Direct-current power supply protection circuit
By introducing reverse voltage protection diodes and overvoltage protection circuits into the DC power supply system, the safety hazards caused by reverse polarity connection and overvoltage are solved, and the safe and stable operation of the power supply system is achieved.
Patent Information
- Application Number
- CN202520439682.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-13
- Publication Date
- 2026-02-27
- Estimated Expiration
- 2035-03-13
AI Technical Summary
Existing DC power supply systems are prone to damage under conditions of reverse polarity, incorrect voltage, or overvoltage, posing safety hazards such as sparks, smoke, and fire.
Design a DC power supply protection circuit, including a reverse voltage protection diode, a time-delay conduction circuit, and an overvoltage protection circuit. The reverse voltage protection diode prevents damage from reverse voltage, the time-delay conduction circuit reduces sparking, the overvoltage protection circuit prevents damage from excessive voltage, and the MOSFET controls the circuit to turn on and off.
It effectively prevents damage to DC power supply systems caused by reverse polarity or overvoltage, reduces spark generation, improves system safety and reliability, and lowers the risk of equipment damage.
Smart Images
Figure CN223957282U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to power supply technology field, concretely relates to a direct current power protection circuit. BACKGROUND
[0002] With the popularity of DC safety direct current appliance, the application of various DC input power supply and adapter becomes more and more extensive. However, in the actual use process, the non-standard DC external power supply may cause some problems:
[0003] If the DC plug of the power supply end is connected to the DC socket of the product end in reverse polarity, it may cause the product to be damaged due to reverse voltage, and in extreme cases, it may also cause safety accidents such as smoking and fire.
[0004] When the DC plug of the external power supply is inserted, a spark may be generated instantaneously, which may not only pop out and hurt people, but also ignite other objects and cause a fire.
[0005] If the voltage of the used external DC power supply does not meet the requirements of the equipment, especially when the input voltage is higher than the rated operating voltage of the product, it may cause abnormal operation of the product, even cause overvoltage damage, and also exist safety hazards such as smoking and fire. Therefore, a DC power protection circuit needs to be designed. INVENTION CONTENTS
[0006] The utility model discloses to solve the defects and deficiencies of prior art processing, provide a kind of direct current power protection circuit for preventing input power voltage higher than the rated operating voltage of product and causing overvoltage damage.
[0007] To achieve the above purpose, the utility model takes the technical scheme that a kind of direct current power protection circuit, including direct current input power supply, reverse voltage protection diode, output positive terminal, output negative terminal, current-limiting resistor, MOS tube, delay conduction circuit and overvoltage protection circuit;The anode of the reverse voltage protection diode is electrically connected with the direct current input power supply, and the cathode is grounded, the delay conduction circuit is arranged between the reverse voltage protection diode and the overvoltage protection circuit;The output positive terminal is connected at the anode of the reverse voltage protection diode and the common terminal of the delay conduction circuit, and the output negative terminal is electrically connected with the drain of the MOS tube;The gate of the MOS tube is electrically connected with the overvoltage protection circuit, one end of the current-limiting resistor is electrically connected with the output negative terminal, and the other end is electrically connected with the overvoltage protection circuit, the source of the MOS tube and the current-limiting resistor.
[0008] Further, the delay conduction circuit comprises a first resistor, a second resistor and a capacitor; one end of the first resistor is electrically connected with the anode of the reverse voltage protection diode, and the other end is electrically connected with the overvoltage protection circuit; the second resistor and the capacitor are connected in parallel, one end of which is electrically connected with the first resistor, and the other end is electrically connected with the cathode of the reverse voltage protection diode.
[0009] Further, the overvoltage protection circuit comprises a third resistor, a fourth resistor and a transistor; the third resistor and the fourth resistor are connected in series, one end of which is electrically connected with the first resistor, and the other end is electrically connected with the capacitor; the base of the transistor is electrically connected with the common end of the third resistor and the fourth resistor; the collector of the transistor is electrically connected with the common end of the third resistor and the gate of the MOS tube; and the emitter of the transistor is electrically connected with the common end of the third resistor and the drain of the MOS tube.
[0010] Further, the transistor is an NPN transistor.
[0011] Further, the MOS tube is an N-channel enhancement mode MOS tube.
[0012] The utility model discloses a beneficial effect has:
[0013] The utility model provides a kind of DC power protection circuit, by connecting the anode of reverse voltage protection diode with DC input power supply, cathode ground, ensure when the polarity of DC input power supply is reversed, other components in circuit can be avoided by short-circuiting of reverse voltage protection diode damaged due to reverse voltage.Delay conduction circuit can be accessed when external power supply, by controlling MOS tube delay opening, to effectively reduce the spark generated in access instant, reduce security risks.Overvoltage protection circuit is electrically connected with output negative end, and further guarantees the safety of circuit by current-limiting resistor.Once detecting that input voltage exceeds the safety range set, overvoltage protection circuit will prompt MOS tube delay to close, prevent excessive voltage from damaging subsequent circuit, ensure that entire circuit system can work stably within safety range.The circuit design of the application not only effectively improves the safety of DC power supply system, reduces the risk of equipment damage caused by power supply problems (such as reverse voltage and overvoltage), but also improves the safety of use by reducing spark generation.The application not only has simple structure but also low manufacturing cost. BRIEF DESCRIPTION OF DRAWINGS
[0014] Figure 1 It is the circuit schematic diagram of the utility model a kind of DC power protection circuit;
[0015] Figure 2 It is the circuit schematic diagram of the utility model one embodiment;
[0016] Figure 3The circuit principle diagram of another embodiment of the utility model;
[0017] Figure 4 The circuit principle diagram of still another embodiment of the utility model. DETAILED DESCRIPTION
[0018] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the utility model.
[0019] It should be noted that all the directionality indications (such as up, down, left, right, front, back, etc.) in the embodiments of the utility model are only used to explain the relative positional relationship, movement condition, etc. between the components in a certain specific posture (as shown in the drawings), and if the specific posture changes, the directionality indications also change accordingly.
[0020] In addition, the description of "first", "second" and the like in the utility model is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first" and "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of the various embodiments can be combined with each other, but must be based on the fact that a person skilled in the art can realize it, and when the combination of technical solutions appears to be contradictory or unachievable, it should be considered that the combination of technical solutions does not exist and is not within the scope of protection required by the utility model.
[0021] The utility model provides a kind of DC power protection circuit.
[0022] In the embodiments of the utility model, as shown in Figure 1 The utility model discloses a kind of DC power protection circuit, including DC input power supply, reverse voltage protection diode, output positive terminal, output negative terminal, current-limiting resistor, MOS tube, delay conduction circuit and overvoltage protection circuit;The anode of the reverse voltage protection diode is electrically connected with DC input power supply, cathode is grounded, the delay conduction circuit is arranged between the reverse voltage protection diode and the overvoltage protection circuit;The output positive terminal is connected in the anode of the reverse voltage protection diode and the common terminal of the delay conduction circuit, the output negative terminal is electrically connected with the drain of the MOS tube;The gate of the MOS tube is electrically connected with the overvoltage protection circuit, one end of the current-limiting resistor is electrically connected with the output negative terminal, the other end is electrically connected with the overvoltage protection circuit, the source of the MOS tube and the current-limiting resistor.
[0023] In the embodiment, the delay-on circuit comprises a first resistor, a second resistor and a capacitor; one end of the first resistor is electrically connected with the anode of the reverse voltage protection diode, and the other end is electrically connected with the overvoltage protection circuit; the second resistor and the capacitor are connected in parallel, one end of which is electrically connected with the first resistor, and the other end is electrically connected with the cathode of the reverse voltage protection diode.
[0024] In the embodiment, the overvoltage protection circuit comprises a third resistor, a fourth resistor and a transistor; the third resistor and the fourth resistor are connected in series, one end of which is electrically connected with the first resistor, and the other end is electrically connected with the capacitor; the base of the transistor is electrically connected with the common end of the third resistor and the fourth resistor; the collector of the transistor is electrically connected with the common end of the third resistor and the gate of the MOS tube; and the emitter of the transistor is electrically connected with the common end of the third resistor and the drain of the MOS tube.
[0025] In the embodiment, the transistor is an NPN transistor.
[0026] In the embodiment, the MOS tube is an N-channel enhancement mode MOS tube.
[0027] Specifically, the reverse voltage protection is realized by connecting the anode of the reverse voltage protection diode D1 with the direct current input power supply and grounding the cathode to form a loop. Once the polarity of the direct current input power supply is reversed, the reverse voltage protection diode D1 will be short-circuited, thereby avoiding damage to the current limiting resistor, the delay-on circuit and the overvoltage protection circuit caused by the reverse voltage.
[0028] The spark elimination loop is composed of a circuit composed of the first resistor R1, the second resistor R2, the capacitor CCl and the MOS tube MOS1. When the external power supply is connected with the direct current input power supply VD and the GND end, the delay-on circuit composed of the first resistor R1, the second resistor R2 and the capacitor CCl will delay the opening of the MOS tube MOS1, so as to reduce the spark generated at the direct current input power supply VD and the GND end when the external power supply is connected.
[0029] The overvoltage protection circuit is composed of the third resistor R3, the fourth resistor R4, the transistor T1 and the MOS tube MOS1. When the connected external power supply voltage exceeds the range that can be borne by the circuit, the protection loop composed of the third resistor R3, the fourth resistor R4 and the transistor T1 will delay the closing of the MOS tube MOS1, thereby preventing damage to the direct current input power supply VD and the GND end caused by the connection of the external power supply with excessively high voltage. Here, the protection voltage value can be set by adjusting the resistance values of the third resistor R3 and the fourth resistor R4.
[0030] In addition, the utility model still has another embodiment, such as Figure 2As shown, the reverse voltage protection is realized by connecting the anode of the reverse voltage protection diode D1 to the DC input power supply and grounding the cathode to form a loop.
[0031] The spark elimination circuit is composed of the first resistor R1, the second resistor R2, the capacitor CCl and the MOS transistor MOS1.
[0032] The overvoltage protection circuit is composed of the diode ZD1, the third resistor R3, the fourth resistor R4, the triode T1 and the MOS transistor MOS1.
[0033] In addition, the utility model has another embodiment, such as Figure 3 As shown, the reverse voltage protection is realized by connecting the anode of the reverse voltage protection diode D1 to the DC input power supply and grounding the cathode to form a loop.
[0034] The spark elimination circuit is composed of the first resistor R1, the second resistor R2, the capacitor CCl and the MOS transistor MOS1.
[0035] The overvoltage protection circuit is composed of the diode ZD1, the third resistor R3, the fourth resistor R4, the triode T1 and the MOS transistor MOS1.
[0036] In addition, the utility model still has another embodiment, as shown in Figure 4 The reverse pressure protection is realized by connecting the anode of the reverse pressure protection diode D1 with the direct current input power supply and grounding the cathode to form a loop. Once the polarity of the direct current input power supply is reversed, the reverse pressure protection diode D1 will be short-circuited, thereby avoiding damage to the current limiting resistor, the delay turn-on circuit and the overvoltage protection circuit due to the reverse voltage.
[0037] The spark elimination loop is composed of a circuit composed of the third resistor R3, the fourth resistor R4, the capacitor CC1 and the MOS tube MOS1. When the external power supply is connected to the direct current input power supply VD and the GND terminal, the delay turn-on circuit composed of the third resistor R3, the fourth resistor R4 and the capacitor CC1 will delay the opening of the MOS tube MOS1, thereby reducing the spark generated at the direct current input power supply VD and the GND terminal when the external power supply is connected.
[0038] The overvoltage protection circuit is composed of the diode ZD1, the third resistor R3, the fourth resistor R4, the triode T1 and the MOS tube MOS1. When the connected external power supply voltage exceeds the range that the circuit can withstand, the protection circuit composed of the diode ZD1, the third resistor R3, the fourth resistor R4 and the triode T1 will delay the closing of the MOS tube MOS1, thereby preventing damage to the direct current input power supply VD and the GND terminal due to the connection of the external power supply with excessively high voltage. Here, the protection voltage value can be set by adjusting the diode ZD1.
[0039] The above only describes the preferred embodiments of the utility model, and does not limit the patent range of the utility model, and any equivalent structural transformation made by using the utility model specification and the attached drawings, or direct / indirect application in other related technical fields under the utility model concept of the utility model is included in the patent protection range of the utility model.
Claims
1. A direct current power supply protection circuit, characterized by, The direct current input power supply, the reverse pressure protection diode, the output positive terminal, the output negative terminal, the current limiting resistor, the MOS tube, the delay conduction circuit and the overvoltage protection circuit are connected in series.
2. The DC power supply protection circuit of claim 1, wherein, The anode of the reverse pressure protection diode is connected with the direct current input power supply, and the cathode is grounded.
3. The DC power supply protection circuit of claim 2, wherein, The delay conduction circuit is arranged between the reverse pressure protection diode and the overvoltage protection circuit.
4. The DC power supply protection circuit of claim 3, wherein, The output positive terminal is connected with the anode of the reverse pressure protection diode and the common terminal of the delay conduction circuit.
5. The DC power supply protection circuit of claim 3, wherein, The gate of the MOS tube is connected with the overvoltage protection circuit. The other end of the current limiting resistor is connected with the overvoltage protection circuit, the source of the MOS tube and the current limiting resistor. The delay conduction circuit comprises a first resistor, a second resistor and a capacitor. The first resistor is connected with the anode of the reverse pressure protection diode at one end and connected with the overvoltage protection circuit at the other end. The second resistor and the capacitor are connected in parallel, connected with the first resistor at one end and connected with the cathode of the reverse pressure protection diode at the other end. The overvoltage protection circuit comprises a third resistor, a fourth resistor and a transistor. The third resistor and the fourth resistor are connected in series, connected with the first resistor at one end and connected with the capacitor at the other end. The base of the transistor is connected with the common terminal of the third resistor and the fourth resistor. The collector of the transistor is connected with the common terminal of the third resistor and the gate of the MOS tube. The emitter of the transistor is connected with the common terminal of the third resistor and the drain of the MOS tube. The transistor is an NPN transistor. The MOS tube is an N-channel enhancement mode MOS tube.