Surge current protection and suppression circuit

Abstract

The invention discloses a surge current protection and suppression circuit, which belongs to the field of avionics, and can control surge current more accurately by adjusting the resistance value of an adjusting resistor R2, and meanwhile, the debugging of the whole circuit is more convenient, and the flexibility and the practicability are stronger. The circuit mainly comprises an instruction control module M1 and a surge current suppression module M4, the instruction control module M1 comprises a magnetic latching relay K11, a power supply pin of the magnetic latching relay K11 is connected with a current limiting circuit, the surge current suppression module M4 comprises a divider resistor R1 and a divider resistor R4 which are connected in series, two ends of the divider resistor R1 are connected with an RC oscillation circuit in parallel, and the RC oscillation circuit is connected with a power supply pin of the magnetic latching relay K11. And the RC oscillating circuit is also connected with an adjusting resistor R2. The method is mainly used for surge current protection and suppression in the aviation field.

Description

Technical Field

[0001] The present invention relates to the field of avionics, and in particular to a surge current protection and suppression circuit. Background Art

[0002] With the rapid development of electronic technology, various electronic devices and systems are widely used in home appliances, communications, national defense, aviation and other fields. Therefore, the safety, reliability and quality of the power supply system have a huge impact on people's lives and work. Due to the presence of a large number of capacitive devices such as capacitors inside electronic equipment, the circuit has capacitive properties. At the moment of starting up high-power electronic equipment, a large charging current can be generated; in addition, due to the large power of the electronic equipment itself, the input working current is large, and the superposition of the instantaneous charging current and the input working current will produce a larger starting current. This instantaneous large starting current is the surge current. The surge current will not only damage the electronic equipment, but also interfere with and damage the power supply facilities, so the surge current must be suppressed.

[0003] In order to suppress the surge current, there are currently several solutions:

[0004] (1) Traditional method: Add a suitable negative temperature coefficient thermistor (NTC) to the power supply circuit, such as a surge suppression circuit and surge suppression method with publication number CN116207727A, which uses the characteristic that its impedance is affected by temperature to achieve the purpose of suppressing surge current; however, the surge suppression effect is poor when the power supply is repeatedly turned on and off for a short period of time.

[0005] (2) Using a surge suppressor solution: The MOS tube inside the DC surge suppressor is required to have a higher single avalanche energy (EAS single avalanche energy), but its on-resistance (Rds) is large and the loss is large under normal operating voltage, which is not suitable for equipment with strict power consumption requirements.

[0006] (3) Using controller and MOS tube solution: It requires a special PWM controller or single-chip microcomputer for control. The circuit design is complex and the risk is high. It is not suitable for aviation design requirements where the hardware is as simple as possible. Summary of the invention

[0007] The purpose of the present invention is to provide a surge current protection and suppression circuit, which can make the surge current control more precise by adjusting the resistance value of the regulating resistor R2, and at the same time make the debugging of the entire circuit more convenient, more flexible and more practical.

[0008] The present invention is achieved through the following technical solutions:

[0009] A surge current protection and suppression circuit comprises an instruction control module M1 and an surge current suppression module M4, wherein the instruction control module M1 comprises a magnetic latching relay K11, a power supply pin of the magnetic latching relay K11 is connected to a current limiting circuit, the surge current suppression module M4 comprises a voltage-dividing resistor R1 and a voltage-dividing resistor R4 connected in series, an RC oscillation circuit is connected in parallel at both ends of the voltage-dividing resistor R1, the RC oscillation circuit is further connected to an adjustment resistor R2, the adjustment resistor R2 is connected to the voltage-dividing resistor R1, the RC oscillation circuit is connected to a MOS tube Q1, the MOS tube Q1 is connected to a load module M5, the voltage-dividing resistor R1 is further connected to a surge current protection module M3, and the surge current protection module M3 is connected to a primary power supply module M2.

[0010] Furthermore, the RC oscillator circuit includes a filter circuit I, a filter circuit II and a current limiting resistor R3. The filter circuit I and the filter circuit II are connected in parallel and are respectively connected to the current limiting resistor R3 and the adjustment resistor R2. The drain D of the MOS tube Q1 is connected to the parallel end of the filter circuit I and the filter circuit II. The gate G of the MOS tube Q1 is connected to the current limiting resistor R3. The source S of the MOS tube Q1 is connected to the load module M5.

[0011] Furthermore, the filter circuit I includes a filter capacitor C1 and a filter capacitor C3, and the filter circuit II includes a filter capacitor C2 and a filter capacitor C4. The filter capacitor C1 and the filter capacitor C3 are connected in series. The filter capacitor C1 and the filter capacitor C3 are connected in series.

[0012] Furthermore, the current limiting circuit includes a current limiting resistor R30, a current limiting resistor R31, a current limiting resistor R8 and a current limiting resistor R10. The current limiting resistor R30 and the current limiting resistor R31 are connected in parallel to the X1 end of the magnetic latching relay K11. The X2 end of the magnetic latching relay K11 is connected in series with a diode D2 and a diode D1, and the diode D1 is connected to the X1 end of the magnetic latching relay K11; the current limiting resistor R8 and the current limiting resistor R10 are connected in parallel to the Y1 end of the magnetic latching relay K11. The Y2 end of the magnetic latching relay K11 is connected in series with a diode D4 and a diode D3, and the diode D3 is connected to the Y1 end of the magnetic latching relay K11. The A3 end of the magnetic latching relay K11 is connected to the voltage divider resistor R1.

[0013] Furthermore, the surge current protection module M3 includes a fuse F1, a fuse F2 and a protective resistor R5. The fuse F2 and the protective resistor R5 are connected in series and then in parallel with the fuse F1. The parallel ends of the protective resistor R5 and the fuse F1 are connected to the primary power supply module M2. On the one hand, it can play a role in current derating, and on the other hand, it can improve the fuse's ability to resist surge current, increase the number of times the line can withstand surge current, and play a double insurance role.

[0014] Furthermore, the primary power supply module M2 is a satellite solar power supply circuit.

[0015] Furthermore, the load module M5 is a load resistor R20.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. It is built with discrete devices, which makes the circuit simple, easy to build and low cost; the magnetic latching relay has strong anti-interference ability and stable power supply.

[0018] 2. The parallel fuse design can improve the fuse's surge resistance, increase the number of times the line can withstand surge current, delay the circuit power-off time, and play a double insurance role.

[0019] 3. By adjusting the resistance of the regulating resistor R2, the surge current can be controlled more accurately, and the debugging of the entire circuit can be more convenient, more flexible and more practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a circuit schematic diagram of the present invention. DETAILED DESCRIPTION

[0021] The present invention will be further described below in conjunction with the accompanying drawings.

[0022] Example 1

[0023] like Figure 1 As shown, a surge current protection and suppression circuit includes a command control module M1 and a surge current suppression module M4, wherein the command control module M1 includes a magnetic latching relay K11, and the power pin of the magnetic latching relay K11 is connected to a current limiting circuit, and the surge current suppression module M4 includes a voltage-dividing resistor R1 and a voltage-dividing resistor R4 connected in series, and an RC oscillation circuit is connected in parallel at both ends of the voltage-dividing resistor R1, and the RC oscillation circuit is also connected to an adjustment resistor R2, and the adjustment resistor R2 is connected to the voltage-dividing resistor R1, and the RC oscillation circuit is connected to a MOS tube Q1, and the MOS tube Q1 is connected to a load module M5, and the voltage-dividing resistor R1 is also connected to a surge current protection module M3, and the surge current protection module M3 is connected to a primary power supply module M2.

[0024] Example 2

[0025] A surge current protection and suppression circuit, the RC oscillation circuit comprises a filter circuit I, a filter circuit II and a current limiting resistor R3, the filter circuit I and the filter circuit II are connected in parallel and are respectively connected to the current limiting resistor R3 and the regulating resistor R2, the drain D of the MOS tube Q1 is connected to the parallel end of the filter circuit I and the filter circuit II, the gate G of the MOS tube Q1 is connected to the current limiting resistor R3, and the source S of the MOS tube Q1 is connected to the load module M5; the filter circuit I comprises a filter capacitor C1 and a filter capacitor C3, the filter circuit II comprises a filter capacitor C2 and a filter capacitor C4, the filter capacitor C1 and the filter capacitor C3 are connected in series, and the filter capacitor C1 and the filter capacitor C3 are connected in series; the current limiting circuit comprises a current limiting resistor R30, a current limiting resistor R31, a current limiting resistor R8 and a current limiting resistor R10, the current limiting resistor R30 and the current limiting resistor R31 are connected in parallel and are connected to the X1 end of the magnetic latching relay K11, the X2 end of the magnetic latching relay K11 is connected in series with a diode D2 and a diode D1, and the diode D1 is connected to the magnetic latching relay K11 11 is connected to the X1 end of the magnetic latching relay K11; the current limiting resistor R8 and the current limiting resistor R10 are connected in parallel and connected to the Y1 end of the magnetic latching relay K11, the Y2 end of the magnetic latching relay K11 is connected in series with a diode D4 and a diode D3, the diode D3 is connected to the Y1 end of the magnetic latching relay K11, and the A3 end of the magnetic latching relay K11 is connected to the voltage divider resistor R1; the surge current protection module M3 includes a fuse F1, a fuse F2 and a protection resistor R5, the fuse F2 and the protection resistor R5 are connected in series and then connected in parallel with the fuse F1, and the parallel end of the protection resistor R5 and the fuse F1 is connected to a primary power module M2; on the one hand, it can play a role in current derating, and on the other hand, it can achieve the purpose of improving the ability of the fuse to resist surge current, increase the number of times the line withstands surge current, and play a role of double insurance; the primary power module M2 is a satellite solar power supply circuit (existing technology), which provides a primary power supply for the subsequent load; the load module M5 is a load resistor R20 or other energy consumption circuit, and the rest is the same as Example 1.

[0026] Instruction control module M1: POWER_CTRL+ is connected to the positive pole of the control power supply. The coil of the magnetic latching relay K11 is not energized by default. The internal contacts A2 and A3 of the magnetic latching relay K11 are connected. At this time, both ends of the voltage divider resistor R1 are the primary power supply voltage VCC, and the VGS of the MOS tube Q1 is 0V, which is not conductive; when the device needs to be powered on, a low-level pulse control instruction is given to POWER_ON, which makes the internal coil of the magnetic latching relay K11 energized instantly, and the contacts A2 and A1 are connected. At this time, the contacts The voltage of A3 is the divided voltage of the voltage-dividing resistor R1 and the voltage-dividing resistor R4, UA3 = VCC_M*R4 / (R1+R4). At this time, the VGS of the MOS tube Q1 is less than 0V, it is turned on, and the load is powered. When the power supply of the device needs to be disconnected, a low-level pulse control instruction is given to POWER_DOWN, so that the internal coil of the magnetic latching relay K11 is instantly de-energized, and the contact A2 and the contact A3 are connected. Both ends of the voltage-dividing resistor R1 are the primary power supply voltage VCC, and the VGS of the MOS tube Q1 is 0V. The path is disconnected and the load loses power. Diodes D1-D4 are Schottky diodes and are connected in parallel at both ends of the coil. The main function is to freewheel, prevent voltage and current mutations when the coil is turned on and off, and protect the components in the circuit from being damaged.

[0027] Surge current protection module M3: When a surge current occurs at the moment the equipment is turned on, fuse F1 carries the main current. When the surge lasts for a certain time or a certain number of times, it will reach the melting point and burn out. If the surge still continues at this time, fuse F2 begins to carry the entire surge current until it burns out. When the surge is eliminated or the peak current is reduced or the number of times is not enough to cause fuse F2 to burn out, fuse F2 can ensure the normal operation of the circuit. When a line fails or a short-circuit current is generated, fuse F1 and fuse F2 will burn out in turn to protect the subsequent circuit. Under the same surge current conditions, this parallel circuit design can improve the surge resistance of the fuse, increase the number of times the line can withstand surge current, delay the power-off time of the circuit, and play a double insurance role.

[0028] Surge current suppression module M4: The present invention can easily change the RC time constant by only changing the resistance of the adjustment resistor R2 (in the traditional circuit, it is necessary to adjust the capacitance of each filter capacitor or adjust the resistance of the voltage divider resistor R4, but after adjusting the voltage divider resistor R4, in order to ensure that the final VGS voltage remains unchanged, the resistance of the voltage divider resistor R1 also needs to be changed, so the debugging of the entire circuit is very cumbersome), without having to adjust the resistance of the voltage divider resistor R1 and the voltage divider resistor R4 at the same time, thereby making the entire circuit more flexible, convenient and practical.

Claims

1. A surge current protection and suppression circuit, comprising a command control module M1 and a surge current suppression module M4, characterized in that: The instruction control module M1 includes a magnetic latching relay K11, a power pin of the magnetic latching relay K11 is connected to a current limiting circuit, an inrush current suppression module M4 includes a voltage-dividing resistor R1 and a voltage-dividing resistor R4 connected in series, an RC oscillation circuit is connected in parallel at both ends of the voltage-dividing resistor R1, the RC oscillation circuit is also connected to an adjustment resistor R2, the adjustment resistor R2 is connected to the voltage-dividing resistor R1, the RC oscillation circuit is connected to a MOS tube Q1, the MOS tube Q1 is connected to a load module M5, the voltage-dividing resistor R1 is also connected to a surge current protection module M3, and the surge current protection module M3 is connected to the primary power supply module M2.

2. The surge current protection and suppression circuit according to claim 1, characterized in that: The RC oscillator circuit includes a filter circuit I, a filter circuit II and a current limiting resistor R3. The filter circuit I and the filter circuit II are connected in parallel and are respectively connected to the current limiting resistor R3 and the adjustment resistor R2. The drain D of the MOS tube Q1 is connected to the parallel end of the filter circuit I and the filter circuit II. The gate G of the MOS tube Q1 is connected to the current limiting resistor R3. The source S of the MOS tube Q1 is connected to the load module M5.

3. The surge current protection and suppression circuit according to claim 2, characterized in that: The filter circuit I includes filter capacitors C1 and C3, and the filter circuit II includes filter capacitors C2 and C4. The filter capacitors C1 and C3 are connected in series. The filter capacitors C1 and C3 are connected in series.

4. The surge current protection and suppression circuit according to claim 1, characterized in that: The current limiting circuit includes a current limiting resistor R30, a current limiting resistor R31, a current limiting resistor R8 and a current limiting resistor R10. The current limiting resistor R30 and the current limiting resistor R31 are connected in parallel to the X1 end of the magnetic latching relay K11. The X2 end of the magnetic latching relay K11 is connected in series with a diode D2 and a diode D1, and the diode D1 is connected to the X1 end of the magnetic latching relay K11; the current limiting resistor R8 and the current limiting resistor R10 are connected in parallel to the Y1 end of the magnetic latching relay K11. The Y2 end of the magnetic latching relay K11 is connected in series with a diode D4 and a diode D3, and the diode D3 is connected to the Y1 end of the magnetic latching relay K11. The A3 end of the magnetic latching relay K11 is connected to the voltage divider resistor R1.

5. The surge current protection and suppression circuit according to claim 1, characterized in that: The surge current protection module M3 includes a fuse F1, a fuse F2 and a protective resistor R5. The fuse F2 and the protective resistor R5 are connected in series and then connected in parallel with the fuse F1. The parallel end of the protective resistor R5 and the fuse F1 is connected to the primary power supply module M2. On the one hand, it can play a role in current derating, and on the other hand, it can improve the fuse's ability to resist surge current, increase the number of times the line can withstand surge current, and play a double insurance role.

6. The surge current protection and suppression circuit according to claim 1, characterized in that: The primary power supply module M2 is a satellite solar power supply circuit.

7. The surge current protection and suppression circuit according to claim 1, characterized in that: The load module M5 is a load resistor R20.

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