CN103687259B - The protection circuit of inverter that fluorescent tube comes off - Google Patents
The protection circuit of inverter that fluorescent tube comes off Download PDFInfo
- Publication number
- CN103687259B CN103687259B CN201210328189.8A CN201210328189A CN103687259B CN 103687259 B CN103687259 B CN 103687259B CN 201210328189 A CN201210328189 A CN 201210328189A CN 103687259 B CN103687259 B CN 103687259B
- Authority
- CN
- China
- Prior art keywords
- mos
- pin
- mos pipe
- resistance
- diode
- 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 Arrangements For Discharge Lamps (AREA)
- Protection Of Static Devices (AREA)
- Inverter Devices (AREA)
Abstract
The present invention discloses the protection circuit of inverter that a kind of fluorescent tube comes off, and comprising: some detecting branch roads, and it is a corresponding fluorescent tube respectively, and described detecting branch road comprises the first diode group, the first resistance, the second resistance; Several detectings N-MOS pipe; Current Control branch road, it comprises a reference voltage source, the 3rd resistance, control N-MOS pipe, the 4th resistance; Cold cathode ray tube driver, it has current detecting pin, a N-MOS drives pin, the 2nd N-MOS drives pin, a P-MOS drives pin, the 2nd P-MOS drives pin; Transistor group, it comprises a N-MOS pipe, the 2nd N-MOS pipe, a P-MOS pipe, the 2nd P-MOS pipe; Resonant branch, it comprises transformer, the first electric capacity; Export branch road, comprise connector and the second diode group.If there is a fluorescent tube to come off, all fluorescent tubes all do not work, and display result is obvious, can detect very soon, can not be undetected.
Description
[technical field]
The present invention relates to a kind of protection circuit of inverter, the protection circuit of inverter that the fluorescent tube particularly relating to a kind of LCD display panel comes off.
[background technology]
Along with popularizing of electronic product, LCD (LiquidCrystalDisplay) display is also employed more and more widely.LCD display panel is normally such as, by lamp luminescence, the LCD display of 23 cun, and we can use 12 fluorescent tubes (up and down each 6 lamp luminescence), more guide-lighting uniformly by light-guiding pillar.
Due to one of them or several fluorescent tube comes off time, screen intensity can be caused uneven, affect whole LCD display panel visual effect.But when testing LCD display panel, sometimes indivedual fluorescent tube comes off not too obvious, can not detect very soon, even likely undetected, the trouble that the LCD display causing subsequent group to install is done over again.
In view of this, be necessary in fact to develop the protection circuit of inverter that a kind of fluorescent tube comes off, to solve the problem.
[summary of the invention]
Therefore, the object of this invention is to provide the protection circuit of inverter that a kind of fluorescent tube comes off, with solve LCD display panel test time, indivedual fluorescent tube comes off not too obvious, can not detect very soon, even likely undetected problem.
In order to achieve the above object, the protection circuit of inverter that fluorescent tube provided by the invention comes off, described protection circuit comprises:
Some detecting branch roads, it is a corresponding fluorescent tube respectively, described detecting branch road comprises the first diode group, the first resistance, the second resistance, described first diode group comprises the first diode and the second diode, the negative pole of described first diode and the positive pole of described second diode connect described fluorescent tube, the plus earth of described first diode, the negative pole of described second diode, described first resistance, the second resistance are sequentially connected in series with between ground;
Several detectings N-MOS pipe, it is a corresponding detecting branch road respectively, the grid of described detecting N-MOS pipe is connected between described first resistance, the second resistance, and the source electrode of each described detecting N-MOS pipe sequentially connects the drain electrode of next described detecting N-MOS pipe until detect the source ground of N-MOS pipe described in last from first;
Current Control branch road, it comprises a reference voltage source, the 3rd resistance, control N-MOS pipe, the 4th resistance, reference voltage source described in the drain electrode of described 3rd resistance one end adaper described detecting N-MOS pipe, another termination, the drain electrode of a described control N-MOS tube grid adaper described detecting N-MOS pipe, source ground, described 4th resistance one end ground connection;
Cold cathode ray tube driver, it has current detecting pin, a N-MOS drives pin, the 2nd N-MOS drives pin, a P-MOS drives pin, the 2nd P-MOS drives pin, and described current detecting pin connects the drain electrode of the described 4th resistance other end and described control N-MOS pipe;
Transistor group, it comprises a N-MOS pipe, the 2nd N-MOS pipe, a P-MOS pipe, the 2nd P-MOS pipe, its grid sequentially meets a described N-MOS respectively and drives pin, the 2nd N-MOS driving pin, a P-MOS to drive pin, the 2nd P-MOS driving pin, the source ground of a described N-MOS pipe, the 2nd N-MOS pipe;
Resonant branch, it comprises transformer, the first electric capacity, described transformer first input end connects the drain electrode of a described N-MOS pipe, a P-MOS pipe, one end of first electric capacity described in second input termination of described transformer, first output head grounding of described transformer, the drain electrode of the 2nd N-MOS pipe, the 2nd P-MOS pipe described in another termination of described first electric capacity;
Export branch road, comprise connector and the second diode group, described connector has the first pin and the second pin, described first pin connects the second output terminal of described transformer, described second pin connects described fluorescent tube, described second diode group comprises the 3rd diode and the 4th diode, the second pin, oppositely current detecting pin described in termination described in described 3rd diode forward termination, described 4th diode forward end ground connection, oppositely the second pin described in termination.
Optionally, when the input voltage of described current detecting pin is less than 0.6V, turn off the output that a described N-MOS drives pin, the 2nd N-MOS drives pin, a P-MOS drives pin, the 2nd P-MOS drives pin; When the input voltage of described current detecting pin is more than or equal to 0.6V, open the output that a described N-MOS drives pin, the 2nd N-MOS drives pin, a P-MOS drives pin, the 2nd P-MOS drives pin.
Optionally, described cold cathode ray tube driver also has input pin, and described input pin and a P-MOS manage, the source electrode of the 2nd P-MOS pipe connects input signal.
Optionally, described detecting branch road also comprises filter capacitor, and described filter capacitor is parallel to described second resistance two ends, and described filter capacitor is used for filtering, denoising.
Optionally, described Current Control branch road also comprises control capacitance, and described control capacitance is parallel to described 4th resistance two ends.
Compared to prior art, utilize the protection circuit of inverter that fluorescent tube of the present invention comes off, when described fluorescent tube has one or more to come off, the grid of the detecting N-MOS pipe corresponding to detecting branch road that it is connected in series is low level, then this detecting N-MOS pipe cut-off, the voltage-drop loading of described reference voltage source is in the grid of the control N-MOS pipe of described Current Control branch road, this control N-MOS tube grid is high level and conducting, the voltage of the current detecting pin of described cold cathode ray tube driver is low level, turn off a described N-MOS and drive pin, 2nd N-MOS drives pin, one P-MOS drives pin, 2nd P-MOS drives the output of pin, thus all fluorescent tubes are no longer luminous, reach the protective effect to fluorescent tube.Adopt the protection circuit of inverter that this fluorescent tube comes off, due to when detecting, if there is a fluorescent tube to come off, all fluorescent tubes all do not work, and therefore show result obvious, can detect very soon, can not cause undetected.
[accompanying drawing explanation]
Fig. 1 illustrates the electrical block diagram of protection circuit of inverter one preferred embodiment come off for fluorescent tube of the present invention.
[embodiment]
Refer to Fig. 1, Fig. 1 illustrates the electrical block diagram of protection circuit of inverter one preferred embodiment come off for fluorescent tube of the present invention.
In order to achieve the above object, the protection circuit of inverter that fluorescent tube provided by the invention comes off, described protection circuit comprises:
Some detecting branch roads, it is a corresponding fluorescent tube 100 respectively, described detecting branch road comprises the first diode group, first resistance 103, second resistance 104, described first diode group comprises the first diode 101 and the second diode 102, the negative pole of described first diode 101 and the positive pole of described second diode 102 connect described fluorescent tube 100, the plus earth of described first diode 101, the negative pole of described second diode 102, described first resistance 103, second resistance 104 is sequentially connected in series with between ground, described first diode 101 and the second diode 102 are in order to filter negative voltage, retain positive voltage,
Several detectings N-MOS pipe 200, it is a corresponding detecting branch road respectively, the grid of described detecting N-MOS pipe 200 is connected between described first resistance 103, second resistance 104, and the source electrode of each described detecting N-MOS pipe 200 sequentially connects the drain electrode of next described detecting N-MOS pipe 200 until detect the source ground of N-MOS pipe 200 described in last from first;
Current Control branch road, it comprises a reference voltage source 300, the 3rd resistance 301, control N-MOS pipe the 302, the 4th resistance 303, reference voltage source 300 described in the drain electrode of described 3rd resistance 301 one end adaper described detecting N-MOS pipe 200, another termination, the drain electrode of a described control N-MOS pipe 302 grid adaper described detecting N-MOS pipe 200, described control N-MOS pipe 302 source ground, described 4th resistance 303 one end ground connection;
Cold cathode ray tube (CCFL, ColdCathodeFluorescentLamp) driver 400, it has current detecting pin 410, a N-MOS drives pin 401, the 2nd N-MOS drives pin 402, a P-MOS drives pin 403, the 2nd P-MOS drives pin 404, and described current detecting pin 410 connects the drain electrode of described 4th resistance 303 other end and described control N-MOS pipe 302;
Transistor group, it comprises a N-MOS pipe 501, the 2nd N-MOS pipe 502, a P-MOS pipe 503, the 2nd P-MOS pipe 504, its grid sequentially meets a described N-MOS respectively and drives pin 401, the 2nd N-MOS driving pin 402, a P-MOS to drive pin 403, the 2nd P-MOS driving pin 404, the source ground of a described N-MOS pipe 501, the 2nd N-MOS pipe 502;
Resonant branch, it comprises transformer 600, first electric capacity 601, described transformer 600 first input end connects the drain electrode of a described N-MOS pipe 501, a P-MOS pipe 503, one end of first electric capacity 601 described in second input termination of described transformer 600, first output head grounding of described transformer 600, the drain electrode of the 2nd N-MOS pipe 502, the 2nd P-MOS pipe 504 described in another termination of described first electric capacity 601;
Export branch road, comprise connector 700 and the second diode group, described connector 700 has the first pin and the second pin, described first pin connects the second output terminal of described transformer 600, described second pin connects described fluorescent tube 100, described second diode group comprises the 3rd diode 701 and the 4th diode 702, second pin described in described 3rd diode 701 forward termination, current detecting pin 410 described in reverse termination, described 4th diode 702 forward end ground connection, second pin described in reverse termination, described 3rd diode 701 and the 4th diode 702 are also filter negative voltage, retain positive voltage.
Wherein, the mode that can select is: when the input voltage of described current detecting pin 410 is less than 0.6V, turns off the output that a described N-MOS drives pin 401, the 2nd N-MOS drives pin 402, a P-MOS drives pin 403, the 2nd P-MOS drives pin 404; When the input voltage of described current detecting pin 410 is more than or equal to 0.6V, open the output that a described N-MOS drives pin 401, the 2nd N-MOS drives pin 402, a P-MOS drives pin 403, the 2nd P-MOS drives pin 404.
Wherein, described cold cathode ray tube driver 400 can also have input pin 405, and the source electrode of described input pin 405 and a P-MOS pipe 503, the 2nd P-MOS pipe 504 connects input signal.
Wherein, described detecting branch road can also comprise filter capacitor 105, and described filter capacitor 105 is parallel to described second resistance 104 two ends, and described filter capacitor is used for filtering, denoising.
Wherein, described Current Control branch road can also comprise control capacitance 304, and described control capacitance 304 is parallel to described 4th resistance 303 two ends.
Utilize the protection circuit of inverter that fluorescent tube of the present invention comes off, in time testing, when described fluorescent tube 100 is all normal, the grid of the detecting N-MOS pipe 200 corresponding to detecting branch road that it is connected in series is high level, then this detecting N-MOS pipe 200 conducting, the grid of the control N-MOS pipe 302 of described Current Control branch road is dragged down ground connection, this control N-MOS pipe 302 grid is that low level is ended, the voltage of the current detecting pin 410 of described cold cathode ray tube driver 400 is come from described 4th diode 702 of the described second diode group of described output branch road, for high level.Open the output that a described N-MOS drives pin 401, the 2nd N-MOS drives pin 402, a P-MOS drives pin 403, the 2nd P-MOS drives pin 403, thus all fluorescent tubes 100 still normal luminous.
When described fluorescent tube 100 has one or more to come off, the grid of the detecting N-MOS pipe 200 corresponding to detecting branch road that it is connected in series is low level, then this detecting N-MOS pipe 200 ends, the voltage-drop loading of described reference voltage source 300 is in the grid of the control N-MOS pipe 302 of described Current Control branch road, this control N-MOS pipe 302 grid is high level and conducting, the voltage of the current detecting pin 410 of described cold cathode ray tube driver 400 is low level, turn off a described N-MOS and drive pin 401, 2nd N-MOS drives pin 402, one P-MOS drives pin 403, 2nd P-MOS drives the output of pin 404, thus all fluorescent tubes 100 are no longer luminous, reach the protective effect to fluorescent tube 100.
Adopt the protection circuit of inverter that this fluorescent tube comes off, due to when detecting, if there is a fluorescent tube 100 to come off, all fluorescent tubes 100 all do not work, and therefore show result obvious, can detect very soon, can not cause undetected.
Claims (5)
1. the protection circuit of inverter that comes off of fluorescent tube, it is characterized in that, described protection circuit comprises:
Some detecting branch roads, it is a corresponding fluorescent tube respectively, described detecting branch road comprises the first diode group, the first resistance, the second resistance, described first diode group comprises the first diode and the second diode, the negative pole of described first diode and the positive pole of described second diode connect described fluorescent tube, the plus earth of described first diode, the negative pole of described second diode, described first resistance, the second resistance are sequentially connected in series with between ground;
Several detectings N-MOS pipe, it is a corresponding detecting branch road respectively, the grid of described detecting N-MOS pipe is connected between described first resistance, the second resistance, and the source electrode of each described detecting N-MOS pipe sequentially connects the drain electrode of next described detecting N-MOS pipe until detect the source ground of N-MOS pipe described in last from first;
Current Control branch road, it comprises a reference voltage source, the 3rd resistance, control N-MOS pipe, the 4th resistance, reference voltage source described in the drain electrode of described 3rd resistance one end adaper described detecting N-MOS pipe, another termination, the drain electrode of a described control N-MOS tube grid adaper described detecting N-MOS pipe, source ground, described 4th resistance one end ground connection;
Cold cathode ray tube driver, it has current detecting pin, a N-MOS drives pin, the 2nd N-MOS drives pin, a P-MOS drives pin, the 2nd P-MOS drives pin, and described current detecting pin connects the drain electrode of the described 4th resistance other end and described control N-MOS pipe;
Transistor group, it comprises a N-MOS pipe, the 2nd N-MOS pipe, a P-MOS pipe, the 2nd P-MOS pipe, its grid sequentially meets a described N-MOS respectively and drives pin, the 2nd N-MOS driving pin, a P-MOS to drive pin, the 2nd P-MOS driving pin, the source ground of a described N-MOS pipe, the 2nd N-MOS pipe;
Resonant branch, it comprises transformer, the first electric capacity, described transformer first input end connects the drain electrode of a described N-MOS pipe, a P-MOS pipe, one end of first electric capacity described in second input termination of described transformer, first output head grounding of described transformer, the drain electrode of the 2nd N-MOS pipe, the 2nd P-MOS pipe described in another termination of described first electric capacity;
Export branch road, comprise connector and the second diode group, described connector has the first pin and the second pin, described first pin connects the second output terminal of described transformer, described second pin connects described fluorescent tube, described second diode group comprises the 3rd diode and the 4th diode, the second pin, oppositely current detecting pin described in termination described in described 3rd diode forward termination, described 4th diode forward end ground connection, oppositely the second pin described in termination.
2. the protection circuit of inverter that comes off of fluorescent tube as claimed in claim 1, it is characterized in that, when the input voltage of described current detecting pin is less than 0.6V, turn off the output that a described N-MOS drives pin, the 2nd N-MOS drives pin, a P-MOS drives pin, the 2nd P-MOS drives pin; When the input voltage of described current detecting pin is more than or equal to 0.6V, open the output that a described N-MOS drives pin, the 2nd N-MOS drives pin, a P-MOS drives pin, the 2nd P-MOS drives pin.
3. the protection circuit of inverter that comes off of fluorescent tube as claimed in claim 1, it is characterized in that, described cold cathode ray tube driver also has input pin, and described input pin and a P-MOS manage, the source electrode of the 2nd P-MOS pipe connects input signal.
4. the protection circuit of inverter that comes off of fluorescent tube as claimed in claim 1, it is characterized in that, described detecting branch road also comprises filter capacitor, and described filter capacitor is parallel to described second resistance two ends.
5. the protection circuit of inverter that comes off of fluorescent tube as claimed in claim 1, it is characterized in that, described Current Control branch road also comprises control capacitance, and described control capacitance is parallel to described 4th resistance two ends.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210328189.8A CN103687259B (en) | 2012-09-07 | 2012-09-07 | The protection circuit of inverter that fluorescent tube comes off |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210328189.8A CN103687259B (en) | 2012-09-07 | 2012-09-07 | The protection circuit of inverter that fluorescent tube comes off |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103687259A CN103687259A (en) | 2014-03-26 |
| CN103687259B true CN103687259B (en) | 2015-12-30 |
Family
ID=50323154
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210328189.8A Active CN103687259B (en) | 2012-09-07 | 2012-09-07 | The protection circuit of inverter that fluorescent tube comes off |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103687259B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002063996A (en) * | 2000-08-15 | 2002-02-28 | Murata Mfg Co Ltd | Protective circuit from abnormality for high-voltage power device for lighting discharge tube |
| CN101399007A (en) * | 2007-09-28 | 2009-04-01 | 群康科技(深圳)有限公司 | Backlight open-circuit proctive circuit |
| CN202034899U (en) * | 2011-03-09 | 2011-11-09 | 深圳Tcl新技术有限公司 | Double-pipe parallel connection power factor correction (PFC) circuit |
| CN202799349U (en) * | 2012-09-07 | 2013-03-13 | 神讯电脑(昆山)有限公司 | Inverter protective circuit when lamp tube drops |
-
2012
- 2012-09-07 CN CN201210328189.8A patent/CN103687259B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002063996A (en) * | 2000-08-15 | 2002-02-28 | Murata Mfg Co Ltd | Protective circuit from abnormality for high-voltage power device for lighting discharge tube |
| CN101399007A (en) * | 2007-09-28 | 2009-04-01 | 群康科技(深圳)有限公司 | Backlight open-circuit proctive circuit |
| CN202034899U (en) * | 2011-03-09 | 2011-11-09 | 深圳Tcl新技术有限公司 | Double-pipe parallel connection power factor correction (PFC) circuit |
| CN202799349U (en) * | 2012-09-07 | 2013-03-13 | 神讯电脑(昆山)有限公司 | Inverter protective circuit when lamp tube drops |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103687259A (en) | 2014-03-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103150997B (en) | LED (light emitting diode) backlight driving circuit | |
| CN104407481B (en) | Array substrate, detection method of failure of signal line, display panel and display device | |
| CN103680444B (en) | LED boost converter and apply its backlight LED drive unit | |
| CN104459400A (en) | Detection circuit and detection method used for self-contained touch screen | |
| CN103698953A (en) | Array substrate, display panel and display device | |
| CN104280908A (en) | Detection circuit, liquid crystal display panel and manufacturing method of liquid crystal display panel | |
| CN103293795A (en) | Electrostatic protection circuit of liquid crystal display | |
| CN104916243A (en) | Detection method and device for scan driving circuit and liquid crystal panel | |
| CN100443994C (en) | Backlight open circuit protection circuit | |
| CN103454794A (en) | Lighting test fixture and liquid crystal display panel testing method | |
| CN202799349U (en) | Inverter protective circuit when lamp tube drops | |
| CN102566102A (en) | Method for repairing line defects of liquid crystal panels | |
| CN103687259B (en) | The protection circuit of inverter that fluorescent tube comes off | |
| CN105609022B (en) | GIP detection circuits and panel display apparatus | |
| CN102646382A (en) | Method and device for detecting anomaly of liquid crystal display module differential signal receiving terminal | |
| CN208488960U (en) | Pixel circuit, display panel, display device | |
| CN206848624U (en) | Detection means | |
| CN201590222U (en) | LCD (Liquid crystal display) back light power circuit with high voltage transformer damage protection | |
| CN109389919B (en) | Display panel detection method and device | |
| CN105548727A (en) | CKV signal detection circuit and liquid crystal panel control panel with same | |
| CN103247269A (en) | LED backlight and liquid crystal display device | |
| CN104217688B (en) | A kind of LCD and display device | |
| CN105045008A (en) | ESD protection circuit of liquid crystal display panel | |
| CN201188712Y (en) | Backlight module unit lamp tube set capable of preventing wire rod from connecting inversely base on phase control | |
| CN102339581B (en) | Virtual load board and testing system and testing method for liquid crystal display control panel |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | 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 |