CN109714864B - Bleeder current control circuit and method and LED driving system - Google Patents
Bleeder current control circuit and method and LED driving system Download PDFInfo
- Publication number
- CN109714864B CN109714864B CN201910127578.6A CN201910127578A CN109714864B CN 109714864 B CN109714864 B CN 109714864B CN 201910127578 A CN201910127578 A CN 201910127578A CN 109714864 B CN109714864 B CN 109714864B
- Authority
- CN
- China
- Prior art keywords
- power tube
- current
- bleeder
- sampling
- control
- 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
- 238000000034 method Methods 0.000 title claims description 14
- 238000005070 sampling Methods 0.000 claims abstract description 52
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 claims description 3
- 230000011664 signaling Effects 0.000 claims description 3
- 230000003111 delayed effect Effects 0.000 claims 1
- 238000010586 diagram Methods 0.000 description 7
- 229910052736 halogen Inorganic materials 0.000 description 2
- 150000002367 halogens Chemical class 0.000 description 2
- 238000005286 illumination Methods 0.000 description 2
- 238000013459 approach Methods 0.000 description 1
- 230000002457 bidirectional effect Effects 0.000 description 1
- 238000004590 computer program Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000001960 triggered effect Effects 0.000 description 1
Landscapes
- Circuit Arrangement For Electric Light Sources In General (AREA)
Abstract
The application discloses a bleeder current control circuit, which is applied to an LED driving system with a bleeder power tube, and is characterized in that the bleeder current control circuit comprises: the sampling circuit is used for sampling a first sampling signal representing current flowing through a main power tube of the LED driving system; sampling a second sampled signal representative of the LED drive system line voltage; the control signal generating circuit generates control signals according to the first sampling signal and the second sampling signal, and controls the on and off of the discharge power tube according to different control signals, so that the normal operation of the Triac dimmer is ensured, the generated power consumption is effectively reduced, and the problem of the prior art is solved.
Description
Technical Field
The application relates to the technical field of bleeder current control, in particular to a bleeder current control circuit in an LED dimming system.
Background
At present, the LED is used as a fourth-generation light source, has the characteristics of environmental protection, long service life, high light efficiency and the like, and has been widely used as an illumination light source in various fields.
Conventional household bidirectional thyristor (Triac) dimmers are suitable for adjusting resistive loads such as incandescent and halogen lamps, and have the problem of flickering when they are used for dimming common LED-driven switching power supply loads, and thus cannot realize a wide range of dimming control.
Typically, a Triac dimmer can only operate in the 1, 3 quadrants and requires a latch current IL and a hold current (holding current) IH for proper operation, the minimum current that the Triac dimmer can be triggered when the trigger current is primarily the trigger signal. The minimum current for normal operation of the Triac dimmer is maintained after triggering the Triac dimmer when the current is maintained. Once the Triac dimmer has insufficient trigger current at the moment of triggering or insufficient holding current during normal operation, it causes re-triggering of the Triac dimmer.
Therefore, considering the characteristics of the Triac dimmer, if the original dimmer is not changed, the LED is directly used to replace the incandescent lamp and the halogen lamp with the Triac dimmer, which is a bottleneck problem for realizing green energy-saving illumination.
Bleeder circuits are currently available to solve the above problems, but the addition of bleeder circuits brings about a problem of power consumption.
Therefore, how to reduce the power consumption caused by adding the bleeder circuit is a technical problem to be solved by those skilled in the art.
Disclosure of Invention
In view of the above, it is an object of the present application to provide a bleed-off current control circuit and an LED driving system using the same, which ensure normal use of a Triac dimmer in the LED driving system and minimize power consumption due to the addition of the bleed-off circuit.
In order to achieve the above purpose, the present application provides the following technical solutions:
a bleed-off current control circuit for use in an LED drive system having a bleed-off power tube, the bleed-off current control circuit comprising:
the sampling circuit is used for sampling a first sampling signal representing current flowing through a main power tube of the LED driving system; sampling a second sampled signal representative of the LED drive system line voltage;
the control signal generating circuit generates a control signal according to the first sampling signal and the second sampling signal, and controls the on and off of the bleeder power tube according to the control signal, so that the bleeder power tube can be turned on after a period of time after the main power tube is turned off.
Preferably, the control signal generating circuit compares the first and second sampling circuits with different reference voltages, and generates the control signal such that:
The release power tube has latch current required by a Triac dimmer in the LED driving system before the main power tube is conducted;
the discharge power tube is conducted and at least has the holding current required by the Triac dimmer; and
The bleeder power tube can be turned on after a period of time after the main power tube is turned off.
Preferably, the control signal includes:
a first type of control signal for controlling the on and off of the bleeder power tube; and
And a second type of control signal for controlling the magnitude of the current flowing through the bleeder power tube.
In an embodiment, the control signal generating circuit further includes a current selecting circuit including at least one current branch capable of being coupled to the bleeder power tube by a control switch to control the magnitude of the current flowing through the bleeder power tube.
In an embodiment, the bleeder current control circuit further comprises a comparison circuit for comparing the first and second sampled signals with different reference voltages to generate a plurality of control signals.
Preferably, the current selection circuit comprises a plurality of current branches and a control switch controllable by the second type of control signal, and the control switch of each branch can couple the bleeder power tube with a current source for providing different current magnitudes.
The application also provides an LED driving system applying the technical scheme, and the system comprises the bleeder current control circuit.
The invention also provides a bleeder current control method applied to the LED driving system with the bleeder power tube, which comprises the following steps:
sampling a first sampling signal representing current flowing through a main power tube of the LED driving system;
sampling a second sampled signal representative of the LED drive system line voltage;
and generating control signals according to the first sampling signal and the second sampling signal, and controlling the on and off of the bleeder power tube according to the control signals, so that the bleeder power tube can be turned on after a period of time after the main power tube is turned off.
Preferably, the method further comprises providing different currents for the bleeder power tube, so that when the bleeder power tube is conducted, the currents flowing through the bleeder power tube can ensure that:
Before the main power tube is conducted, the discharge power tube has latch current required by a Triac dimmer in the LED driving system;
the discharge power tube is conducted and at least has the holding current required by the Triac dimmer; and
After the main power tube is cut off, the bleeder power tube can be turned on after a period of time.
According to the technical scheme, the line voltage and the current flowing through the main power tube are subjected to signal sampling, the sampled two signals are compared with different reference voltages, and the control signals are generated to enable the two signals to be: the release power tube has latch current required by a Triac dimmer in the LED driving system before the main power tube is conducted; the discharge power tube is conducted and at least has the holding current required by the Triac dimmer; and the bleeder power tube can be turned on after a period of time after the main power tube is cut off, so that the normal operation of the Triac dimmer is ensured, the power consumption generated by the Triac dimmer is effectively reduced, and the problems in the prior art are solved.
Drawings
In order to more clearly illustrate the embodiments of the application or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a basic block diagram of a bleed current control circuit of the present invention;
FIG. 2 is a schematic diagram of an embodiment of a bleed current control circuit and an LED driver system according to the present invention;
Fig. 3 is a waveform diagram of the back-cut and front-cut Triac dimmer output;
FIG. 4 is a waveform diagram illustrating the Bleeder power tube current and reactive load current voltage corresponding to the embodiment of FIG. 2, using a previous dimmer cut as an example;
Detailed Description
The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.
The embodiment of the application discloses a bleeder current control circuit and an LED driving system using the same, which are used for ensuring the normal use of a Triac dimmer in the LED driving system and reducing the power consumption generated by adding the bleeder circuit to the minimum.
An embodiment of the present application provides a bleeder current control circuit, which is applied to an LED driving system, and the first and second sampling signals are compared with different reference voltages, so that the generated control signals enable: the release power tube has latch current required by a Triac dimmer in the LED driving system before the main power tube is conducted; the discharge power tube is conducted and at least has the holding current required by the Triac dimmer; and the bleeder power tube can be turned on after a period of time after the main power tube is turned off.
Referring to fig. 1, a basic frame diagram of a bleeder current control circuit according to the present invention is shown. As shown in the figure, the bleeder current control circuit of the present invention is applied to an LED driving system having a bleeder power tube M2, and includes a sampling circuit (it should be noted that, since different sampling modes and sampling grounds can be adopted, only Vbus modules are shown in the figure, but the present invention is not limited thereto), for sampling a first sampling signal Visen representing the current flowing through the main power tube of the LED driving system, and for sampling a second sampling signal Vbus representing the line voltage of the LED driving system; the control signal generating circuit 24 generates control signals according to the first and second sampling signals, and controls the on and off of the bleeder power tube and the magnitude of the current flowing through the bleeder power tube according to different control signals. Only a portion of the LED driving system is shown, and will be described in detail with reference to specific embodiments.
Referring to fig. 2, fig. 2 is a schematic diagram of an embodiment of a bleed current control circuit and an LED driving system according to the present invention. The above-mentioned LED driving system will be briefly described first. As shown in fig. 2, in this embodiment, the LED driving system at least includes:
an input ac power source Vac, a rectifier bridge 1, and a Triac dimmer 2 coupled between the power source Vac and the rectifier bridge 1, a main power tube M1 controlling a load LED, and a bleeder power tube M2.
In general, under the action of Triac dimmer 2, the line voltage generates a half-wave mode with a cut angle and Vbus is generated by dividing R1 and R2, and reference is made to fig. 3, which shows the basic waveform generated by the Triac dimmer. Triac dimmers are broadly divided into two types, front-cut dimmers and rear-cut dimmers, respectively, with waveforms as shown.
Fig. 4 is a waveform diagram illustrating a Bleeder power tube current and a reactive load current voltage corresponding to the embodiment of fig. 2, using a previous dimmer as an example. In the embodiment, the bleeder current control circuit 3 includes a sampling circuit, and as shown in fig. 3, in the embodiment, line voltage sampling is implemented by dividing voltages of R1 and R2, and Vbus is obtained by sampling, but other approaches are also possible in other embodiments, and the invention is not limited thereto; similarly, the current flowing through the main power tube is sampled by R3, and the current flowing through R3 are the currents flowing through the main power tube M1.
The bleeder current control circuit of the present invention further comprises a control signal generation circuit, as shown in fig. 3, by comparing the first sampling signal Visen and the second sampling signal Vbus with different reference voltages, and then generating a plurality of control signals by the logic circuit 32. The first control signal is a SWA signal in the figure and is used for controlling the on and off of the discharge power tube; another type of control signal is to control the control switches in three branches as in fig. 3: signals SWB, SWC, SWD, respectively; the three branches are provided with current sources I1, I2 and I3 which can control the current flowing when the bleeder power tube is conducted. While this example presents only one implementation of the inventive arrangements.
Next, with reference to fig. 4, a circuit and a method for controlling a bleed current are further provided in the present invention. When the line voltage Vbus is detected to be greater than the reference voltage Vbusref a, the control switches SWA and SWB are turned on, the current flowing through the Bleeder power tube at this time is set to be I1, the SWB is conducted for a fixed time T1, the current set by I1 is greater, and the current magnitude and the conduction time T1 are set by I1 so as to meet the requirement of maintaining the normal operation of the dimmer (latch current). After the time T1, SWB is turned off, SWA is kept on, SWC is turned on, at the moment, the current flowing through the Bleeder power tube is set to be I2, I2 is always turned on until Vbus is larger than VLED, and after the current flows through the main power tube, SWC and SWA are turned off when the current of the main power tube is larger than a preset value Visen/R3. As the Vbus voltage over-peak value gradually decreases to be smaller than VLED, the main power tube is turned off, but the Bleeder power tube is not turned on at this time, when the Vbus voltage is lower than Vbusref, SWA and SWD are turned on, the current flowing through the Bleeder power tube at this time is set to be I3, and the magnitude of the I3 value is selected as holding current (holding current) for maintaining the normal operation of the forward cut dimmer; when the Vbus voltage is smaller than Vbusref < 2 >, the SWD is turned off, the SWB is turned on, the current flowing through the Bleeder power tube is I2, and the size of the I2 is selected to pull the residual voltage of the part of the BUS voltage cut off by the dimmer as low as possible. For proper detection of the cutting edge of the dimmer for the next cycle. Note that, vbusref in this embodiment selects the same reference voltage as Vbusref2, and may be different in other embodiments.
The method for controlling the Bleeder power tube in a sectionalized mode is an open-loop control method, the circuit is simple to realize, the problem of closed-loop control stability is not needed to be considered, and different current, rather than unified current, of the Bleeder power tube is given to each stage according to the requirements of the dimmer, so that the power consumption of the Bleeder power tube is reduced. When the Bus voltage is reduced by the over-peak value, the Bleeder power tube is not started between the Vbus=Vo and Vbusref (R1+R2)/R2, so that the power consumption of the Bleeder tube is further reduced, and the efficiency of a dimming system is improved.
The application also provides an LED driving system applying the technical scheme, and the system comprises the bleeder current control circuit.
The application also provides a bleeder current control method applied to the LED driving system with the bleeder power tube, which comprises the following steps:
sampling a first sampling signal representing current flowing through a main power tube of the LED driving system;
sampling a second sampled signal representative of the LED drive system line voltage;
and generating control signals according to the first sampling signal and the second sampling signal, and controlling the on and off of the bleeder power tube according to the control signals, so that the bleeder power tube can be turned on after a period of time after the main power tube is turned off.
In a specific embodiment, the method further includes providing different currents for the bleeder power tube, so that when the bleeder power tube is conducted, the currents flowing through the bleeder power tube can ensure that:
Before the main power tube is conducted, the discharge power tube has latch current required by a Triac dimmer in the LED driving system;
the discharge power tube is conducted and at least has the holding current required by the Triac dimmer; and
After the main power tube is cut off, the bleeder power tube can be turned on after a period of time.
Those skilled in the art will appreciate that implementing all or part of the above-described methods in accordance with the embodiments may be accomplished by way of a computer program stored on a computer readable storage medium, which when executed may comprise the steps of the embodiments of the methods described above. The storage medium may be a magnetic disk, an optical disk, a Read-Only Memory (ROM), a random-access Memory (Random Access Memory, RAM), or the like.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (6)
1. A bleed-off current control circuit for use in an LED drive system having a bleed-off power tube, the bleed-off current control circuit comprising:
the sampling circuit is used for sampling a first sampling signal representing current flowing through a main power tube of the LED driving system; sampling a second sampled signal representative of the LED drive system line voltage;
The control signal generation circuit generates a control signal according to the first sampling signal and the second sampling signal, and controls the on and off of the bleeder power tube according to the control signal, so that the bleeder power tube can be turned on after a period of time is delayed after the main power tube is turned off; the control signal generating circuit further comprises a current selecting circuit, wherein the current selecting circuit comprises at least one current branch which can be coupled with the bleeder power tube through a control switch so as to control the current flowing through the bleeder power tube;
The control signal includes: a first type control signal for controlling the on and off of the bleeder power tube and a second type control signal for controlling the current flowing through the bleeder power tube; the current selection circuit comprises three current branches and control switches which can be controlled by the second type of control signals, and the control switches of all the branches can couple a discharge power tube with current sources I1, I2 and I3 which provide different current magnitudes; and
When the second sampling signal is larger than the reference voltage, the first control signal controls the conduction of the discharge power tube, and the second control signal controls the conduction of the current source I1 and the discharge power tube, so that the discharge power tube has latch current required by a Triac dimmer in the LED driving system before the main power tube is conducted;
After the current branch with the current source I1 is conducted for a fixed time, the second type of control signals control the current branch with the current source I1 to be disconnected, and the current source I2 is conducted with the discharge power tube until the main power tube is conducted;
when the current of the main power tube is larger than a preset value, the second type of control signal controls the current source I2 and the discharge power tube to be closed;
When the main power tube is turned off, the second sampling signal is smaller than the reference voltage Vbusref, the first type of control signal controls the conduction of the bleeder power tube, and the second type of control signal controls the conduction of the current source I3 and the bleeder power tube; and when the second sampling signal is smaller than the reference voltage Vbusref, the second type of control signal controls the current branch with the current source I3 to be turned off, and controls the current source I1 to be turned on with the bleeder power tube.
2. The bleeder current control circuit of claim 1, wherein the control signal generation circuit compares the first and second sampled signals with different reference voltages, the control signal generated such that:
Before the main power tube is conducted, the discharge power tube has latch current required by a Triac dimmer in the LED driving system;
the discharge power tube is conducted and at least has the holding current required by the Triac dimmer; and
After the main power tube is cut off, the bleeder power tube can be turned on after a period of time.
3. The bleeder current control circuit of claim 2, further comprising a comparison circuit for comparing the first and second sampled signals to different reference voltages to generate a plurality of the control signals.
4. An LED driving system comprising the bleed current control circuit of any of claims 1-3.
5. A bleed current control method for use in an LED drive system having a bleed power tube, the method comprising:
sampling a first sampling signal representing current flowing through a main power tube of the LED driving system;
sampling a second sampled signal representative of the LED drive system line voltage;
and generating control signals according to the first sampling signal and the second sampling signal, and controlling the on and off of the bleeder power tube according to the control signals, so that the bleeder power tube can be turned on after a period of time after the main power tube is turned off.
6. The method of claim 5, further comprising providing different currents to the bleeder power tube such that when the bleeder power tube is on, the current flowing through the bleeder power tube ensures that:
Before the main power tube is conducted, the discharge power tube has latch current required by a Triac dimmer in the LED driving system;
the discharge power tube is conducted and at least has the holding current required by the Triac dimmer; and
After the main power tube is cut off, the bleeder power tube can be turned on after a period of time.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910127578.6A CN109714864B (en) | 2019-02-20 | 2019-02-20 | Bleeder current control circuit and method and LED driving system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910127578.6A CN109714864B (en) | 2019-02-20 | 2019-02-20 | Bleeder current control circuit and method and LED driving system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109714864A CN109714864A (en) | 2019-05-03 |
| CN109714864B true CN109714864B (en) | 2024-10-25 |
Family
ID=66263643
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910127578.6A Active CN109714864B (en) | 2019-02-20 | 2019-02-20 | Bleeder current control circuit and method and LED driving system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109714864B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114980423A (en) * | 2022-05-11 | 2022-08-30 | 福建晶旭半导体科技有限公司 | LED light engine circuit and lighting device |
| CN117477910B (en) * | 2023-12-26 | 2024-03-08 | 钰泰半导体股份有限公司 | Load current detection circuit of power tube |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN203872419U (en) * | 2014-06-13 | 2014-10-08 | 成都芯源系统有限公司 | LED driving device and controller thereof |
| CN106358337A (en) * | 2016-10-26 | 2017-01-25 | 杰华特微电子（杭州）有限公司 | Leakage circuit, leakage current control method and LED (Light Emitting Diode) control circuit |
| CN109275230A (en) * | 2018-10-24 | 2019-01-25 | 矽力杰半导体技术(杭州)有限公司 | Leadage circuit and the LED drive circuit for applying it |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20150016650A (en) * | 2013-08-05 | 2015-02-13 | 유상우 | Power Supply Device for Lighting Apparatus connected and used to Triac Dimming Circuit |
| US9220138B1 (en) * | 2013-12-09 | 2015-12-22 | Marvell International Ltd. | Soft bleeder to remove step dimming |
| US10153684B2 (en) * | 2016-10-26 | 2018-12-11 | Joulwatt Technology (Hangzhou) Co., Ltd. | Bleeder circuit |
| US10143051B2 (en) * | 2016-11-16 | 2018-11-27 | Joulwatt Technology (Hangzhou) Co., Ltd. | Bleeder circuit and control method thereof, and LED control circuit |
| CN106793246B (en) * | 2016-11-16 | 2019-04-02 | 杰华特微电子（杭州）有限公司 | Leadage circuit and its control method and LED control circuit |
| CN106912144B (en) * | 2017-04-06 | 2018-01-23 | 矽力杰半导体技术(杭州)有限公司 | LED drive circuit, circuit module and control method with controllable silicon dimmer |
| CN108848598B (en) * | 2018-08-31 | 2024-04-12 | 厦门市必易微电子技术有限公司 | Bleeder module for silicon controlled rectifier dimmer, LED driving circuit and driving method |
-
2019
- 2019-02-20 CN CN201910127578.6A patent/CN109714864B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN203872419U (en) * | 2014-06-13 | 2014-10-08 | 成都芯源系统有限公司 | LED driving device and controller thereof |
| CN106358337A (en) * | 2016-10-26 | 2017-01-25 | 杰华特微电子（杭州）有限公司 | Leakage circuit, leakage current control method and LED (Light Emitting Diode) control circuit |
| CN109275230A (en) * | 2018-10-24 | 2019-01-25 | 矽力杰半导体技术(杭州)有限公司 | Leadage circuit and the LED drive circuit for applying it |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109714864A (en) | 2019-05-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102843836B (en) | Controlled-silicon adapting LED (light-emitting diode) driving circuit, method and switch power supply | |
| US8890419B2 (en) | System and method providing LED emulation of incandescent bulb brightness and color response to varying power input and dimmer circuit therefor | |
| US9282598B2 (en) | System and method for learning dimmer characteristics | |
| US8581498B1 (en) | Control of bleed current in drivers for dimmable lighting devices | |
| CN105025632B (en) | A kind of LED lamp and its control circuit of switch toning | |
| JP5667290B2 (en) | Active damping for dimmable drivers for lighting units | |
| CN111225475B (en) | Current driving circuit and method and LED lighting device applying same | |
| JP4700289B2 (en) | Load power consumption adjustment method, load power consumption adjustment circuit, and electric lighting device for lamp | |
| US11438979B2 (en) | LED driving circuit and LED driving method | |
| EP4203616B1 (en) | Load control device having an overcurrent protection circuit | |
| US20100295478A1 (en) | Led driving circuit | |
| CN109714864B (en) | Bleeder current control circuit and method and LED driving system | |
| US8878444B2 (en) | Controller, a driver circuit and a method for controlling a dimmable LED lighting circuit, and a dimmable LED lighting circuit | |
| CN101982022A (en) | Waveform detection and combined step and linear dim control | |
| CN109246891B (en) | Dimmer detection method, detection circuit and lighting circuit | |
| JP5500476B2 (en) | Power supply device and lighting system for LED lamp for lighting | |
| CA3070831C (en) | A pwm dimming circuit with low stand-by power | |
| CN211019319U (en) | Control circuit compatible with silicon controlled rectifier dimmer | |
| CN101640967B (en) | Fluorescent lamp driving circuit, fluorescent lamp dimming circuit and method | |
| JP6077824B2 (en) | LED driving device and LED driving method | |
| CN209693111U (en) | Leakage current control circuit and LED drive system | |
| CN110769544B (en) | Control circuit and control method compatible with thyristor dimmer | |
| JP4095850B2 (en) | Light control device and light control system and phase control device in studio, theater, etc. | |
| CN116744520B (en) | An intelligent stepless dimming control system and control method thereof | |
| US20050162095A1 (en) | Method of converting a line voltage to an RMS load voltage independently of variations in line voltage magnitude |
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 | ||
| TA01 | Transfer of patent application right | ||
| TA01 | Transfer of patent application right |
Effective date of registration: 20210119 Address after: No. 1600, Zixing Road, Minhang District, Shanghai 200241 Applicant after: BCD (SHANGHAI) MICRO-ELECTRONICS Ltd. Address before: No. 1600, Zixing Road, Minhang District, Shanghai 200241 Applicant before: BCD (SHANGHAI) MICRO-ELECTRONICS Ltd. Applicant before: BCD Semiconductor Manufacturing Limited |
|
| GR01 | Patent grant | ||
| GR01 | Patent grant |