CN1996026A - Discharge lamp drive device and voltage detection circuit using same - Google Patents
Discharge lamp drive device and voltage detection circuit using same Download PDFInfo
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- CN1996026A CN1996026A CN 200610032811 CN200610032811A CN1996026A CN 1996026 A CN1996026 A CN 1996026A CN 200610032811 CN200610032811 CN 200610032811 CN 200610032811 A CN200610032811 A CN 200610032811A CN 1996026 A CN1996026 A CN 1996026A
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Abstract
The voltage detecting circuit comprises voltage acquisition circuit, excess voltage detection circuit and under voltage detection circuit. The voltage acquisition circuit is used to convert the input exchange signal to voltage signal. It detects the voltage input exchange signal to judge whether the voltage exceeds the normal level, with the composition of No. 1 transistor. The said transistor comprises Nol1 control end, No. 1 electrode and No. 2 electrode. It detects the voltage input exchange signal to judge whether the voltage under the normal level, with the composition of No. 2 transistor. The said transistor comprises No2 control end, No. 3 electrode and No. 4 electrode. The No. 1 and No. 2 control ends connected to the voltage to complete the circuit. It uses two transistors to detect with low output resistance, hard to be interfered.
Description
[technical field]
The present invention relates to a kind of lamp-tube driving system, especially about a kind of discharge lamp driven apparatus.
[background technology]
(Liquid Crystal Display, LCD) (Cold Cathode Fluorescent Lamp is CCFL) as the light source of (Backlight) backlight system with discharge lamp (DischargeLamp), particularly cold-cathode fluorescence lamp for panel in liquid crystal display.Typically, cold-cathode fluorescence lamp is driven by converter circuit (Inverter Circuit), and it can supply AC signal to fluorescent tube.When the AC signal overtension of converter circuit output, will cause damage to fluorescent tube, even burn fluorescent tube.When the AC signal brownout of converter circuit output, can't start fluorescent tube.So, need in converter circuit, to increase voltage detection circuit and holding circuit.
Figure 1 shows that the functional block diagram of an existing discharge lamp driven apparatus 10.Discharge lamp driven apparatus 10 comprises that one drives and on-off circuit 100, a transformer circuit 110, a holding circuit 120 and a voltage detection circuit 130.The AC signal that voltage detection circuit 130 exports transformer circuit 110 to light tube group 140 is converted to voltage signal via capacitor C 1, C2 and C3, and via directly exporting an overvoltage signal after the half-wave rectifying circuit D1 half-wave rectification 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 transformer 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 the whether overvoltage or under-voltage of AC signal of the discharge lamp of flowing through, and output impedance be lower.
So, also need provide a kind of voltage detecting circuit, can detect the whether overvoltage or under-voltage of AC signal of input, and output impedance be lower.
A kind of discharge lamp driven apparatus is used to drive discharge lamp, and it comprises driving and on-off circuit, transformer circuit and voltage detection circuit.Driving and on-off circuit are used for direct current signal is converted to AC signal.Transformer circuit links to each other with driving and on-off circuit, is used for AC signal is converted to another AC signal to drive discharge lamp.Voltage detection circuit is used to detect the whether overvoltage or under-voltage of AC signal of discharge lamp of flowing through, and it comprises that voltage obtains circuit, overvoltage circuit for detecting and under-voltage circuit for detecting.Voltage is obtained circuit and is used for the AC signal of the discharge lamp of flowing through is converted to voltage signal.The overvoltage circuit for detecting is obtained circuit with voltage and is linked to each other, and be used for according to flow through the whether overvoltage of AC signal of discharge lamp of voltage signal detecting, and if overvoltage produces the overvoltage signal, it comprises the first transistor.The first transistor comprises first the control utmost point, first electrode and second electrode, and the first control utmost point is connected to voltage and obtains circuit.Whether under-voltage circuit for detecting is obtained circuit with voltage and is linked to each other, be used for according to the flow through AC signal of discharge lamp of voltage signal detecting under-voltagely, and if the under-voltage signal of under-voltage generation, it comprises transistor seconds.Transistor seconds comprises second the control utmost point, third electrode and the 4th electrode, and the second control utmost point is connected to voltage and obtains circuit.
A kind of voltage detection circuit is used to detect whether overvoltage or under-voltage of input exchange signal, and it comprises that voltage obtains circuit, overvoltage circuit for detecting and under-voltage circuit for detecting.Voltage is obtained circuit and is used for input exchange signal is converted to voltage signal.The overvoltage circuit for detecting is obtained circuit with voltage and is linked to each other, and be used for according to the whether overvoltage of voltage signal detecting input exchange signal, and if overvoltage produces the overvoltage signal, it comprises the first transistor.The first transistor comprises first the control utmost point, first electrode and second electrode, and the first control utmost point is connected to voltage and obtains circuit.Under-voltage circuit for detecting is obtained circuit with voltage and is linked to each other, and whether be used for detecting input exchange signal according to voltage signal under-voltage, and if the under-voltage signal of under-voltage generation, it comprises transistor seconds.Transistor seconds comprises second the control utmost point, third electrode and the 4th electrode, and the second control utmost point is connected to voltage and obtains circuit.
Above-mentioned voltage detection circuit can be detected overvoltage and under-voltage condition, and utilizes two transistor to detect, and output impedance is lower, is not subject to disturb.
[description of drawings]
Fig. 1 is the functional block diagram of an 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 in an embodiment of the present invention.
Fig. 4 is the functional block diagram of discharge lamp driven apparatus in another embodiment of the present invention.
Fig. 5 is the physical circuit figure of voltage detection circuit in an embodiment of the present invention.
[embodiment]
See also Fig. 3, be the functional block diagram of discharge lamp driven apparatus in an embodiment of the present invention 20.Discharge lamp driven apparatus 20 is used to drive light tube group 240.In the present embodiment, discharge lamp driven apparatus 20 comprises: drive and on-off circuit 200, transformer circuit 210, holding circuit 220 and voltage detection circuit 230.Driving and on-off circuit 200 are used for direct current signal is converted to AC signal, and export this AC signal.In the present embodiment, the AC signal of driving and on-off circuit 200 outputs is a square-wave signal.Transformer circuit 210 links to each other with driving and on-off circuit 200, is used for the AC signal that drives and on-off circuit 200 is exported is converted to another AC signal and exports light tube group 240 to.Wherein, this another AC signal is a string ripple signal.Voltage detection circuit 230 is used to detect the whether overvoltage or under-voltage of AC signal of light tube group 240 of flowing through.In the present embodiment, voltage detection circuit 230 links to each other with transformer circuit 210, is used to detect the whether overvoltage or under-voltage of another AC signal of transformer circuit 210 outputs, and output overvoltage signal during overvoltage, exports under-voltage signal when under-voltage.Holding circuit 220 and voltage detection circuit 230 and driving and on-off circuit 200 link to each other, and are used for driving and on-off circuit 200 according to overvoltage signal and under-voltage signal controlling.
Figure 4 shows that the functional block diagram of discharge lamp driven apparatus 20 ' in another embodiment of the present invention.In the present embodiment, the voltage detection circuit 230 of discharge lamp driven apparatus 20 ' is connected to light tube group 240, and all the other are partly identical with the discharge lamp driven apparatus among Fig. 3 20.In the present embodiment, voltage detection circuit 230 is used to detect the whether overvoltage or under-voltage of AC signal of light tube group 240 of flowing through.
Figure 5 shows that the physical circuit figure of voltage detection circuit 230 in an embodiment of the present invention.In the present embodiment, voltage is obtained circuit 2300 and is comprised first capacitor C 5, second capacitor C 6 and half-wave rectifying circuit D4.One termination of first capacitor C 5 is received the AC signal of the light tube group 240 of flowing through, and the other end is connected to an end of second capacitor C 6.In the embodiment of Fig. 3, an end of first capacitor C 5 connects transformer circuit 210.In the embodiment of Fig. 4, an end of first capacitor C 5 connects light tube group 240.The other end ground connection of second capacitor C 6.In the present embodiment, half-wave rectifying circuit D4 comprises two diodes, the anode of one diode is first end of half-wave rectifying circuit D4, and negative electrode links to each other with the anode of another diode and is that second end of half-wave rectifying circuit D4, the negative electrode of another diode are the 3rd end of half-wave rectifying circuit D4.The first end ground connection of half-wave rectifying circuit D4, second end are connected between first capacitor C 5 and second capacitor C 6, and the 3rd end is connected to overvoltage circuit for detecting 2310 and under-voltage circuit for detecting 2320.
Overvoltage circuit for detecting 2310 comprises the first transistor Q1, and the first transistor Q1 comprises first the control utmost point, first electrode and second electrode, and the first control utmost point is connected to the 3rd end that voltage is obtained the half-wave rectifying circuit D4 of circuit 2300.First electrode of the first transistor Q1 connects reference voltage Vref, the second electrode output overvoltage signal.In the present embodiment, the first transistor Q1 is a NPN transistor, and first controls very base stage, and first electrode is a collector, and second electrode is an emitter.In other embodiment of the present invention, the first transistor Q1 also can be the transistor of other type.In other embodiment of the present invention, the first control utmost point is connected to voltage via first resistance R 3 and obtains between circuit 2300, the first control utmost points and second electrode and be connected second resistance R 4.First resistance R 3 and second resistance R 4 are used to carry out dividing potential drop.In the present embodiment, reference voltage Vref is 12V.In other embodiment of the present invention, reference voltage Vref is 15V.
Under-voltage circuit for detecting 2320 comprises transistor seconds Q2, and transistor seconds Q2 comprises second the control utmost point, third electrode and the 4th electrode, and the second control utmost point is connected to the 3rd end that voltage is obtained the half-wave rectifying circuit D4 of circuit 2300.The 4th electrode grounding of transistor seconds Q2, third electrode is exported under-voltage signal.In the present embodiment, transistor seconds Q2 is a PNP transistor, and second controls very base stage, and third electrode is an emitter, and the 4th electrode is a collector.In other embodiment of the present invention, transistor seconds Q2 also can be the transistor of other type.In other embodiment of the present invention, the second control utmost point is connected to voltage via the 3rd resistance R 5 and obtains between circuit 2300, the second control utmost points and the third electrode and be connected the 4th resistance R 6.The 3rd resistance R 5 and the 4th resistance R 6 are used to carry out dividing potential drop.
The AC signal of the light tube group of flowing through 240 is converted to voltage signal via first capacitor C 5 and second capacitor C 6, carries out half-wave rectification via half-wave rectifying circuit D4 again, is transformed to direct current signal.When the AC signal of the light tube group 240 of flowing through just often, the first transistor Q1 and transistor seconds Q2 all end, no overvoltage or under-voltage signal produce.
When the AC signal overvoltage of the light tube group 240 of flowing through, the first transistor Q1 conducting, transistor seconds Q2 ends, and the second electrode output overvoltage signal of the first transistor Q1 is to holding circuit 220.In the present embodiment, the overvoltage signal is a direct current signal.
When the AC signal of the light tube group 240 of flowing through was under-voltage, the first transistor Q1 ended, transistor seconds Q2 conducting, and the third electrode of transistor seconds Q2 is exported under-voltage signal to holding circuit 220.In the present embodiment, under-voltage signal is a direct current signal.
Claims (16)
1. voltage detection circuit is used to detect whether overvoltage or under-voltage of input exchange signal, it is characterized in that described voltage detection circuit comprises:
Voltage is obtained circuit, is used for described input exchange signal is converted to voltage signal;
The overvoltage circuit for detecting, obtaining circuit with described voltage links to each other, be used for detecting the whether overvoltage of described input exchange signal according to described voltage signal, and if overvoltage produces the overvoltage signal, described overvoltage circuit for detecting comprises the first transistor, described the first transistor comprises first the control utmost point, first electrode and second electrode, and the described first control utmost point is connected to described voltage and obtains circuit; And
Under-voltage circuit for detecting, obtaining circuit with described voltage links to each other, whether be used for detecting described input exchange signal according to described voltage signal under-voltage, and if the under-voltage signal of under-voltage generation, described under-voltage circuit for detecting comprises transistor seconds, described transistor seconds comprises second the control utmost point, third electrode and the 4th electrode, and the described second control utmost point is connected to described voltage and obtains circuit.
2. voltage detection circuit as claimed in claim 1 is characterized in that first electrode of described the first transistor connects reference voltage, and second electrode is exported described overvoltage signal.
3. voltage detection circuit as claimed in claim 2 is characterized in that the first control utmost point of described the first transistor is connected to described voltage via first resistance and obtains circuit, is connected second resistance between the first control utmost point of described the first transistor and second electrode.
4. voltage detection circuit as claimed in claim 1 is characterized in that the third electrode of described transistor seconds is exported described under-voltage signal, described the 4th electrode grounding.
5. voltage detection circuit as claimed in claim 4 is characterized in that the second control utmost point of described transistor seconds is connected to described voltage via the 3rd resistance and obtains circuit, is connected the 4th resistance between the second control utmost point of described transistor seconds and the third electrode.
6. voltage detection circuit as claimed in claim 1 is characterized in that described the first transistor is a NPN transistor.
7. voltage detection circuit as claimed in claim 6 is characterized in that first of described the first transistor controlled very base stage, and first electrode is a collector, and second electrode is an emitter.
8. voltage detection circuit as claimed in claim 1 is characterized in that described transistor seconds is a PNP transistor.
9. voltage detection circuit as claimed in claim 8 is characterized in that second of described transistor seconds controlled very base stage, and third electrode is an emitter, and the 4th electrode is a collector.
10. voltage detection circuit as claimed in claim 1 is characterized in that described voltage obtains circuit and comprise:
First electric capacity, the one termination is received described input exchange signal;
Second electric capacity, the one end is connected to the other end of described first electric capacity, other end ground connection; And
Half-wave rectifying circuit, its first end ground connection, second end is connected to the other end of described first electric capacity, and the 3rd end is connected to described overvoltage circuit for detecting and described under-voltage circuit for detecting.
11. a discharge lamp driven apparatus is used to drive discharge lamp, it is characterized in that described discharge lamp driven apparatus comprises:
Drive and on-off circuit, be used for the direct current signal of input is converted to AC signal;
Transformer circuit links to each other with described driving and on-off circuit, is used for described AC signal is converted to another AC signal; And
As each described voltage detection circuit of claim 1 to 10, be used to detect the whether overvoltage or under-voltage of AC signal of described discharge lamp of flowing through.
12. discharge lamp driven apparatus as claimed in claim 11; it is characterized in that more comprising holding circuit; link to each other with described voltage detection circuit and described driving and on-off circuit, be used for according to described overvoltage signal and described driving of described under-voltage signal controlling and on-off circuit.
13. discharge lamp driven apparatus as claimed in claim 11 is characterized in that the AC signal of described driving and on-off circuit output is a square-wave signal.
14. discharge lamp driven apparatus as claimed in claim 11 is characterized in that another AC signal of described transformer circuit output is a string ripple signal.
15. discharge lamp driven apparatus as claimed in claim 11 is characterized in that described voltage detection circuit links to each other with described transformer circuit, is used to detect the whether overvoltage or under-voltage of another AC signal of described transformer circuit output.
16. discharge lamp driven apparatus as claimed in claim 11 is characterized in that described voltage detection circuit links to each other with described discharge lamp.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2006100328115A CN100516895C (en) | 2006-01-06 | 2006-01-06 | Discharge lamp drive device and voltage detection circuit using same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2006100328115A CN100516895C (en) | 2006-01-06 | 2006-01-06 | Discharge lamp drive device and voltage detection circuit using same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1996026A true CN1996026A (en) | 2007-07-11 |
| CN100516895C CN100516895C (en) | 2009-07-22 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2006100328115A Expired - Fee Related CN100516895C (en) | 2006-01-06 | 2006-01-06 | Discharge lamp drive device and voltage detection circuit using same |
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| CN (1) | CN100516895C (en) |
Cited By (2)
| 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 |
| CN108196109A (en) * | 2018-03-16 | 2018-06-22 | 南方电网科学研究院有限责任公司 | A kind of circuit for being used to monitor supply voltage |
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 (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN88202349U (en) * | 1988-03-25 | 1988-12-14 | 中国人民解放军重庆通信学院 | Multi-purpose integrated regulator of generator of car |
| CN2052519U (en) * | 1989-03-31 | 1990-02-07 | 涿州市运输器材厂 | Refrigerator protector |
| JP3418905B2 (en) * | 1997-11-28 | 2003-06-23 | 三菱電機株式会社 | High pressure discharge lamp lighting device |
| CN2344942Y (en) * | 1998-04-10 | 1999-10-20 | 刘立吾 | Secondary voltage light modulator |
| JP3932773B2 (en) * | 2000-06-14 | 2007-06-20 | 松下電工株式会社 | Discharge lamp lighting device |
| CN1254046C (en) * | 2002-09-03 | 2006-04-26 | 鸿海精密工业股份有限公司 | Circuit for testing low voltage of input voltage of modem |
| JP4312673B2 (en) * | 2003-08-21 | 2009-08-12 | 株式会社デンソー | Discharge lamp device |
-
2006
- 2006-01-06 CN CNB2006100328115A patent/CN100516895C/en not_active Expired - Fee Related
Cited By (2)
| 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 |
| CN108196109A (en) * | 2018-03-16 | 2018-06-22 | 南方电网科学研究院有限责任公司 | A kind of circuit for being used to monitor supply voltage |
Also Published As
| Publication number | Publication date |
|---|---|
| CN100516895C (en) | 2009-07-22 |
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Granted publication date: 20090722 Termination date: 20140106 |