CN101118323A - Backlight drive having isolated form power factor correcting structure and control circuit thereof - Google Patents
Backlight drive having isolated form power factor correcting structure and control circuit thereof Download PDFInfo
- Publication number
- CN101118323A CN101118323A CNA2006101040410A CN200610104041A CN101118323A CN 101118323 A CN101118323 A CN 101118323A CN A2006101040410 A CNA2006101040410 A CN A2006101040410A CN 200610104041 A CN200610104041 A CN 200610104041A CN 101118323 A CN101118323 A CN 101118323A
- Authority
- CN
- China
- Prior art keywords
- unit
- merit
- framework
- adjustment unit
- power factor
- 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
Links
- 238000002955 isolation Methods 0.000 claims abstract description 14
- 230000002463 transducing effect Effects 0.000 claims description 30
- 230000009466 transformation Effects 0.000 claims description 17
- 230000015572 biosynthetic process Effects 0.000 claims description 4
- 238000006243 chemical reaction Methods 0.000 abstract 3
- 230000008859 change Effects 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 3
- 230000008878 coupling Effects 0.000 description 2
- 238000010168 coupling process Methods 0.000 description 2
- 238000005859 coupling reaction Methods 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 1
- 238000005286 illumination Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Images
Landscapes
- Circuit Arrangement For Electric Light Sources In General (AREA)
- Circuit Arrangements For Discharge Lamps (AREA)
- Liquid Crystal (AREA)
Abstract
The present invention relates to a backlight driving and controlling circuit with an isolating-type power factor correction configuration, and comprises a power stage for providing the power supply; a driver stage with a first power factor adjustment unit for adjusting the power factor of the power supply and outputting DC source, and with a conversion unit for converting a medium voltage DC power into a high power output to further drive the back-light light emitting elements to work; and a control/dimming stage with a second power factor adjustment unit and a DC variable voltage unit and an AD board arranged on the secondary of the DC variable voltage unit and connected with the ground commonly with the conversion unit. The present invention adopts the design of electric isolation and circuit configuration of communal connection with the ground, which forms the electric isolation between the power factor adjustment unit and the power stage, and allows the AD board to directly control/dim the above-mentioned conversion unit of the diver stage, thereby changing the working state of back-light light emitting elements.
Description
Technical field
The present invention relates to a kind of driving and control circuit of electronic load, particularly a kind of backlight drive and control circuit with isolated form power factor correction function framework.
Background technology
Known applications is in the driving and the control circuit framework of the back light member of control display (as LCD), as shown in Figure 1, after the alternating current that power end 10 provides (AC) involves rectification after filtration, two parts are given in supply respectively, first is used to drive load (as the cold cathode fluorescent lamp pipe, light-emitting components such as CCFL) work, second portion then are the required electric power of supply control circuit (as control circuit board, AD Board).
The circuit framework of first includes: first merit is because of adjustment unit 11, be connected with power end 10, be used to adjust power factor and output DC source (the medium voltage DC source of about 380-400V) of power supply unit, with transducing unit 12 (including pwm control circuit and inverter (Inverter) usually), be used for the medium voltage DC source is converted to high-voltage power supply output and then drives light-emitting component backlight 18 (as the cold cathode fluorescent lamp pipe); The circuit framework of second portion includes: second merit is because of adjustment unit 13, be connected with power end 10, be used to adjust the power factor of power supply unit, direct current transformation unit (DC/DC) 14 (is generally the isolated form transformer, primary and secondary is isolated from each other and common ground not, and elementary and first merit of this direct current transformation unit 14 is all the design of power supply common ground because of adjustment unit 13 because of the adjustment unit 11 and second merit), with signal plate 15 (AD Board), be arranged at the secondary of direct current transformation unit 14, and by isolating optocoupler 16,17 with transducing unit 12 coupling of aforementioned driving stage, be used for transducing unit 12 is controlled or adjusted, and then change the duty of light-emitting component backlight 18.
Because the transducing unit 12 in the conventional art is the circuit framework of common ground (power ground of high pressure) because of adjustment unit 11 with aforesaid first merit, signal plate 15 is the isolated circuit framework of non-common ground with transducing unit 12, so the control signal in the signal plate 15 (as controlling bright/dark (On/Off) backlight or adjusting backlight illumination (Dimming)) can't directly be connected with transducing unit 12, isolate optocoupler 16 thereby must utilize, 17 mode is controlled (comprising the control of back light member being carried out light modulation (Dimming) and bright/dark (On/Off)) to transducing unit 12, yet this to isolate optocoupler 16, the mode of 17 transmission of control signals certainly will cause the increase of optical coupling element quantity; On the other hand,, but do not have elementary and secondary separating, thereby easy safety to the user threatens because merit all adopts the design of common ground because of adjustment unit (comprise first merit because of adjustment unit 11 and second merit because of adjustment unit 13) with power end.
Summary of the invention
Fundamental purpose of the present invention is to provide a kind of safe backlight drive and control circuit.
The possible technique scheme that realizes the purpose that the present invention is above-mentioned is a kind of backlight drive and control circuit with isolated form power factor correction function framework; Wherein, merit can adopt isolating transformer because of adjustment unit, make merit because of connect in the adjustment unit power supply elementary can with secondary formation electrical isolation (isolation), avoid merit to clash, also can avoid transducing unit and power supply to clash or produce the danger of electric shock because of adjustment unit and power supply.
Another object of the present invention is to provide a kind of the needs to isolate optocoupler just can directly be controlled (comprise back light member is carried out light modulation (Dimming) and controls bright/dark (On/Off)) to the transducing unit backlight drive and control circuit, be used to change the duty of light-emitting component backlight.
The possible technique scheme that realizes the purpose that the present invention is above-mentioned is to use the means of electrical isolation with transducing unit and signal plate common ground, and form electrical isolation because of adjustment unit with the merit of front end, make the transducing unit directly to be connected with the signal plate of control/adjustment level, just can directly not control (comprising the control of back light member being carried out light modulation (Dimming) and bright/dark (On/Off)) yet signal plate does not need to isolate optocoupler, change the duty of light-emitting component backlight the transducing unit.
About preferred embodiment of the present invention and technology contents, existing conjunction with figs. is described as follows:
Description of drawings
Fig. 1 is traditional backlight drive with power factor correction function function and control circuit framework.
Fig. 2 is the circuit framework of preferred embodiment of the present invention.
Embodiment
The circuit framework of preferred embodiment of the present invention as shown in Figure 2, includes:
Power stage 20 (Power Stage), be used to provide power supply, it is converted to the required direct supply of equipment with civil power (AC power), wherein the power specification of civil power is according to various countries' power specification different (for example AC-110V or AC-220V), generally speaking, can be provided with electromagnetic interference (EMI) filter unit (EMI) in the alleged power stage 20 and by the bridge rectifier that diode constitutes, be used for to alternating current carry out filtering and rectification handle back output complete/half-wave DC power supply (electromagnetic interference (EMI) filter unit (EMI) wherein need determine whether be provided with according to the specification of various countries' electric system);
Driving stage (Driver Stage) 30, has first merit because of adjustment unit 31, be used to adjust the power factor of power supply and the medium voltage DC source that output is about 380-400V, with transducing unit 32 (can be inverter (Inverter)), be used for the medium voltage DC source is converted to high-voltage power supply output and then drives light-emitting component backlight 50 work; And
Control/adjustment level (Control/Dimming Stage) 40, has second merit because of adjustment unit 41, direct current transformation unit 42 and signal plate 43 (AD Board), second merit wherein is used to adjust the power factor and the output DC source of power supply because of 41 of adjustment units, be converted to low pressure (as 5V via direct current transformation unit 42 again, 12V, direct supply 24V) are used to provide the required direct supply of signal plate 43; Signal plate 43 wherein is connected in the secondary of direct current transformation unit 42, and constitute the circuit framework of common grounds with transducing unit 32, be used to send the control signal of light modulation (Dimming) or bright/dark (On/Off), the direct transducing unit 32 of the aforementioned driving stage 30 of control/adjustment changes the duty (as the brightness of light-emitting component 50 or open/close) of light-emitting component backlight 50.
First merit wherein is because of adjustment unit 31, look the needs of practical application, it can be the circuit framework of booster type or voltage-dropping type, first merit can link variable resistor or fixed resistance usually because of adjustment unit 31, be used for obtaining voltage reference value, so that first merit is adjusted the power factor of power supply with this voltage reference value because of adjustment unit 31; The core of transducing unit 32 is exactly an inverter, looks the specification of light-emitting component 50 complete/half-wave DC power supply is carried out voltage transitions, is used for exporting the required voltage of driven light-emitting element 50 work; If (Cold Cathode Fluorescent Lamp CCFL) as light-emitting component 50, then need use the inverter of high voltage output to adopt the cold cathode fluorescent lamp pipe.
Generally speaking, between the inverter of first merit, also be provided with pulse width modulation (Pulse-Width Modulation because of adjustment unit 31 and transducing unit 32, PWM) controller (not shown), and the PWM controller can be integrated into single control IC with power factor controller usually, thereby the user can utilize signal plate 43 to send the control signal of dim signal or bright/dark (On/Off), be used for light-emitting component 50 is carried out the control of light modulation (Dimming) and bright/dark (On/Off), change the duty of light-emitting component backlight 50.
Can understand by the shielding wire 60 that is indicated among Fig. 2, first merit is the circuit framework of common ground (power ground) because of adjustment unit 31 and second merit because of adjustment unit 41, the power stage 20 of itself and the earth ground connection forms the framework of electrical isolation, and transducing unit 32 and signal plate 43 are except common ground (chassics earth or ground connection) greatly, also form the circuit framework of common ground with power stage 20, can avoid first merit to clash because of adjustment unit 41 and power stage 20 thus, also can avoid power supply and be connected the danger that secondary transducing unit 32 clashed or produced electric shock because of adjustment unit 31 and second merit.
According to preferred embodiment of the present invention, wherein, first merit is to adopt isolating transformer because of the preferred embodiment of adjustment unit 31 and direct current transformation unit 42, first merit is because of the isolating transformer 310 of adjustment unit 31, and the primary and secondary of direct current transformation unit 42 is all and is isolated from each other but do not form the circuit framework of common ground, and second merit because of adjustment unit 41 and direct current transformation unit 42 elementary also with the circuit framework of first merit because of the elementary formation common ground (power ground) of adjustment unit 31; Therefore, the present invention is by the design of the circuit framework of electrical isolation and formation common ground, make the transducing unit 32 of the signal plate 43 of control/adjustments grades 40 and driving stage 30 form the circuit framework of common ground (chassics earth or ground connection) greatly each other, make signal plate 43 not need just can directly send the control signal of dim signal or bright/dark (On/Off) to transducing unit 32 by the mode of optocoupler, be used for light-emitting component 50 is carried out the control of light modulation (Dimming) and bright/dark (On/Off), change the duty of light-emitting component backlight 50.
Being preferred embodiment of the present invention only in sum, is not to be used for limiting practical range of the present invention.Being that every equivalence of doing according to the content of the present patent application claim changes and modification, all should be technology category of the present invention.
Claims (9)
1. a backlight drive and the control circuit with isolated form power factor correction function framework is used for driving and the work of control light-emitting component, it is characterized in that described backlight drive and control circuit with isolated form power factor correction function framework comprises:
Power stage is used to provide power supply;
Driving stage, has first merit because of adjustment unit, be used to adjust the power factor and the output DC source of aforementioned power source, with the transducing unit, be used for described direct supply is converted to high-voltage power supply output and then drives described light-emitting component work, wherein said transducing unit and described first merit are the non-common ground circuit framework of electrical isolation because of adjustment unit; And
Control/adjustment level, has second merit because of adjustment unit, direct current transformation unit and signal plate, described second merit is the circuit framework of common ground because of the adjustment unit three because of elementary and described first merit of adjustment unit, described direct current transformation unit, and circuit framework with described power stage formation electrical isolation, described signal plate be arranged at the secondary of described direct current transformation unit and and described transducing unit be the circuit framework of common ground, the transducing unit that is used for direct control/aforementioned driving stage of adjustment, and then described light-emitting component carried out light modulation and bright/dark control.
2. backlight drive and the control circuit with isolated form power factor correction function framework according to claim 1 is characterized in that, described light-emitting component is cold cathode fluorescent lamp (CCFL).
3. backlight drive and the control circuit with isolated form power factor correction function framework according to claim 1, it is characterized in that, described first merit has isolating transformer because of adjustment unit, and the primary and secondary of described isolating transformer is isolated from each other and does not form the circuit framework of common ground.
4. backlight drive and the control circuit with isolated form power factor correction function framework according to claim 3, it is characterized in that, described first merit keeps the electrical isolation framework of non-common ground because of the elementary and described power stage of the isolating transformer of adjustment unit, and the secondary and described transducing unit of described isolating transformer is the circuit framework of common ground.
5. backlight drive and the control circuit with isolated form power factor correction function framework according to claim 1, it is characterized in that, described direct current transformation unit is a kind of isolating transformer, and the primary and secondary of described direct current transformation unit is isolated from each other and does not form the circuit framework of common ground.
6. a backlight drive and control circuit with isolated form power factor correction function framework, include: power stage is used to provide power supply; Driving stage has first merit because of adjustment unit and transducing unit, is used for transferring described power supply to high-voltage power supply output to drive load; And control/adjustment level, have second merit because of adjustment unit, direct current transformation unit and signal plate, control described transducing unit and then adjustment or control the work of described load by described signal plate; It is characterized in that:
Described first merit is the circuit framework of common ground (power ground) because of adjustment unit because of adjustment unit and described second merit, the described power stage of itself and the earth ground connection forms the framework of electrical isolation, and described transducing unit, described signal plate then form the circuit framework of common ground with described power stage.
7. backlight drive and the control circuit with isolated form power factor correction function framework according to claim 6, it is characterized in that, described first merit has isolating transformer because of adjustment unit, and the primary and secondary of described isolating transformer is isolated from each other and does not form the circuit framework of common ground.
8. backlight drive and the control circuit with isolated form power factor correction function framework according to claim 7, it is characterized in that, described first merit keeps the electrical isolation framework of non-common ground because of the elementary and described power stage of the isolating transformer of adjustment unit, and the secondary of described isolating transformer is the circuit framework of common ground with described transducing unit then.
9. backlight drive and the control circuit with isolated form power factor correction function framework according to claim 6, it is characterized in that, described direct current transformation unit is a kind of isolating transformer, described second merit is the circuit framework of common ground because of elementary and described first merit of adjustment unit, described direct current transformation unit because of the adjustment unit three, and forms the circuit framework of electrical isolation with described power stage.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2006101040410A CN100472288C (en) | 2006-07-31 | 2006-07-31 | Backlight drive having isolated form power factor correcting structure and control circuit thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2006101040410A CN100472288C (en) | 2006-07-31 | 2006-07-31 | Backlight drive having isolated form power factor correcting structure and control circuit thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101118323A true CN101118323A (en) | 2008-02-06 |
| CN100472288C CN100472288C (en) | 2009-03-25 |
Family
ID=39054508
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2006101040410A Expired - Fee Related CN100472288C (en) | 2006-07-31 | 2006-07-31 | Backlight drive having isolated form power factor correcting structure and control circuit thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100472288C (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102238768A (en) * | 2010-04-26 | 2011-11-09 | 旭丽电子(广州)有限公司 | Light-emitting diode (LED) backlight source driving module |
| CN102497699A (en) * | 2011-12-05 | 2012-06-13 | 北方工业大学 | Method for adjusting brightness of LED (light emitting diode) illuminating lamp and LED driving circuit for PF (power factor) light dimming function |
| CN102612202A (en) * | 2011-12-05 | 2012-07-25 | 北方工业大学 | Flyback framework-based switch-type light-emitting diode (LED) illumination dimming method |
| CN102612203A (en) * | 2011-12-05 | 2012-07-25 | 北方工业大学 | LED (Light-Emitting Diode) illumination driving circuit with night light function |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TW502487B (en) * | 2000-10-27 | 2002-09-11 | Ambit Microsystems Corp | DC/AC converter |
-
2006
- 2006-07-31 CN CNB2006101040410A patent/CN100472288C/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102238768A (en) * | 2010-04-26 | 2011-11-09 | 旭丽电子(广州)有限公司 | Light-emitting diode (LED) backlight source driving module |
| CN102238768B (en) * | 2010-04-26 | 2014-04-09 | 光宝电子(广州)有限公司 | Light-emitting diode (LED) backlight source driving module |
| CN102497699A (en) * | 2011-12-05 | 2012-06-13 | 北方工业大学 | Method for adjusting brightness of LED (light emitting diode) illuminating lamp and LED driving circuit for PF (power factor) light dimming function |
| CN102612202A (en) * | 2011-12-05 | 2012-07-25 | 北方工业大学 | Flyback framework-based switch-type light-emitting diode (LED) illumination dimming method |
| CN102612203A (en) * | 2011-12-05 | 2012-07-25 | 北方工业大学 | LED (Light-Emitting Diode) illumination driving circuit with night light function |
Also Published As
| Publication number | Publication date |
|---|---|
| CN100472288C (en) | 2009-03-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101203084B (en) | Power supply circuit for LCD backlight and method thereof | |
| CN101848577B (en) | LED driving system and driving method | |
| CN2664338Y (en) | Power supply for LCD screen | |
| CN102548101B (en) | LED dimming system | |
| US8476843B2 (en) | Driving circuit for single-string LED lamp | |
| CN101511142B (en) | Switch constant-current source circuit without feedback on load end | |
| CN103763842A (en) | LED Lamp | |
| CN106304481A (en) | Stepping light adjusting circuit and drive circuit for power supply | |
| CN101404840A (en) | Two-wire system light-adjustable LED controller | |
| CN103392380A (en) | Device and method for interfacing a dimming control input to a dimmable lighting driver with galvanic isolation | |
| CN201773565U (en) | Special type backlight source driving circuit with MOS tube driving circuit | |
| CN101163361A (en) | Light source driving device | |
| TW200400395A (en) | Apparatus of driving light source for display device | |
| EP2458943A1 (en) | Illumination device | |
| CN203193980U (en) | Drive circuit for multi-channel dimmable LED (light-emitting diode) lamp tube | |
| CN100472288C (en) | Backlight drive having isolated form power factor correcting structure and control circuit thereof | |
| US8143804B2 (en) | Light source driving device | |
| CN201726571U (en) | Current-sharing type backlight driving system with function of adaptive control | |
| US7518317B2 (en) | Backlight driving and control circuit with an isolated power factor correction structure | |
| CN201859637U (en) | Isolated light-emitting diode driver | |
| CN102244951A (en) | Light emitting diode (LED) drive circuit | |
| CN1387394A (en) | Drive system of fluorescent lamp and fluorescent lamp system using it | |
| WO2016141558A1 (en) | Isolated interface with current transformer | |
| CN101568219A (en) | Light source driving device | |
| CN101291117B (en) | Inverter, back light assembly and display device possessing same |
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 | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20090325 Termination date: 20110731 |