CN108964267B - DC voltage type PLC photovoltaic shutoff ware circuit - Google Patents
DC voltage type PLC photovoltaic shutoff ware circuit Download PDFInfo
- Publication number
- CN108964267B CN108964267B CN201810697600.6A CN201810697600A CN108964267B CN 108964267 B CN108964267 B CN 108964267B CN 201810697600 A CN201810697600 A CN 201810697600A CN 108964267 B CN108964267 B CN 108964267B
- Authority
- CN
- China
- Prior art keywords
- trap
- capacitor
- switching tube
- photovoltaic
- plc
- 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
- 239000003990 capacitor Substances 0.000 claims abstract description 43
- 238000004891 communication Methods 0.000 claims abstract description 27
- 230000008878 coupling Effects 0.000 claims abstract description 11
- 238000010168 coupling process Methods 0.000 claims abstract description 11
- 238000005859 coupling reaction Methods 0.000 claims abstract description 11
- 238000010586 diagram Methods 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 2
- 230000006855 networking Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
- H02J13/00006—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment
- H02J13/00007—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment using the power network as support for the transmission
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
- Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
- Y04S40/00—Systems for electrical power generation, transmission, distribution or end-user application management characterised by the use of communication or information technologies, or communication or information technology specific aspects supporting them
- Y04S40/12—Systems for electrical power generation, transmission, distribution or end-user application management characterised by the use of communication or information technologies, or communication or information technology specific aspects supporting them characterised by data transport means between the monitoring, controlling or managing units and monitored, controlled or operated electrical equipment
- Y04S40/121—Systems for electrical power generation, transmission, distribution or end-user application management characterised by the use of communication or information technologies, or communication or information technology specific aspects supporting them characterised by data transport means between the monitoring, controlling or managing units and monitored, controlled or operated electrical equipment using the power network as support for the transmission
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
- Inverter Devices (AREA)
Abstract
The invention discloses a direct-current voltage type PLC photovoltaic shutoff circuit which comprises a photovoltaic module VPV, an input capacitor C4, a switching tube Q1, a freewheeling diode D1, a first LC trap, an output capacitor C5, a transformer T1, a coupling capacitor C6, a third LC trap, a signal filter resistor R1, a signal filter capacitor C7 and a second LC trap, wherein two ends of the output capacitor C5 are output terminals; when the switching tube Q1 is disconnected, the string current and the PLC signal pass through the freewheeling diode D1, so that normal power line carrier communication is realized; when the switching tube Q1 is closed, the power line carrier communication is stopped, and the string current passes through the switching tube Q, so that the efficiency and the stability of the system are not affected. The invention can effectively improve the efficiency of the system, the stability of the system and the reliability of communication.
Description
Technical Field
The invention relates to a PLC photovoltaic shutoff circuit, in particular to a DC voltage type PLC photovoltaic shutoff circuit, and belongs to the technical field of power electronic converters and communication.
Background
The traditional wireless communication mode needs collector and summarizer, and the collector is placed outdoors, and the summarizer is placed indoors, needs 485 communication between, brings very big installation and space problem, and secondly, wireless communication receives factor more that interfere, still must adopt different frequency channels between the adjacent power station, also has the interference between frequency channel and the frequency channel, leads to losing the package, influences the reliability of communication.
The power line carrier communication technology (Power Line Communication, PLC for short) is a communication system that uses a power line as a signal path to transmit data. The technology is that the high frequency signal carrying information is loaded in the current, then the power line is used for transmission, and the modem receiving the information separates the high frequency from the current and transmits the high frequency to the monitoring center to realize information transmission.
The power line carrier communication is a more intelligent communication scheme, and the trouble of the RS485 communication cable of the photovoltaic inverter and the laying of the RS485 communication cable can be eliminated by adopting the technology. The direct-current PLC photovoltaic system has the following advantages: ① The communication is carried out by using the already laid power lines, and no additional construction is needed to lay communication lines, so that the total cost is low; ② Belongs to wired communication, and has the advantages of good stability and the like.
Disclosure of Invention
The technical problem to be solved by the invention is to provide the direct-current voltage type PLC photovoltaic shutoff circuit which can reduce the cost, improve the reliability and stability of products, is easy to implement and meets the requirement of quick shutoff of American regulations.
The technical scheme adopted by the invention for solving the technical problems is to provide a direct-current voltage type PLC photovoltaic shutoff circuit, which comprises the following components: the photovoltaic module VPV, an input capacitor C4, a switching tube Q1, a freewheeling diode D1, a first LC trap, an output capacitor C5, a transformer T1, a coupling capacitor C6, a third LC trap, a signal filter resistor R1, a signal filter capacitor C7 and a second LC trap, wherein output terminals are arranged at two ends of the output capacitor C5;
The input capacitor C4 is connected with the photovoltaic module VPV in parallel, the anode of the photovoltaic module VPV is connected with the cathode of the freewheeling diode D1, one end of the coupling capacitor C6 and one end of the output capacitor C5 are connected, the cathode of the photovoltaic module VPV is connected with the drain electrode of the switching tube Q1, the source electrode of the switching tube Q1 is connected with one end of the first LC trap, one end of the primary side of the transformer T1 and the other end of the output capacitor C5 are connected, the other end of the first LC trap is connected with the anode of the freewheeling diode D1, and the other end of the primary side of the transformer T1 is connected with the other end of the coupling capacitor C6;
one end of the secondary side of the transformer T1 is connected with one end of a third LC trap, the other end of the third LC trap is connected with one end of a second LC trap, the other end of the second LC trap is connected with one end of a signal filter resistor R1, the other end of the signal filter resistor R1 is connected with one end of a signal filter capacitor C7, and the other end of the signal filter capacitor C7 is connected with the other end of the secondary side of the transformer T1.
According to the direct-current voltage-type PLC photovoltaic shutoff circuit, the first LC trap is a PLC signal frequency trap consisting of L1 and C1, the first LC trap is connected in series with the freewheel diode D1, and when the switching tube Q1 is disconnected, the string current and the PLC signal pass through the freewheel diode D1 to realize normal power line carrier communication; when the switching tube Q1 is closed, the power line carrier communication is stopped, and the string current passes through the switching tube Q1.
The direct-current voltage-type PLC photovoltaic shutoff circuit is characterized in that the third LC trap is an interference frequency trap consisting of L3 and C3, and the third LC trap is used for filtering interference signals within 50K.
In the dc voltage PLC photovoltaic shutdown circuit, the inductance value L3 of the third LC trap is 150uH, and the capacitance value C3 is 22 nf-68 nf.
Compared with the prior art, the invention has the following beneficial effects: the direct-current voltage type PLC photovoltaic shutoff circuit provided by the invention has the following advantages: (1) The anti-interference capability of the signals is very high, and the signal communication is stable; (2) The PLC signal frequency wave traps L1 and C1 are connected with the freewheel diode D1 in series, so that the efficiency of the system is improved, and the stability of the system is not affected.
Drawings
Fig. 1 is a schematic circuit diagram of a dc voltage PLC photovoltaic shutdown in an embodiment of the present invention;
Fig. 2 is a schematic diagram of networking connection of multiple dc voltage PLC photovoltaic switches in an embodiment of the present invention.
Detailed Description
The direct-current voltage type PLC photovoltaic shutoff circuit in the embodiment of the invention has high efficiency, does not influence the characteristics of the original system, and has high reliability and simple implementation.
In order to make the above objects, features and advantages of the present invention more comprehensible, embodiments accompanied with figures are described in detail below.
Fig. 1 is a schematic circuit diagram of a dc voltage PLC photovoltaic shutdown in an embodiment of the present invention; fig. 2 is a schematic diagram of networking connection of multiple dc voltage PLC photovoltaic switches in an embodiment of the present invention.
Referring to fig. 1 and 2, the dc voltage PLC photovoltaic shutdown circuit provided by the present invention includes a photovoltaic module VPV, an input capacitor C4, a switching tube Q1, a freewheeling diode D1, a first LC trap, an output capacitor C5, a transformer T1, a coupling capacitor C6, a third LC trap L3, C3, a signal filter resistor R1, a signal filter capacitor C7, a second LC trap L2, C2, and output terminals 1-1 and 1-2;
The input capacitor C4 is connected with the photovoltaic module VPV in parallel, the anode of the photovoltaic module VPV is connected with the cathode of the freewheeling diode D1, one end of the coupling capacitor C6 and one end of the output capacitor C5 are connected, the cathode of the photovoltaic module VPV is connected with the drain electrode of the switching tube Q1, the source electrode of the switching tube Q1 is connected with one end of the first LC trap L1 and one end of the C1, one end of the primary side of the transformer T1 is connected with the other end of the output capacitor C5, the other ends of the first LC trap L1 and the C1 are connected with the anode of the freewheeling diode D1, and the other end of the primary side of the transformer T1 is connected with the other end of the coupling capacitor C6;
The output terminals 1-1 and 1-2 are connected in parallel with an output capacitor C5;
The other ends of the first LC wave traps L1 and C1 are connected with the anode of a freewheel diode D1, and the other end of the primary side of the transformer T1 is connected with the other end of a coupling capacitor C6; the output terminals 1-1 and 1-2 are connected with the output capacitor C5 in parallel, one end of the secondary side of the transformer T1 is connected with one end of the third LC trap L3 and one end of the third LC trap L3, the other end of the third LC trap L3 is connected with one end of the second LC trap L2 and one end of the second LC trap C2, the other end of the second LC trap L2 is connected with the signal filter resistor R1, the other end of the signal filter resistor R1 is connected with the signal filter capacitor C7, and the other end of the signal filter capacitor C7 is connected with the other end of the secondary side of the transformer T1.
According to the direct-current voltage-type PLC photovoltaic shutoff circuit, the first LC trap is the PLC signal frequency trap consisting of L1 and C1, the first LC trap is connected with the freewheeling diode D1 in series, when the switching tube Q1 is disconnected, the impedance of a freewheeling circuit can be greatly improved, signals pass through the transformer T1, communication is normal, and when the switching tube Q1 is closed, current passes through the switching tube Q1, so that the efficiency of a system and the stability of the system are not affected. The PLC signal frequency wave traps L1 and C1 are connected with the follow current diode D1 in series, current passes through the follow current diode L1 only when the shutoff device does not work, current passes through the follow current Q1 only when the shutoff device works, the direct output of the photovoltaic module is equivalent, the shutoff device is high in efficiency, the shutoff device system is the same as a pure photovoltaic system, the original characteristics of the system cannot be influenced, and working oscillation of an inverter at the later stage cannot be caused.
In addition, the switching tubes of the inverter input Boost circuit and the inverter circuit can work at a switching frequency within 50K, which can cause voltage ripple within 50K on the input line, generate certain interference on the PLC signal, cause signal distortion and make the system unstable. The third LC trap is an interference frequency trap composed of L3 and C3, and the third LC trap L3 and C3 pass through configuration parameters (such as l3=150uh, c3=22 nf-68 nf); signals within 50K can be perfectly filtered out. The specific interference frequency wave traps L3 and C3 can filter the interference of specific switching frequency signals brought by the back-stage inverter, so that the PLC signals cannot be distorted, the communication packet is lost, and the reliability of the system communication is improved.
With reference to fig. 2, the plurality of switches of the present invention are connected end to end, and the maximum number of the switches is less than 30, and since the input of the inverter at the rear stage has a large capacitance and a very low high frequency impedance, the PLC signal is distorted, so a fourth LC trap is required to be connected between the PCL signal generator and the input of the inverter, the cut-off frequency of the fourth LC trap is 135k, the LC parameter is l=20uh, and c=68nf, and the fourth trap functions to filter the interference signal with the same frequency as the PLC signal brought by the inverter at the rear stage, and simultaneously make the PLC signal system in a high impedance state, so as to prevent the system from being distorted due to the low impedance.
The direct-current voltage type PLC photovoltaic shutoff circuit provided by the invention has the following advantages:
(1) The efficiency is high, the characteristics of the original system are not affected, and the reliability is high;
(2) The PLC signal has very strong anti-interference capability, stable signal communication and stable system.
While the invention has been described with reference to the preferred embodiments, it is not intended to limit the invention thereto, and it is to be understood that other modifications and improvements may be made by those skilled in the art without departing from the spirit and scope of the invention, which is therefore defined by the appended claims.
Claims (4)
1. A dc voltage PLC photovoltaic shutdown circuit, comprising:
The photovoltaic module VPV, an input capacitor C4, a switching tube Q1, a freewheeling diode D1, a first LC trap, an output capacitor C5, a transformer T1, a coupling capacitor C6, a third LC trap, a signal filter resistor R1, a signal filter capacitor C7 and a second LC trap, wherein output terminals are arranged at two ends of the output capacitor C5;
The input capacitor C4 is connected with the photovoltaic module VPV in parallel, the positive electrode of the photovoltaic module VPV is connected with the cathode of the freewheel diode D1, one end of the coupling capacitor C6 and one end of the output capacitor C5, the negative electrode of the photovoltaic module VPV is connected with the drain electrode of the switching tube Q1, the source electrode of the switching tube Q1 is connected with one end of the first LC trap, one end of the primary side of the transformer T1 and the other end of the output capacitor C5 are connected, the other end of the first LC trap is connected with the anode of the freewheel diode D1, and the other end of the primary side of the transformer T1 is connected with the other end of the coupling capacitor C6;
One end of the secondary side of the transformer T1 is connected with one end of a third LC trap, the other end of the third LC trap is connected with one end of a second LC trap, the other end of the second LC trap is connected with one end of a signal filter resistor R1, the other end of the signal filter resistor R1 is connected with one end of a signal filter capacitor C7, and the other end of the signal filter capacitor C7 is connected with the other end of the secondary side of the transformer T1.
2. The direct current voltage type PLC photovoltaic shutoff circuit according to claim 1, wherein the first LC trap is a PLC signal frequency trap consisting of L1 and C1, the first LC trap is connected in series with a freewheeling diode D1, and when a switching tube Q1 is disconnected, a group string current and a PLC signal pass through the freewheeling diode D1 to realize normal power line carrier communication; when the switching tube Q1 is closed, the power line carrier communication is stopped, and the string current passes through the switching tube Q1.
3. The direct current mode PLC photovoltaic shutdown circuit of claim 1, wherein the third LC trap is an interference frequency trap comprised of L3, C3, the third LC trap being configured to filter interference signals within 50K.
4. The direct current voltage type PLC photovoltaic shutdown circuit according to claim 3, wherein the inductance value L3 of the third LC trap is 150uH and the capacitance value C3 is 22nf to 68nf.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810697600.6A CN108964267B (en) | 2018-06-29 | 2018-06-29 | DC voltage type PLC photovoltaic shutoff ware circuit |
| PCT/CN2018/115020 WO2020000864A1 (en) | 2018-06-29 | 2018-11-12 | Direct current voltage-type plc photovoltaic shutdown device circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810697600.6A CN108964267B (en) | 2018-06-29 | 2018-06-29 | DC voltage type PLC photovoltaic shutoff ware circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108964267A CN108964267A (en) | 2018-12-07 |
| CN108964267B true CN108964267B (en) | 2024-04-19 |
Family
ID=64484427
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810697600.6A Active CN108964267B (en) | 2018-06-29 | 2018-06-29 | DC voltage type PLC photovoltaic shutoff ware circuit |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN108964267B (en) |
| WO (1) | WO2020000864A1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112821458B (en) * | 2021-03-23 | 2024-05-14 | 阳光电源股份有限公司 | Photovoltaic rapid turn-off system and control method thereof |
| CN116547881A (en) * | 2021-10-20 | 2023-08-04 | 杭州禾迈电力电子股份有限公司 | Shutoff device, communication method of shutoff device and quick shutoff photovoltaic system |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104953946A (en) * | 2015-06-12 | 2015-09-30 | 内蒙古电力勘测设计院有限责任公司 | Alternating-current header box adopting carrier communication and photovoltaic power station |
| CN206323214U (en) * | 2016-12-09 | 2017-07-11 | 上海致达智能科技股份有限公司 | Photovoltaic power station power carrier communication system |
| CN206611172U (en) * | 2017-04-11 | 2017-11-03 | 丰郅(上海)新能源科技有限公司 | Photovoltaic module rapidly switches off circuit |
| CN208401627U (en) * | 2018-06-29 | 2019-01-18 | 江苏集能易新能源技术有限公司 | A kind of direct voltage PLC photovoltaic switching off device circuit |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5757122B2 (en) * | 2011-03-25 | 2015-07-29 | 住友電気工業株式会社 | Monitoring system for photovoltaic power generation |
| EP2816547A1 (en) * | 2013-06-17 | 2014-12-24 | ABB Research Ltd. | Adaptive RCD snubber and method for switching converter |
| CN106936474B (en) * | 2015-12-31 | 2020-04-24 | 上海盐巴信息科技有限公司 | Power line carrier communication method and output coupling filter circuit |
| CN205883159U (en) * | 2016-07-20 | 2017-01-11 | 弥亚微电子（上海）有限公司 | Solar PV modules's watch -dog, monitored control system |
-
2018
- 2018-06-29 CN CN201810697600.6A patent/CN108964267B/en active Active
- 2018-11-12 WO PCT/CN2018/115020 patent/WO2020000864A1/en active Application Filing
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104953946A (en) * | 2015-06-12 | 2015-09-30 | 内蒙古电力勘测设计院有限责任公司 | Alternating-current header box adopting carrier communication and photovoltaic power station |
| CN206323214U (en) * | 2016-12-09 | 2017-07-11 | 上海致达智能科技股份有限公司 | Photovoltaic power station power carrier communication system |
| CN206611172U (en) * | 2017-04-11 | 2017-11-03 | 丰郅(上海)新能源科技有限公司 | Photovoltaic module rapidly switches off circuit |
| CN208401627U (en) * | 2018-06-29 | 2019-01-18 | 江苏集能易新能源技术有限公司 | A kind of direct voltage PLC photovoltaic switching off device circuit |
Non-Patent Citations (2)
| Title |
|---|
| 基于电力载波的光伏数据采集***设计;朱锐;王小宁;朱锦明;钱林瀚;王林;;中国科技信息;20130601(第11期);第115页 * |
| 电力通信技术在分布式光伏并网接入***中的相关研究;罗虎;王玲;;经贸实践;20170915(第18期);第328页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108964267A (en) | 2018-12-07 |
| WO2020000864A1 (en) | 2020-01-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105337483A (en) | Device for preventing current from flowing backwards | |
| CN101860237B (en) | High-power factor constant-current circuit and power source | |
| CN103779951A (en) | Electric bicycle magnetic coupling resonance type wireless charger | |
| CN205265685U (en) | Power line carrier communication device | |
| CN101950984B (en) | Low-cost interface structure and method for monitoring direct current side information of solar cell panel | |
| CN108964267B (en) | DC voltage type PLC photovoltaic shutoff ware circuit | |
| CN110854919A (en) | Direct current type PLC photovoltaic fast turn-off device | |
| CN100552740C (en) | Signal isolation transmission circuit | |
| CN203119748U (en) | Driving control circuit for direct parallel connection IGBTs | |
| CN104734516A (en) | Switching power supply circuit and computer power supply | |
| CN105262138A (en) | Photovoltaic module optimizer | |
| CN206389350U (en) | A kind of light-coupled isolation communicating circuit | |
| US11637589B2 (en) | Power line communication apparatus and power generating system | |
| CN203590560U (en) | LED drive circuit and LED lamp | |
| CN113381612B (en) | Series coupling converter | |
| CN208401627U (en) | A kind of direct voltage PLC photovoltaic switching off device circuit | |
| CN105353822A (en) | Cascade connection intelligent optimization device for battery strings of photovoltaic module | |
| CN204733094U (en) | Plasma cutting power supply circuit | |
| CN204481686U (en) | Switching power circuit and computer power supply | |
| CN108233340B (en) | Damp type blocks circuit | |
| CN203086360U (en) | Energy-saving high-frequency switching power supply | |
| CN106100330A (en) | Direct-type digital power amplifier circuit | |
| CN202679355U (en) | Voltage stabilizing circuit for frequency modulation interphone | |
| CN205596022U (en) | Synchronous Rectifier type switching power supply circuit | |
| CN211377703U (en) | Power line carrier communication device and photovoltaic inverter system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |