment of the present application, the self-locking unit 4 includes a conducting MOS transistor 41 and a self-locking circuit 42. The conducting MOS transistor 41 is connected in series to the output module 1 and the adjustable resistor 11; the self-locking circuit 42 is connected to the comparison unit 3 and is connected in parallel to both ends of the conducting MOS transistor 41. The self-locking circuit 42 is configured to receive a self-locking signal sent by the comparison unit and be turned on, so as to shield the conducting MOS transistor 41 when a short circuit occurs in the output module 1.

[0039] In an output short circuit and anti-backflow protection circuit of the present application, the self-locking unit 4 includes a conducting MOS tube 41 and a self-locking circuit 42. In this embodiment, the conducting MOS tube 41 is Q2, and the self-locking circuit 42 includes multiple MOS tubes and triodes, namely Q6, Q10, Q5, and Q8. When the self-locking circuit 42 receives a self-locking signal, Q6 will be turned on, thereby turning on Q10, and Q10 will activate Q5, and Q5 will shield Q2, so that the circuit is short-circuited to achieve a protection effect. Through the above structure, the protection device can be more stably protected.

[0040] See also Figure 2 In one embodiment of the present application, the self-locking unit 4 also includes an activation unit 43. The activation unit 43 is provided with a driving switch 44. One end of the driving switch 44 is electrically connected to the conductive MOS tube 41, and the other end is electrically connected to the self-locking circuit 42, which is used to reactivate the conductive MOS tube 41 and turn off the self-locking circuit 42.

[0041] In an output short circuit and anti-backflow protection circuit of the present application, the self-locking unit 4 also includes an activation unit 43. The activation unit 43 in this embodiment is a MOS tube Q7. Q7 is configured with a drive switch 44S3. One end of Q8 is connected to Q6 and the other end is connected to S3. When the circuit is repaired and Q2 needs to be reactivated to make the circuit conductive, the switch S3 is used to activate Q7, and Q7 restarts Q2, while Q8 can assist in closing the self-locking circuit 42, which can make the entire circuit structure more stable.

[0042] The same or similar numbers in the drawings of this embodiment correspond to the same or similar parts; in the description of this application, it should be understood that if the terms "upper", "lower", "left", "right", etc. indicate an orientation or position relationship, they are based on the orientation or position relationship shown in the drawings. This is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as a limitation on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0043] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. An output short circuit and anti-backflow protection circuit, characterized in that: include: An output module, wherein the output module is connected in parallel with an adjustable resistor, and the adjustable resistor is connected in series with a multi-position switch; A short-circuit self-locking module, the short-circuit self-locking module is electrically connected to the output module, the short-circuit self-locking module is provided with a comparison unit and a self-locking unit, the comparison unit is connected in series to the adjustable resistor and in series to the self-locking unit; an anti-backflow module, the anti-backflow module being connected in parallel to the output module; as well as An analog module is electrically connected to the multi-position switch and is connected in parallel to the output module and the backflow prevention module.

2. The output short circuit and backflow protection circuit according to claim 1, characterized in that: The anti-backflow module includes: an anti-backflow MOS transistor, one end of which is connected in series to the output module, and the other end of which is connected in series to the analog module; and Anti-backflow transistors, wherein two groups of anti-backflow transistors are provided, the two anti-backflow transistors are arranged opposite to the anti-backflow MOS transistor, the emitters of the two anti-backflow transistors are electrically connected to the input section and output end of the anti-backflow MOS transistor, the bases of the two anti-backflow transistors are connected to each other, the collectors of the anti-backflow transistors are connected in series with a resistor, and the anti-backflow transistors are connected in parallel to the analog module.

3. The output short circuit and backflow protection circuit according to claim 2, characterized in that: Anti-reverse connection diodes are provided between the base of the anti-backflow transistor and the input and output ends of the anti-backflow MOS tube, and between the collector of the anti-backflow transistor and the gate source of the anti-backflow MOS tube. The anti-reverse connection diodes are provided in multiple groups, and the multiple groups of anti-reverse connection diodes are arranged at intervals.

4. The output short circuit and backflow protection circuit according to claim 1, characterized in that: The comparison unit comprises: a step-down detection resistor, wherein both ends of the step-down detection resistor are electrically connected to the output module and the adjustable resistor respectively; and A comparator, wherein the positive electrode of the comparator is electrically connected to the step-down detection resistor, and a boost resistor is provided relative to the step-down detection resistor, the step-down detection resistor and the boost resistor are connected in parallel with a protection unit, the negative electrode of the comparator is provided with a comparison reference generation module, and the comparator is connected in series to the self-locking unit.

5. The output short circuit and backflow protection circuit according to claim 1, characterized in that: The self-locking unit comprises: A conducting MOS transistor, the conducting MOS transistor being connected in series to the output module and the adjustable resistor; and A self-locking circuit is connected to the comparison unit and is connected in parallel to both ends of the conductive MOS tube. The self-locking circuit is configured to receive a self-locking signal sent by the comparison unit and be turned on, and is used to shield the conductive MOS tube when a short circuit occurs in the output module.

6. The output short circuit and backflow protection circuit according to claim 5, characterized in that: The self-locking unit also includes an activation unit, which is provided with a drive switch. One end of the drive switch is electrically connected to the conductive MOS tube, and the other end is electrically connected to the self-locking circuit, for reactivating the conductive MOS tube and closing the self-locking circuit.

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