CN217240325U

CN217240325U - Lossless reverse connection prevention protection circuit of direct current input power supply

Info

Publication number: CN217240325U
Application number: CN202123170563.XU
Authority: CN
Inventors: 董文龙
Original assignee: Beijing Dahua Radio Instrument Co ltd
Current assignee: Beijing Dahua Radio Instrument Co ltd
Priority date: 2021-12-16
Filing date: 2021-12-16
Publication date: 2022-08-19
Anticipated expiration: 2031-12-16

Abstract

The utility model discloses a lossless reverse-connection prevention protection circuit of a direct-current input power supply, wherein an input filtering nonpolar capacitor C57 is added at the input end of the power supply, and a positive end of an input filtering nonpolar capacitor C57 is connected in series with a reverse-connection prevention diode VD10 and a starting current suppression resistor R74; the normally open contact of the relay is connected in parallel with the two ends of the VD10 and the resistor R74; the reverse freewheeling diode VD12 of the relay is connected in parallel with the two ends of the electromagnetic coil of the slow starting circuit relay JDQ5, the anode of the reverse freewheeling diode VD12 of the relay is connected with the positive power supply of the relay, and the cathode is connected with the drain of the relay control attraction MOS tube VM 9; the grid source electrode of the relay pull-in MOS tube VM9 is connected with a grid source electrode discharge resistor R76 of the relay pull-in MOS tube and a grid source electrode filter capacitor C60 of the relay pull-in MOS tube in parallel. The circuit reduces the input reverse connection protection loss to be close to zero, improves the efficiency of the whole machine and realizes the input reverse connection prevention without loss.

Description

Lossless reverse connection prevention protection circuit of direct current input power supply

Technical Field

The utility model relates to a direct current input circuit technical field especially relates to a direct current input power's lossless prevents reverse-connection protection circuit.

Background

With the rapid development of power electronic technology, related products are widely applied to industries such as national defense, aerospace, consumer electronics, communication, new energy, inversion and the like, wherein the direct current input power supply has a large occupation ratio, in some use environments, in order to avoid requirements of professional use personnel, misoperation during design is considered as much as possible, the products are not invalid, users of direct current input equipment often need to avoid damage caused by adding reverse power, meanwhile, input starting current needs to be limited in some occasions, larger starting current is generated in the power-on process of an input capacitor in low-voltage large-input capacitive loads and high-voltage input occasions, larger impact current of power-on is not avoided, and in order to avoid power-on ignition, the power supply generally needs to have a slow start function, and reverse connection prevention and slow start are simultaneously considered.

In the anti-reverse connection circuit in the prior art, a diode or an MOS (metal oxide semiconductor) tube is generally connected in series into an input loop of a protected device, under the condition of large-current input, the loss of the anti-reverse connection diode or the MOS tube seriously affects the efficiency of the whole machine, the heat dissipation cost and space are increased, the miniaturization of a product is not facilitated, and the cost is reduced, so that a solution which can realize the anti-reverse connection and reduce the loss of the anti-reverse connection circuit to be close to zero loss after judging the correct connection needs to be researched.

Disclosure of Invention

The utility model aims at providing a protection circuit is prevented joining conversely by direct current input power's lossless, this circuit can be under the condition of extra increase device as far as possible, and the rational utilization delays starting circuit's relay to realize preventing joining conversely circuit's bypass, and the protection loss that joins conversely with the input falls to near zero, improves complete machine efficiency, realizes that lossless input prevents joining conversely.

The utility model aims at realizing through the following technical scheme:

the utility model provides a protection circuit is prevented joining conversely by no loss of direct current input power, the circuit is including preventing joining conversely diode VD10, starting current suppression resistance R74, input filtering nonpolar electric capacity C57, join conversely behind the protection circuit filtering electrolytic capacitor C61, high frequency filter electric capacity C58, slow starting circuit relay JDQ5, the reverse freewheeling diode VD12 of relay, relay control actuation MOS pipe VM9, relay actuation MOS pipe bars source discharge resistance R76, relay actuation MOS pipe bars source filter electric capacity C60, relay actuation drive resistance R78, wherein:

the input filtering non-polar capacitor C57 is added at the input end of a power supply, and the positive end of the input filtering non-polar capacitor C57 is connected in series with the anti-reverse diode VD10 and the starting current suppression resistor R74;

the two ends of the reverse connection prevention diode VD10 and the two ends of the starting current suppression resistor R74 are connected with the normally open contacts of the relay in parallel, and after reverse connection prevention and slow starting are finished, the contacts of the slow starting circuit relay JDQ5 are pulled to short circuit the reverse connection prevention diode VD10 and the starting current suppression resistor R74;

the relay reverse freewheeling diode VD12 is connected in parallel at two ends of an electromagnetic coil of the slow starting circuit relay JDQ5, the anode of the relay reverse freewheeling diode VD12 is connected with a positive power supply of the relay, and the cathode is connected with the drain of the relay control attraction MOS tube VM 9;

the grid source electrode of the relay attraction MOS tube VM9 is connected in parallel, the grid source electrode discharging resistor R76 of the relay attraction MOS tube and the grid source electrode filtering capacitor C60 of the relay attraction MOS tube, the grid electrode of the relay control attraction MOS tube VM9 is connected in series, the relay attraction driving resistor R78 is connected, and attraction control of the relay is achieved.

By the aforesaid the technical scheme provided by the utility model, above-mentioned circuit can be under the condition of extra increase device as far as possible, and the bypass of preventing reverse connection circuit is realized to the relay that the rational utilization was slowly starting circuit, with the input reverse connection loss of protection fall to being close to zero, improves complete machine efficiency, realizes that lossless input prevents reverse connection.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly described below, and it is obvious that the drawings in the description below are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic diagram of an overall structure of a lossless reverse connection prevention protection circuit of a dc input power supply according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments, and this does not limit the present invention. Based on the embodiment of the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

As shown in fig. 1 is the utility model provides a direct current input power supply's lossless prevents reverse connection protection circuit's overall structure schematic diagram, the circuit is including preventing reverse connection diode VD10, starting current restraines resistance R74, input filter nonpolar electric capacity C57, reverse connection protection circuit back filter electrolytic capacitor C61, high frequency filter electric capacity C58, slow starting circuit relay JDQ5, the reverse free-wheeling diode VD12 of relay, relay control actuation MOS pipe VM9, relay actuation MOS pipe bars source electrode (GS) discharge resistance R76, relay actuation MOS pipe bars source electrode (GS) filter electric capacity C60, relay actuation drive resistance R78, wherein:

the two ends of the reverse connection prevention diode VD10 and the two ends of the starting current suppression resistor R74 are connected with the normally open contacts of the relay in parallel, after reverse connection prevention and slow starting are finished, the contacts of the slow starting circuit relay JDQ5 are attracted to short the reverse connection prevention diode VD10 and the starting current suppression resistor R74, and therefore a key power loop of the lossless reverse connection prevention protection circuit is achieved;

the grid source electrode (GS) of the relay pull-in MOS tube VM9 is connected in parallel with the grid source electrode (GS) discharge resistor R76 of the relay pull-in MOS tube and the grid source electrode (GS) filter capacitor C60 of the relay pull-in MOS tube, and the grid electrode of the relay control pull-in MOS tube VM9 is connected in series with the relay pull-in drive resistor R78 to realize pull-in control of the relay;

in the initial stage of power-on, the input current is limited through an anti-reverse connection diode VD10 and a starting current suppression resistor R74, and a filtering electrolytic capacitor C61 and a high-frequency filtering capacitor C58 behind a reverse connection protection circuit are charged;

when the charging reaches an auxiliary power starting point, the auxiliary power supply supplies power for pull-in of a slow starting circuit relay JDQ5, an auxiliary power input is connected behind an anti-reverse-connection protection diode, namely the auxiliary power input is connected in parallel with a filtering electrolytic capacitor C61 behind the anti-reverse-connection protection circuit;

the soft start circuit relay JDQ5 pulls in the relay switch after judging that the voltage reaches a certain value or a certain delay time; specifically, the time required for the delay capacitor to be fully charged with 100% of the voltage after the voltage reaches 80% of the full voltage threshold of the filter electrolytic capacitor C61 and the high-frequency filter capacitor C58 after the reverse connection protection circuit is judged; or the relay switch is attracted after the delay time of 5 tau is directly delayed until the starting current suppression resistor R74 is fully charged for the filter electrolytic capacitor C61 and the high-frequency filter capacitor C58 of the reverse connection protection circuit;

after the slow starting circuit relay JDQ5 is pulled in, the anti-reverse diode VD10 does not carry current any more, and the current flows through a pull-in contact loop of the slow starting circuit relay JDQ 5;

when the input current is added with reverse power, the reverse connection prevention diode VD10 is reversely cut off, and the slow starting circuit relay JDQ5 cannot pull in, so that lossless input reverse connection prevention is realized.

In specific implementation, selection of VD10 is matched with the value of R74 for selection, and currents flowing through R74 and VD10 are calculated under the maximum input voltage;

the value of R74 needs to consider the charging time constant of the filter electrolytic capacitor C61 and the high-frequency filter capacitor C58 after the reverse connection protection circuit, and under the condition that the startup time of the whole machine is met, the current flowing through VD10 and R74 is limited by larger impedance through increasing the starting current suppression resistor R74, so that the volumes of VD10 and R74 are reduced.

In addition, the VD10 adopts a common rectifier diode; and an NTC thermistor is selected as R74.

It is noted that the embodiments of the present invention not described in detail belong to the prior art known to those skilled in the art.

To sum up, the embodiment of the utility model provides a circuit has following advantage:

1) the input reverse connection protection loss can be effectively reduced to be close to zero under the condition of large direct current input current, and the efficiency of the whole machine is improved;

2) the heat dissipation design of the reverse connection protection device can be omitted, and the heat dissipation space and the heat design cost occupied by the reverse connection protection circuit are reduced;

3) the reverse connection prevention protection diode is reversely cut off after reverse connection, the filter capacitor cannot be charged after the reverse connection protection circuit is reversely connected, the reverse connection prevention protection diode is in a reverse connection protection state and cannot be damaged, the reverse connection prevention protection diode is in forward conduction after the polarity connection is normal, the filter capacitor is normally charged after the reverse connection prevention protection circuit is normally connected, and reverse connection self-recovery is realized;

4) the bypass of the reverse connection preventing circuit can be realized by reasonably utilizing the relay of the slow starting circuit under the condition of not additionally increasing too many devices as far as possible, the design cost is saved, and the reverse connection preventing efficiency is improved.

The above description is only for the preferred embodiment of the present invention, but the protection scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are all covered by the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims. The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information constitutes prior art already known to a person skilled in the art.

Claims

1. The utility model provides a lossless reverse-connection-prevention protection circuit of a direct current input power supply, which is characterized in that, the circuit includes reverse-connection-prevention diode VD10, starting current suppression resistor R74, input filtering nonpolar capacitor C57, reverse-connection protection circuit back filtering electrolytic capacitor C61, high-frequency filter capacitor C58, slow starting circuit relay JDQ5, relay reverse freewheeling diode VD12, relay control pull-in MOS pipe VM9, relay pull-in MOS pipe grid source discharge resistor R76, relay pull-in MOS pipe grid source filter capacitor C60, relay pull-in driving resistor R78, wherein:

the normally open contacts of the relay are connected in parallel at the two ends of the reverse connection prevention diode VD10 and the starting current suppression resistor R74, and after reverse connection prevention and slow starting are finished, the contact of the slow starting circuit relay JDQ5 is pulled in to short circuit the reverse connection prevention diode VD10 and the starting current suppression resistor R74;

the relay reverse freewheeling diode VD12 is connected in parallel with two ends of an electromagnetic coil of the slow start circuit relay JDQ5, the anode of the relay reverse freewheeling diode VD12 is connected with a relay power supply positive power supply, and the cathode of the relay reverse freewheeling diode VD12 is connected with the drain of the relay control pull-in MOS tube VM 9;

the grid source of the relay pull-in MOS tube VM9 is connected in parallel, the grid source discharge resistor R76 of the relay pull-in MOS tube and the grid source filter capacitor C60 of the relay pull-in MOS tube, the grid of the relay control pull-in MOS tube VM9 is connected in series, the relay pull-in drive resistor R78 is connected, and pull-in control of the relay is achieved.

2. A lossless reverse-connection prevention protection circuit for a DC input power supply according to claim 1,

the reverse connection preventing diode VD10 adopts a common rectifying diode;

the starting current suppression resistor R74 is selected from an NTC thermistor.