CN109194104A - A kind of linear high stable DC filtering circuit - Google Patents

A kind of linear high stable DC filtering circuit Download PDF

Info

Publication number
CN109194104A
CN109194104A CN201811079243.3A CN201811079243A CN109194104A CN 109194104 A CN109194104 A CN 109194104A CN 201811079243 A CN201811079243 A CN 201811079243A CN 109194104 A CN109194104 A CN 109194104A
Authority
CN
China
Prior art keywords
pole
igbt
igbt switch
capacitor
cbuck
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.)
Granted
Application number
CN201811079243.3A
Other languages
Chinese (zh)
Other versions
CN109194104B (en
Inventor
李俊
薄翠梅
刘小宁
高世达
钱文浩
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Zhenjiang Bohui Automation Technology Research Institute Co Ltd
Original Assignee
Zhenjiang Bohui Automation Technology Research Institute Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Zhenjiang Bohui Automation Technology Research Institute Co Ltd filed Critical Zhenjiang Bohui Automation Technology Research Institute Co Ltd
Priority to CN201811079243.3A priority Critical patent/CN109194104B/en
Publication of CN109194104A publication Critical patent/CN109194104A/en
Application granted granted Critical
Publication of CN109194104B publication Critical patent/CN109194104B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/14—Arrangements for reducing ripples from dc input or output
    • H02M1/15—Arrangements for reducing ripples from dc input or output using active elements

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Dc-Dc Converters (AREA)
  • Power Conversion In General (AREA)

Abstract

The invention discloses a kind of linear high stable DC filtering circuit, which includes IGBT switch K1, K2, adjustable power of direct current, capacitor Cbuck, capacitor Cbuck charge power supply, IGBT switching group SD, IGBT switch Sk and switch SW；The adjustable power of direct current is set there are two output port, respectively the first output port AFPS1 and second output terminal mouth AFPS2, and the "-" pole of the first output port AFPS1 is connect with the "-" pole of second output terminal mouth AFPS2；The IGBT switch K1 connects IGBT switch controller with the pole G of IGBT switch K2, the pole E and the pole C of each IGBT switch in the IGBT switching group SD are sequentially connected with, and the pole G, the pole G of IGBT switch Sk and the control signal input of capacitor Cbuck charge power supply of each IGBT switch are separately connected the signal output end of capacitor Cbuck both end voltage controller in IGBT switching group SD.The present invention can rectify output low frequency harmonic voltage to 50Hz, 100Hz etc. in high-power AC/DC conversion electric power circuit and be inhibited well.

Description

A kind of linear high stable DC filtering circuit
Technical field
The invention belongs to large power supply filtering device field, specifically a kind of linear high stable DC filtering circuit.
Background technique
In the prior art, high-power AC/DC conversion electric power is filtered using passive LC filter circuit, still, by It is more difficult in inhibition of the LC filter circuit to low-frequency ripple, therefore, because trigger circuit pulse is uneven, power grid three-phase voltage is uneven The rectification output low frequency harmonic voltage such as 50Hz, 100Hz generated that weighs is unable to get fine inhibition.
Summary of the invention
In order to solve the above-mentioned problems in the prior art, the present invention proposes a kind of linear high stable DC filtering electricity Road can rectify output low frequency harmonic wave to 50Hz, 100Hz etc. in high-power AC/DC conversion electric power circuit using the circuit Voltage is inhibited well.
To achieve the above object, the technical solution adopted by the present invention is as follows:
A kind of linear high stable DC filtering circuit, the circuit include IGBT switch K1, IGBT switch K2, direct current adjustable electric Source, capacitor Cbuck, capacitor Cbuck charge power supply, IGBT switching group SD, IGBT switch Sk and switch SW；
The adjustable power of direct current is set there are two output port, respectively the first output port AFPS1 and second output terminal Mouth AFPS2, and the "-" pole of the first output port AFPS1 is connect with the "-" pole of second output terminal mouth AFPS2；
The pole C of the pole the E connection IGBT switch K2 of the IGBT switch K1, and the "+" pole as this active filter circuit； The pole C of IGBT switch K1 connects the "+" pole of the first output port AFPS1, and the pole E of IGBT switch K2 connects the first output port The "-" pole of AFPS1；The IGBT switch K1 connects IGBT switch controller, IGBT switch control with the pole G of IGBT switch K2 Device control IGBT switch K1 and IGBT switch K2 works in " linear amplification region "；
The two poles of the earth of the capacitor Cbuck are separately connected the "+" of capacitor Cbuck charge power supply output end, "-" pole；It is described The "+" pole of the pole the C connection second output terminal mouth AFPS2 of IGBT switch Sk, the pole the E connection capacitor Cbuck charging of IGBT switch Sk The "-" pole of power output end；The switch SW is connected to "+" pole and the first output end of capacitor Cbuck charge power supply output end Between the "-" pole of mouth AFPS1；
The pole E and the pole C of each IGBT switch in the IGBT switching group SD are sequentially connected with, wherein first IGBT is opened The "+" pole of the pole the C connection capacitor Cbuck charge power supply output end of pass, the pole E of the last one IGBT switch connects capacitor Cbuck The "-" pole of charge power supply output end, and discharge resistance is respectively connected between the pole E and the pole C of each IGBT switch；
The pole G of each IGBT switch, the pole G of IGBT switch Sk and capacitor Cbuck charging in the IGBT switching group SD The control signal input of power supply is separately connected the signal output end of capacitor Cbuck both end voltage controller, the capacitor Cbuck Both end voltage controller signal output receives voltage signal, and the voltage signal includes the filtering of external passive LC filter circuit The voltage V at capacitor both ends0Signal, the both ends capacitor Cbuck voltage VCbuck signal.
Further, the G of signal output end connection the IGBT switch K1 and IGBT switch K2 of the IGBT switch controller Pole, signal input part receive foreign current signal, and the current signal includes the filter capacitor electricity of external passive LC filter circuit Flow IfThe input current I of signal, this linear high stable DC filtering circuitafSignal, water cooling magnet current actual value IMWith setting Value IrefError current IerrSignal.
Further, the IGBT switching group SD includes six IGBT switches, is denoted as IGBT switch S respectively0~S5, wherein IGBT switch S5The pole C connection capacitor Cbuck charge power supply output end "+" pole, IGBT switch S0Connect capacitor Cbuck charging The "-" pole of power output end.
Further, the pole G of each IGBT switch is respectively connected with IGBT driver.
Further, the IGBT switch controller and capacitor Cbuck both end voltage controller can be all made of PLC control Device.
Further, the capacitor Cbuck both end voltage controller is to capacitor Cbuck both end voltage VCbuckControlling party Method is as follows:
Charge and discharge are carried out to capacitor Cbuck by control, make the C grade and E voltage across poles V of IGBT switch K2o-VCbuckInstantaneously Value meets:
3V≤Vo-VCbuck≤17V
(1) capacitor CbuckRepid discharge control:
Work as Vo-VCbuckWhen < 3, to capacitor CbuckRepid discharge be by be connected IGBT switch S0Or IGBT switch SKIt is real Existing, VCbuckAverage valueWhen, IGBT switch S is connectedK,When for other values, IGBT switch S is connected0,As VCbuckLow-pass filter value, be connected IGBT switch S0CbuckDischarge resistance value RFIt is calculated by following formula:
Pass through samplingOutput valve, to control IGBT switch S1~S5On/off, this be withValue determines at any time； IGBT switch S1~S5Working condition byThe binary computations negated are rounded to determine；
(2) capacitor CbuckQuick charge control:
Work as Vo-VCbuckWhen > 17V, start-up capacitance Cbuck charge power supply is capacitor C immediatelybuckQuick charge, capacitor Cbuck charge power supply works in maximum current output mode；
(3) stablizeControl:
As Vo-VCbuckLow-pass filter value, byPositive deviation value determine electricity Appearance Cbuck charge power supply is capacitor CbuckThe size of charging battery electric current, maximum charging battery electric current are 5A.
The beneficial effects of the present invention are: the circuit can in high-power AC/DC conversion electric power circuit 50Hz, The rectification output low frequency harmonic voltage such as 100Hz is inhibited well.
Additional aspect and advantage of the invention will be set forth in part in the description, and will partially become from the following description Obviously, or practice through the invention is recognized.
Detailed description of the invention
Fig. 1 is a kind of this linear high stable DC filtering circuit and its application schematic diagram；
In figure, the unit of resistance is Ω.
Specific embodiment
The present invention is described in detail with specific embodiment below in conjunction with the accompanying drawings.
A kind of linear high stable DC filtering circuit, including IGBT switch K1, IGBT switch K2, IGBT switch K1 and K2 Controller, adjustable power of direct current, capacitor Cbuck, capacitor Cbuck charge power supply, capacitor Cbuck both end voltage controller, IGBT Switching group SD, IGBT switch Sk and switch SW.
There are two output ports, respectively the first output port AFPS1 and second output terminal mouth for the adjustable power of direct current AFPS2, and the "-" pole of AFPS1 and the "-" pole of AFPS2 connect.
Main circuit are as follows:
The pole C of the pole the E connection K2 of the K1, and the "+" pole as this linear high stable DC filtering circuit；The pole C of K1 Connect the "+" pole of AFPS1, the "-" pole of the pole the E connection AFPS1 of K2；The control output end of the controller of K1 and K2 is separately connected The pole G of K1 and K2 controls K1 and K2 work in linear amplification region；The controller of K1 and K2 receives foreign current signal, these electricity Stream signal includes the filter capacitor electric current I of external passive LC filter circuitfThe input current I of signal, this active filter circuitafLetter Number, water cooling magnet current actual value IMWith setting value IrefError current IerrSignal.
The two poles of the earth of the capacitor Cbuck are separately connected the "+" of the charge power supply output end of Cbuck, "-" pole；The SD's In each IGBT switch the pole E and the pole C be sequentially connected with, wherein the charging electricity of the pole the C connection Cbuck of first IGBT switch The "+" pole of source output terminal, the "-" pole of the charge power supply output end of the pole the E connection Cbuck of the last one IGBT switch；It is each Discharge resistance is respectively connected between the pole E and the pole C of IGBT switch；The "+" pole of the pole the C connection AFPS2 of the IGBT switch Sk, Sk The pole E connection Cbuck charge power supply output end "-" pole；The control of the controller of the capacitor Cbuck both end voltage is believed Number output end is separately connected the control letter of the charge power supply of the pole G of the switch of each IGBT in SD, the pole G of Sk and Cbuck Number input terminal；The received voltage signal of the controller of Cbuck both end voltage, these voltage signals include external passive LC filtered electrical The voltage V of the both ends of filter capacitor on road0Signal, the both ends capacitor Cbuck voltage VCbuck signal.
The switch SW is connected between the "+" pole of the charge power supply output end of Cbuck and the "-" pole of AFPS1.
The IGBT switching group SD includes that six IGBT switches are denoted as S respectively0~S5, wherein S5C pole connection Cbuck The "+" pole of charge power supply output end, S0Connect the "-" pole of the charge power supply output end of Cbuck.
The pole G of each IGBT switch in described linear high stable DC filtering circuit is respectively connected with IGBT driver.
The technical program is further described below with specific embodiment with reference to the accompanying drawing:
In this example, this filter circuit is used for high stability high power power supply for magnet coils, the requirement of the power supply are as follows: rated output electricity Press 700V, separate unit output-current rating 20kA, overload capacity (%) 10/10min, current ripples peak-to-peak value 10ppm, stability (8 hours) 10ppm, the resolution ratio 2ppm of setting electric current, current precision 100ppm.The "+" pole of this active filter circuit is connected to One end of the filter capacitor C of the LC passive filter circuit of power supply, the charge power supply output end of the Cbuck of this active filter circuit "-" pole is connected to the other end of filter capacitor C.
This linear high stable DC filtering circuit includes three parts: 1) main circuit, and 2) insulated gate bipolar transistor IGBT The control circuit of switch K1 and K2,3) control circuit of capacitor Cbuck voltage VCbuck；It is described below in detail:
1, main circuit
Main circuit is as shown in Fig. 1 dashed box.
2, the controller of IGBT switch K1, K2
For K1, K2 control independently of to CbuckCharge and discharge control, for the controller of K1 and K2, (control circuit can The available circuit of selection can there are many, such as PLC etc. has the function of that output signal is calculated according to input signal, Similarly, the controller of the capacitor Cbuck both end voltage VCbuck of lower section is also the same):
A, the signal of the Differential Input of control circuit has: filter capacitor electric current If, flow into active filter circuit electric current Iaf、 Water cooling magnet current actual value IMWith setting value IrefError current Ierr。
B, the output signal of control circuit has: two-way is used to drive the signal of IGBT switch K1 and K2, this two paths of signals warp Isolation (isolation uses IGBT driver, such as high-speed isolated amplifier AD215BY) exports afterwards.The output line of this two paths of signals is used Twisted pair, the public end COM of twisted pair connects the pole E of K1 and K2 respectively, the signal end of twisted pair connects the pole G of K1 and K2 respectively.
C, in addition to as the power supply of AFPS1 and AFPS2, also need the linear power supply of ± 15V about 10W of the two-way through being isolated for height Fast isolated amplifier AD215BY and other IGBT drivers (pole G that IGBT driver is connected to K1, K2) power supply, isolation voltage 1kVDC, stability of power supply and precision must be better than 1% ,+15V because caused by driving IGBT pressure drop less than 2%.
3, the controller of capacitor Cbuck both end voltage VCbuck
To make K1, K2 reliably working, charge and discharge need to be carried out to Cbuck by control, make the CE pole tension V of K2o-VCbuckWink Duration meets:
3V≤Vo-VCbuck≤17V
One) CbuckRepid discharge control:
S0~S5、SKIt is switched for the IGBT of main circuit, each IGBT is furnished with the IGBT driver for playing buffer action.
Vo-VCbuckTo C when < 3buckRepid discharge be by be connected S0Or SKIt realizes, average valueIt leads Logical SK,S is connected at present for other values0,It is VCbuckLow-pass filter value, be connected S0CbuckDischarge resistance Value RFIt is calculated by following formula:
PLC analog-to-digital conversion (A/D) samplingOutput control S1~S5On-off (withIt is true to be worth any moment It is fixed), S1~S5Working condition byIt is rounded the binary computations negated and determines that calculations list is as follows:
Two) CbuckQuick charge control:
Work as Vo-VCbuckWhen > 17V (instantaneous value), starting " HF-PS " immediately is CbuckQuick charge, " HF-PS " work exist Maximum current output mode.
Three) stablizeControl
Vo-VCbuckAverage valueControl stabilization can be reduced in 10V to CbuckFast charging and discharging need,For Vo-VCbuckLow-pass filter value, byPositive deviation value determine " HF-PS " be Cbuck The size of charging battery electric current, maximum charging battery electric current are 5A.
4, the charge power supply of Cbuck can use Switching Power Supply, be denoted as HF-PS；HF-PS power supply, AFPS1 corresponding power and The requirement of AFPS2 corresponding power:
" HF-PS " power supply has two kinds of charge modes of speed, the high level signal that charging quickly mode response controller is sent, Have in 0.1ms and be up to the output of 150A electric current, trickle charge power mode can make output electric current adjustable between 0~5A.
" HF-PS " maximum output voltage is 700V, maximum output current 150A, and operative duty cycles are about 100mS/ 1S, then output-current rating takes 30A, and rated power takes less than 25kW.
AFPS1 and AFPS2 rated output power 6kW, output voltage is adjustable between 0~20V, output-current rating 300A, Their all current limiting functions, current limliting is adjustable in 100~300A, but does not cut off the power when overcurrent protection, but maintains power supply output Maximum allowed current allows output voltage to decline.
The basic principles, main features and advantages of the invention have been shown and described above.Those skilled in the art It should be appreciated that the protection scope that the above embodiments do not limit the invention in any form, all to be obtained using modes such as equivalent replacements The technical solution obtained, falls in protection scope of the present invention.
Part that the present invention does not relate to is the same as those in the prior art or can be realized by using the prior art.

Claims (6)

1. a kind of linear high stable DC filtering circuit, it is characterised in that: the circuit include IGBT switch K1, IGBT switch K2, Adjustable power of direct current, capacitor Cbuck, capacitor Cbuck charge power supply, IGBT switching group SD, IGBT switch Sk and switch SW；
The adjustable power of direct current is set there are two output port, respectively the first output port AFPS1 and second output terminal mouth AFPS2, and the "-" pole of the first output port AFPS1 is connect with the "-" pole of second output terminal mouth AFPS2；
The pole C of the pole the E connection IGBT switch K2 of the IGBT switch K1, and the "+" pole as this active filter circuit；IGBT is opened The pole C for closing K1 connects the "+" pole of the first output port AFPS1, and the pole E of IGBT switch K2 connects the first output port AFPS1's "-" pole；The IGBT switch K1 connects IGBT switch controller, the control of IGBT switch controller with the pole G of IGBT switch K2 IGBT switch K1 and IGBT switch K2 works in " linear amplification region "；
The two poles of the earth of the capacitor Cbuck are separately connected the "+" of capacitor Cbuck charge power supply output end, "-" pole；The IGBT is opened The "+" pole of the pole the C connection second output terminal mouth AFPS2 of Sk is closed, the pole the E connection capacitor Cbuck charge power supply of IGBT switch Sk is defeated The "-" pole of outlet；The switch SW is connected to "+" pole and the first output port of capacitor Cbuck charge power supply output end Between the "-" pole of AFPS1；
The pole E and the pole C of each IGBT switch in the IGBT switching group SD are sequentially connected with, wherein the C of first IGBT switch Pole connects the "+" pole of capacitor Cbuck charge power supply output end, the pole the E connection capacitor Cbuck charging electricity of the last one IGBT switch The "-" pole of source output terminal, and discharge resistance is respectively connected between the pole E and the pole C of each IGBT switch；
The pole G of each IGBT switch, the pole G of IGBT switch Sk and capacitor Cbuck charge power supply in the IGBT switching group SD Control signal input be separately connected the signal output end of capacitor Cbuck both end voltage controller, the both ends the capacitor Cbuck Voltage controller signal output end receives voltage signal, and the voltage signal includes the filter capacitor of external passive LC filter circuit The voltage V at both ends0Signal, the both ends capacitor Cbuck voltage VCbuck signal.
2. a kind of linear high stable DC filtering circuit according to claim 1, it is characterised in that: the IGBT switch control The pole G of signal output end connection the IGBT switch K1 and IGBT switch K2 of device processed, signal input part receive foreign current signal, institute State the filter capacitor electric current I that current signal includes external passive LC filter circuitfThe input current of signal, this active filter circuit IafSignal, water cooling magnet current actual value IMWith setting value IrefError current IerrSignal.
3. a kind of linear high stable DC filtering circuit according to claim 1, it is characterised in that: the IGBT switching group SD includes six IGBT switches, is denoted as IGBT switch S respectively0~S5, wherein IGBT switch S5The pole C connection capacitor Cbuck charging The "+" pole of power output end, IGBT switch S0Connect the "-" pole of capacitor Cbuck charge power supply output end.
4. a kind of linear high stable DC filtering circuit according to claim 1 or 3, it is characterised in that: each IGBT is opened The pole G of pass is respectively connected with IGBT driver.
5. a kind of linear high stable DC filtering circuit according to claim 1, it is characterised in that: the IGBT switch control Device and capacitor Cbuck both end voltage controller processed is all made of PLC controller.
6. a kind of linear high stable DC filtering circuit according to claim 3, it is characterised in that: the capacitor Cbuck Both end voltage controller is to capacitor Cbuck both end voltage VCbuckControl method it is as follows:
Charge and discharge are carried out to capacitor Cbuck by control, make the C grade and E voltage across poles V of IGBT switch K2o-VCbuckInstantaneous value is full Foot:
3V≤Vo-VCbuck≤17V
(1) capacitor CbuckRepid discharge control:
Work as Vo-VCbuckWhen < 3, to capacitor CbuckRepid discharge be by be connected IGBT switch S0Or IGBT switch SKIt realizes, VCbuckAverage valueWhen, IGBT switch S is connectedK,When for other values, IGBT switch S is connected0,Make For VCbuckLow-pass filter value, be connected IGBT switch S0CbuckDischarge resistance value RFIt is calculated by following formula:
Pass through samplingOutput valve, to control IGBT switch S1~S5On/off, this be withValue determines at any time；IGBT is opened Close S1~S5Working condition byThe binary computations negated are rounded to determine；
(2) capacitor CbuckQuick charge control:
Work as Vo-VCbuckWhen > 17V, start-up capacitance Cbuck charge power supply is capacitor C immediatelybuckQuick charge, capacitor Cbuck fill Electric power work is in maximum current output mode；
(3) stablizeControl:
As Vo-VCbuckLow-pass filter value, byThe positive deviation value of V determines capacitor Cbuck charge power supply is capacitor CbuckThe size of charging battery electric current, maximum charging battery electric current are 5A.
CN201811079243.3A 2018-09-17 2018-09-17 Linear high-stability direct-current filter circuit Active CN109194104B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201811079243.3A CN109194104B (en) 2018-09-17 2018-09-17 Linear high-stability direct-current filter circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201811079243.3A CN109194104B (en) 2018-09-17 2018-09-17 Linear high-stability direct-current filter circuit

Publications (2)

Publication Number Publication Date
CN109194104A true CN109194104A (en) 2019-01-11
CN109194104B CN109194104B (en) 2020-04-21

Family

ID=64911306

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201811079243.3A Active CN109194104B (en) 2018-09-17 2018-09-17 Linear high-stability direct-current filter circuit

Country Status (1)

Country Link
CN (1) CN109194104B (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5502628A (en) * 1991-12-27 1996-03-26 Toko, Inc. AC-DC converter
CN1346173A (en) * 2000-09-26 2002-04-24 殷刚 Self-correction step-up active filtering switch power source
CN104795981A (en) * 2015-04-24 2015-07-22 山东大学 Current ripple active restraining method of DC-grid-connection-operation hybrid micro-grid bidirectional transducers

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5502628A (en) * 1991-12-27 1996-03-26 Toko, Inc. AC-DC converter
CN1346173A (en) * 2000-09-26 2002-04-24 殷刚 Self-correction step-up active filtering switch power source
CN104795981A (en) * 2015-04-24 2015-07-22 山东大学 Current ripple active restraining method of DC-grid-connection-operation hybrid micro-grid bidirectional transducers

Also Published As

Publication number Publication date
CN109194104B (en) 2020-04-21

Similar Documents

Publication Publication Date Title
CN101902126B (en) Power supply device for sputter ion pumps
CN104319761B (en) PV air-conditioner system and the PV air-conditioner with which
CN106059548B (en) Switch unit and power circuit
CN209948954U (en) Non-isolated type double-switch voltage reduction circuit and direct current-direct current converter
CN107276388A (en) Pfc circuit and transducer air conditioning
CN103022978B (en) For the over under-voltage protection circuit of multiple pulse rectification circuit
CN110943499A (en) Novel energy storage circuit
CN104021978A (en) Constant-current charging switching device for switching-on switching-off capacitor of permanent magnet vacuum switch and control method thereof
CN108400719A (en) A kind of novel switched regulated power supply based on TL494
CN108199461A (en) A kind of ac-dc converter circuit with charge function
CN109194104A (en) A kind of linear high stable DC filtering circuit
CN108712070A (en) Based on ZCS PWM bi-directional DC-DC CUK converters, transformation system and method
CN106887904A (en) A kind of wireless electric energy transmission device with overvoltage protection
CN208112510U (en) A kind of constant voltage outputting circuit of twin-stage input inverter
CN203967814U (en) A kind of without dead band induction power taking power-supply system
CN103078516A (en) Automatic input voltage switching device for mah-jong machine
CN108879719A (en) The novel series voltage quality regulator administered for low-voltage
CN209571821U (en) A kind of inrush current suppression circuit
CN108123591A (en) Power-switching circuit and power supply changeover device
CN205453078U (en) Current foldback circuit and constant voltage power supply
CN209730791U (en) Driving power circuit with self-protection function
CN208986627U (en) A kind of novel energy-storing circuit
CN201065814Y (en) Body-building device converting biological energy into AC
CN107069909A (en) A kind of energy-saving mobile phone charger that can be automatically powered off
CN207827607U (en) AC DC bi-directional conversion circuit and elevator automatic help operating device

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