CN101064093A - Electric voltage detecting circuit and electric discharge lamp driven apparatus using same - Google Patents
Electric voltage detecting circuit and electric discharge lamp driven apparatus using same Download PDFInfo
- Publication number
- CN101064093A CN101064093A CN 200610060521 CN200610060521A CN101064093A CN 101064093 A CN101064093 A CN 101064093A CN 200610060521 CN200610060521 CN 200610060521 CN 200610060521 A CN200610060521 A CN 200610060521A CN 101064093 A CN101064093 A CN 101064093A
- Authority
- CN
- China
- Prior art keywords
- circuit
- signal
- discharge lamp
- voltage
- voltage detection
- 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
Images
Landscapes
- Circuit Arrangements For Discharge Lamps (AREA)
Abstract
This invention relates to one discharge lamp drive device to drive discharge lamp, which comprises drive switch circuit, variable resonance circuit and voltage detection circuit, wherein the drive switch circuit is to convert the input direct current signals into alternating signals; the variable resonance circuit and drive switch are connected to convert the alternating signals into other alternating signals to drive discharge lamp; the voltage detection circuit is connected between variable resonance circuit and discharge lamp composed of multiple division circuits and reverse charge circuit; the said division circuit and discharge lamp are responding for load voltage on discharge lamp.
Description
Technical field
The present invention relates to a kind of discharge lamp driven apparatus, relate in particular to a kind of LCD (liquidcrystal display, LCD) discharge lamp driven apparatus of backlight module of being applied to.
Background technology
(Liquid Crystal Display, LCD) panel is that (Cold Cathode Fluorescent Lamp is CCFL) as the light source of (Backlight) backlight system with discharge lamp (Discharge Lamp), particularly cold-cathode fluorescence lamp in liquid crystal display.Typically, cold-cathode fluorescence lamp is to be driven by converter circuit (Inverter Circuit), and it can supply AC signal to discharge lamp.When the AC signal overtension of converter circuit output, will cause damage to discharge lamp, even burn discharge lamp.When the AC signal brownout of converter circuit output, can't start discharge lamp.So, need in converter circuit, to increase voltage detection circuit and holding circuit.
Figure 1 shows that the functional block diagram of existing discharge lamp driven apparatus 10.Discharge lamp driven apparatus 10 comprises driving switch circuit 100, transformation resonance circuit 110, holding circuit 120 and voltage detection circuit 130.The AC signal that voltage detection circuit 130 exports transformation resonance circuit 110 to light tube group 140 is converted to voltage signal via capacitor C 1, C2 and C3, and via after the half-wave rectifying circuit D1 half-wave rectification directly the output overvoltage signal to holding circuit 120.Yet this framework can't carry out under-voltage protection.
Figure 2 shows that the functional block diagram of another existing discharge lamp driven apparatus 10 '.The voltage detection circuit 130 ' of discharge lamp driven apparatus 10 ' is different with the voltage detection circuit 130 of discharge lamp driven apparatus 10.The AC signal that voltage detection circuit 130 ' exports transformation resonance circuit 110 to light tube group 140 is converted to voltage signal via capacitor C 1, C2 and C3; and via after the half-wave rectifying circuit D1 half-wave rectification; separate through two diode D2, D3, to export under-voltage signal Vuvp and overvoltage signal Vovp respectively to holding circuit 120 '.Yet the circuit impedance height of this framework is subject to disturb.
Summary of the invention
In view of this, need provide a kind of discharge lamp driven apparatus, can detect discharge lamp and whether be operated under the abnormality, and make entire circuit output impedance lower.
So, also need provide a kind of voltage detecting circuit, whether the AC signal that can detect input is unusual, and output impedance is lower.
A kind of discharge lamp driven apparatus is used to drive discharge lamp, and it comprises driving switch circuit, transformation resonance circuit and voltage detection circuit.The driving switch circuit is used for the direct current signal of input is converted to AC signal.Transformation resonance circuit links to each other with the driving switch circuit, is used for described AC signal is converted to another AC signal to drive discharge lamp.Voltage detection circuit is connected between transformation resonance circuit and the discharge lamp, and whether be used to detect discharge lamp unusual, and the output voltage detection signal, and voltage detection circuit comprises a plurality of bleeder circuits and reverse charging circuit.Bleeder circuit and discharge lamp are corresponding one by one to link to each other, and is used for dividing potential drop and is carried in voltage on the discharge lamp.And bleeder circuit is connected to reverse charging circuit, charges each other by reverse charging circuit, with the accurate position of the direct current that promotes voltage after partial.
A kind of voltage detection circuit, whether be used to detect input exchange signal unusual, and described voltage detection circuit comprises a plurality of bleeder circuits and reverse charging circuit.Bleeder circuit is used for the voltage of dividing potential drop input exchange signal, is connected to reverse charging circuit, charges each other by reverse charging circuit, with the accurate position of the direct current that promotes voltage after partial.
In the voltage detection circuit of the present invention, bleeder circuit charges each other by reverse charging circuit, and whether with the accurate position of lifting voltage after partial signal direct current, thereby it is unusual accurately to detect discharge lamp; And the output impedance of whole discharge lamp driven apparatus circuit is lower, is not subject to noise.
Description of drawings
Fig. 1 is the functional block diagram of existing discharge lamp driven apparatus.
Fig. 2 is the functional block diagram of another existing discharge lamp driven apparatus.
Fig. 3 is the functional block diagram of discharge lamp driven apparatus of the present invention.
Fig. 4 is the physical circuit figure of holding circuit, voltage detection circuit and light tube group among Fig. 3.
Fig. 5 is another physical circuit figure of holding circuit, voltage detection circuit and light tube group among Fig. 3.
Embodiment
Figure 3 shows that the functional block diagram of discharge lamp driven apparatus 20 of the present invention.Discharge lamp driven apparatus 20 is used to drive light tube group 240, and wherein, light tube group 240 comprises a plurality of discharge lamps.In the present embodiment, discharge lamp driven apparatus 20 comprises driving switch circuit 200, transformation resonance circuit 210, holding circuit 220 and voltage detection circuit 230.Driving switch circuit 200 is used for the direct current signal of input is converted to AC signal, and exports this AC signal.In the present embodiment, the AC signal of driving switch circuit 200 outputs is a square-wave signal.Transformation resonance circuit 210 links to each other with driving switch circuit 200, is used for the AC signal of driving switch circuit 200 outputs is converted to another AC signal and exports light tube group 240 to, to drive light tube group 240.Wherein, another AC signal is a string ripple signal.Voltage detection circuit 230 links to each other with transformation resonance circuit 210, is used to detect the voltage that is carried on the light tube group 240, thereby whether detect each discharge lamp unusual, as: superpotential, under-voltage, short circuit etc., and output voltage detection signal.Holding circuit 220 is connected between voltage detection circuit 230 and the driving switch circuit 200, is used to judge whether the detecting voltage signal is unusual, and the output protection signal, thus the AC signal of controlling and driving on-off circuit 200 outputs.
Figure 4 shows that the physical circuit figure of holding circuit 220 of the present invention, voltage detection circuit 230 and light tube group 240.In the present embodiment, light tube group 240 comprise a plurality of discharge lamp Ln (n=1,2,3 ..., n).Voltage detection circuit 230 comprise a plurality of bleeder circuit 231n (n=1,2,3 ..., n), each bleeder circuit comprises two dividing potential drop electric capacity and a diode.Dividing potential drop electric capacity is connected in series between corresponding discharge lamp and ground, is used for dividing potential drop and is carried in voltage on the discharge lamp.The plus earth of diode, its negative electrode are connected between the dividing potential drop electric capacity connected in series, are used to adjust the accurate position of direct current of voltage after partial signal.For example: dividing potential drop capacitor C H1 and CL1 are connected in series between discharge lamp L1 and ground in the bleeder circuit 231, the plus earth of diode DS1, and its negative electrode is connected between dividing potential drop capacitor C H1 and the CL1.Equally, bleeder circuit 23n (n=2,3 ..., particular circuit configurations n) is all identical with bleeder circuit 231, does not repeat them here.
In the present embodiment, be the principle of work of example account for voltage circuit for detecting 23 with 23n, transistor Q1 and Qn, holding circuit 220 only with discharge lamp L1 and Ln, bleeder circuit 231.The negative electrode of diode DS1 is defined as node A in the bleeder circuit 231, and the negative electrode of diode DSn is defined as Node B among the bleeder circuit 23n, and the negative electrode of diode D is defined as node C in the holding circuit 220.
When discharge lamp L1 and Ln were in normal condition, node A equated with the voltage at Node B place, the voltage at the diode D detecting node A place in the holding circuit 220 or the voltage at Node B place, and compare by comparer A1 and reference voltage Vref.
When any one takes place when unusual among discharge lamp L1 and the Ln, for example discharge lamp L1 takes place when unusual, the impedance of discharge lamp L1 also can change, and makes the ac voltage signal generation phase deviation at node A place, thereby makes synchronization node A have different magnitudes of voltage with the alternating voltage of Node B.If the voltage at a certain moment node A place is higher than the voltage at Node B place, then the voltage at node A place promptly can promote the accurate position of direct current of the voltage signal at Node B place by transistor Q1 and the reverse capacitor C Ln charging in bleeder circuit 23n of Qn.If another constantly the voltage at node A place be lower than the voltage at Node B place, then the voltage at Node B place promptly can be by Qn and the reverse capacitor C L1 charging in bleeder circuit 231 of Q1, promote accurate of the direct current of node A place voltage signal, reversely so repeatedly charge to transistor Q1 and Qn ends.
In the present embodiment, reverse charging is the characteristic that can regard zener diode when utilizing transistor emitter-base bandgap grading and base stage reverse bias as between the bleeder circuit, when its reverse breakdown with the voltage clamp between transistor base and the emitter-base bandgap grading to fixed value, as 7V.When considering the transistor forward conduction simultaneously, the pressure drop between base stage and the emitter-base bandgap grading is 0.7V, and therefore, only more than the voltage about 7.7V of voltage greater than Node B or A place at node A or B place, just reversible making to conducting charged between bleeder circuit 231 and the 23n mutually.In other words, between the bleeder circuit mutually the condition of charging be that the voltage difference of diode output in any two bleeder circuits is greater than forward forward voltage between transistor base and the emitter-base bandgap grading and reverse forward voltage sum.
The diode D detecting real-time node A in the holding circuit 220 and the voltage max at Node B place, its by capacitor C 1 with the voltage voltage stabilizing that detects to steady state value, and export the negative input of comparer A1 to.Comparer A1 compares magnitude of voltage and the reference voltage level Verf after the voltage stabilizing, and less than reference voltage level Verf, comparer A1 no signal is exported as if the magnitude of voltage after the voltage stabilizing; If the magnitude of voltage after the voltage stabilizing is greater than reference voltage level Verf, comparer A1 output protection signal then.Simultaneously, resistance R and capacitor C 1 constitute discharge loop.
Figure 5 shows that another variation example of the physical circuit figure of holding circuit 220 of the present invention, voltage detection circuit 230 ' and light tube group 240.The physical circuit figure of itself and holding circuit 220, voltage detection circuit 230 and light tube group 240 shown in Figure 4 is basic identical; difference is: in the present embodiment; reverse charging circuit 232 ' comprises a plurality of clamp circuits, is connected between corresponding transistor base stage and the emitter-base bandgap grading.Each clamp circuit includes catching diode and diode, for example: the clamp circuit that is connected between transistor Q1 base stage and the emitter-base bandgap grading comprises catching diode ZD1 and diode D1, the anode of catching diode ZD1 links to each other with the base stage of transistor Q1, its negative electrode links to each other with the negative electrode of diode D1, and the anode of diode D1 links to each other with the emitter-base bandgap grading of transistor Q1.In the present embodiment, be connected in transistor Qn (n=2,3 ..., n) base stage is all identical with the clamp circuit that is connected between transistor Q1 base stage and the emitter-base bandgap grading with clamp circuit between the emitter-base bandgap grading, therefore, does not repeat them here.In the present embodiment, catching diode ZDn (n=1,2,3 ..., n) be zener diode.
In the present embodiment, even consider that the difference of the dividing potential drop that bleeder circuit is exported does not reach reverse turn-on condition when a certain discharge lamp is unusual, i.e. 7.7V, it is unusual to make voltage detection circuit 232 ' can't accurately detect discharge lamp.Therefore, utilize clamp circuit with transistor Qn (n=1,2,3 ..., n) reverse turning circuit is clamped at certain particular value, it can be less than 7.7V, as 3.7V, thereby reduces reverse turn-on condition.Therefore, bleeder circuit 23n in the voltage detection circuit 230 (n=2,3 ..., n) can pass through clamp circuit, be not that transistor charges each other.
In the pressure circuit for detecting of the present invention, bleeder circuit charges each other by reverse charging circuit, and whether with the accurate position of lifting voltage after partial direct current, thereby it is unusual accurately to detect discharge lamp; And the output impedance of whole discharge lamp driven apparatus circuit is lower, is not subject to noise.
Claims (9)
1. voltage detection circuit, whether unusual, it is characterized in that if being used to detect input exchange signal, and described voltage detection circuit comprises:
A plurality of bleeder circuits are used for the voltage of dividing potential drop input exchange signal; And
Reverse charging circuit;
Wherein, described bleeder circuit is connected to reverse charging circuit, and charges each other by reverse charging circuit, with the accurate position of the direct current that promotes the voltage after partial signal.
2. voltage detection circuit as claimed in claim 1 is characterized in that, each bleeder circuit includes:
The first dividing potential drop electric capacity;
The second dividing potential drop electric capacity, itself and the first dividing potential drop electric capacity are connected in series, are used for the voltage of dividing potential drop input exchange signal; And
First diode, negative electrode are connected between the first dividing potential drop electric capacity and the second dividing potential drop electric capacity, and its plus earth is used to adjust the accurate position of direct current of voltage after partial signal.
3. voltage detection circuit as claimed in claim 2, it is characterized in that, described reverse charging circuit comprises a plurality of transistors, each transistor all has base stage, emitter-base bandgap grading and the collection utmost point, wherein, transistorized base stage is connected in the negative electrode of first diode in the corresponding bleeder circuit, and its collection connects power supply extremely jointly.
4. voltage detection circuit as claimed in claim 3 is characterized in that, described reverse charging circuit also comprises clamp circuit, and it is connected between corresponding transistor base stage and the emitter-base bandgap grading, is used for the reverse forward voltage of clamping transistor.
5. voltage detection circuit as claimed in claim 4 is characterized in that, each clamp circuit includes:
Catching diode, its anode links to each other with the corresponding transistor base stage;
Second diode, its negative electrode links to each other with the negative electrode of catching diode, and its anode links to each other with transistorized emitter-base bandgap grading.
6. a discharge lamp driven apparatus is used to drive a plurality of discharge lamps, it is characterized in that, described discharge lamp driven apparatus comprises:
The driving switch circuit is used for the direct current signal of input is converted to AC signal;
Transformation resonance circuit links to each other with the driving switch circuit, is used for described AC signal is converted to another AC signal to drive discharge lamp; And
As each described voltage detection circuit of claim 1 to 5, it links to each other with transformation resonance circuit, and whether unusual, and the output voltage detection signal if being used to detect discharge lamp.
7. discharge lamp driven apparatus as claimed in claim 6 is characterized in that, also comprises holding circuit, is connected between voltage detection circuit and the driving switch circuit, is used to judge whether the detecting voltage signal is unusual, and the output protection signal.
8. a discharge lamp driven apparatus is used to drive a plurality of discharge lamps, it is characterized in that, described discharge lamp driven apparatus comprises:
The driving switch circuit is used for the direct current signal of input is converted to AC signal;
Transformation resonance circuit links to each other with the driving switch circuit, is used for described AC signal is converted to another AC signal to drive discharge lamp;
Voltage detection circuit is used for taking place when unusual according to one or more discharge lamps, the variation output voltage detection signal of the accurate position of discharge lamp voltage detection signal direct current; And
Holding circuit is connected between transformation resonance circuit and the voltage detection circuit, is used to judge whether the detecting voltage signal is normal, and the output protection signal, and discharge lamp is protected.
9. discharge lamp driven apparatus as claimed in claim 8 is characterized in that, being changed to when one or more discharge lamps of the accurate position of described detecting voltage signal direct current takes place when unusual, and the discharge lamp voltage difference that phase differential produced each other produces.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2006100605211A CN100530320C (en) | 2006-04-28 | 2006-04-28 | Electric voltage detecting circuit and electric discharge lamp driven apparatus using same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2006100605211A CN100530320C (en) | 2006-04-28 | 2006-04-28 | Electric voltage detecting circuit and electric discharge lamp driven apparatus using same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101064093A true CN101064093A (en) | 2007-10-31 |
| CN100530320C CN100530320C (en) | 2009-08-19 |
Family
ID=38965086
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2006100605211A Expired - Fee Related CN100530320C (en) | 2006-04-28 | 2006-04-28 | Electric voltage detecting circuit and electric discharge lamp driven apparatus using same |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100530320C (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102279303A (en) * | 2010-06-09 | 2011-12-14 | 上海宏力半导体制造有限公司 | Voltage detection circuit |
| CN103177698A (en) * | 2013-03-27 | 2013-06-26 | 深圳市华星光电技术有限公司 | Light-emitting diode (LED) backlight driving circuit and backlight module |
| CN103559869A (en) * | 2013-11-15 | 2014-02-05 | 青岛海信电器股份有限公司 | Backlight circuit, driving method thereof and display device |
| CN104464677A (en) * | 2014-12-26 | 2015-03-25 | 上海中航光电子有限公司 | Data access circuit, display panel, display device and driving method |
| CN105242766A (en) * | 2015-10-22 | 2016-01-13 | 深圳拓邦股份有限公司 | Voltage leap detection circuit, reset circuit and electronic device |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102694473A (en) * | 2011-03-21 | 2012-09-26 | 国琏电子（上海）有限公司 | Power supply system |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4866350A (en) * | 1988-04-04 | 1989-09-12 | Usi Lighting, Inc. | Fluorescent lamp system |
| JP2001015289A (en) * | 1999-04-28 | 2001-01-19 | Mitsubishi Electric Corp | Discharge lamp lighting device |
| DE10244412A1 (en) * | 2001-09-25 | 2003-05-28 | Toshiba Lighting & Technology | Electronic ballast and light |
| JP4109484B2 (en) * | 2002-04-19 | 2008-07-02 | 株式会社エスアイエレクトロニクス | Multi-lamp discharge tube lighting device |
-
2006
- 2006-04-28 CN CNB2006100605211A patent/CN100530320C/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102279303A (en) * | 2010-06-09 | 2011-12-14 | 上海宏力半导体制造有限公司 | Voltage detection circuit |
| CN103177698A (en) * | 2013-03-27 | 2013-06-26 | 深圳市华星光电技术有限公司 | Light-emitting diode (LED) backlight driving circuit and backlight module |
| CN103559869A (en) * | 2013-11-15 | 2014-02-05 | 青岛海信电器股份有限公司 | Backlight circuit, driving method thereof and display device |
| CN104464677A (en) * | 2014-12-26 | 2015-03-25 | 上海中航光电子有限公司 | Data access circuit, display panel, display device and driving method |
| CN105242766A (en) * | 2015-10-22 | 2016-01-13 | 深圳拓邦股份有限公司 | Voltage leap detection circuit, reset circuit and electronic device |
| CN105242766B (en) * | 2015-10-22 | 2017-11-28 | 深圳拓邦股份有限公司 | A kind of voltage jump detection circuit, reset circuit and electronic installation |
Also Published As
| Publication number | Publication date |
|---|---|
| CN100530320C (en) | 2009-08-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9230490B2 (en) | LED backlight driver circuit | |
| CN103354086B (en) | LED backlight and liquid crystal display | |
| CN202759636U (en) | LED driving device, lighting device and liquid crystal display device | |
| US7800318B2 (en) | Power supply device for a LCD backlight panel | |
| CN103021346B (en) | A kind of LED backlight drive circuit, driving method and liquid crystal indicator | |
| CN100530320C (en) | Electric voltage detecting circuit and electric discharge lamp driven apparatus using same | |
| CN102647828A (en) | Lighting device and illumination fixture using the same | |
| CN103050096A (en) | Backlight drive circuit overvoltage protection method | |
| CN1784107A (en) | Methods and protection schemes for driving discharge lamps in large panel applications | |
| CN100539782C (en) | Light source driving circuit and driving method thereof | |
| CN101317324B (en) | Power supply device and light-emitting device and electronic equipment using such power supply device | |
| CN107750076A (en) | A kind of LED drive circuit | |
| EP2427033B1 (en) | Bypass circuitry for serially coupled light emitting diodes and associated methods of operation | |
| CN100516895C (en) | Discharge lamp drive device and voltage detection circuit using same | |
| US8575852B2 (en) | Multi-lamp driving system | |
| CN101115340A (en) | Inverter circuit | |
| JP5074087B2 (en) | Discharge lamp driving device | |
| CN220106005U (en) | Display backlight control circuit, circuit board, display screen and television | |
| US20140139419A1 (en) | Backlight driving circuit, backlight module, and lcd device | |
| US9196202B2 (en) | LED backlight driving circuit, LCD device, and method for driving the LED backlight driving circuit | |
| CN101605422B (en) | Fluorescent lighting tube driving circuit | |
| US20140002772A1 (en) | Led backlight driving circuit, backlight module, and lcd device | |
| WO2011021836A2 (en) | Light-emitting diode driving circuit capable of controlling the current of a constant light-emitting diode | |
| KR101020383B1 (en) | Apparatus for detecting current of Light Emitting Diode unit | |
| US9373284B2 (en) | LED backlight driving circuit, LCD device, and method for driving the LED backlight driving circuit |
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 | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20090819 Termination date: 20150428 |
|
| EXPY | Termination of patent right or utility model |