Filtering module with rapid voltage discharge and reversed polarity protection functions

Abstract

The utility model relates to the technical field of high-capacity capacitors, and discloses a filtering module with fast voltage discharge and reversed polarity protection functions, which comprises a reversed polarity protection circuit; a voltage rapid bleeder circuit; a filter circuit; when an interference signal flows backward from electric equipment to a power supply, the filter circuit effectively suppresses the interference signal or guides the interference signal to the ground, thereby achieving the purpose of suppressing line interference. When a line is connected to a power supply according to a normal polarity, the voltage rapid discharge circuit is in an unexcited state and basically does not consume electric energy, so that the heating is extremely low when the circuit works normally; when a line power supply is cut off, the voltage rapid discharge circuit is immediately activated to rapidly release electric energy stored in each energy storage unit of rear-end equipment, and in conclusion, the filtering module integrates a reversed polarity protection function and a rapid voltage discharge function on the basis that the electromagnetic compatibility requirement is met; the purposes of stable work, high reliability, low heating and high efficiency are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of large-capacity capacitors, and particularly to a filtering module with functions of rapid voltage discharge and reverse-polarity protection. Background Art

[0002] With the extensive use of DC / DC modules in electrical equipment, in order to ensure the stable operation of DC / DC modules and other electrical units, more and more large-capacity capacitors are applied to all levels of electrical equipment units. As a result, after the power supply at the system inlet is cut off, a large amount of electrical energy still remains stored in the capacitors, and some electrical units cannot stop working in time, posing a certain safety risk. For large-capacity capacitor components, the currently mainstream ones are still polarized electrolytic capacitors. When a negative voltage appears in the circuit, such capacitors are prone to breakdown and even explosion risks. Therefore, it is particularly important to add reverse-polarity protection and rapid residual voltage discharge functions to the circuit.

[0003] At the same time, according to GJB1389A-2005 "System Electromagnetic Compatibility Requirements", electrical equipment needs to meet electromagnetic compatibility requirements. In electrical equipment, when DC / DC modules and other electrical units are working, they will generate a large amount of electromagnetic interference noise, resulting in the system being unable to pass the test items specified in GJB151B. Therefore, filtering treatment measures must be added to the power supply system circuit of electrical equipment.

[0004] Currently, mature reverse-polarity protection usually uses diodes to build a circuit to achieve it. The rapid voltage release circuit usually adds a power resistor between lines or uses transistors, IGBT devices to build a switching circuit to achieve discharge. The above methods have defects such as high circuit heating and large reactive power loss, and cannot meet the requirements of large-power and large-current electrical use places.

[0005] Therefore, we need to propose a filtering module with functions of rapid voltage discharge and reverse-polarity protection, which has stable operation, strong reliability, low heat generation, high efficiency, and integrates reverse-polarity protection function and rapid voltage discharge function, while meeting electromagnetic compatibility requirements. Summary of the Utility Model

[0006] The purpose of the present utility model is to provide a filtering module with functions of rapid voltage discharge and reverse polarity protection. Through the design of the filtering circuit, when interference signals pour from the electrical equipment to the power supply, the filtering circuit can effectively suppress the interference signals or direct them to the ground, achieving the purpose of suppressing line interference. Through the design of the reverse polarity protection circuit, when the line is connected to the power supply with the normal polarity, the voltage rapid discharge circuit is in an unactivated state, and the voltage rapid discharge circuit basically does not consume electric energy. Therefore, when this circuit is working normally, the heat generation is extremely low. When the line power supply is disconnected, the voltage rapid discharge circuit is immediately activated to quickly release the electric energy stored in each energy storage unit of the rear-end equipment. In summary, on the basis of meeting the requirements of electromagnetic compatibility, this filtering module integrates the functions of reverse polarity protection and rapid voltage discharge, achieving the purpose of stable operation, strong reliability, low heat generation, and high efficiency, so as to solve the problems raised in the above background technology.

[0007] To achieve the above object, the present utility model provides the following technical solution: A filtering module with functions of rapid voltage discharge and reverse polarity protection, comprising:

[0008] A reverse polarity protection circuit for quickly cutting off the circuit to prevent current backflow or reverse voltage application to the circuit when the power input terminal is reversely connected;

[0009] A voltage rapid discharge circuit for quickly releasing the electric energy stored in the energy storage device of the rear-end equipment after the power supply is cut off;

[0010] A filtering circuit for filtering out the interference noise generated by the input power supply and the electrical equipment;

[0011] The reverse polarity protection circuit, the voltage rapid discharge circuit, and the filtering circuit are connected in sequence, and the reverse polarity protection circuit is connected to the input terminal of the power supply, and the filtering circuit is connected to the output terminal of the power supply.

[0012] Preferably, the reverse polarity protection circuit includes a MOS transistor Q1 connected to the positive input terminal of the power supply, a resistor R2 connected to the negative input terminal of the power supply, one end of the resistor R2 is connected to the G pole of the MOS transistor Q1, and a zener diode D1 and a resistor R1 connected in parallel are connected between the G pole and the S pole of the MOS transistor Q1.

[0013] Preferably, the voltage rapid discharge circuit includes a triode Q2 and a MOS transistor Q3. A diode D2 and a resistor R3 are connected between the base of the triode Q2 and the D pole of the MOS transistor Q1. A zener diode D3 and a resistor R4 connected in parallel are also connected to the base of the triode Q2. One end of the emitter of the triode Q2, one end of the zener diode D3, and one end of the resistor R4 are all connected to the negative input terminal of the power supply.

[0014] Preferably, a voltage stabilizing diode D4 and a capacitor C1 are connected in parallel between the collector and the emitter of the triode Q2. A resistor R5 and a resistor R7 are connected between the G pole and the D pole of the MOS transistor Q3, and the G pole of the MOS transistor Q3 is connected to the connection terminal of the voltage stabilizing diode D4 and the capacitor C1. The connection terminals of the resistor R5 and the resistor R7 are connected to the S pole of the MOS transistor Q1.

[0015] Preferably, the filter circuit includes a common mode inductor L3, a differential mode inductor L1 and a differential mode inductor L2 connected in parallel. One end of the differential mode inductor L1 is connected to the connection terminal of the resistor R5 and the resistor R7. One end of the differential mode inductor L2 is connected to the S pole of the MOS transistor Q3. A capacitor C2 is connected between one side of the differential mode inductor L1 and one side of the differential mode inductor L2. A capacitor C3 is connected between the other side of the differential mode inductor L1 and the other side of the differential mode inductor L2.

[0016] Preferably, a capacitor C4 and a capacitor C5 connected in series are connected in parallel to one side of the common mode inductor L3. The capacitor C4 is connected to the differential mode inductor L1. The capacitor C5 is connected to the differential mode inductor L2.

[0017] Preferably, a capacitor C6, and a capacitor C7 and a capacitor C8 connected in series are connected in parallel to the other side of the common mode inductor L3. One end of the capacitor C7 is connected to the positive output terminal of the power supply. One end of the capacitor C8 is connected to the negative output terminal of the power supply.

[0018] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0019] Through the design of the filter circuit, when the interference signal is inverted from the electrical equipment to the power supply, the filter circuit effectively suppresses the interference signal or guides it to the ground, achieving the purpose of suppressing line interference.

[0020] Through the design of the reverse polarity protection circuit, when the circuit is connected to the power supply in the normal polarity, the voltage rapid discharge circuit is in an unexcited state, and the voltage rapid discharge circuit basically does not consume electric energy. Therefore, when this circuit is working normally, the heat generation is extremely low.

[0021] When the line power supply is disconnected, the voltage rapid discharge circuit is immediately activated to quickly release the electric energy stored in each energy storage unit of the rear-end equipment.

[0022] In summary, on the basis of meeting the electromagnetic compatibility requirements, this filter module integrates the reverse polarity protection function and the fast voltage discharge function, achieving the purpose of stable operation, strong reliability, low heat generation and high efficiency. Description of the Drawings

[0023] Figure 1 It is the circuit diagram of the present utility model. Detailed Embodiment

[0024] Next, in conjunction with the accompanying drawings in the embodiments of the present utility model, the technical solutions in the embodiments of the present utility model will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0025] Please refer to Figure 1 , the present utility model provides a technical solution: a filtering module with fast voltage discharge and reverse polarity protection functions, including:

[0026] A reverse polarity protection circuit for quickly cutting off the circuit to prevent current backflow or reverse voltage from being applied to the circuit when the power input end is reversely connected;

[0027] When the circuit is connected to the power supply with the normal polarity, the low on-resistance MOS device (MOS transistor Q1) on the positive line is in a fully conducting state at this time, and the voltage signal normally supplies power to the electrical equipment through the circuit. And at this time, the voltage fast discharge circuit is in an unexcited state, and the circuit basically does not consume electric energy. Therefore, when the circuit is working normally, the heat generation is extremely low.

[0028] When a reverse voltage is applied to the circuit inlet end, the low on-resistance MOS device (MOS transistor Q1) on the positive line is in a cut-off state at this time, and the circuit current cannot flow normally. Therefore, no voltage drop can be formed at the inlet end of the subsequent electrical equipment, which can effectively protect the safety of the subsequent polar electrical units.

[0029] A voltage fast discharge circuit for quickly releasing the electric energy stored in the energy storage device of the subsequent device after the power supply is cut off;

[0030] When the circuit power supply is disconnected, at this time, after the voltage fast discharge circuit detects the power-off state, it immediately activates the voltage fast discharge circuit to quickly release the electric energy stored in each energy storage unit of the subsequent device until the voltage is basically 0V.

[0031] A filtering circuit for filtering out the interference noises generated by the input power supply and the electrical equipment, and the interference noises include differential mode interference noises and common mode interference noises;

[0032] When differential mode or common mode interference signals are poured in from the power supply inlet end or backflow from the electrical equipment end to the power supply end, the filtering circuit effectively suppresses or guides the differential and common mode interferences in the circuit to the ground through the internal inductors and capacitors, so as to achieve the purpose of suppressing the circuit interference.

[0033] This application integrates the functions of reverse polarity protection, voltage fast discharge, and electromagnetic interference suppression, and can stably and reliably implement various protection functions;

[0034] The circuit function is constructed by using PMOS devices with low on-resistance. The circuit structure is simple, and its function is independent of other functional circuits, with rapid, stable, and reliable response. The circuit can expand the working current by paralleling multiple PMOS devices;

[0035] Relying on the reverse polarity protection circuit, a voltage signal is taken from the circuit input end by a diode and compared with the voltage at the circuit output end, and a functional circuit is constructed using a power MOS device and a power resistor. On the premise of ensuring that the circuit has low power consumption and does not lose the reverse polarity protection function during normal operation, the function of quickly discharging the residual voltage of the electrical equipment is realized;

[0036] An LC filter circuit is constructed by using a common-mode inductor, a differential-mode inductor, and a capacitor to suppress differential-mode and common-mode interference noises in the range of 10 kHz to 30 MHz.

[0037] The reverse polarity protection circuit, the voltage rapid discharge circuit, and the filter circuit are connected in sequence, and the reverse polarity protection circuit is connected to the input end of the power supply, and the filter circuit is connected to the output end of the power supply.

[0038] The reverse polarity protection circuit includes a MOS transistor Q1 connected to the positive input end of the power supply, a resistor R2 connected to the negative input end of the power supply, one end of the resistor R2 is connected to the G pole of the MOS transistor Q1, and a zener diode D1 and a resistor R1 are connected in parallel between the G pole and the S pole of the MOS transistor Q1.

[0039] When a positive voltage enters the circuit, the voltage division of the resistor R1 and the resistor R2 makes the voltage at the G pole of the MOS transistor Q1 lower than the voltage at the S pole, and the voltage is limited to about 15V by using the zener diode D1. At this time, the MOS transistor Q1 is in the conducting state, and the power supply voltage normally supplies power to the backend device through this circuit.

[0040] When a reverse polarity voltage appears at the input end, the zener diode D1 conducts in the reverse direction, causing the MOS transistor Q1 to cut off, and the circuit is in the open circuit mode. The reverse voltage cannot reach the backend electrical equipment through the circuit, thereby protecting the safety of the backend electrical equipment.

[0041] The voltage rapid discharge circuit includes a triode Q2 and a MOS transistor Q3. A diode D2 and a resistor R3 are connected between the base of the triode Q2 and the D pole of the MOS transistor Q1. A zener diode D3 and a resistor R4 are also connected in parallel to the base of the triode Q2. One end of the emitter of the triode Q2, one end of the zener diode D3, and one end of the resistor R4 are all connected to the negative input end of the power supply.

[0042] A zener diode D4 and a capacitor C1 are connected in parallel between the collector and the emitter of the triode Q2. A resistor R5 and a resistor R7 are connected between the G pole and the D pole of the MOS transistor Q3, and the G pole of the MOS transistor Q3 is connected to the connection terminal of the zener diode D4 and the capacitor C1. The connection terminals of the resistor R5 and the resistor R7 are connected to the S pole of the MOS transistor Q1.

[0043] When the circuit is powered on and working normally, the voltage after voltage division by the resistor R3 and the resistor R4 causes the triode Q2 to conduct. The zener diode D3 is used to ensure that the base voltage of the triode Q2 is within a safe range. At this time, the G pole voltage of the MOS transistor Q3 is pulled down to about 0.3V, and the MOS transistor Q3 is turned off. The voltage fast discharge circuit is in a non-working state.

[0044] When the power supply at the Vi terminal is disconnected, the base voltage of the triode Q2 becomes zero, the triode Q2 is turned off, and the resistor R5 and the resistor R6 divide the voltage to charge the capacitor C1, limiting the G pole voltage of the MOS transistor Q3 within the regulated voltage value of the zener diode D4. At this time, the MOS transistor Q3 conducts, and the resistor R7 and the MOS transistor Q3 form a voltage discharge circuit to quickly release the electrical energy in the energy storage device of the backend device until it drops to about 0V.

[0045] The filtering circuit includes a common-mode inductor L3, a differential-mode inductor L1 and a differential-mode inductor L2 connected in parallel. One end of the differential-mode inductor L1 is connected to the connection terminal of the resistor R5 and the resistor R7. One end of the differential-mode inductor L2 is connected to the S pole of the MOS transistor Q3. A capacitor C2 is connected between one side of the differential-mode inductor L1 and one side of the differential-mode inductor L2. A capacitor C3 is connected between the other side of the differential-mode inductor L1 and the other side of the differential-mode inductor L2.

[0046] A capacitor C4 and a capacitor C5 connected in series are connected in parallel on one side of the common-mode inductor L3. The capacitor C4 is connected to the differential-mode inductor L1. The capacitor C5 is connected to the differential-mode inductor L2.

[0047] The connection terminals of the capacitor C4 and the capacitor C5 are grounded.

[0048] A capacitor C6, and a capacitor C7 and a capacitor C8 connected in series are connected in parallel on the other side of the common-mode inductor L3. One end of the capacitor C7 is connected to the positive output terminal of the power supply. One end of the capacitor C8 is connected to the negative output terminal of the power supply.

[0049] The connection terminals of the capacitor C7 and the capacitor C8 are grounded.

[0050] The filter circuit filters out the differential-mode and common-mode interference noises generated by the input power supply and electrical equipment. It can provide an insertion loss of about 60 dB at the DC / DC switching frequency points from 200 kHz to 300 kHz, and has good insertion loss characteristics in the wide frequency band range from 10 kHz to 30 MHz.

[0051] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A filtering module with fast voltage discharge and reverse polarity protection functions, characterized in that Including: An anti-polarity protection circuit for quickly cutting off the circuit to prevent current backflow or reverse voltage application to the circuit when the power input terminal is reversely connected; A voltage rapid discharge circuit for quickly releasing the electric energy in the energy storage device of the backend device after the power supply is cut off; A filtering circuit for filtering out the interference noise generated by the input power supply and the electrical equipment; The anti-polarity protection circuit, the voltage rapid discharge circuit, and the filtering circuit are connected in sequence, and the anti-polarity protection circuit is connected to the input terminal of the power supply, and the filtering circuit is connected to the output terminal of the power supply.

2. The filtering module with a fast voltage discharge and reverse polarity protection function according to claim 1, wherein: The anti-polarity protection circuit includes an MOS transistor Q1 connected to the positive input terminal of the power supply and a resistor R2 connected to the negative input terminal of the power supply. One end of the resistor R2 is connected to the G pole of the MOS transistor Q1, and a zener diode D1 and a resistor R1 connected in parallel are connected between the G pole and the S pole of the MOS transistor Q1.

3. The filtering module with the functions of fast voltage discharge and reverse polarity protection according to claim 2, characterized in that: The voltage rapid discharge circuit includes a triode Q2 and an MOS transistor Q3. A diode D2 and a resistor R3 are connected between the base of the triode Q2 and the D pole of the MOS transistor Q1. A zener diode D3 and a resistor R4 connected in parallel are also connected to the base of the triode Q2. One end of the emitter of the triode Q2, one end of the zener diode D3, and one end of the resistor R4 are all connected to the negative input terminal of the power supply.

4. The filtering module with a fast voltage discharge and reverse polarity protection function according to claim 3, characterized in that: A zener diode D4 and a capacitor C1 connected in parallel are connected between the collector and the emitter of the triode Q2. A resistor R5 and a resistor R7 are connected between the G pole and the D pole of the MOS transistor Q3, and the G pole of the MOS transistor Q3 is connected to the connection terminal of the zener diode D4 and the capacitor C1. The connection terminal of the resistor R5 and the resistor R7 is connected to the S pole of the MOS transistor Q1.

5. A filtering module with a fast voltage discharge and reverse polarity protection function according to claim 4, characterized in that: The filtering circuit includes a common-mode inductor L3, a differential-mode inductor L1 and a differential-mode inductor L2 connected in parallel. One end of the differential-mode inductor L1 is connected to the connection terminal of the resistor R5 and the resistor R7. One end of the differential-mode inductor L2 is connected to the S pole of the MOS transistor Q3. A capacitor C2 is connected between one side of the differential-mode inductor L1 and one side of the differential-mode inductor L2. A capacitor C3 is connected between the other side of the differential-mode inductor L1 and the other side of the differential-mode inductor L2.

6. The filtering module with the functions of fast voltage discharge and reverse polarity protection according to claim 5, characterized in that: A capacitor C4 and a capacitor C5 connected in series are connected in parallel to one side of the common-mode inductor L3. The capacitor C4 is connected to the differential-mode inductor L1, and the capacitor C5 is connected to the differential-mode inductor L2.

7. A filtering module with a fast voltage discharge and reverse polarity protection function according to claim 6, characterized in that: A capacitor C6, and a capacitor C7 and a capacitor C8 connected in series are connected in parallel to the other side of the common-mode inductor L3. One end of the capacitor C7 is connected to the positive output terminal of the power supply, and one end of the capacitor C8 is connected to the negative output terminal of the power supply.

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