DC switch controller with surge suppression

Abstract

The utility model discloses a DC switch controller with surge suppression, which relates to the field of switches, and comprises a current-limiting voltage-stabilizing module used for limiting the magnitude of voltage and current of a DC input power supply and providing reverse connection protection; the surge protection module is used for gradually reducing impedance in a load loop at the output end by controlling conduction of a switching tube (specifically an MOS tube M2) during power-on so as to realize power-on surge protection; the system has the beneficial effects that the system has multiple protection functions, so that the safety of the system is enhanced; through linear conduction characteristics of an RC time-delay circuit and an MOS tube, smooth charging of a capacitive load is realized, instantaneous current impact is eliminated, and the limitation that a traditional relay needs to be used in a derating manner is avoided. A core circuit is built by adopting universal elements such as resistors, MOS (Metal Oxide Semiconductor) tubes, triodes and the like, and special chips or mechanical contacts are not needed, so that the material cost is obviously reduced.

Description

Technical Field

[0001] This utility model relates to the field of switches, specifically a DC switch controller with surge suppression. Background Technology

[0002] DC switch controllers are widely used in communication equipment rooms, vehicle electronic systems, airborne equipment, and rail transit electronic systems. Their core function is to reliably control the switching of power supplies and ensure the safe operation of downstream loads. However, existing DC relays or solid-state switches have significant shortcomings in performance and application scenarios.

[0003] The DC relay lacks reverse polarity protection, which can damage downstream equipment if the user connects the wires in reverse. It also lacks overcurrent protection, which can cause the current to far exceed the relay's rated operating current if the user's downstream equipment fails and short-circuits, resulting in instantaneous damage to the relay. Improvements are needed. Utility Model Content

[0004] The purpose of this invention is to provide a DC switch controller with surge suppression to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A DC switching controller with surge suppression includes:

[0007] The current limiting and voltage regulating module is used to limit the voltage and current of the DC input power supply and provide reverse connection protection.

[0008] The surge protection module is used to gradually reduce the impedance in the output load circuit by controlling the conduction of the switching transistor (specifically MOSFET M2) when power is applied, thereby achieving power-on surge protection.

[0009] The overvoltage and undervoltage protection module is used to control the switching transistor to disconnect when the voltage of the DC input power supply is higher than the upper voltage threshold or lower than the lower voltage threshold.

[0010] The overcurrent protection module is used to control the switching transistor to disconnect when the current flowing through the load at the output terminal exceeds the upper limit current threshold.

[0011] The current limiting and voltage regulating module is connected to the surge protection module, overvoltage and undervoltage protection module, and overcurrent protection module. The overvoltage and undervoltage protection module is connected to the surge protection module, and the overcurrent protection module is connected to the surge protection module.

[0012] As a further embodiment of this utility model: the current limiting and voltage regulating module includes resistor R3, resistor R12, diode D3, capacitor C1, and MOSFET M1. One end of resistor R3 is connected to the positive terminal of the DC input power supply +VIN and the positive terminal of the DC output power supply +V0. The other end of resistor R3 is connected to the second terminal of MOSFET M1, one end of resistor R12, the negative terminal of diode D3, and one end of capacitor C1. The first terminal of MOSFET M1 is connected to the other end of resistor R12, the positive terminal of diode D3, the other end of capacitor C1, and the common point G1. The third terminal of MOSFET M1 is connected to the negative terminal of the DC input power supply -VIN.

[0013] As a further embodiment of this utility model: the surge protection module includes resistor R4, diode D2, resistor R5, capacitor C2, capacitor C3, resistor R13, diode D4, and MOSFET M2. One end of resistor R4 is connected to the positive terminal of the DC input power supply +VIN and the positive terminal of the DC output power supply +V0 through a switch. The other end of resistor R4 is connected to one end of capacitor C2, the negative terminal of diode D2, the overvoltage / undervoltage protection module, and the overcurrent protection module. The positive terminal of diode D2 is connected to one end of resistor R5. The other end of resistor R5 is connected to one end of capacitor C3, one end of resistor R13, the negative terminal of diode D4, and the second end of MOSFET M2. The first end of MOSFET M2 is connected to the other end of capacitor C2, the other end of capacitor C3, the other end of resistor R13, the positive terminal of diode D4, and the common point G2. The third end of MOSFET M2 is connected to the negative terminal of the DC output power supply -V0.

[0014] As a further improvement of this utility model: the overvoltage and undervoltage protection module includes resistors R6, R7, R8, R9, R11, R14, R16, R17, capacitors C4 and C5, transistor Q3, three-terminal regulator IC2, and three-terminal regulator IC1. One end of resistor R6 is connected to one end of resistors R7, R8, and R9, the positive terminal of the DC input power supply (+VIN), and the positive terminal of the DC output power supply (+V0). The other end of resistor R7 is connected to one end of capacitor C4, one end of resistor R14, and the reference terminal of three-terminal regulator IC2. The negative terminal of three-terminal regulator IC2 is connected to... The other end of resistor R8, one end of capacitor C5, the other end of resistor R9, one end of resistor R17, the reference terminal of three-terminal regulator IC1, the negative terminal of three-terminal regulator IC1 is connected to the other end of resistor R6, one end of resistor R11, the other end of resistor R11 is connected to one end of resistor R16, the base of transistor Q3, the collector of transistor Q3 is connected to the surge protection module, the emitter of transistor Q3 is connected to the common point G2, the other end of resistor R16, the positive terminal of three-terminal regulator IC1, the positive terminal of three-terminal regulator IC2, the other end of resistor R17, the other end of resistor R14, the other end of capacitor C4, and the other end of capacitor C5.

[0015] As a further embodiment of this utility model: the overcurrent protection module includes resistors R1 and R2, transistors Q1 and Q2, resistors R10, R15, and R18, capacitor C6, and diode D1. One end of resistor R1 is connected to the positive terminal of the DC input power supply +VIN and the positive terminal of the DC output power supply +V0. The other end of resistor R1 is connected to the collector of transistor Q2 and the negative terminal of diode D1. The positive terminal of diode D1 is connected to the surge protection module. The emitter of transistor Q2 is connected to the common point G1, one end of resistor R18, and one end of capacitor C6. The base of transistor Q2 is connected to one end of resistor R10 and one end of resistor R15. The other end of resistor R15 is connected to the other end of resistor R18, the other end of capacitor C6, the emitter of transistor Q1, and the common point G2. The other end of resistor R10 is connected to the other end of resistor R2, the collector of transistor Q1, and the base of transistor Q1.

[0016] Compared with the prior art, the beneficial effects of this utility model are: the present invention has multiple protection functions, enhancing system safety; it sets up surge suppression and soft start: through the linear conduction characteristics of the RC delay circuit (R4, R5, C3) and the MOSFET (M2), it realizes smooth charging of capacitive load, eliminates instantaneous current surges, and avoids the limitation of traditional relays requiring derating; it uses general-purpose components such as resistors, MOSFETs, and transistors to build the core circuit, eliminating the need for dedicated chips or mechanical contacts, significantly reducing material costs. Attached Figure Description

[0017] Figure 1 This is a circuit diagram of a DC switch controller with surge suppression. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0019] Please see Figure 1 A DC switching controller with surge suppression, comprising:

[0020] The current limiting and voltage regulating module is used to limit the voltage and current of the DC input power supply and provide reverse connection protection.

[0021] The surge protection module is used to gradually reduce the impedance in the output load circuit by controlling the conduction of the switching transistor (specifically MOSFET M2) when power is applied, thereby achieving power-on surge protection.

[0022] The overvoltage and undervoltage protection module is used to control the switching transistor to disconnect when the voltage of the DC input power supply is higher than the upper voltage threshold or lower than the lower voltage threshold.

[0023] The overcurrent protection module is used to control the switching transistor to disconnect when the current flowing through the load at the output terminal exceeds the upper limit current threshold.

[0024] The current limiting and voltage regulating module is connected to the surge protection module, overvoltage and undervoltage protection module, and overcurrent protection module. The overvoltage and undervoltage protection module is connected to the surge protection module, and the overcurrent protection module is connected to the surge protection module.

[0025] In this embodiment: Please refer to Figure 1 The current limiting and voltage regulating module includes resistor R3, resistor R12, diode D3, capacitor C1, and MOSFET M1. One end of resistor R3 is connected to the positive terminal of the DC input power supply +VIN and the positive terminal of the DC output power supply +V0. The other end of resistor R3 is connected to the second terminal of MOSFET M1, one end of resistor R12, the negative terminal of diode D3, and one end of capacitor C1. The first terminal of MOSFET M1 is connected to the other end of resistor R12, the positive terminal of diode D3, the other end of capacitor C1, and the common point G1. The third terminal of MOSFET M1 is connected to the negative terminal of the DC input power supply -VIN.

[0026] When the circuit is operating normally, current is limited by resistor R3 and voltage is regulated by diode D3, which turns on MOSFET M1. When the input is reversed, MOSFET M1 does not conduct, protecting downstream devices.

[0027] In this embodiment: Please refer to Figure 1 The surge protection module includes resistor R4, diode D2, resistor R5, capacitor C2, capacitor C3, resistor R13, diode D4, and MOSFET M2. One end of resistor R4 is connected to the positive terminal of the DC input power supply (+VIN) and the positive terminal of the DC output power supply (+V0) via a switch. The other end of resistor R4 is connected to one end of capacitor C2, the negative terminal of diode D2, the overvoltage / undervoltage protection module, and the overcurrent protection module. The positive terminal of diode D2 is connected to one end of resistor R5. The other end of resistor R5 is connected to one end of capacitor C3, one end of resistor R13, the negative terminal of diode D4, and the second terminal of MOSFET M2. The first terminal of MOSFET M2 is connected to the other terminals of capacitor C2, capacitor C3, resistor R13, the positive terminal of diode D4, and the common point G2. The third terminal of MOSFET M2 is connected to the negative terminal of the DC output power supply (-V0).

[0028] When the switch is closed, resistors R4 and R5 limit the current and charge capacitor C3. As the voltage of capacitor C3 rises from 0V to 2.5V, MOSFET M2 operates in the variable resistance region, and its resistance gradually decreases from infinity, limiting the inrush current during power-on. When the voltage of capacitor C3 rises above 2.5V, (VIN-V D2 Since R13 / (R4+R5+R13) > 2.5V, MOSFET M2 operates in the saturation region and is fully turned on. The positive and negative terminals of the subsequent load are connected to the positive terminal +V0 and the negative terminal -V0 of the DC output power supply, respectively. Both MOSFETs M1 and M2 are turned on, and the circuit containing the subsequent load is connected. When the switch is open, the gate (second terminal) of MOSFET M2 is not driven, MOSFET M2 is turned off, and the output is shut down.

[0029] In this embodiment: Please refer to Figure 1 The overvoltage and undervoltage protection module includes resistors R6, R7, R8, R9, R11, R14, R16, and R17, capacitors C4 and C5, transistor Q3, three-terminal regulator IC2, and three-terminal regulator IC1. One end of resistor R6 is connected to one end of resistors R7, R8, and R9, the positive terminal of the DC input power supply (+VIN), and the positive terminal of the DC output power supply (+V0). The other end of resistor R7 is connected to one end of capacitor C4, one end of resistor R14, and the reference terminal of three-terminal regulator IC2. The negative terminal of three-terminal regulator IC2 is connected to the other end of resistor R8. One end of capacitor C5, the other end of resistor R9, one end of resistor R17, the reference terminal of three-terminal regulator IC1, the negative terminal of three-terminal regulator IC1 connected to the other end of resistor R6, one end of resistor R11, the other end of resistor R11 connected to one end of resistor R16, the base of transistor Q3, the collector of transistor Q3 connected to the surge protection module, the emitter of transistor Q3 connected to common point G2, the other end of resistor R16, the positive terminal of three-terminal regulator IC1, the positive terminal of three-terminal regulator IC2, the other end of resistor R17, the other end of resistor R14, the other end of capacitor C4, and the other end of capacitor C5.

[0030] When VIN*R14 / (R14+R7)>2.5V, the common point C is at a low level, the reference voltage of the three-terminal regulator IC1 is <2.5V, VIN*R16 / (R6+R11+R16)>0.7V, the transistor Q3 is turned on, pulling down the voltage of the common point E. The gate (second terminal) of the MOSFET M2 is not driven and is not turned on, thus shutting off the output. That is, changing the resistors R7 and R14 can set the input overvoltage protection value.

[0031] When VIN*R17 / (R17+R9) < 2.5V, the common point D is at a high level. When VIN*R16 / (R6+R11+R16) > 0.7V, transistor Q3 is turned on, MOSFET M2 is not driven at the gate and is not turned on, thus shutting off the output. That is, changing resistors R17 and R9 can set the input undervoltage protection value.

[0032] In this embodiment: Please refer to Figure 1 The overcurrent protection module includes resistors R1 and R2, transistors Q1 and Q2, resistors R10, R15, and R18, capacitor C6, and diode D1. One end of resistor R1 is connected to the positive terminal of the DC input power supply (+VIN) and the positive terminal of the DC output power supply (+V0). The other end of resistor R2 is connected to the collector of transistor Q2 and the negative terminal of diode D1. The positive terminal of diode D1 is connected to the surge protection module. The emitter of transistor Q2 is connected to the common point G1, one end of resistor R18, and one end of capacitor C6. The base of transistor Q2 is connected to one end of resistor R10 and one end of resistor R15. The other end of resistor R15 is connected to the other end of resistor R18, the other end of capacitor C6, the emitter of transistor Q1, and the common point G2. The other end of resistor R10 is connected to the other end of resistor R2, the collector of transistor Q1, and the base of transistor Q1.

[0033] Since the collector and base of transistor Q1 are connected, it can be considered equivalent to a diode. The sum of the voltages across resistors R10 and R15 remains at 0.7V, meaning the voltage across resistor R15 will not change with increasing input voltage. Resistor R18 samples the output current; when there is an overcurrent in the output, V... R18 +V R15 If the voltage is greater than 0.7V, transistor Q2 will conduct, pulling the common point E potential to 0.7V. Zener diode D2 will not conduct, and MOSFET M2 will not conduct due to lack of gate drive. Therefore, changing resistor R18 can set the output overcurrent protection value. When the output is off, VIN charges capacitor C2 through resistor R4. After a delay, the potential at common point A gradually increases. When it exceeds 2.5V, MOSFET M2 will fully conduct. If the output overcurrent fault persists, the above process repeats until the output overcurrent fault is resolved.

[0034] The working principle of this utility model is as follows: the current limiting and voltage regulating module is used to limit the voltage and current of the DC input power supply and provide reverse connection protection; the surge protection module is used to gradually reduce the impedance in the output load circuit by controlling the conduction of the switching transistor (specifically MOSFET M2) when power is applied, thereby achieving power-on surge protection; the overvoltage and undervoltage protection module is used to control the switching transistor to disconnect when the voltage of the DC input power supply is higher than the upper limit voltage threshold or lower than the lower limit voltage threshold; the overcurrent protection module is used to control the switching transistor to disconnect when the current flowing through the output load is higher than the upper limit current threshold.

[0035] This invention has multiple protection functions, enhancing system security.

[0036] Reverse polarity protection: By combining MOSFET control logic with diodes, it prevents damage to downstream equipment when the input polarity is reversed, reducing the risk of user misoperation.

[0037] Overcurrent protection: The current sampling resistor (R18) and transistor (Q2) are linked to monitor the output current in real time. In case of overload, the circuit is quickly cut off to prevent the device from burning out.

[0038] Input overvoltage / undervoltage protection: Through a voltage divider resistor network (such as R7, R14, R9, R17) and comparator logic, the input voltage threshold is dynamically adjusted to ensure stable operation in battery-powered scenarios and extend battery life.

[0039] This invention is compatible with multiple load types and does not require derating.

[0040] Surge suppression and soft start: By utilizing the linear conduction characteristics of the RC delay circuit (R4, R5, C3) and the MOSFET (M2), the capacitive load is smoothly charged, eliminating instantaneous current surges and avoiding the limitation of traditional relays requiring derating.

[0041] Resistive / capacitive load versatility: Optimized drive circuit design supports direct switching between resistive and capacitive loads, improving equipment utilization and scenario adaptability.

[0042] This invention features a compact design and cost optimization.

[0043] Fully discrete device architecture: The core circuit is built using common components such as resistors, MOSFETs, and transistors, eliminating the need for dedicated chips or mechanical contacts, which significantly reduces material costs (more than 40% lower than solid-state relays).

[0044] Miniaturization: Through highly integrated layout and mechanical-free design, its size is only 1 / 3 of that of a traditional relay, making it suitable for space-sensitive scenarios such as automotive and airborne applications.

[0045] This invention features long lifespan and high reliability.

[0046] No mechanical wear: Pure electronic switch control avoids the problems of contact oxidation or mechanical fatigue of traditional relays, and extends the life to more than 100,000 cycles (compared to about 50,000 cycles for traditional relays).

[0047] Adaptive protection mechanism: After the input undervoltage, overvoltage and output overcurrent faults are cleared, power supply is automatically restored, reducing manual intervention and improving system maintenance efficiency.

[0048] This invention simplifies operation and saves energy.

[0049] No external control power supply required: Power on / off control is achieved directly through the main power line, simplifying wiring and reducing additional power consumption (typical standby power consumption <0.1W).

[0050] Low conduction loss: The MOSFET (M2) has a low on-resistance of 10mΩ in the saturation region, reducing energy loss and making it suitable for high current (30A+) applications.

[0051] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects.

[0052] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A DC switch controller with surge suppression, characterized in that, The DC switching controller with surge suppression includes: The current limiting and voltage regulating module is used to limit the voltage and current of the DC input power supply and provide reverse connection protection. The surge protection module is used to gradually reduce the impedance in the output load circuit by controlling the conduction of the switching transistor when power is applied, thereby achieving power-on surge protection. The overvoltage and undervoltage protection module is used to control the switching transistor to disconnect when the voltage of the DC input power supply is higher than the upper voltage threshold or lower than the lower voltage threshold. The overcurrent protection module is used to control the switching transistor to disconnect when the current flowing through the load at the output terminal exceeds the upper limit current threshold. The current limiting and voltage regulating module is connected to the surge protection module, overvoltage and undervoltage protection module, and overcurrent protection module. The overvoltage and undervoltage protection module is connected to the surge protection module, and the overcurrent protection module is connected to the surge protection module.

2. The DC switch controller with surge suppression according to claim 1, characterized in that, The current limiting and voltage regulating module includes resistor R3, resistor R12, diode D3, capacitor C1, and MOSFET M1. One end of resistor R3 is connected to the positive terminal of the DC input power supply +VIN and the positive terminal of the DC output power supply +V0. The other end of resistor R3 is connected to the second terminal of MOSFET M1, one end of resistor R12, the negative terminal of diode D3, and one end of capacitor C1. The first terminal of MOSFET M1 is connected to the other end of resistor R12, the positive terminal of diode D3, the other end of capacitor C1, and the common point G1. The third terminal of MOSFET M1 is connected to the negative terminal of the DC input power supply -VIN.

3. The DC switch controller with surge suppression according to claim 1, characterized in that, The surge protection module includes resistor R4, diode D2, resistor R5, capacitor C2, capacitor C3, resistor R13, diode D4, and MOSFET M2. One end of resistor R4 is connected to the positive terminal of the DC input power supply (+VIN) and the positive terminal of the DC output power supply (+V0) via a switch. The other end of resistor R4 is connected to one end of capacitor C2, the negative terminal of diode D2, the overvoltage / undervoltage protection module, and the overcurrent protection module. The positive terminal of diode D2 is connected to one end of resistor R5. The other end of resistor R5 is connected to one end of capacitor C3, one end of resistor R13, the negative terminal of diode D4, and the second terminal of MOSFET M2. The first terminal of MOSFET M2 is connected to the other terminals of capacitor C2, capacitor C3, resistor R13, the positive terminal of diode D4, and the common point G2. The third terminal of MOSFET M2 is connected to the negative terminal of the DC output power supply (-V0).

4. The DC switch controller with surge suppression according to claim 3, characterized in that, The overvoltage and undervoltage protection module includes resistors R6, R7, R8, R9, R11, R14, R16, and R17, capacitors C4 and C5, transistor Q3, three-terminal regulator IC2, and three-terminal regulator IC1. One end of resistor R6 is connected to one end of resistors R7, R8, and R9, the positive terminal of the DC input power supply (+VIN), and the positive terminal of the DC output power supply (+V0). The other end of resistor R7 is connected to one end of capacitor C4, one end of resistor R14, and the reference terminal of three-terminal regulator IC2. The negative terminal of three-terminal regulator IC2 is connected to the other end of resistor R8. One end of capacitor C5, the other end of resistor R9, one end of resistor R17, the reference terminal of three-terminal regulator IC1, the negative terminal of three-terminal regulator IC1 connected to the other end of resistor R6, one end of resistor R11, the other end of resistor R11 connected to one end of resistor R16, the base of transistor Q3, the collector of transistor Q3 connected to the surge protection module, the emitter of transistor Q3 connected to common point G2, the other end of resistor R16, the positive terminal of three-terminal regulator IC1, the positive terminal of three-terminal regulator IC2, the other end of resistor R17, the other end of resistor R14, the other end of capacitor C4, and the other end of capacitor C5.

5. The DC switch controller with surge suppression according to claim 3, characterized in that, The overcurrent protection module includes resistors R1 and R2, transistors Q1 and Q2, resistors R10, R15, and R18, capacitor C6, and diode D1. One end of resistor R1 is connected to the positive terminal of the DC input power supply (+VIN) and the positive terminal of the DC output power supply (+V0). The other end of resistor R1 is connected to the collector of transistor Q2 and the negative terminal of diode D1. The positive terminal of diode D1 is connected to the surge protection module. The emitter of transistor Q2 is connected to the common point G1, one end of resistor R18, and one end of capacitor C6. The base of transistor Q2 is connected to one end of resistor R10 and one end of resistor R15. The other end of resistor R15 is connected to the other end of resistor R18, the other end of capacitor C6, the emitter of transistor Q1, and the common point G2. The other end of resistor R10 is connected to the other end of resistor R2, the collector of transistor Q1, and the base of transistor Q1.

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