Protection circuit, module and equipment applied to secondary power supply

Abstract

The embodiment of the invention relates to a protection circuit, a module and equipment applied to a secondary power supply. A pre-stage protection unit is used for leading the pressure relief of a first electromagnetic pulse and a second electromagnetic pulse on the input end of an L line and the input end of an N line into a grounding end through two branches respectively; filtering a common-mode interference signal and a differential-mode interference signal in the first input signal through a filtering unit to obtain a second input signal; and clamping the voltage of the second input signal to the maximum working voltage of the secondary power supply through the post-stage protection unit. The protection circuit adopts two-stage protection, the first stage can discharge high-voltage and large-current strong electromagnetic pulses, and the second stage can perform relatively accurate overvoltage protection, so that comprehensive protection on strong electromagnetic pulses such as nuclear electromagnetic pulses, lightning electromagnetic pulses, high-power microwaves and the like is realized, and the situation that the maximum withstand voltage of a secondary power supply is exceeded is avoided; the high electromagnetic pulse protection efficiency of the secondary power supply is maximized, and the high electromagnetic pulse protection device has the advantages of short response time, high discharge capacity, high insertion loss and the like.

Description

Technical Field

[0001] Embodiments of the present application relate to the field of electromagnetic protection technology, and in particular, to a protection circuit, module, and device applied to a secondary power supply. Background Art

[0002] Strong electromagnetic pulses include nuclear electromagnetic pulses, lightning electromagnetic pulses, high-power microwaves, etc. When coupled to the power line, strong electromagnetic pulses will generate overvoltage or overcurrent, which will damage the secondary power module. The strong electromagnetic pulse protection circuit is installed on the power port to absorb or discharge the strong electromagnetic pulse energy, which can protect the secondary power module. The protection circuit is generally composed of a series-parallel combination of a varistor, a gas discharge tube and a transient suppression diode. Due to the different characteristic parameters of the strong electromagnetic pulse, the topological structure of the protection circuit is also different. Therefore, it is necessary to design a comprehensive strong electromagnetic pulse protection circuit to improve the strong electromagnetic pulse protection capability of the secondary power supply. Summary of the invention

[0003] In view of this, the embodiments of the present application propose a protection circuit, module and device applied to a secondary power supply, aiming to design a comprehensive strong electromagnetic pulse protection circuit to enhance the strong electromagnetic pulse protection capability of the secondary power supply.

[0004] To achieve the above-mentioned purpose, an embodiment of the present application provides a protection circuit applied to a secondary power supply, including a front-stage protection unit, a filtering unit and a rear-stage protection unit which are arranged at the input end of the secondary power supply and are connected in series in sequence; wherein the front-stage protection unit is used to introduce the first electromagnetic pulse and the second electromagnetic pulse pressure relief on the input end of the L line and the input end of the N line to the ground end through two branches respectively; the filtering unit is used to filter out the common-mode interference signal and the differential-mode interference signal in the first input signal to obtain the second input signal; the rear-stage protection unit is used to suppress the voltage of the second input signal to the maximum operating voltage of the secondary power supply.

[0005] Optionally, the front-stage protection unit includes a first voltage limiting subunit and a second voltage limiting subunit, and the first voltage limiting subunit and the second voltage limiting subunit both include a first branch and a second branch connected in parallel; the first end of the first branch of the first voltage limiting subunit and the second voltage limiting subunit is respectively connected to the input end of the L line and the input end of the N line, and the second end of each is grounded; the first end of the second branch of the first voltage limiting subunit and the second voltage limiting subunit is respectively connected to the input end of the L line and the input end of the N line, and the second end of each is grounded; the first branch is used to introduce the first electromagnetic pulse to the ground terminal; the second branch is used to introduce the second electromagnetic pulse to the ground terminal, wherein the rise time of the second electromagnetic pulse is slower than the rise time of the first electromagnetic pulse.

[0006] Optionally, the first branch includes a first transient suppression diode, and the second branch includes a varistor and a gas discharge tube connected in series: the first end of the varistor is respectively connected to the input end of the L line or the input end of the N line, and the second end is connected to the first end of the gas discharge tube, and the second end of the gas discharge tube is grounded; the first end of the first transient suppression diode is connected to the input end of the L line or the input end of the N line, and the second end of the first transient suppression diode is grounded; wherein the first transient suppression diode is used to introduce the first electromagnetic pulse into the ground end to obtain a first clamping voltage; the varistor and the gas discharge tube are used to introduce a second electromagnetic pulse with a voltage value less than the first clamping voltage into the ground end.

[0007] Optionally, the first clamping voltage is greater than a breakdown voltage of the gas discharge tube, the breakdown voltage of the gas discharge tube is greater than a clamping voltage of the varistor, and the clamping voltage of the varistor is equal to a maximum operating voltage of the secondary power supply.

[0008] Optionally, the filtering unit includes a first resistor, a first differential mode capacitor, a two-stage common mode filtering subunit and a second differential mode capacitor; the first resistor and the first differential mode capacitor constitute an RC loop; the first resistor and the first differential mode capacitor are both connected in parallel between the input end of the L line and the input end of the N line; the two input ends of the two-stage common mode filtering subunit are connected in parallel between the input end of the L line and the input end of the N line, and the two output ends of the two-stage common mode filtering subunit are connected in parallel with the second differential mode capacitor; the RC loop is used to perform power-off protection on the input end of the secondary power supply; the two-stage common mode filtering subunit is used to eliminate common mode electromagnetic interference on the input end of the L line or the input end of the N line; the first differential mode capacitor and the second differential mode capacitor are both used to eliminate differential mode electromagnetic interference on the input end of the L line or the input end of the N line.

[0009] Optionally, the two-stage common-mode filtering subunit includes two first common-mode inductors, two first common-mode capacitors, two second common-mode inductors and two second common-mode capacitors: the two first input ends of the two first common-mode inductors are respectively connected to the input end of the L line and the input end of the N line, the two first output ends are respectively grounded through the two first common-mode capacitors, the first input ends of the two second common-mode inductors are respectively connected to the two first output ends, and the two second output ends are respectively grounded through the two second common-mode capacitors.

[0010] Optionally, the post-stage protection unit includes: a third voltage limiting subunit, a first end of which is connected to the input end of the L line, and a second end is grounded; a fourth voltage limiting subunit, a first end of which is connected to the input end of the N line, and a second end is grounded; the third voltage limiting subunit and the fourth voltage limiting subunit are respectively used to suppress the voltages of the two output ends of the two-stage common-mode filtering subunit to obtain the maximum operating voltage of the secondary power supply.

[0011] Optionally, the third voltage limiting subunit and the fourth voltage limiting subunit both include a second transient suppression diode; the first end of each of the two second transient suppression diodes is respectively connected to the two output ends of the two-stage common-mode filtering subunit, and the second end of each is grounded, and the clamping voltage of the two second transient suppression diodes is equal to the maximum operating voltage of the secondary power supply.

[0012] To achieve the above objectives, an embodiment of the present application further provides a protection module applied to a secondary power supply, which has a protection circuit applied to a secondary power supply provided by any of the above embodiments.

[0013] To achieve the above objectives, an embodiment of the present application further provides a protection device applied to a secondary power source, which has a protection module applied to a secondary power source provided by any of the above embodiments.

[0014] The embodiment of the present application proposes a protection circuit, module and device for a secondary power supply, which is used to discharge the first electromagnetic pulse and the second electromagnetic pulse on the input end of the L line and the input end of the N line through two branches to the ground end respectively through the front-stage protection unit; the common-mode interference signal and the differential-mode interference signal in the first input signal are filtered out by the filtering unit to obtain the second input signal; the voltage of the second input signal is suppressed to the secondary power supply equal to the maximum working voltage of the secondary power supply through the rear-stage protection unit. The protection circuit adopts two-stage protection, the first stage can discharge strong electromagnetic pulses with high voltage and high current, and the second stage can provide more accurate overvoltage protection, realizing comprehensive protection against strong electromagnetic pulses such as nuclear electromagnetic pulses, lightning electromagnetic pulses, and high-power microwaves, avoiding exceeding the maximum withstand voltage of the secondary power supply, and maximizing the protection efficiency of strong electromagnetic pulses of the secondary power supply, and has the advantages of fast response time, strong discharge capacity, and high insertion loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic diagram of a protection circuit applied to a secondary power supply provided in one embodiment of the present application;

[0016] Figure 2 is a circuit diagram of a protection circuit applied to a secondary power supply provided in one embodiment of the present application;

[0017] Figure 3A simulation of a protection circuit for a secondary power supply provided in an embodiment of the present application Figure 1 ;

[0018] Figure 4 A simulation of a protection circuit for a secondary power supply provided in an embodiment of the present application Figure 2 . DETAILED DESCRIPTION

[0019] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the embodiments of the present application will be described in detail below in conjunction with the accompanying drawings. However, it will be appreciated by those skilled in the art that in the present application, many technical details are proposed in order to enable the reader to better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical scheme claimed in the present application can also be implemented. The division of the following embodiments is for the convenience of description, and the specific implementation of the present application should not be limited in any way, and the various embodiments can be combined and referenced with each other without contradiction.

[0020] Figure 1 is a schematic diagram of a protection circuit for a secondary power supply provided in one embodiment of the present application, refer to Figure 1 The protection circuit 10 of the secondary power supply provided in the present application includes a front-stage protection unit 11, a filter unit 12 and a rear-stage protection unit 13 which are arranged at the input end of the secondary power supply and are connected in series in sequence; wherein the front-stage protection unit 11 is used to introduce the first electromagnetic pulse on the input end of the L line and the input end Nin of the N line and the second electromagnetic pulse pressure relief to the ground terminal GND through two branches respectively; the filter unit 12 is used to filter out the common-mode interference signal and the differential-mode interference signal in the first input signal to obtain the second input signal; the rear-stage protection unit 13 is used to suppress the voltage of the second input signal to the maximum working voltage of the secondary power supply.

[0021] It should be noted that strong electromagnetic pulses such as nuclear electromagnetic pulses, lightning electromagnetic pulses, and high-power microwaves are absorbed and discharged with most of their energy by the front-stage protection unit 11, and then clamped and absorbed by the rear-stage protection unit 13 to achieve more accurate overvoltage protection; the filter unit 12 filters out electromagnetic interference signals to improve the electromagnetic compatibility of the secondary power supply.

[0022] Specifically, the present invention uses a front-stage protection unit 11 to discharge the first electromagnetic pulse and the second electromagnetic pulse on the input terminal Lin of the L line and the input terminal Nin of the N line and introduce them into the ground terminal GND through two branches respectively; the filtering unit 12 is used to filter out the common-mode interference signal and the differential-mode interference signal in the first input signal to obtain the second input signal; the rear-stage protection unit 13 is used to suppress the voltage of the second input signal to a secondary power supply equal to the maximum working voltage of the secondary power supply. The first stage of the two-stage protection unit can discharge strong electromagnetic pulses with high voltage and large current, and the second stage can provide more accurate overvoltage protection, thereby realizing comprehensive protection against strong electromagnetic pulses such as nuclear electromagnetic pulses, lightning electromagnetic pulses, and high-power microwaves, avoiding exceeding the maximum withstand voltage of the secondary power supply, maximizing the protection efficiency of the strong electromagnetic pulses of the secondary power supply, and having the advantages of fast response time, strong discharge capacity, and high insertion loss.

[0023] In an embodiment of the present invention, the front-stage protection unit 11 includes a first voltage limiting subunit 111 and a second voltage limiting subunit 112, and the first voltage limiting subunit 111 and the second voltage limiting subunit 112 both include a first branch 113 and a second branch 114 connected in parallel; the first ends of the first branches of the first voltage limiting subunit 111 and the second voltage limiting subunit 112 are respectively connected to the input terminal Lin of the L line and the input terminal Nin of the N line, and the second ends of each are grounded; the first ends of the second branches 114 of the first voltage limiting subunit 111 and the second voltage limiting subunit 112 are respectively connected to the input terminal Lin of the L line and the input terminal Nin of the N line, and the second ends of each are grounded; the first branch 113 is used to introduce the first electromagnetic pulse into the ground terminal GND; the second branch 114 is used to introduce the second electromagnetic pulse into the ground terminal GND, wherein the rise time of the second electromagnetic pulse is slower than the rise time of the first electromagnetic pulse.

[0024] Specifically, the first branch includes a first transient suppression diode V1, and the second branch includes a varistor R1 and a gas discharge tube G1 connected in series. The first end of the varistor R1 is respectively connected to the input end Lin of the L line or the input end Nin of the N line, and the second end is connected to the first end of the gas discharge tube G1, and the second end of the gas discharge tube G1 is grounded. The first end of the first transient suppression diode V1 is connected to the input end Lin of the L line or the input end Nin of the N line, and the second end of the first transient suppression diode V1 is grounded, wherein the first transient suppression diode V1 is used to introduce the first electromagnetic pulse to the ground terminal GND to obtain the first clamping voltage; the varistor R1 and the gas discharge tube G1 are used to introduce the second electromagnetic pulse with a voltage value less than the first clamping voltage to the ground terminal GND.

[0025] When strong electromagnetic pulses with fast rise time such as nuclear electromagnetic pulses and high-power microwaves enter the input port, the first transient suppression diode V1 in the front-stage protection unit 11 responds quickly, and the voltage across the first transient suppression diode V1 is maintained at the first clamping voltage. The clamping voltage of the first transient suppression diode V1 is greater than the breakdown voltage of the gas discharge tube G1, causing the varistor R1 to act on the gas discharge tube G1 to discharge strong electromagnetic pulses with slow rise time.

[0026] Among them, when a strong electromagnetic pulse with a slow rise time such as a lightning electromagnetic pulse enters the input port, the varistor R1 in the front-stage protection unit 11 responds quickly, the resistance value drops sharply, and the varistor R1 is turned on, so that the voltage across the gas discharge tube G1 reaches the breakdown threshold, and the gas discharge tube G1 undergoes gas discharge, which drains the strong electromagnetic pulse to the ground. Since the gas discharge tube G1 has an arc discharge phenomenon, that is, the gas discharge tube G1 can maintain discharge for a period of time under a low voltage state after discharge, it cannot be restored in time under normal working conditions after the strong electromagnetic pulse has passed, and the discharge phenomenon still occurs. Therefore, it is necessary to combine with the varistor R1 to control the state recovery of the gas discharge tube G1. When the strong electromagnetic pulse is discharged to the clamping voltage of the varistor R1, the resistance value of the varistor R1 is restored, and it is in an open circuit state, so that the gas discharge tube G1 cannot maintain the discharge phenomenon. After the gas discharge tube G1 is used in series with the varistor R1, the gas discharge tube G1 can isolate the varistor R1 from the system in a discharge state, reducing the voltage and leakage current flowing through the varistor R1, thereby effectively slowing down the performance degradation of the varistor R1 and extending its service life.

[0027] In an embodiment of the present application, the first clamping voltage is greater than the breakdown voltage of the gas discharge tube G1, the breakdown voltage of the gas discharge tube G1 is greater than the clamping voltage of the varistor R1, and the clamping voltage of the varistor R1 is equal to the maximum operating voltage of the secondary power supply.

[0028] The resistance of the first resistor R2 is megohms, which is equivalent to an open circuit when the circuit is working normally, with almost no consumption. When the secondary power input is cut off, the first differential mode capacitor C1 and the first resistor R2 form a loop to consume the energy on the capacitor, protecting personnel from danger caused by capacitor discharge.

[0029] Exemplarily, the capacitance values ​​of the first differential mode capacitor C1 and the second differential mode capacitor C2 are both 1 μF, and the resistance value of the first resistor R2 is 1 MΩ.

[0030] In an embodiment of the present application, the two-stage common-mode filter subunit 115 includes two first common-mode inductors L1, two first common-mode capacitors C3, two second common-mode inductors L2 and two second common-mode capacitors C4, the two first input ends of the two first common-mode inductors L1 are respectively connected to the input end Lin of the L line and the input end Nin of the N line, the two first output ends are respectively grounded through the two first common-mode capacitors C3, the first input ends of the two second common-mode inductors L2 are respectively connected to the two first output ends, and the two second output ends are respectively grounded through the two second common-mode capacitors C4.

[0031] Specifically, when the rising edge of a strong electromagnetic pulse is at the sub-nanosecond level, the two first common-mode inductors L1 play a delay function. The frequency of a strong electromagnetic pulse with a sub-nanosecond rising edge is as high as hundreds of megahertz or even gigahertz. The two first common-mode inductors L1 and the two second common-mode inductors L2 are in a high impedance state at high frequencies, isolating the strong electromagnetic pulse, so that the front-stage protection unit 11 works and discharges the strong electromagnetic pulse. When the electromagnetic interference signal enters the input terminal Lin of the L line and the input terminal Nin of the N line, the two-stage common-mode filter subunit 115 is used to filter out the common-mode interference in the interference signal.

[0032] Exemplarily, the capacitive reactance value of the two first common-mode capacitors C3 may be 0.1 μF, the capacitive reactance value of the two second common-mode capacitors C4 may be 22 nF, and the inductive reactance values ​​of the two first common-mode inductors L1 and the two second common-mode inductors L2 may both be 10 mH.

[0033] Among them, the two first common-mode inductors L1 and the two second common-mode inductors L2 are two independent coils wound on the same magnetic ring, with the same number of turns and opposite winding directions. The magnetic flux generated by the current in the two coils cancels each other in the magnetic ring, and the magnetic ring will not reach a magnetic saturation state, so that the inductance of the two coils remains unchanged. However, due to the uneven material of the magnetic ring and the asymmetric winding of the two coils, the inductance of the two coils is not completely equal. The difference in their inductance can be used as a differential mode inductance to filter out differential mode interference in the interference signal.

[0034] In an embodiment of the present application, the post-stage protection unit 103 may include a third voltage limiting sub-unit 116 and a fourth voltage limiting sub-unit 117, wherein the first end of the third voltage limiting sub-unit 116 is connected to the input terminal Lin of the L line, and the second end is grounded; the first end of the fourth voltage limiting sub-unit 117 is connected to the input terminal Nin of the N line, and the second end is grounded; the third voltage limiting sub-unit 116 and the fourth voltage limiting sub-unit 117 are respectively used to suppress the voltages of the two output terminals of the two-stage common-mode filtering sub-unit 115 to obtain the maximum operating voltage of the secondary power supply.

[0035] Specifically, the third voltage limiting subunit 116 and the fourth voltage limiting subunit 117 both include a second transient suppression diode V2; the first ends of the two second transient suppression diodes V2 are respectively connected to the two output ends of the two-stage common mode filter subunit 115, and the second ends of the two second transient suppression diodes V2 are grounded, and the clamping voltages of the two second transient suppression diodes V2 are both equal to the maximum operating voltage of the secondary power supply. The third voltage limiting subunit 116 and the fourth voltage limiting subunit 117 can provide relatively accurate overvoltage protection for the secondary power supply.

[0036] like Figure 3 As shown, when the frequency is greater than 20 kHz, the insertion loss is greater than 40 dB (i.e., attenuation is 100 times); the differential mode interference signal is filtered out by the first differential mode capacitor C1 and the second differential mode capacitor C2 and the two first common mode inductors L1 and the two second common mode inductors L2, and the differential mode insertion loss is as follows: Figure 4 As shown, when the frequency is greater than 50k Hz, the insertion loss is greater than 40dB.

[0037] Based on the above embodiments, the present application also provides a secondary power supply protection module having the secondary power supply protection circuit provided by any of the above embodiments.

[0038] Based on the above embodiments, the present application further provides a secondary power supply protection device having the secondary power supply protection module provided by the above embodiments.

[0039] Those skilled in the art will appreciate that the above embodiments are specific embodiments for implementing the present application, and in actual applications, various changes may be made thereto in form and detail without departing from the spirit and scope of the present application.

Claims

1. A protection circuit for a secondary power supply, characterized in that: include: A front-stage protection unit, a filter unit and a rear-stage protection unit are arranged at the input end of the secondary power supply and connected in series in sequence; The front-stage protection unit is used to guide the first electromagnetic pulse and the second electromagnetic pulse of the input end of the L line and the input end of the N line to the ground end through two branches respectively; The filtering unit is used to filter out the common-mode interference signal and the differential-mode interference signal in the first input signal to obtain a second input signal; The post-stage protection unit is used to clamp the voltage of the second input signal to the maximum operating voltage of the secondary power supply.

2. A protection circuit for a secondary power supply according to claim 1, characterized in that: The front-stage protection unit includes a first voltage limiting subunit and a second voltage limiting subunit, and the first voltage limiting subunit and the second voltage limiting subunit both include a first branch and a second branch connected in parallel; The first ends of the first branches of the first voltage limiting subunit and the second voltage limiting subunit are respectively connected to the input end of the L line and the input end of the N line, and the second ends of the first branches are grounded; The first ends of the second branches of the first voltage limiting subunit and the second voltage limiting subunit are respectively connected to the input end of the L line and the input end of the N line, and the second ends of the second branches are grounded; The first branch is used to introduce the first electromagnetic pulse to the ground terminal; The second branch is used to introduce a second electromagnetic pulse to the ground terminal, wherein a rise time of the second electromagnetic pulse is slower than a rise time of the first electromagnetic pulse.

3. A protection circuit for a secondary power supply according to claim 2, characterized in that: The first branch includes a first transient suppression diode, and the second branch includes a varistor and a gas discharge tube connected in series: The first end of the varistor is connected to the input end of the L line or the input end of the N line respectively, the second end is connected to the first end of the gas discharge tube, the second end of the gas discharge tube is grounded, the first end of the first transient suppression diode is connected to the input end of the L line or the input end of the N line, and the second end of the first transient suppression diode is grounded; Wherein, the first transient suppression diode is used to introduce the first electromagnetic pulse into the ground terminal to obtain a first clamping voltage; The varistor and the gas discharge tube are used to introduce the second electromagnetic pulse having a voltage value less than the first clamping voltage to the ground terminal.

4. A protection circuit for a secondary power supply according to claim 3, characterized in that: The first clamping voltage is greater than the breakdown voltage of the gas discharge tube, the breakdown voltage of the gas discharge tube is greater than the clamping voltage of the varistor, and the clamping voltage of the varistor is equal to the maximum operating voltage of the secondary power supply.

5. A protection circuit for a secondary power supply according to claim 1, characterized in that: The filtering unit comprises a first resistor, a first differential mode capacitor, a two-stage common mode filtering sub-unit and a second differential mode capacitor; The first resistor and the first differential mode capacitor form an RC loop; The first resistor and the first differential mode capacitor are both connected in parallel between the input end of the L line and the input end of the N line; The two input ends of the two-stage common-mode filter subunit are connected in parallel between the input end of the L line and the input end of the N line, and the two output ends of the two-stage common-mode filter subunit are connected in parallel with the second differential mode capacitor; The RC circuit is used to protect the input end of the secondary power supply from power failure; The two-stage common mode filter subunit is used to eliminate the common mode electromagnetic interference on the input end of the L line and the input end of the N line; The first differential mode capacitor and the second differential mode capacitor are both used to eliminate differential mode electromagnetic interference on the input end of the L line and the input end of the N line.

6. A protection circuit for a secondary power supply according to claim 5, characterized in that: The two-stage common-mode filter subunit includes two first common-mode inductors, two first common-mode capacitors, two second common-mode inductors and two second common-mode capacitors: The first input ends of the two first common-mode inductors are respectively connected to the input end of the L line and the input end of the N line, and the first output ends of the two first common-mode inductors are respectively grounded through the two first common-mode capacitors; the first input ends of the two second common-mode inductors are respectively connected to the first output ends of the two second common-mode inductors, and the second output ends of the two second common-mode capacitors are respectively grounded.

7. The protection circuit for secondary power supply according to claim 6, characterized in that: The back-end protection unit comprises: A third voltage limiting subunit, a first end of which is connected to the input end of the L line, and a second end of which is grounded; A fourth voltage limiting subunit, a first end of which is connected to the input end of the N line, and a second end of which is grounded; The third voltage limiting subunit and the fourth voltage limiting subunit are respectively used to suppress the voltages of the two output ends of the two-stage common-mode filtering subunit to obtain the maximum operating voltage of the secondary power supply.

8. A protection circuit for a secondary power supply according to claim 7, characterized in that: The third voltage limiting subunit and the fourth voltage limiting subunit each include a second transient suppression diode; The first ends of the two second transient suppression diodes are respectively connected to the two output ends of the two second common-mode inductors, and the second ends of the two second transient suppression diodes are grounded. The clamping voltages of the two second transient suppression diodes are both equal to the maximum operating voltage of the secondary power supply.

9. A protection module applied to a secondary power supply, characterized in that: A protection circuit applied to a secondary power supply as described in any one of claims 1 to 7.

10. A protective device applied to a secondary power supply, characterized in that: A protection module applied to a secondary power supply as claimed in claim 9.

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