Direct-current power supply input protection circuit, power supply circuit board and electronic equipment
Through the circuit design of the combination of self-recovery fuse and the second diode, combined with the field effect tube and the voltage stabilization unit, the problem of electronic equipment damage caused by the reverse of the positive and negative electrodes of the DC power supply is solved, and safety protection is achieved against reverse insertion, fire prevention and overvoltage prevention.
Patent Information
- Application Number
- CN202422392567.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-30
- Publication Date
- 2025-08-19
- Estimated Expiration
- 2034-09-30
AI Technical Summary
When electronic equipment is connected to a DC power socket, it is easy to cause damage to the subsequent circuit due to the reverse of the positive and negative electrodes, and it is difficult for the existing technology to effectively protect it.
The combination of a self-recovery fuse and a second diode is adopted to form a loop to automatically disconnect the circuit, and combine the circuit design of the field effect tube, capacitor, resistor and voltage stabilization unit to achieve anti-reverse plugging, anti-ignition and anti-overvoltage protection.
Effectively prevent capacitor explosion or chip damage caused by reverse connection of positive and negative electrodes, and achieve safety protection through integrated circuit design.
Smart Images
Figure CN223246281U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of electronic technology, and in particular to a direct current power input protection circuit, a power circuit board and electronic equipment. Background Art
[0002] When electronic devices are connected to a DC power source via an outlet, the following safety issues are prone to occur: if the positive and negative polarity of the DC power source are reversed, damage to subsequent electronic products can occur. Therefore, how to protect against these safety issues through integrated circuit design has become a pressing technical issue. Utility Model Content
[0003] In order to solve the above problems, the utility model proposes a DC power input protection circuit, a power circuit board and an electronic device.
[0004] In the first aspect, the utility model provides a DC power input protection circuit, which includes a resettable fuse F1 and a second diode D2, wherein the first end of the resettable fuse F1 is electrically connected to the power input end, and the second end of the resettable fuse F1 is electrically connected to the power output end; the anode of the second diode D2 is grounded, and the cathode of the second diode D2 is electrically connected to the second end of the resettable fuse F1.
[0005] Beneficial effects:
[0006] This utility model incorporates a resettable fuse F1 and a second diode D2. When the input power supply is connected in reverse, the second diode D2 conducts, forming a circuit with the resettable fuse F1 and the power input. Due to the high current, the resettable fuse automatically disconnects the circuit, thus protecting the subsequent circuit from reversed polarity. Furthermore, the conduction of the second diode D2 reduces the voltage difference across the second diode D2, resulting in a loss of power to the subsequent circuit due to the low voltage. This also protects the subsequent circuit from the risk of capacitor explosion or chip damage caused by reversed polarity. Therefore, this utility model provides a hardware architecture that, through an integrated circuit design, provides safety protection against reversed polarity DC power supply connections in charging circuits.
[0007] Furthermore, the circuit further includes a field effect transistor Q1, a first capacitor C1, a first resistor R1, a fourth resistor R4, a voltage stabilizing unit and a switch unit;
[0008] The source of the field effect transistor Q1 is electrically connected to the second end of the resettable fuse F1, the drain of the field effect transistor Q1 is electrically connected to the power output terminal, the gate of the field effect transistor Q1 is electrically connected to the first end of the first resistor R1, the first end of the first resistor R1 is electrically connected to the second end of the resettable fuse F1, and the second end of the first resistor R1 is grounded;
[0009] A first end of the first capacitor C1 is electrically connected to the source of the field effect transistor Q1, and a second end of the first capacitor C1 is electrically connected to the gate of the field effect transistor Q1;
[0010] The first end of the fourth resistor R4 is electrically connected to the second end of the resettable fuse F1, the second end of the fourth resistor R4 is electrically connected to the first end of the voltage stabilizing unit, and the second end of the voltage stabilizing unit is grounded;
[0011] The first connection end of the switch unit is electrically connected to the second end of the resettable fuse F1, the second connection end of the switch unit is electrically connected to the gate of the field effect transistor Q1, and the controlled end of the switch unit is electrically connected to the first end of the voltage stabilizing unit.
[0012] Beneficial effects:
[0013] This embodiment provides a field-effect transistor (FET) Q1 and a first resistor (R1). When the power supply is reversed, the voltage is negative, and the negative voltage is applied to the source of the FET Q1. Since one end of the first resistor (R1) is connected to the gate of the FET Q1 and the other end is grounded, the positive voltage is applied. At this time, the FET Q1 cannot establish an operating voltage and is cut off, thereby further providing an anti-reverse insertion protection function. In addition, a first capacitor (C1) is provided. When the external power supply is inserted, the first capacitor (C1) charges the capacitor at the moment of power-on, which is equivalent to a short circuit. During this period, the capacitor charging time delay prevents contact current sparks during insertion, thus providing an anti-spark protection function. Furthermore, due to the provision of a switch unit and a voltage stabilizing unit, when the DC power supply operating voltage is greater than the operating voltage of the voltage stabilizing unit, the voltage forms a loop through the fourth resistor (R4) and the voltage stabilizing unit, the voltage stabilizing unit is broken down and turned on, thereby turning on the switch unit. The DC power supply applies voltage to the gate of the FET Q1 through the switch unit, causing the FET Q1 to be cut off, thus providing an anti-overvoltage protection function. Therefore, the present invention provides a hardware architecture that can protect the safety of the charging circuit through an integrated circuit design.
[0014] Furthermore, the voltage stabilizing unit includes a voltage stabilizing diode D1 , a cathode of the voltage stabilizing diode D1 is electrically connected to the second end of the fourth resistor R4 and the controlled end of the switch unit, and an anode of the voltage stabilizing diode D1 is grounded.
[0015] Furthermore, the switching unit includes a transistor Q2, the emitter of the transistor Q2 is electrically connected to the second end of the resettable fuse F1, the collector of the transistor Q2 is electrically connected to the gate of the field effect transistor Q1, and the base of the transistor Q2 is electrically connected to the cathode of the zener diode D1.
[0016] Furthermore, the switch unit further includes a third resistor R3 , a first end of the third resistor R3 is electrically connected to the cathode of the voltage stabilizing diode D1 , and a second end of the third resistor R3 is electrically connected to the base of the transistor Q2 .
[0017] Furthermore, the circuit further includes a second capacitor C2, a first end of the second capacitor C2 is electrically connected to the second end of the resettable fuse F1, and a second end of the second capacitor C2 is electrically connected to the first end of the third resistor R3.
[0018] Furthermore, the circuit further includes a second resistor R2, and the second resistor R2 is connected in parallel with the first capacitor C1.
[0019] Furthermore, the circuit further includes a second capacitor C2, and the second capacitor C2 is connected in parallel with the fourth resistor R4.
[0020] In a second aspect, the present invention provides a power supply circuit board, comprising a DC power input protection circuit as described in any one of the above embodiments.
[0021] In a third aspect, the present invention provides an electronic device comprising a power supply circuit board as described in the above embodiment. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The present invention will be further described in detail below with reference to the accompanying drawings and specific implementation methods.
[0023] Figure 1 The utility model provides a circuit diagram of a DC power input protection circuit. DETAILED DESCRIPTION
[0024] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. It will be understood that the specific embodiments described herein are only used to explain the present application, rather than to limit the present application. It should also be noted that, for ease of description, only some, rather than all, structures related to the present application are shown in the accompanying drawings. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.
[0025] References to "embodiments" herein mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.
[0026] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the described features. In the description of this application, "plurality" means two or more, unless otherwise specifically specified.
[0027] In this specification, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.
[0028] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, electrical connections, or mutual communication; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.
[0029] like Figure 1 As shown, the utility model provides a DC power input protection circuit, which includes a resettable fuse F1 and a second diode D2. The first end of the resettable fuse F1 is electrically connected to the power input end, and the second end of the resettable fuse F1 is electrically connected to the power output end; the anode of the second diode D2 is grounded, and the cathode of the second diode D2 is electrically connected to the second end of the resettable fuse F1.
[0030] This embodiment provides a resettable fuse F1 and a second diode D2. When the input power source is connected in reverse, the second diode D2 conducts, forming a loop with the resettable fuse F1 and the power input. Due to the high current, the resettable fuse automatically disconnects the circuit, thus protecting the subsequent circuit from reversed polarity. Furthermore, the conduction of the second diode D2 reduces the voltage difference across the second diode D2, resulting in a loss of power to the subsequent circuit due to the low voltage. This also protects the subsequent circuit from the risk of capacitor explosion or chip damage caused by reversed polarity. Therefore, the present invention provides a hardware architecture that, through an integrated circuit design, provides safety protection against reversed polarity DC power supply connections in charging circuits.
[0031] Preferably, the circuit further includes a field effect transistor Q1, a first capacitor C1, a first resistor R1, a fourth resistor R4, a voltage stabilizing unit and a switch unit;
[0032] The source of the field effect transistor Q1 is electrically connected to the second end of the resettable fuse F1, the drain of the field effect transistor Q1 is electrically connected to the power output terminal, the gate of the field effect transistor Q1 is electrically connected to the first end of the first resistor R1, the first end of the first resistor R1 is electrically connected to the second end of the resettable fuse F1, and the second end of the first resistor R1 is grounded;
[0033] A first end of the first capacitor C1 is electrically connected to the source of the field effect transistor Q1, and a second end of the first capacitor C1 is electrically connected to the gate of the field effect transistor Q1;
[0034] The first end of the fourth resistor R4 is electrically connected to the second end of the resettable fuse F1, the second end of the fourth resistor R4 is electrically connected to the first end of the voltage stabilizing unit, and the second end of the voltage stabilizing unit is grounded;
[0035] The first connection end of the switch unit is electrically connected to the second end of the resettable fuse F1, the second connection end of the switch unit is electrically connected to the gate of the field effect transistor Q1, and the controlled end of the switch unit is electrically connected to the first end of the voltage stabilizing unit.
[0036] This embodiment provides a field-effect transistor (FET) Q1 and a first resistor (R1). When the power supply is reversed, the voltage is negative, and the negative voltage is applied to the source of the FET Q1. Since one end of the first resistor (R1) is connected to the gate of the FET Q1 and the other end is grounded, the positive voltage is applied. At this time, the FET Q1 cannot establish an operating voltage and is cut off, thereby providing an anti-reverse insertion protection function. In addition, a first capacitor (C1) is provided. When the external power supply is inserted, the first capacitor (C1) charges the capacitor at the moment of power-on, which is equivalent to a short circuit. During this period, the capacitor charging time delay prevents contact current sparks during insertion, thus providing an anti-spark protection function. Furthermore, due to the provision of a switch unit and a voltage stabilizing unit, when the DC power supply operating voltage (VCC) is greater than the operating voltage of the voltage stabilizing unit, the voltage forms a loop through the fourth resistor (R4) and the voltage stabilizing unit, the voltage stabilizing unit is broken down and turned on, thereby turning on the switch unit. The DC power supply (VCC) applies voltage to the gate of the FET Q1 through the switch unit, causing the FET Q1 to be cut off, thus providing an anti-overvoltage protection function. Therefore, the present invention provides a hardware architecture that can protect the safety of the charging circuit through an integrated circuit design.
[0037] Specifically, the reverse connection protection works as follows: when the DC power supply VCC is plugged in, the positive voltage of the DC power supply VCC is applied to the source of the FET Q1. Since the first terminal of the first resistor R1 is connected to the gate of the FET Q1 and the second terminal of the first resistor R1 is grounded, the FET Q1 now establishes an operating voltage and turns on. When the DC power supply VCC is plugged in reverse, the negative voltage of the VCC is applied to the source of the FET Q1. Since the first terminal of the first resistor R1 is connected to the gate of the FET Q1 and the other terminal is grounded, the voltage becomes positive. At this time, the FET Q1 cannot establish an operating voltage and turns off, thus achieving the reverse connection protection function.
[0038] Specifically, the anti-spark working principle is that when the DC power supply VCC is inserted, the first capacitor C1 charges the capacitor at the moment of power-on, which is equivalent to a short circuit. The field effect tube Q1 cannot establish a normal working conduction voltage. When the capacitor is continuously charged to full charge, the current on the first capacitor C1 is approximately 0, and the DC power supply VCC establishes a conduction working voltage through the first resistor R1. During this period, due to the delay in capacitor charging time, contact current sparks are avoided during insertion, thereby playing an anti-spark protection function.
[0039] Preferably, the voltage stabilizing unit includes a voltage stabilizing diode D1 , a cathode of the voltage stabilizing diode D1 is electrically connected to the second end of the fourth resistor R4 and the controlled end of the switch unit, and an anode of the voltage stabilizing diode D1 is grounded.
[0040] Specifically, when the operating voltage exceeds the voltage setting value of the Zener diode D1 , the Zener diode D1 is turned on.
[0041] Preferably, the switching unit includes a transistor Q2, the emitter of the transistor Q2 is electrically connected to the second end of the resettable fuse F1, the collector of the transistor Q2 is electrically connected to the gate of the field effect transistor Q1, and the base of the transistor Q2 is electrically connected to the cathode of the voltage regulator diode D1.
[0042] Specifically, the overvoltage protection operates as follows: when the DC power supply VCC is connected and the operating voltage of the DC power supply VCC exceeds the regulated voltage of the Zener diode D1, the voltage forms a loop through the fourth resistor R4 and the Zener diode D1, causing the Zener diode D1 to break down and conduct. The BE junction of the transistor Q2 forms a loop through the Zener diode D1, causing the transistor Q2 to conduct. The DC power supply VCC applies voltage to the gate of the field-effect transistor Q1 through the CE junction of the transistor Q2, at which point the field-effect transistor Q1 is turned off, providing overvoltage protection. When the operating voltage of the DC power supply VCC is less than the regulated voltage of the Zener diode D1, the transistor Q2 is turned off and does not operate, and the field-effect transistor Q1 is turned on.
[0043] Preferably, the switch unit further includes a third resistor R3 , a first end of the third resistor R3 is electrically connected to the cathode of the voltage stabilizing diode D1 , and a second end of the third resistor R3 is electrically connected to the base of the transistor Q2 .
[0044] Preferably, the circuit further includes a second capacitor C2, a first end of the second capacitor C2 being electrically connected to the second end of the resettable fuse F1, and a second end of the second capacitor C2 being electrically connected to the first end of the third resistor R3. The second capacitor C2 has a decoupling function.
[0045] Preferably, the circuit further includes a second resistor R2 connected in parallel with the first capacitor C1. During the anti-spark process, the DC power supply VCC establishes a conducting working voltage through the first resistor R1 and the second resistor R2.
[0046] Preferably, the circuit further includes a second capacitor C2, which is connected in parallel with the fourth resistor R4. The second capacitor C2 has a decoupling function.
[0047] This embodiment further provides a power supply circuit board, which includes a DC power input protection circuit as described in any of the above embodiments.
[0048] The power supply circuit board provided in this embodiment is provided with a resettable fuse F1 and a second diode D2. When the positive and negative poles of the input power supply are reversed, the second diode D2 is turned on, forming a loop with the resettable fuse F1 and the power input terminal. Due to the high current, the resettable fuse automatically disconnects the circuit, thereby protecting the subsequent circuit from the reverse connection of the positive and negative poles. At the same time, because the second diode D2 is turned on, the voltage difference across the second diode D2 is small, resulting in the subsequent circuit being unable to supply power due to the low voltage. This also protects the subsequent circuit from the risk of capacitor explosion or chip damage caused by the reverse connection of the positive and negative poles.
[0049] The present invention provides an electronic device, comprising the power supply circuit board described in the above embodiment.
[0050] The electronic device provided in this embodiment is provided with a resettable fuse F1 and a second diode D2. When the positive and negative poles of the input power supply are reversed, the second diode D2 is turned on, forming a loop with the resettable fuse F1 and the power input terminal. Due to the high current, the resettable fuse automatically disconnects the circuit, thereby protecting the subsequent circuit from the reverse connection of the positive and negative poles. At the same time, because the second diode D2 is turned on, the voltage difference across the second diode D2 is small, so that the subsequent circuit cannot be powered due to the low voltage. This also protects the subsequent circuit from the risk of capacitor explosion or chip damage caused by the reverse connection of the positive and negative poles.
[0051] It should be noted that terms such as "horizontal" and "vertical" do not imply that components must be absolutely horizontal or vertical, but rather that they may be slightly tilted. Terms such as "parallel" and "perpendicular" do not imply that components are absolutely parallel or perpendicular to each other, but rather that a certain angle deviation may be formed. For example, "horizontal" simply means that its direction is more horizontal than "vertical" and does not mean that the structure must be completely horizontal, but rather that it may be slightly tilted. Furthermore, terms such as "center," "longitudinal," "transverse," "length," "width," "thickness," "up," "down," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," "outside," "clockwise," and "counterclockwise" indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships typically used when the products of this application are used. These terms are used solely to facilitate the description of the embodiments of this application and to simplify the description, and do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application.
[0052] It is understood that the meaning of "plurality" herein is at least two, such as two, three, etc., unless there is a special limitation. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units that are inherent to these processes, methods, products or devices. The term "and / or" is merely a description of the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the related objects before and after are in an "or" relationship.
[0053] The above description is only an implementation method of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.
Claims
1. A DC power input protection circuit, characterized in that: The circuit includes a resettable fuse F1 and a second diode D2, wherein a first end of the resettable fuse F1 is electrically connected to a power input end, and a second end of the resettable fuse F1 is electrically connected to a power output end; an anode of the second diode D2 is grounded, and a cathode of the second diode D2 is electrically connected to the second end of the resettable fuse F1; The circuit further includes a field effect transistor Q1, a first capacitor C1, a first resistor R1, a fourth resistor R4, a voltage stabilizing unit and a switch unit; The source of the field effect transistor Q1 is electrically connected to the second end of the resettable fuse F1, the drain of the field effect transistor Q1 is electrically connected to the power output terminal, the gate of the field effect transistor Q1 is electrically connected to the first end of the first resistor R1, the first end of the first resistor R1 is electrically connected to the second end of the resettable fuse F1, and the second end of the first resistor R1 is grounded; A first end of the first capacitor C1 is electrically connected to the source of the field effect transistor Q1, and a second end of the first capacitor C1 is electrically connected to the gate of the field effect transistor Q1; The first end of the fourth resistor R4 is electrically connected to the second end of the resettable fuse F1, the second end of the fourth resistor R4 is electrically connected to the first end of the voltage stabilizing unit, and the second end of the voltage stabilizing unit is grounded; The first connection end of the switch unit is electrically connected to the second end of the resettable fuse F1, the second connection end of the switch unit is electrically connected to the gate of the field effect transistor Q1, and the controlled end of the switch unit is electrically connected to the first end of the voltage stabilizing unit.
2. A DC power input protection circuit according to claim 1, characterized in that: The voltage stabilizing unit includes a voltage stabilizing diode D1 , a cathode of the voltage stabilizing diode D1 is electrically connected to the second end of the fourth resistor R4 and the controlled end of the switch unit, and an anode of the voltage stabilizing diode D1 is grounded.
3. A DC power input protection circuit according to claim 2, characterized in that: The switch unit includes a transistor Q2, the emitter of the transistor Q2 is electrically connected to the second end of the resettable fuse F1, the collector of the transistor Q2 is electrically connected to the gate of the field effect transistor Q1, and the base of the transistor Q2 is electrically connected to the cathode of the voltage regulator diode D1.
4. A DC power input protection circuit according to claim 3, characterized in that: The switch unit further includes a third resistor R3 , a first end of the third resistor R3 is electrically connected to the cathode of the voltage stabilizing diode D1 , and a second end of the third resistor R3 is electrically connected to the base of the transistor Q2 .
5. A DC power input protection circuit according to claim 4, characterized in that: The circuit further includes a second capacitor C2 , a first end of the second capacitor C2 is electrically connected to the second end of the resettable fuse F1 , and a second end of the second capacitor C2 is electrically connected to the first end of the third resistor R3 .
6. The DC power input protection circuit according to claim 1, characterized in that: The circuit further includes a second resistor R2 , which is connected in parallel with the first capacitor C1 .
7. The DC power input protection circuit according to claim 1, characterized in that: The circuit further includes a second capacitor C2, and the second capacitor C2 is connected in parallel with the fourth resistor R4.
8. A power circuit board, characterized in that: The invention comprises a DC power input protection circuit as described in any one of claims 1 to 7.
9. An electronic device, characterized in that: The invention comprises a power supply circuit board as claimed in claim 8.