CN208424204U - Voltage-reduction protection device and electronic equipment - Google Patents

Abstract

The utility model provides a kind of voltage-reduction protection device and electronic equipment, belongs to electronic circuit technology field.The voltage-reduction protection device includes voltage reduction module and regulation module; the voltage reduction module includes voltage conversion circuit and switching circuit, and the voltage transformer in the voltage conversion circuit is connect by the field-effect tube in the switching circuit with the modulation chip of the regulation module；The first input end of the voltage transformer and the second input terminal input a high power supply voltage, and the first output end of the voltage transformer and second output terminal export a low-voltage current under the regulation of the modulation chip.The modulation chip of the voltage-reduction protection device is connect under the protection of the switching circuit with the high power supply voltage, and circuit integration is high, is reduced the short trouble rate of circuit, is improved the safety of the voltage-reduction protection device.

Description

Voltage-reduction protection device and electronic equipment

Technical field

The utility model relates to electronic circuit technology fields, set in particular to a kind of voltage-reduction protection device and electronics It is standby.

Background technique

With the rapid development of scientific and technological level and social economy, more and more electronic products enter the life of average family Among, at the same time, the significance level of electrical safety problems also increasingly improves.Automobile, kitchen and bath's electric appliance or other make with product User's personal safety is directly related, or safety accident occurs easily and influence the electrical Related product field of public safety, will be high It is a crucial step that voltage, which is down to after the low-voltage for meeting safety standard and is powered to relevant device,.Especially certain Natural gas facilities or vehicle fuel power supply relevant apparatus require high in terms of safe voltage control a bit, need the facility or dress The power supply set, which meets essential safety source standard, to be launched.

But the integration of existing dropping equipment is lower, is not easy to maintenance and management, causes automobile or other use drops The device line of volt circuit device is many and diverse unsightly, while when being depressured using power management chip control reduction voltage circuit, It is less to the safeguard measure of the power management chip, cause the power management chip to be easy to appear failure, while being easy Existing short-circuit conditions make to be depressured work and carry out unstable, and then lead to existing dropping equipment there are biggish security risks.

Utility model content

The purpose of this utility model is to provide a kind of voltage-reduction protection device and electronic equipments, to improve existing dropping equipment Integration is lower, few to power management chip safeguard measure, and the power management chip is easy to appear failure, is easy to appear simultaneously There is larger security risk in short-circuit conditions.

The embodiments of the present invention are achieved in that

The utility model provides a kind of voltage-reduction protection device, and the voltage-reduction protection device includes voltage reduction module and regulation mould Block.The voltage reduction module includes voltage conversion circuit and switching circuit, and the voltage conversion circuit includes voltage transformer and One capacitor, the switching circuit include field-effect tube, the first input end of the voltage transformer respectively with the mutual induction of voltage The grid of first output end of device, the first end of the first capacitor and the field-effect tube connects, the first capacitor Second end is connect with the drain electrode of the field-effect tube, the external high voltage power supply of the second input terminal of the voltage transformer, described The second output terminal of voltage transformer exports a low-tension supply outward.The regulation module includes circuit for regulating and controlling, the regulation electricity Road includes modulation chip, the first output end company of the second pin of the modulation chip and the 7th pin and the voltage transformer It connects, the 7th pin is also connect with the second end of the first capacitor, the 5th pin and the 6th pin of the modulation chip It is connect with the source electrode of the field-effect tube.The high-tension current for stating high voltage power supply is transmitted to the second input of the voltage transformer End is also transmitted to the modulation chip by the field-effect tube, and mutual by the voltage under the regulation of the modulation chip The low-tension current that sensor is converted to low-tension supply exports outward.

In the utility model optional embodiment, the voltage conversion circuit further includes bilateral diode, the voltage First output end of mutual inductor passes through the first end of the bilateral diode and the first capacitor and the field-effect tube Grid connection.

In the utility model optional embodiment, the voltage conversion circuit further includes the second capacitor and third capacitor, The first end of second capacitor is connect with the first output end of the voltage transformer, also by the third capacitor with it is described The drain electrode of field-effect tube connects, and the second pin and the 7th pin of the second end of second capacitor and the modulation chip connect It connects.

In the utility model optional embodiment, the voltage conversion circuit further includes third capacitor, the third electricity It is installed with and sets between the drain electrode of the first end and the field-effect tube of second capacitor.

In the utility model optional embodiment, the field-effect tube is N-type metal-oxide-semiconductor.

In the utility model optional embodiment, the modulation chip is the current-control type pulsewidth tune of UC3842 model Coremaking piece.

In the utility model optional embodiment, the regulation module further includes protection circuit, the protection circuit packet Photoelectrical coupler is included, the first port of the photoelectrical coupler is connect with the first pin of the modulation chip, the photoelectricity coupling The second port of clutch is connect with the second pin of the modulation chip and the 5th pin, the third end of the photoelectrical coupler Mouth and the 4th port are connect by second capacitor with the first output end of the voltage transformer.The photoelectrical coupler will The electric current that the voltage reduction module transmission comes is transmitted to the modulation chip under the conditions of electrical isolation.

In the utility model optional embodiment, the regulation module further includes voltage regulator circuit, the voltage regulator circuit packet Include source of stable pressure, first resistor, second resistance and the 4th capacitor, the anode of the source of stable pressure passes through the first resistor and described the The first of two capacitance connections, the reference pole of the source of stable pressure and the 4th port of the photoelectrical coupler and the 4th capacitor End connection, the second end of the 4th capacitor connect with the anode of the source of stable pressure, the both ends of the second resistance respectively with institute State the third port connection of the anode and the photoelectrical coupler of source of stable pressure, the minus earth of the source of stable pressure.

In the utility model optional embodiment, the source of stable pressure is the controllable accurate source of stable pressure of TL431 model.

The utility model additionally provides a kind of electronic equipment, and the electronic equipment includes above-mentioned voltage-reduction protection device.

The beneficial effect of the utility model embodiment is:

The utility model embodiment provides a kind of voltage-reduction protection device and electronic equipment, the voltage-reduction protection device include Voltage reduction module and regulation module, high-voltage power supply are converted to low-voltage by the voltage reduction module under the regulation of the regulation module Power supply output, enhances decompression safety；The voltage reduction module includes voltage conversion circuit and switching circuit, the voltage conversion Voltage transformer in circuit is connect by the field-effect tube in the switching circuit with the regulation module, avoids occurring short Road has ensured the energization safety of the regulation module；The regulation module includes circuit for regulating and controlling and protection circuit, the protection electricity Road includes the photoelectrical coupler that both ends are connect with the voltage conversion circuit and the circuit for regulating and controlling respectively, the photoelectrical coupler It avoids the modulation chip in the circuit for regulating and controlling from being influenced by input electrical signal by electrical isolation, the modulation chip is played Protective effect；The protection circuit further includes the voltage regulator circuit connecting with the photoelectrical coupler, and the voltage regulator circuit passes through can It controls precision voltage regulator and voltage-stabilizing protection is carried out to the modulation chip, further improve decompression safety；The decompression is protected simultaneously Protection unit converts the voltage into the circuit integrations such as circuit, circuit for regulating and controlling and simplifies, and keeps voltage-reduction protection device more beautiful and easy to maintain.

Detailed description of the invention

It, below will be to use required in embodiment in order to illustrate more clearly of the technical solution of the utility model embodiment Attached drawing be briefly described, it should be understood that the following drawings illustrates only some embodiments of the utility model, therefore should not be by Regard the restriction to range as, for those of ordinary skill in the art, without creative efforts, may be used also To obtain other relevant attached drawings according to these attached drawings.

By the way that shown in attached drawing, the above and other purpose, feature and advantage of the utility model will be more clear, all attached Identical appended drawing reference indicates identical part in figure, does not deliberately draw attached drawing by actual size equal proportion scaling, with emphasis on In the purport for showing the utility model.

Fig. 1 is a kind of module map of voltage-reduction protection device provided by the embodiment of the utility model；

Fig. 2 is a kind of circuit diagram of voltage reduction module provided by the embodiment of the utility model；

Fig. 3 is a kind of circuit diagram of regulation module provided by the embodiment of the utility model；

Fig. 4 is a kind of circuit diagram of voltage regulator circuit provided by the embodiment of the utility model.

Icon: 100- voltage-reduction protection device；110- voltage reduction module；112- voltage conversion circuit；114- switching circuit；120- Regulate and control module；122- circuit for regulating and controlling；124- protects circuit；126- voltage regulator circuit.

Specific embodiment

It is practical new below in conjunction with this to keep the objectives, technical solutions, and advantages of the embodiments of the present invention clearer Attached drawing in type embodiment, the technical scheme in the utility model embodiment is clearly and completely described, it is clear that is retouched The embodiment stated is the utility model a part of the embodiment, instead of all the embodiments.Usually here in attached drawing description and The component of the utility model embodiment shown can be arranged and be designed with a variety of different configurations.

Therefore, requirement is not intended to limit to the detailed description of the embodiments of the present invention provided in the accompanying drawings below The scope of the utility model of protection, but it is merely representative of the selected embodiment of the utility model.Based in the utility model Embodiment, every other embodiment obtained by those of ordinary skill in the art without making creative efforts, all Belong to the range of the utility model protection.

It should also be noted that similar label and letter indicate similar terms in following attached drawing, therefore, once a certain Xiang Yi It is defined in a attached drawing, does not then need that it is further defined and explained in subsequent attached drawing.

In the description of the present invention, it should be noted that the orientation or positional relationship of the instructions such as term "inner", "outside" For be based on the orientation or positional relationship shown in the drawings or the utility model product using when the orientation or position usually put Relationship is merely for convenience of describing the present invention and simplifying the description, rather than the device or element of indication or suggestion meaning must There must be specific orientation, be constructed and operated in a specific orientation, therefore should not be understood as limiting the present invention.This Outside, term " first ", " second " etc. are only used for distinguishing description, are not understood to indicate or imply relative importance.

In addition, the terms such as term "horizontal", "vertical" are not offered as requiring component abswolute level or pendency, but can be slightly Low dip.It is not to indicate that the structure has been had to if "horizontal" only refers to that its direction is more horizontal with respect to for "vertical" It is complete horizontal, but can be slightly tilted.

In the description of the present invention, it should also be noted that, unless otherwise clearly defined and limited, term " is set Set ", " connected ", " connection " shall be understood in a broad sense, for example, it may be being fixedly connected, may be a detachable connection, or integrally Connection；It can be mechanical connection, be also possible to be electrically connected；Can be directly connected, can also indirectly connected through an intermediary, It can be the connection inside two elements.For the ordinary skill in the art, above-mentioned art can be understood with concrete condition The concrete meaning of language in the present invention.

Other feature and advantage of the utility model will illustrate in subsequent specification, also, partly from specification It becomes apparent, or is understood and implementing the utility model embodiment.The purpose of this utility model and other advantages can It is achieved and obtained by structure specifically indicated in the written description, claims, and drawings.

Through the applicant the study found that popularizing with electronic component, more and more electrical equipments are needed to high voltage The voltage of power supply be powered after decompression processing again operation, especially car combustion engine to body control system power supply, Chu Wei electricity The electricity consumption of gas equipment or other electrical equipments for being related to user and other people personal safeties have safe and reliable dropping equipment higher Demand.Meanwhile existing dropping equipment does not often carry out dropping equipment itself when converting to high-voltage power supply Protection, especially in certain dropping equipments using modulation chip, modulation chip is more sensitive to voltage or curent change, if There is no safeguard procedures, is easy to break down in decompression regulation process, and then influence the reliability of the dropping equipment, or even lead Cause serious safety problem.In order to solve the problem above-mentioned, the utility model embodiment provides a kind of voltage-reduction protection device.

Referring to FIG. 1, Fig. 1 is a kind of module map of voltage-reduction protection device provided by the embodiment of the utility model.

Voltage-reduction protection device 100 include voltage reduction module 110 and regulation module 120, voltage reduction module 110 respectively with high voltage power supply And regulation module 120 connects, voltage reduction module 110, which converts the high voltage power supply under the regulation of regulation module 120, to be met The low-tension supply of safe voltage standard simultaneously exports outward.

Referring to FIG. 2, Fig. 2 is a kind of module map of voltage reduction module provided by the embodiment of the utility model.

Voltage reduction module 110 includes voltage conversion circuit 112 and switching circuit 114, and voltage conversion circuit 112 passes through switch electricity Road 114 is connect with regulation module 120.

Voltage conversion circuit 112 includes voltage transformer T1 and first capacitor C1, and switching circuit 114 includes field-effect tube Q1.Voltage transformer T1 includes input side and outlet side, and voltage transformer T1 is generally based on electromagnetic induction principle for input side I.e. the electric current of the first voltage value of first winding is converted to the electric current of second voltage value by predetermined ratio and passes through outlet side i.e. two Secondary winding exports the electrical component of the electric current of the second voltage value.In the present embodiment, field-effect tube Q1 includes drain electrode, source electrode And grid.Further, the input side of voltage transformer T1 has first input end and the second input terminal, and outlet side has first Output end and second output terminal, the first input end of voltage transformer T1 respectively with the first output end of voltage transformer T1, The first end of one capacitor C1 and the grid connection of field-effect tube Q1.The second end of first capacitor C1 and the drain electrode of field-effect tube Q1 Connection.The external high voltage power supply of the second input terminal of voltage transformer T1, the second output terminal of voltage transformer T1 is to outer diameter institute State the low-tension supply that high voltage power supply is converted to.

As an implementation, wherein the low-tension supply of the output end output of the voltage transformer T1 can give vapour The power supply of the devices such as turn signal, headlight, high beam, loudspeaker and brake lamp in the body control system of vehicle.It should be understood that institute State low-tension supply can be also used for kitchen and bath's electric appliance or other need the power electrical apparatus of voltage security power supply.

Further, voltage conversion circuit 112 further includes bilateral diode D1, and one end of bilateral diode D1 is respectively with The first end of one capacitor C1 and the grid connection of field-effect tube Q1, the other end of bilateral diode D1 is with voltage transformer T1's First output end connect and ground.Bilateral diode D1 carries out short-circuit protection to circuit, efficiently avoids the hair of short-circuit conditions It is raw.

Optionally, voltage conversion circuit 112 further includes the second capacitor C2 and third capacitor C3, the first end of the second capacitor C2 It connect with the first output end of voltage transformer T1, is also connect by third capacitor C3 with the drain electrode of field-effect tube Q1.Optionally, The second segment of second capacitor C2 is also connect with regulation module 120.

As an implementation, first capacitor C1, the second capacitor C2 and third capacitor C3 are electrolytic capacitor, first capacitor The first end of C1, the second capacitor C2 and third capacitor C3 are cathode, and second segment is anode.Meanwhile field-effect tube Q1 can be N-type Metal-oxide-semiconductor in circuit plays a protective role to regulation module 120 as electronic switch, further prevents short circuit.Metal-oxide-semiconductor is gold Belong to (Metal)-oxide (Oxide)-semiconductor (Semiconductor) field effect transistor, or claims to be metal-insulator (Insulator)-semiconductor field effect transistor, this name describe the structure of metal-oxide-semiconductor in integrated circuit, it may be assumed that certain On the semiconductor devices of structure, in addition silica and metal, form grid.It is mainly characterized by metal gates and channel it Between have a layer of silicon dioxide insulating layer, therefore there is very high input resistance, spread sections in two high concentration n when which is connected Form N-shaped conducting channel.

Referring to FIG. 3, Fig. 3 is a kind of circuit diagram of regulation module provided by the embodiment of the utility model.

Regulate and control module 120 include circuit for regulating and controlling 122 and protection circuit 124, circuit for regulating and controlling 122 by protection circuit 124 with Voltage reduction module 110 connects, and protection circuit 124 shields to circuit for regulating and controlling 122.

Circuit for regulating and controlling 122 includes modulating chip U1 and its peripheral circuit, optionally, as an implementation, this implementation Modulation chip U1 in example is the current-control type pulse width modulating chip of UC3842 model, and UC3842 is a kind of function admirable, answers With the better simply PWM Switching Power Supply integrated manipulator of extensive, structure, i.e. current-control type pulse width modulating chip, the modulator list End output, can directly drive ambipolar power tube or field-effect tube.Its major advantage is that its pin effect is few, peripheral circuit letter Single, for voltage regulation factor up to 0.01%, working frequency is up to 500KHz, and starting current is less than 1mA, and running current is 5mA, and realize using high frequency transformer and be isolated with power grid.As an implementation, modulation chip U1, that is, UC3842 tool There are eight pins, modulates third pin and the connection of the 8th pin of chip U1, meanwhile, modulate the third pin and the 8th of chip U1 Pin is also connect with the grid of field-effect tube Q1.

Further, the first pin for modulating chip U1 passes through the 8th pin of two concatenated capacitors and modulation chip U1 The second pin of connection, modulation chip U1 is connected between described two concatenated capacitors also by the first access point.Optionally, First access point is also connect with the first output end of voltage transformer T1.Modulate the 4th pin, the 5th pin of chip U1 It is connected with the 6th pin, meanwhile, the 4th pin, the source of the 5th pin and the 6th pin also with field-effect tube Q1 Pole connection.Optionally, the 7th pin for modulating chip U1 is connect also by a capacitor with the source electrode of field-effect tube Q1, and the described 7th Pin is also connect with the second end of first capacitor C1, and is connect by a diode with the second end of the second capacitor C2.

As an implementation, protection circuit 124 includes photoelectrical coupler U2, wherein photoelectrical coupler is to be with light A kind of electrical-optical-electrical switching device of media transmission electric signal, it is made of light emitting source and light-receiving device two parts, light emitting source and Light-receiving device is assembled in same closed shell, is isolated to each other with transparent insulator.The pin of light emitting source is input terminal, light The pin of device is output end, meanwhile, common light emitting source has light emitting diode, and light-receiving device has photodiode, phototriode. In the present embodiment, photoelectrical coupler U2 completes electrical isolation, the safety of enhancing regulation module 120 for exchanging coremaking piece U1 And reliability.Optionally, photoelectrical coupler U2 includes first port, second port, third port and the 4th port, photoelectric coupling The first port of device U2 is connect with the first pin of modulation chip U1, and the second port of photoelectrical coupler U2 is with modulation chip U1's The third port of second pin connection, photoelectrical coupler U2 is connect by a resistance with the second end of the second capacitor C2, photoelectricity coupling The 4th port of clutch U2 is also connect with the second end of the second capacitor C2.

Further, regulation module 120 provided in this embodiment further includes voltage regulator circuit 126.Referring to FIG. 4, Fig. 4 is this A kind of circuit diagram for voltage regulator circuit that utility model embodiment provides.Voltage regulator circuit 126 include source of stable pressure Q2, first resistor R1, Second resistance R2 and the 4th capacitor C4.Source of stable pressure Q2 includes anode, cathode and with reference to pole, the 4th port of photoelectrical coupler U2 with The first end of 4th capacitor C4 connects, and the first end of the 4th capacitor C4 is connect with the anode of source of stable pressure Q2, and the of the 4th capacitor C4 Two ends are connect with the reference pole of source of stable pressure Q2, and the reference pole of source of stable pressure Q2 also passes through the cathode of first resistor R1 Yu above-mentioned diode Connection.Optionally, the reference pole of source of stable pressure Q2 also passes through second resistance R2 and connect with the third port of photoelectrical coupler U2.

The working principle of voltage-reduction protection device 100 provided by the embodiment of the utility model is:

The external high voltage power supply of the input side of voltage transformer T1, the high voltage power supply are converted to low by voltage transformer T1 From the outlet side of voltage transformer T1 after current voltage, meanwhile, the input side is connect by field-effect tube Q1 with modulation chip U1, The input side by protection circuit 124 in photoelectrical coupler U2 and voltage regulator circuit 126 with modulation chip U1 connect, modulation Chip U1 receives voltage based on the electric signal to the voltage transformer T1 after the electric signal that the transmission of voltage reduction module 110 comes Conversion is regulated and controled, and is depressured work with safe and reliable completion, avoids that short trouble occurs.

In addition, the utility model embodiment additionally provides a kind of electronic equipment, electronic equipment includes provided in this embodiment Voltage-reduction protection device 100.Voltage-reduction protection device 100 can be integrated in the microelectronic circuit on printed circuit board, then by institute Printed circuit board is stated to be installed on electronic equipment；As another embodiment, voltage-reduction protection device 100 can also be directly with The electronic circuit of electronic equipment internal circuit connection.

In conclusion the utility model provides a kind of voltage-reduction protection device and electronic equipment, the voltage-reduction protection device Including voltage reduction module and regulation module, high-voltage power supply is converted under the regulation of the regulation module by the voltage reduction module low Voltage source output, enhances decompression safety；The voltage reduction module includes voltage conversion circuit and switching circuit, the voltage Voltage transformer in conversion circuit is connect by the field-effect tube in the switching circuit with the regulation module, avoids occurring Short circuit has ensured the energization safety of the regulation module；The regulation module includes circuit for regulating and controlling and protection circuit, the protection Circuit includes the photoelectrical coupler that both ends are connect with the voltage conversion circuit and the circuit for regulating and controlling respectively, the photoelectric coupling Device avoids the modulation chip in the circuit for regulating and controlling from being influenced by input electrical signal by electrical isolation, rises to the modulation chip To protective effect；The protection circuit further includes the voltage regulator circuit connecting with the photoelectrical coupler, and the voltage regulator circuit passes through Controllable accurate source of stable pressure carries out voltage-stabilizing protection to the modulation chip, further improves decompression safety；The decompression simultaneously Protective device converts the voltage into the circuit integrations such as circuit, circuit for regulating and controlling and simplifies, and keeps voltage-reduction protection device more beautiful and is easy to tie up Shield.

The above descriptions are merely preferred embodiments of the present invention, is not intended to limit the utility model, for this For the technical staff in field, various modifications and changes may be made to the present invention.It is all in the spirit and principles of the utility model Within, any modification, equivalent replacement, improvement and so on should be included within the scope of protection of this utility model.

Claims (10)

1. a kind of voltage-reduction protection device characterized by comprising

Voltage reduction module, including voltage conversion circuit and switching circuit, the voltage conversion circuit include voltage transformer and first Capacitor, the switching circuit include field-effect tube, the first input end of the voltage transformer respectively with the voltage transformer The first output end, the first capacitor first end and the field-effect tube grid connection, the of the first capacitor Two ends are connect with the drain electrode of the field-effect tube, the external high voltage power supply of the second input terminal of the voltage transformer, the electricity The second output terminal of pressure mutual inductor exports a low-tension supply outward；

Regulate and control module, including circuit for regulating and controlling, the circuit for regulating and controlling includes modulation chip, the modulation chip and the mutual induction of voltage The source electrode of first output end of device, the second end of the first capacitor and the field-effect tube connects；

The high-tension current of the high voltage power supply is transmitted to the second input terminal of the voltage transformer, also passes through the field-effect tube It is transmitted to the modulation chip, and the low of low-tension supply is converted to by the voltage transformer under the regulation of the modulation chip Current voltage exports outward.

2. voltage-reduction protection device according to claim 1, which is characterized in that the voltage conversion circuit further includes two-way two Pole pipe, the first end and institute that the first output end of the voltage transformer passes through the bilateral diode and the first capacitor State the grid connection of field-effect tube.

3. voltage-reduction protection device according to claim 1 or 2, which is characterized in that the voltage conversion circuit further includes Two capacitors, the first end of second capacitor are connect with the first output end of the voltage transformer, also with the field-effect tube Drain electrode connection, the second end of second capacitor connect with the modulation chip.

4. voltage-reduction protection device according to claim 3, which is characterized in that the voltage conversion circuit further includes third electricity Hold, the third capacitor is arranged between the drain electrode of first end and the field-effect tube of second capacitor.

5. voltage-reduction protection device according to claim 4, which is characterized in that the field-effect tube is N-type metal-oxide-semiconductor.

6. voltage-reduction protection device according to claim 5, which is characterized in that the modulation chip is the electricity of UC3842 model Flow control type pulse width modulating chip.

7. voltage-reduction protection device according to claim 6, which is characterized in that the regulation module further includes protection circuit, The protection circuit includes photoelectrical coupler, and the first pin of the first port of the photoelectrical coupler and the modulation chip connects It connects, the second port of the photoelectrical coupler is connect with the second pin of the modulation chip and the 5th pin, the photoelectricity The third port of coupler and the 4th port are connect by second capacitor with the first output end of the voltage transformer；

The electric current that voltage reduction module transmission comes is transmitted to the modulation core by the photoelectrical coupler under the conditions of electrical isolation Piece.

8. voltage-reduction protection device according to claim 7, which is characterized in that the regulation module further includes voltage regulator circuit, The voltage regulator circuit includes source of stable pressure, first resistor, second resistance and the 4th capacitor, and the anode of the source of stable pressure passes through described the One resistance and second capacitance connection, the reference pole of the source of stable pressure and the 4th port of the photoelectrical coupler and described The first end of 4th capacitor connects, and the second end of the 4th capacitor is connect with the anode of the source of stable pressure, the second resistance Both ends connect respectively with the third port of the anode of the source of stable pressure and the photoelectrical coupler, the cathode of the source of stable pressure Ground connection.

9. voltage-reduction protection device according to claim 8, which is characterized in that the source of stable pressure is the controllable of TL431 model Precision voltage regulator.

10. a kind of electronic equipment, which is characterized in that the electronic equipment includes the drop as described in any claim of claim 1-9 Press protective device.