CN104023456B - LED sectional dimming circuit - Google Patents
LED sectional dimming circuit Download PDFInfo
- Publication number
- CN104023456B CN104023456B CN201410311195.1A CN201410311195A CN104023456B CN 104023456 B CN104023456 B CN 104023456B CN 201410311195 A CN201410311195 A CN 201410311195A CN 104023456 B CN104023456 B CN 104023456B
- Authority
- CN
- China
- Prior art keywords
- circuit
- output
- decoder
- led
- power
- 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
Landscapes
- Circuit Arrangement For Electric Light Sources In General (AREA)
Abstract
The invention provides a kind of LED sectional dimming circuit, comprising: a light modulation test side, connect the enable signal EN in LED drive chip, in order to detect the system power failure that caused by dimmer switch and to power on; One power generation circuit, with thinking that the circuit of LED sectional dimming inside circuit provides power supply; The output of power generation circuit connects annular counter and decoder; One ring counter, its input connects light modulation test side, in order to calculate the number of times pressing dimmer switch; One decoder, its input connects ring counter, carries out decoding, to control the output of selection circuit to the output signal of ring counter; One selection circuit, it selects signal end to connect decoder, input termination each section of reference voltage, in order to select the reference voltage needed as output.The present invention is applied widely, can be applicable to the LED drive circuit of the multiple frameworks such as isolation, non-isolated, floating ground and band PFC.
Description
Technical field
The present invention relates to LED drive circuit, the sectional dimming circuit of LED drive chip inside in especially a kind of LED drive circuit.
Background technology
LED is widely used in lighting field at present, and becomes the lighting source of a new generation gradually because of the advantage of its uniqueness, and the mode of operation of people to LED it is also proposed requirement, and light modulation is wherein important one.And in the middle of all light regulating technologies, sectional dimming is a kind of simplicity of design relatively, cost is low, the easy to operate and technology of practicality.
Fig. 1 is the schematic diagram that existing sectional dimming technology is applied to LED drive circuit, 101 is AC power, and 102,103,104,105 is bridge rectifier, and 106 is large filter capacitor (the several uF of common value), by ac signal rectifying and wave-filtering together with rectification circuit, output line voltage; 107,108 is divider resistance, and LED drive chip (hereinafter referred chip) pin DIM is by these two resistance sampling line information of voltage; 109 is little filter capacitor (nF level); 110,111 is start-up circuit; 112 is chip; 113 is loop compensation electric capacity; 114, for supplying electric diode, are connected between auxiliary winding and chip power pin VIN; 117 is transformer, and wherein Np is former limit winding, Ns is time limit winding, NA is auxiliary winding; 115,116 is auxiliary winding sampling divider resistance, is connected with chip pin FB; 118 is power tube; 119 is sampling resistor; 120 is fly-wheel diode; 121 is output capacitance; 122 is LED.
Chip internal is designed with light adjusting circuit, and light adjusting circuit connects pin DIM, and chip, by detecting the change of pin DIM information of voltage, judges whether to need to carry out light modulation.Fig. 2 is light adjusting circuit of the prior art, and 201 connect chip pin DIM, sample line information of voltage; 202 is a benchmark; 203 is testing circuit, by detecting the change of pin DIM, determines whether to ring counter 205 clock signal; 204 is clock signal; 205,206 be respectively ring counter and decoding circuit, jointly form shift register; 208 is selection circuit; 207 is n reference voltage of selection circuit; 209 is the output of selection circuit, directly control LED output current size.The nucleus module of light adjusting circuit is shift register, and system each time power down powers on, and shift register just exports next state.System power failure powers on period, and the line voltage after rectifier bridge responds fast, and pin DIM is by divider resistance sample line information of voltage simultaneously, and this pin voltage compares with chip internal reference voltage again, and whether power down powers on can to judge system.Power on if the system of judging experiences a power down, shift register just can process coherent signal, makes the reference voltage V controlling output current
rEF1become V
rEF2, thus realize the light modulation of LED.
But there is following shortcoming in this light adjusting circuit:
The first, for the application scheme of band PFC function, when normally working, line voltage is half waveform, and the height of line voltage can not reflect system, and whether power down powers on, and pin DIM does not judge system by divider resistance sample line information of voltage, and whether power down powers on;
The second, for the application scheme of floating ground framework, the absolute voltage of chip is along with the switch of power tube is in continuous change, and the sample information that chip internal cannot select a fiducial value and pin DIM compares to judge system, and whether power down powers on, etc.
Summary of the invention
The object of the invention is to overcome and fill the deficiencies in the prior art, a kind of LED sectional dimming circuit is provided, can be applicable to the multiple circuit frameworks such as isolation, non-isolated, floating ground and band PFC.
The present invention is to provide can be general sectional dimming circuit, its structure is simple, and application scheme only needs an external small capacitances, cost is low, applied widely, can be applicable to the LED drive circuit of various framework.
In order to realize foregoing invention object, the technical solution used in the present invention is:
A kind of LED sectional dimming circuit, comprising:
One light modulation test side, connects the enable signal EN in LED drive chip, in order to detect the system power failure that caused by dimmer switch and to power on;
One power generation circuit, with thinking that the circuit of LED sectional dimming inside circuit provides power supply; The output of power generation circuit connects annular counter and decoder;
One ring counter, its input connects light modulation test side, in order to calculate the number of times pressing dimmer switch;
One decoder, its input connects ring counter, carries out decoding, to control the output of selection circuit to the output signal of ring counter;
One selection circuit, it selects signal end to connect decoder, input termination each section of reference voltage, in order to select the reference voltage needed as output.
Above-mentioned light modulation test side directly utilizes the inner enable signal EN of LED drive chip (hereinafter referred chip) to reflect the power down of system and to power on, dimmer switch is pressed once, system certainly will be caused to produce a power down and power on, and enable signal EN directly connects the clock signal of ring counter.
The input termination chip power VIN of power generation circuit and chip internal power vd D, exports as ring counter and decoder provide power supply.During application, the output of power generation circuit makes separately a pin, and plug-in capacitor.
Compared with prior art, the LED sectional dimming circuit that the present invention proposes, is applied in LED drive circuit, and its structure is simple on the one hand, only needs an external small capacitances, greatly reduce cost in periphery; On the other hand, applied widely, this sectional dimming circuit can be used in the framework of various LED drive circuit, makes this sectional dimming circuit have more practicality.
Accompanying drawing explanation
Fig. 1 is the sectional dimming LED drive circuit schematic diagram under prior art.
Fig. 2 is the schematic internal view of sectional dimming circuit under prior art.
Fig. 3 is the schematic diagram of first embodiment of the invention LED drive circuit.
Fig. 4 is LED sectional dimming inside circuit schematic diagram of the present invention.
Fig. 5 is the power generation circuit schematic diagram of LED sectional dimming inside circuit of the present invention.
Fig. 6 is the power generation circuit signal waveform schematic diagram of LED sectional dimming inside circuit of the present invention.
Fig. 7 is selection circuit schematic diagram of the present invention.
Fig. 8 is the schematic diagram of second embodiment of the present invention LED drive circuit.
Embodiment
Below in conjunction with concrete drawings and Examples, the invention will be further described.
In order to solve prior art Problems existing, the present invention proposes a kind of sectional dimming circuit being applied to LED drive circuit, only needing a small capacitances in periphery on the one hand, greatly reducing cost; On the other hand, this sectional dimming circuit can be used in the framework of various LED drive circuit, makes this sectional dimming circuit have more practicality.The present invention is only applied in AC/DC switching power converters in an illustrative manner, but will be appreciated that the present invention has more wide range of application.
Fig. 3 is first embodiment of the invention LED drive circuit schematic diagram, and this circuit is isolated form band PFC function.301 is AC power; 302 ~ 305 is bridge rectifier, and 306 is little filter capacitor (as 100nF), and the line voltage after rectifier bridge is half waveform; 309,310 is chip enable circuit; 311 is LED drive chip (hereinafter referred chip); 307 is loop compensation electric capacity, is connected between chip COMP pin and GND pin; 308 for being connected on the electric capacity between pin V_DIM and GND; 317 is transformer; 313,314 is divider resistance, connects the feedback pin FB of chip; 312 for supplying electric diode; 315 is power tube, grid chip termination DRV pin, and source is connected with sampling resistor and CS pin; 316 is sampling resistor; 318 is fly-wheel diode; 319 is output filter capacitor; 320 for exporting LED.
For this framework, the line voltage after rectifier bridge is half waveform, that is line voltage inherently 0 ~
between change, system whether power down cannot be judged by the change of detection line voltage.Embodiments provide a kind of LED sectional dimming circuit, the change can tackling dimmer switch well realizes the sectional dimming function exporting LED.Fig. 4 is the internal module figure of illustrated sectional dimming circuit, comprise light modulation test side 401, here directly reflect whether dimmer switch is pressed with the enable EN of chip internal, mean that a system power down powers on by a dimmer switch, system power failure, chip enable EN disappears, system electrification, chip enable EN is high level, and therefore enable EN can make the clock signal of light adjusting circuit.Power generation circuit 402 provides power supply for shift register (ring counter and decoder), here dimming power source V_DIM is called, this power supply signal V_DIM is made separately a pin to draw, and at the plug-in electric capacity of this pin to ground, like this, during system power failure, after chip power VIN and chip enable EN disappears, dimming power source V_DIM still can maintain a period of time, by the time when system powers on next time, chip enable produces again, ring counter 403 count down to NextState, decoder 404 is also with regard to the corresponding output signal providing NextState, this output signal controls selection circuit 405 and exports which reference voltage 406, reference voltage 406 is V1 in reference voltage 405, V2, one in Vn, the size of this reference voltage determines the output current size of LED, after pressing dimmer switch at every turn, selection circuit all can select a reference voltage V
rEF, thus achieve sectional dimming function.Enable EN is produced by the benchmark & enable module of chip internal.
Fig. 5 is the power generation circuit of illustrated LED sectional dimming inside circuit, comprises resistance R502, PMOS Q504, NMOS tube Q505; One end of resistance R502 and the drain terminal of NMOS tube Q505 meet the power supply VIN of LED drive chip; The grid termination LED drive chip internal electric source VDD of PMOS Q504, drain terminal meets the ground pin GND of LED drive chip, and substrate connects source; The other end of source connecting resistance R502 of Q504 and the grid end of NMOS tube Q505; The substrate of NMOS tube Q505 meets the ground pin GND of LED drive chip, source as pin V_DIM, for connecting the electric capacity between a pin V_DIM being hung on LED drive chip outward and ground pin GND; The source of NMOS tube Q505, simultaneously as the output of power generation circuit, is powered to ring counter and decoder.
Wherein 501 is the power supply VIN of chip; R502 is a high-ohmic resistor, in order to reduce by 501, the electric current of this path of R502, Q504; 503 is chip internal power vd D, is produced by the benchmark & enable module in chip; Q504 is a high voltage PMOS, in order to raise source voltage terminal to (VDD+|V
gSP|), substrate is connected with source; Q505 is a high pressure NMOS, and substrate is connected with ground (in fact ground herein refer to the ground pin GND of chip); 506 is the external electric capacity of a chip, is hung between pin V_DIM and pin GND outward; 507 is the source (the grid end of high pressure NMOS pipe Q505) of high voltage PMOS pipe Q504; 508 is pin V_DIM, is connected between high pressure NMOS pipe Q505 source and external electric capacity 506, and with thinking that ring counter and decoder provide power supply, concrete numerical value is (VDD+|V
gSP|-V
gSN).
After system electrification, chip power 501 slowly rises, and chip internal power vd D also follows rising, and after rising to certain value, VDD is firmly stable, no longer rises, and chip power 501 continues to rise.At this moment, 501, R502, Q504 path just exists electric current, due to the metering function of high-ohmic resistor R502, this leakage current can be controlled, and the source (high pressure NMOS pipe Q505 grid end) 507 of high voltage PMOS pipe Q504 rises to VDD+|V
gSP| after also stable live, at this moment the magnitude of voltage of V_DIM pin 508 can calculate (VDD+|V
gSP|-V
gSN).If some time etching system starts power down, chip power 501 and chip internal power supply 503(VDD) be down to no-voltage fast, chip internal overwhelming majority module all quits work, but V_DIM pin 508 is due to the existence of plug-in capacitor, voltage can continue to maintain a period of time, concrete time span can be regulated by the size of electric capacity 506, that is, chip power-down during this period of time in, ring counter and decoder still can work on, and save corresponding state, by the time next time system electrification time, ring counter can export next state again.It is noted herein that, the substrate of high pressure NMOS pipe Q505 is connected with the ground pin GND of chip, and can not be connected with source, reason is, when system power failure, drain terminal and the grid end of high pressure NMOS pipe Q505 all become low level, prevent source electric current from pouring in down a chimney and make source be discharged to zero rapidly into drain terminal.
Fig. 6 is the exemplary operation waveform of the power generation circuit of illustrated LED sectional dimming inside circuit.System electrification, chip power VIN and chip internal power vd D rises, and V_DIM pin voltage also rises; System power failure, chip power VIN and chip internal power vd D declines rapidly, and V_DIM pin voltage can maintain a period of time, thus ensures that ring counter and decoder still can hold modes after system power failure, until system powers on next time.
Ring counter can design according to the segments of sectional dimming, and such as, four sections of light modulations only need two d type flip flops to design, and eight sections of light modulations need three d type flip flops; The design of decoder only need ensure that each clock of ring counter exports, and decoder can export a high level; Then control follow-up selection circuit with this high level that decoder exports, make output reference can obtain the value of wishing.Selection circuit can adopt the circuit shown in Fig. 7, comprise multiple NOMS to manage, V1 ~ Vn is each section of reference voltage, connect the drain electrode of each NOMS pipe respectively, the grid of each NMOS tube connects decoder as selection signal end, the source electrode of each NMOS tube is connected together as output, in order to export a reference voltage V ref needed.
Based on LED sectional dimming circuit of the present invention, the light modulation operation principle of the first embodiment of the present invention is: in Fig. 3, during system electrification, the line voltage of half waveform is charged to chip by the RC circuit of 309 and 310, chip power VIN voltage raises gradually, chip internal power vd D and pin V_DIM voltage also raise gradually simultaneously, and be stable at a certain value, pin V_DIM is that the ring counter of light adjusting circuit inside and decoder provide power supply, after chip power VIN is raised to chip enable voltage VIN_ON, chip enable signal EN produces, the ring counter of light adjusting circuit inside just obtains first time clock signal, the output of counter is after decoder and selection circuit process, obtain first reference voltage (size of this voltage directly controls output current), LED obtains first brightness, the a certain moment, dimmer switch is pressed, system power failure, it is zero that chip power VIN, chip internal power vd D, chip enable EN signal fall rapidly, but pin V_DIM voltage can maintain a period of time due to the existence of external electric capacity 308, thus ensure that ring counter and decoder still can keep internal state during system power failure, then dimmer switch is upspring, system powers on again, chip power VIN, chip internal power vd D, chip enable EN produce again, ring counter obtains second clock signal, and export the signal of NextState, this signal, through decoder and selection circuit process, obtains second reference voltage, exports LED and obtains second brightness, by that analogy, after the n-th brightness, system power down of having again powers on the operation principle of LED n-th brightness, can get back to again first brightness.
Fig. 8 is second embodiment of the present invention LED drive circuit schematic diagram, adopts non-isolated floating ground type frame structure, and is with PFC function.601 is AC power; 602 ~ 605 is bridge rectifier, and 606 is little filter capacitor (100nF, filtering high frequency spurs, but substantially can not be smoothing to 50Hz alternating voltage), and the line voltage after rectifier bridge is half waveform; 607,608 is start-up circuit, for chip power VIN charges; 609 is COMP pin building-out capacitor; 610 is pin V_DIM plug-in capacitor; 611 is chip internal block diagram; 616 is power tube, the DRV pin of grid chip termination, and source connects CS pin and 617 sampling resistors; 618 is inductance, and 619 for exporting; 620 is fly-wheel diode; 621 is output filter capacitor; 612,613 is divider resistance, is connected with FB pin; 614,615 is chip power supply.
For floating ground framework, chip ground GND with systematically isolate.During power tube conducting, chip GND voltage is close to line voltage, and the absolute voltage of chip internal is even higher than line voltage; When power tube turns off, the voltage of chip GND close to systematically, when the absolute voltage of chip internal is far below conducting.Existing dimming detection circuit cannot be judged the power down of system by detection line voltage and be powered on.Sectional dimming circuit of the present invention can be applicable to this framework.The light modulation operation principle that system is concrete can refer to the first embodiment.
The foregoing is only exemplary embodiments of the present invention, not in order to limit the present invention.All done within the spirit and principles in the present invention any amendment, replacement, improvement etc., all should be included within protection scope of the present invention.
Claims (2)
1. a LED sectional dimming circuit, is characterized in that, comprising:
One light modulation test side, connects the enable signal EN in LED drive chip, in order to detect the system power failure that caused by dimmer switch and to power on;
One power generation circuit, with thinking that the circuit of LED sectional dimming inside circuit provides power supply; The output of power generation circuit connects annular counter and decoder;
One ring counter, its input connects light modulation test side, in order to calculate the number of times pressing dimmer switch;
One decoder, its input connects ring counter, carries out decoding, to control the output of selection circuit to the output signal of ring counter;
One selection circuit, it selects signal end to connect decoder, input termination each section of reference voltage, in order to select the reference voltage needed as output;
Described power generation circuit comprises resistance R502, PMOS Q504, NMOS tube Q505;
One end of resistance R502 and the drain terminal of NMOS tube Q505 meet the power supply VIN of LED drive chip; The grid termination LED drive chip internal electric source VDD of PMOS Q504, drain terminal meets the ground pin GND of LED drive chip, and substrate connects source; The other end of source connecting resistance R502 of PMOS Q504 and the grid end of NMOS tube Q505; The substrate of NMOS tube Q505 meets the ground pin GND of LED drive chip, source as pin V_DIM, for connecting the electric capacity between a pin V_DIM being hung on LED drive chip outward and ground pin GND;
The source of NMOS tube Q505, simultaneously as the output of power generation circuit, is powered to ring counter and decoder.
2. LED sectional dimming circuit as claimed in claim 1, it is characterized in that: described selection circuit comprises multiple NOMS and manages, the drain electrode of each NOMS pipe connects each section of reference voltage respectively, the grid of each NMOS tube connects decoder as selection signal end, and the source electrode of each NMOS tube is connected together as output.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410311195.1A CN104023456B (en) | 2014-07-01 | 2014-07-01 | LED sectional dimming circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410311195.1A CN104023456B (en) | 2014-07-01 | 2014-07-01 | LED sectional dimming circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104023456A CN104023456A (en) | 2014-09-03 |
| CN104023456B true CN104023456B (en) | 2016-01-20 |
Family
ID=51439965
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410311195.1A Active CN104023456B (en) | 2014-07-01 | 2014-07-01 | LED sectional dimming circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104023456B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104394632B (en) * | 2014-11-26 | 2016-09-14 | 无锡硅动力微电子股份有限公司 | LED color-temperature regulating chip and application circuit thereof |
| CN104780688B (en) * | 2015-04-20 | 2017-11-17 | 无锡硅动力微电子股份有限公司 | The LED light adjusting circuits and LED light adjusting circuit chips of switch dimming |
| CN106332390B (en) * | 2015-06-30 | 2019-03-12 | 华润矽威科技（上海）有限公司 | A kind of non-isolated LED constant current driving chip, circuit and method |
| CN108495419B (en) * | 2018-04-28 | 2024-05-14 | 深圳市晟碟半导体有限公司 | LED dimming circuit, dimming device and dimming method for reducing harmonic distortion |
| TWI687132B (en) * | 2018-05-03 | 2020-03-01 | 李玉麟 | Driver device |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201298957Y (en) * | 2008-06-02 | 2009-08-26 | 纵领电子(上海)有限公司 | Staged-dimming control signal control circuit for electronic ballast |
| KR100940042B1 (en) * | 2009-07-22 | 2010-02-04 | 주식회사 동운아나텍 | Light emitting diode light driving apparatus |
| CN102340316A (en) * | 2011-09-07 | 2012-02-01 | 上海大学 | FPGA (Field Programmable Gate Array)-based micro-space oversampling direct-current balance serial deserializer |
| CN202425141U (en) * | 2011-12-31 | 2012-09-05 | 嘉兴大晨光电科技有限公司 | Sectional type dimming control for LED lamp |
| CN103841731A (en) * | 2014-03-21 | 2014-06-04 | 深圳天源中芯半导体有限公司 | Switch piecewise dimming circuit used for LED drive |
| CN203934078U (en) * | 2014-07-01 | 2014-11-05 | 无锡硅动力微电子股份有限公司 | LED sectional dimming circuit |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101057684B1 (en) * | 2011-03-31 | 2011-08-18 | 주식회사 동운아나텍 | Light driving apparatus |
-
2014
- 2014-07-01 CN CN201410311195.1A patent/CN104023456B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201298957Y (en) * | 2008-06-02 | 2009-08-26 | 纵领电子(上海)有限公司 | Staged-dimming control signal control circuit for electronic ballast |
| KR100940042B1 (en) * | 2009-07-22 | 2010-02-04 | 주식회사 동운아나텍 | Light emitting diode light driving apparatus |
| CN102340316A (en) * | 2011-09-07 | 2012-02-01 | 上海大学 | FPGA (Field Programmable Gate Array)-based micro-space oversampling direct-current balance serial deserializer |
| CN202425141U (en) * | 2011-12-31 | 2012-09-05 | 嘉兴大晨光电科技有限公司 | Sectional type dimming control for LED lamp |
| CN103841731A (en) * | 2014-03-21 | 2014-06-04 | 深圳天源中芯半导体有限公司 | Switch piecewise dimming circuit used for LED drive |
| CN203934078U (en) * | 2014-07-01 | 2014-11-05 | 无锡硅动力微电子股份有限公司 | LED sectional dimming circuit |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104023456A (en) | 2014-09-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104023456B (en) | LED sectional dimming circuit | |
| CN102148569B (en) | Method and apparatus to control a power converter having a low loop bandwidth | |
| EP2544512A1 (en) | Auto-selecting holding current circuit | |
| CN103916018A (en) | Switching power supply | |
| CN101783595B (en) | Overpower compensating method and device for wide voltage-input flyback power supply | |
| CN106341925B (en) | LED drive chip, can colour temperature adjust LED drive power system and LED lamp | |
| CN103298195A (en) | Power supply for illumination and luminaire | |
| CN103314639A (en) | Multi-mode dimmer interfacing including attach state control | |
| JP2013239711A (en) | Device and method for driving led lamp | |
| CN102752940A (en) | High-efficiency LED (light-emitting diode) drive circuit and drive method thereof | |
| CN102612224B (en) | A kind of MR16LED lamp drive circuit, driving method and apply its MR16LED lamp illuminating system | |
| CN105898958A (en) | Constant current driving method and circuit for LED lamp light adjustment | |
| US9369048B2 (en) | Dimming edge detection for power converter | |
| CN105792421B (en) | A kind of no bridge type LED drive power | |
| CN103841731B (en) | A kind of switch-segment light adjusting circuit driven for LED | |
| CN103874271A (en) | Power supply converter, related control circuit and related control method | |
| CN203934078U (en) | LED sectional dimming circuit | |
| CN104244517B (en) | The LED drive system of brightness-adjustable module and brightness-adjustable | |
| CN107197561B (en) | A kind of LED energy saving light modulator based on DC bus-bar voltage signal | |
| WO2018024035A1 (en) | Indicating circuit for switching power supply, and using method therefor | |
| CN104124862A (en) | High-PFC constant current control device without loop compensation and voltage converter | |
| CN201360365Y (en) | Power supply control circuit and projector scope with the circuit | |
| CN106208646A (en) | A kind of directly filtering type Switching Power Supply | |
| CN202841608U (en) | LED power supply circuit possessing high power factor | |
| CN102882389B (en) | Constant current source |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| PE01 | Entry into force of the registration of the contract for pledge of patent right | ||
| PE01 | Entry into force of the registration of the contract for pledge of patent right |
Denomination of invention: LED sectional dimming circuit Effective date of registration: 20171225 Granted publication date: 20160120 Pledgee: Agricultural Bank of China Limited by Share Ltd Wuxi science and Technology Branch Pledgor: WUXI SI-POWER MICRO-ELECTRONICS Co., LTD. Registration number: 2017990001219 |
|
| PC01 | Cancellation of the registration of the contract for pledge of patent right | ||
| PC01 | Cancellation of the registration of the contract for pledge of patent right |
Date of cancellation: 20211015 Granted publication date: 20160120 Pledgee: Agricultural Bank of China Limited by Share Ltd. Wuxi science and Technology Branch Pledgor: WUXI SI-POWER MICRO-ELECTRONICS Co.,Ltd. Registration number: 2017990001219 |