CN106210366B - Protection system for external exchange - Google Patents
Protection system for external exchange Download PDFInfo
- Publication number
- CN106210366B CN106210366B CN201610573065.4A CN201610573065A CN106210366B CN 106210366 B CN106210366 B CN 106210366B CN 201610573065 A CN201610573065 A CN 201610573065A CN 106210366 B CN106210366 B CN 106210366B
- Authority
- CN
- China
- Prior art keywords
- module
- common
- inductor
- mode
- mode filtering
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000001914 filtration Methods 0.000 claims abstract description 73
- 239000003990 capacitor Substances 0.000 claims description 35
- 102100028680 Protein patched homolog 1 Human genes 0.000 claims description 9
- 101710161390 Protein patched homolog 1 Proteins 0.000 claims description 9
- 102100036894 Protein patched homolog 2 Human genes 0.000 claims description 7
- 101710161395 Protein patched homolog 2 Proteins 0.000 claims description 7
- 101100314406 Saccharomyces cerevisiae (strain ATCC 204508 / S288c) TPS1 gene Proteins 0.000 claims description 4
- 239000007787 solid Substances 0.000 claims description 4
- 230000005855 radiation Effects 0.000 abstract description 4
- 238000010586 diagram Methods 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 2
- 238000007599 discharging Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000001629 suppression Effects 0.000 description 2
- 230000001052 transient effect Effects 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000005674 electromagnetic induction Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 230000001939 inductive effect Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M7/00—Arrangements for interconnection between switching centres
- H04M7/009—Arrangements for interconnection between switching centres in systems involving PBX or KTS networks
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M7/00—Arrangements for interconnection between switching centres
- H04M7/0096—Trunk circuits
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Emergency Protection Circuit Devices (AREA)
- Filters And Equalizers (AREA)
- Protection Of Static Devices (AREA)
Abstract
The invention relates to a protection system of an external exchange, which divides voltage when the protection system has external continuous high voltage through a current limiting module; meanwhile, a primary surge protection module is adopted to release external instantaneous high-voltage interference in the protection system; and the differential mode filtering module and the common mode filtering module are adopted to carry out differential mode filtering and common mode filtering processing on the output signals of the external exchange in sequence. And finally, converting the alternating current signal into a direct current signal by the rectifying module to supply the post-stage circuit to work. Most of voltage in the whole circuit can be divided by adopting the current limiting module, and the surge high voltage in the circuit is discharged by the primary surge protection module. Therefore, the anti-interference capability of the circuit can be improved, and the requirement of surge protection level 4 is met. After differential mode filtering and common mode filtering, the power curve of the output signal can be ensured to meet the requirement, and the radiation performance is good.
Description
Technical Field
The present invention relates to protection circuits, and more particularly to a protection system for an external exchange.
Background
FXO (Foreign Exchange Office), which is simply understood to be an interface on a PBX (private branch Exchange) used to connect to a public telephone network. I.e., a trunk-side connection between the central office switch and the digital telephone switching system. Compared with the central office, the system simulates a PABX extension, and can realize the connection of a common telephone set and a multiplexer. The existing external exchange interface protection technology cannot meet the requirements of surge protection and power line induction, and the performance of power line lap joint and V/I performance curve is poor.
Disclosure of Invention
In view of the above, it is necessary to provide a protection system for an external exchange with high interference resistance.
A protection system of an external exchange office comprises a rectification module and a current limiting module; the device also comprises a primary surge protection module, a common mode filtering module and a differential mode filtering module;
the rectification module is used for connecting a post-stage circuit and the common-mode filtering module; the common mode filtering module, the differential mode filtering module, the primary surge protection module and the current limiting module are sequentially connected;
the current limiting module is used for dividing voltage when the protection system generates high voltage;
the primary surge protection module is used for discharging high voltage in the protection system;
the differential mode filtering module is used for filtering differential mode interference signals;
the common-mode filtering module is used for filtering common-mode interference signals;
the rectification module is used for converting the alternating current signal into a direct current signal and supplying the direct current signal to the post-stage circuit.
In one embodiment, the system further comprises a secondary surge protection module; the secondary surge protection module is used for connecting the post-stage circuit and the rectification module;
and the secondary surge protection module is used for absorbing residual voltage formed after the processing of the primary surge protection module.
In one embodiment, the rectifying module comprises a rectifying bridge D2, the output end of the rectifying bridge D2 is connected with the post-stage circuit, and the input end of the rectifying bridge D2 is connected with the common-mode filtering module.
In one embodiment, the common mode filtering module comprises a common mode inductor L3, a common mode capacitor CY1 and a common mode capacitor CY 2;
one end of the common-mode capacitor CY1 is connected to the first input end of the common-mode inductor L3, and the other end is grounded;
one end of the common-mode capacitor CY2 is connected to the second input end of the common-mode inductor L3, and the other end is grounded;
and a first output end and a second output end of the common-mode inductor L3 are both connected with the differential-mode filtering module.
In one embodiment, the common mode inductor L3 has a capacitance of 5 ± 0.3 mH.
In one embodiment, the common mode capacitor CY1 and the common mode capacitor CY2 are between 102-222.
In one embodiment, the differential mode filtering module comprises an inductor L1, an inductor L2 and a capacitor C1;
one end of the inductor L1 is connected with the differential mode filtering module, and the other end is connected with the capacitor C1;
one end of the inductor L2 is connected with the differential mode filtering module, and the other end is connected with one end of the capacitor C1 far away from the inductor L1;
the common connection point of the inductor L1 and the capacitor C1 is connected with the primary surge protection module;
the common connection point of the inductor L2 and the capacitor C1 is connected with the primary surge protection module.
In one embodiment, the capacities of the inductor L1 and the inductor L2 are both 100 ± 5 uH.
In one embodiment, the primary surge protection module comprises a discharge tube TSS 1;
two ends of the discharge tube TSS1 are respectively connected with the differential mode filtering module.
In one embodiment, the current limiting module includes a thermistor PTC1 and a thermistor PTC 2;
one end of the thermistor PTC1 is connected with the primary surge protection module, and the other end of the thermistor PTC1 is used as a first connection end of the protection system;
one end of the thermistor PTC2 is connected with the primary surge protection module, and the other end of the thermistor PTC2 is used as a second connecting end of the protection system.
The protection system of the external exchange office divides the voltage when the protection system has external continuous high voltage through the current limiting module; (ii) a Meanwhile, a primary surge protection module is adopted to release external instantaneous high-voltage interference in the protection system; and the differential mode filtering module and the common mode filtering module are adopted to carry out differential mode filtering and common mode filtering processing on the output signals of the external exchange in sequence. And finally, converting the alternating current signal into a direct current signal by the rectifying module to supply the post-stage circuit to work. Most of voltage in the whole circuit can be divided by adopting the current limiting module, and the surge high voltage in the circuit is discharged by the primary surge protection module. Therefore, the anti-interference capability of the circuit can be improved, and the requirement of surge protection level 4 is met. After differential mode filtering and common mode filtering, the power curve of the output signal can be ensured to meet the requirement, and the radiation performance is good.
Drawings
FIG. 1 is a block diagram of a protection system of an outside exchange;
fig. 2 is a circuit diagram of a protection system of an external exchange.
Detailed Description
To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
As shown in fig. 1, a block diagram of a protection system of an outside exchange is shown.
A protection system of an external exchange office comprises a current limiting module 101, a primary surge protection module 103, a differential mode filtering module 105, a common mode filtering module 107 and a rectifying module 109.
The current limiting module 101, the first-stage surge protection module 103, the differential mode filtering module 105 and the common mode filtering module 107 are connected in sequence, and the rectifying module 109 is used for being connected with the post-stage circuit and the common mode filtering module 107.
The current limiting module 101 is used for dividing voltage when the external continuous high voltage occurs in the protection system. Wherein the duration of the external continuous high voltage is more than millisecond.
The primary surge protection module 103 is used for releasing external instantaneous high-voltage interference occurring in the protection system.
The differential mode filtering module 105 is configured to filter out a differential mode interference signal.
The common mode filtering module 107 is used for filtering out a common mode interference signal.
The rectifying module 109 is configured to convert the ac signal into a dc signal and supply the dc signal to a subsequent circuit.
The protection of the output end of the external exchange is performed with EMC (Electro Magnetic Compatibility), common mode filtering, differential mode filtering and surge protection, thereby achieving a more ideal effect. The performance requirements of PSD and V/I curves of FCC Part68 can be met while the requirement of 4-level protection of surge can be met.
In this embodiment, the current limiting module 101 employs a thermistor, so that when acting on the power line lap joint, a good protection effect can be achieved. When the rear-stage protection device is started, the link current is increased, so that the thermistor acts, namely the resistance value of the thermistor is increased instantly, most of voltage in the whole circuit is divided, and the circuit is protected from being damaged. When the fault is eliminated (high voltage is removed), the thermistor automatically recovers to normal.
The starting voltage of the primary surge protection module 103 is about 320-350V, and is used for absorbing the instantaneous high voltage in the circuit. In order to ensure that the rear-stage circuit is not damaged, whether the secondary surge protection module 104 is added or not is determined according to the difference of the anti-interference capability of the rear-stage chip.
The differential mode filtering module 105 is configured to filter out the differential mode signal. The differential mode signals are also called normal mode, series mode, line-to-line inductive and symmetric signals, and the like, and in the two-wire cable transmission loop, the ground voltage of each line is represented by symbols V1 and V2. The differential mode signal component is VDIFF. The pure differential mode signal is V1-V2 with equal magnitude and 180 ° phase difference, VDIFF-V1-V2, because V1 and V2 are symmetrical to ground, no current flows on the ground. All differential mode current (IDIFF) flows through the load. Differential mode interference, which is introduced into and out of two signal lines in a direction corresponding to the signal current square, is generally difficult to suppress, one being generated by the signal source and the other being generated by electromagnetic induction during transmission, which is strung together with the signal and is in phase therewith. Therefore, after the filtering process is performed by the differential mode filtering module 105, the power curve of the PSD is ensured to meet the requirement of the FCC Part 68.
The common mode filtering module 107 is configured to filter a common mode signal, the common mode signal is also called a ground-to-ground sensing signal or an asymmetric signal, a common mode signal component is Vcom, and a pure common mode signal is: vcom is equal to V1 and V2, and the phase difference is 0 o. V3 ═ 0. Differential mode interference signals invade between the line and the ground, and interference currents respectively flow through half of the two lines, so that the ground is a common loop. However, in an actual circuit, due to unbalanced line impedance, common mode signal interference is converted into crosstalk interference which is not easy to eliminate. Therefore, after the common mode filtering module 107 is adopted for filtering, common mode noise can be eliminated, and good performance of radiation is ensured.
Please refer to fig. 2.
The current limiting module 101 includes a thermistor PTC1 and a thermistor PTC 2.
One end of the thermistor PTC1 is connected with the primary surge protection module 103, and the other end is used as a first connection end of the protection system. One end of the thermistor PTC2 is connected with the primary surge protection module 103, and the other end is used as a second connecting end of the protection system. The first connecting end and the second connecting end are both used for connecting a telephone port of an external exchange. The signal of the first connecting end is ring, and the signal of the second connecting end is tip.
The current limiting module 101 uses a thermistor element having a rated voltage of 250V and 5 ohms or less (to satisfy the V/I curve).
The primary surge protection module 103 comprises a discharge tube TSS 1; two ends of the discharge tube TSS1 are respectively connected with the differential mode filtering module 105.
The first-stage surge protection module 103 adopts a solid discharge tube TSS element, provided that Vdrm of the TSS is selected to be larger than the ringing voltage (160V) in the circuit, usually the starting voltage of the first-stage protection circuit TSS is about 320-350V, in order to ensure that the rear-stage circuit is not damaged, whether the second-stage surge protection module 104 is added behind the rectifier bridge is determined according to the difference of the anti-interference capability of the rear-stage chip, and if necessary, the TSS or TVS with the starting voltage below 180V can be added. So as to ensure that the surge residual voltage is about 200V.
That is, in yet another embodiment, the protection system of the external exchange further includes a secondary surge protection module 104; the secondary surge protection module 104 is used for connecting a post-stage circuit and the rectification module 109; the secondary surge protection module 104 is used for clamping and discharging residual voltage formed by external instantaneous high-voltage interference processed by the primary surge protection module 103.
The secondary surge protection module 104 includes a transient suppression diode D1, and two positive terminals of the transient suppression diode D1 are respectively connected to the rectifier module 109.
The differential mode filtering module 105 includes an inductor L1, an inductor L2, and a capacitor C1.
One end of the inductor L1 is connected with the differential mode filtering module 105, and the other end is connected with the capacitor C1; one end of the inductor L2 is connected with the differential mode filtering module 105, and the other end is connected with one end of the capacitor C1 far away from the inductor L1; the common connection point of the inductor L1 and the capacitor C1 is connected with the primary surge protection module 103; the common connection point of the inductor L2 and the capacitor C1 is connected with the primary surge protection module 103.
The capacities of the inductor L1 and the inductor L2 are both 100 + -5 uH.
The capacitance C1 is between 103 and 105.
The common mode filtering module 107 comprises a common mode inductor L3, a common mode capacitor CY1 and a common mode capacitor CY 2;
one end of the common-mode capacitor CY1 is connected with the first input end of the common-mode inductor L3, and the other end is grounded; one end of the common-mode capacitor CY2 is connected with the second input end of the common-mode inductor L3, and the other end of the common-mode capacitor CY2 is grounded; the first output end and the second output end of the common mode inductor L3 are both connected to the differential mode filtering module 105.
The capacity of the common mode inductor L3 is 5 + -0.3 mH.
The common mode capacitance CY1 and the common mode capacitance CY2 are between 102-222.
The rectifying module 109 comprises a rectifying bridge D2, the output end of the rectifying bridge D2 is connected with a post-stage circuit, and the input end of the rectifying bridge D2 is connected with the common-mode filtering module 107.
The rectifier bridge D2 is a full bridge rectifier that rectifies an ac signal into a dc signal for use by a subsequent chip.
Based on all the above embodiments, the working principle of the protection system of the external exchange is as follows:
when the thermal resistance value of the thermistor in the current limiting module 101 is increased instantly when heated, that is, when abnormal high voltage occurs in the circuit, most of the voltage in the whole circuit is divided, and the circuit is protected from being damaged.
The solid discharge tube TSS is then used to absorb the momentary high voltage in the circuit. The inductor L1, the inductor L2 and the capacitor C1 are used for absorbing differential mode signals in the circuit. The common-mode inductor L3, the common-mode capacitor CY1 and the common-mode capacitor CY2 are used for absorbing common-mode signals in the circuit. Finally, the rectifier bridge D2 converts the AC signal into DC signal and outputs the DC signal to the post-stage circuit. If the anti-interference capability of the rear-stage circuit is weak, a secondary surge protection module 104 is additionally arranged between the rectification module 109 and the rear-stage circuit to further absorb residual voltage in the circuit so as to ensure that the residual voltage of the surge is about 200V.
The protection system of the external exchange performs voltage division when the protection system has external continuous high voltage through the current limiting module 101; meanwhile, a primary surge protection module 103 is adopted to relieve external instantaneous high-voltage interference in the protection system; and the differential mode filtering module 105 and the common mode filtering module 107 are adopted to sequentially carry out differential mode filtering and common mode filtering processing on the output signals of the external exchange. Finally, the rectifier module 109 converts the ac signal into a dc signal for the subsequent circuit to work. Most of voltage in the whole circuit can be divided by adopting the current limiting module 101, and the surge high voltage in the circuit is discharged by the primary surge protection module 103. Therefore, the anti-interference capability of the circuit can be improved, and the requirement of surge protection level 4 is met. After differential mode filtering and common mode filtering, the power curve of the output signal can be ensured to meet the requirement, and the radiation performance is good.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (6)
1. A protection system of an external exchange office comprises a rectification module and a current limiting module; the device is characterized by also comprising a primary surge protection module, a common mode filtering module and a differential mode filtering module;
the rectification module is used for connecting a post-stage circuit and the common-mode filtering module; the common mode filtering module, the differential mode filtering module, the primary surge protection module and the current limiting module are sequentially connected;
the current limiting module is used for dividing voltage when external continuous high voltage occurs in the protection system, and the time of the continuous high voltage is longer than millisecond level;
the primary surge protection module is used for releasing external instant high-voltage interference in the protection system;
the differential mode filtering module is used for filtering differential mode interference signals;
the common-mode filtering module is used for filtering common-mode interference signals;
the rectification module is used for converting an alternating current signal into a direct current signal and supplying the direct current signal to the post-stage circuit;
wherein,
the current limiting module comprises a thermistor PTC1 and a thermistor PTC2, the resistance values of the thermistor PTC1 and the thermistor PTC2 are both less than 5 ohms, one end of the thermistor PTC1 is connected with the primary surge protection module, and the other end of the thermistor PTC1 is used as a first connection end of the protection system; one end of the thermistor PTC2 is connected with the primary surge protection module, and the other end of the thermistor PTC2 is used as a second connecting end of the protection system;
the primary surge protection module comprises a solid discharge tube TSS1, and two ends of the solid discharge tube TSS1 are respectively connected with the differential mode filtering module;
the differential mode filtering module comprises an inductor L1, an inductor L2 and a capacitor C1; one end of the inductor L1 is connected with the differential mode filtering module, and the other end is connected with the capacitor C1; one end of the inductor L2 is connected with the differential mode filtering module, and the other end is connected with one end of the capacitor C1 far away from the inductor L1; the common connection point of the inductor L1 and the capacitor C1 is connected with the primary surge protection module; the common connection point of the inductor L2 and the capacitor C1 is connected with the primary surge protection module;
the common mode filtering module comprises a common mode inductor L3, a common mode capacitor CY1 and a common mode capacitor CY 2; one end of the common-mode capacitor CY1 is connected to the first input end of the common-mode inductor L3, and the other end is grounded; one end of the common-mode capacitor CY2 is connected to the second input end of the common-mode inductor L3, and the other end is grounded; and a first output end and a second output end of the common-mode inductor L3 are both connected with the differential-mode filtering module.
2. The protection system of an outside exchange office of claim 1, further comprising a secondary surge protection module; the secondary surge protection module is used for connecting the post-stage circuit and the rectification module;
the secondary surge protection module is used for clamping and releasing residual voltage formed by external instantaneous high-voltage interference processed by the primary surge protection module.
3. The protection system of an external exchange office according to claim 1, wherein the rectification module comprises a rectification bridge D2, the output end of the rectification bridge D2 is connected with the post-stage circuit, and the input end of the rectification bridge D2 is connected with the common mode filtering module.
4. The system of claim 1, wherein the common mode inductor L3 has a capacity of 5 ± 0.3 mH.
5. The protection system of claim 1, wherein the capacities of the common mode capacitor CY1 and the common mode capacitor CY2 are between 102 and 222.
6. The system of claim 1, wherein the inductance L1 and the inductance L2 each have a capacitance of 100 ± 5 uH.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610573065.4A CN106210366B (en) | 2016-07-19 | 2016-07-19 | Protection system for external exchange |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610573065.4A CN106210366B (en) | 2016-07-19 | 2016-07-19 | Protection system for external exchange |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106210366A CN106210366A (en) | 2016-12-07 |
| CN106210366B true CN106210366B (en) | 2020-03-27 |
Family
ID=57494650
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610573065.4A Active CN106210366B (en) | 2016-07-19 | 2016-07-19 | Protection system for external exchange |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106210366B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107592784A (en) * | 2017-10-12 | 2018-01-16 | 深圳市创仕达电子有限公司 | A kind of electromagnetic impact means of defence and system |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201830274U (en) * | 2010-03-03 | 2011-05-11 | 武汉迈威光电技术有限公司 | Ethernet interface circuit integrated module with surge protection function |
| CN203166497U (en) * | 2013-01-22 | 2013-08-28 | 广州金升阳科技有限公司 | Anti-surge DC protective circuit |
| CN103515942A (en) * | 2012-06-28 | 2014-01-15 | 中兴通讯股份有限公司 | Protection circuit of communication interface |
| CN104617571A (en) * | 2015-01-20 | 2015-05-13 | 长沙飞波通信技术有限公司 | Over-voltage over-current protector of electronic and electric equipment |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9054514B2 (en) * | 2012-02-10 | 2015-06-09 | Transtector Systems, Inc. | Reduced let through voltage transient protection or suppression circuit |
-
2016
- 2016-07-19 CN CN201610573065.4A patent/CN106210366B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201830274U (en) * | 2010-03-03 | 2011-05-11 | 武汉迈威光电技术有限公司 | Ethernet interface circuit integrated module with surge protection function |
| CN103515942A (en) * | 2012-06-28 | 2014-01-15 | 中兴通讯股份有限公司 | Protection circuit of communication interface |
| CN203166497U (en) * | 2013-01-22 | 2013-08-28 | 广州金升阳科技有限公司 | Anti-surge DC protective circuit |
| CN104617571A (en) * | 2015-01-20 | 2015-05-13 | 长沙飞波通信技术有限公司 | Over-voltage over-current protector of electronic and electric equipment |
Also Published As
| Publication number | Publication date |
|---|---|
| CN106210366A (en) | 2016-12-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100414798C (en) | Earth leakage protective device and electric switch including the protective device | |
| CN201417941Y (en) | Interface protection circuit | |
| CN102185698B (en) | Ethernet power supply port protective circuit and ethernet power supply equipment | |
| US20100321104A1 (en) | Network filter and use of a network filter | |
| TWI427887B (en) | High voltage power supply module and power supply system using the same | |
| CN103972862B (en) | One automatically resets thunder-proof type overvoltage/undervoltage protection device | |
| CN112019039A (en) | Power interface circuit with high-grade surge protection and high EMI performance | |
| CN106210366B (en) | Protection system for external exchange | |
| CN201466706U (en) | Anti-lightning protection circuit of RS485 serial communication interface | |
| CN202076941U (en) | Power supply with lightning stroke protecting circuit | |
| CN107332675B (en) | PoE equipment without network transformer | |
| CN108808640B (en) | Power distribution network zero line breakage protector and control method thereof | |
| CN115986709A (en) | Computer interface thunder and lightning electromagnetic pulse and electric strength resistance protection device | |
| CN207283569U (en) | Ethernet interface telecommunication circuit without network transformer | |
| CN201663438U (en) | Two-port household appliance signal surge protective device irrespective of input and output | |
| CN206180565U (en) | Leakage protection circuit and charger | |
| CN107707109A (en) | A kind of power circuit and air conditioner | |
| CN109039659B (en) | Fast reverse power supply system and local side equipment | |
| CN205945097U (en) | High -power photovoltaic inverter | |
| CN208971133U (en) | A kind of anti-surge circuit and pressure stabilizing device | |
| CN208955897U (en) | A kind of protection circuit, photovoltaic inverter | |
| CN102497184B (en) | Multifunctional solid-state switch adopting thyristor self-triggering technology | |
| CN215499002U (en) | Protection circuit and POE protection system of POE system | |
| CN111064165A (en) | Protection circuit, frequency converter device and electrical equipment | |
| CN205724871U (en) | Three phase mains signal shares surge protector |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |