CN102735909A - Voltage detection circuit of light-emitting diode (LED) string light and detection method thereof - Google Patents
Voltage detection circuit of light-emitting diode (LED) string light and detection method thereof Download PDFInfo
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- CN102735909A CN102735909A CN2011100825000A CN201110082500A CN102735909A CN 102735909 A CN102735909 A CN 102735909A CN 2011100825000 A CN2011100825000 A CN 2011100825000A CN 201110082500 A CN201110082500 A CN 201110082500A CN 102735909 A CN102735909 A CN 102735909A
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- voltage
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- light string
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Abstract
A voltage detection circuit of a light-emitting diode (LED) string light and a detection method thereof are used to detect a voltage applied to the LED string light. The voltage detection circuit comprises a transformer, a first rectifier, a second rectifier and a voltage detection unit. The transformer comprises a first winding, a second winding and a third winding. The second winding converts an alternating current voltage received by the first winding, and through the first rectifier, a direct current driving voltage which drives the LED string light is acquired. The third winding converts the alternating current voltage received by the first winding, and then through the second rectifier, a detection voltage is acquired. The voltage detection unit is electrically connected with the second rectifier. Through measuring the detection voltage and according to a turn ratio relation of the second winding and the third winding, the direct current driving voltage which drives the LED string light can be obtained.
Description
Technical field
The present invention relates to a kind of voltage detecting circuit and detection method thereof, relate in particular to a kind of voltage detecting circuit and detection method thereof of LED light string.
Background technology
Because advancing by leaps and bounds of semiconductor light emitting technology, (light-emitting diode LED) is used in the TV backlight module and also day by day popularizes light emitting diode.But owing to be used in suitable many of the LED lamp string number of TV backlight, therefore, LED lamp string driver circuit need be able to abnormally high-voltage or the low-voltage of guaranteeing that LED lamp string is produced when being short-circuited or opening a way through detecting the voltage condition of LED lamp string respectively usually.So when LED lamp string quantity was many, detection line also relatively increased, therefore, how to accomplish simple and the high detection line of reliability becomes more important.
See also the divider resistance circuit framework of Fig. 1 for existing LED light string voltage detecting.As shown in the figure, it mainly is to utilize the divider resistance circuit framework that this LED lamp string of existing prior art is pressed detection line, that is; Utilize one first resistance R 1 and one second resistance R, the 2 formed dividing potential drop frameworks of connecting; With a driving voltage Vled dividing potential drop of high-tension LED lamp string and obtain a low-potential voltage, and, again with the cross-pressure Vr on this second resistance R 2 of the resultant low voltage current potential of dividing potential drop; Deliver to an extra controller 10A, to judge the voltage condition of LED lamp string.So, except this first resistance R 1 and this second resistance R 2 of this divider resistance circuit will cause the power consumption loss, also improve the cost of setting up this controller 10A.
Prior art
R1 first resistance
R2 second resistance
The Vled driving voltage
Vr resistance cross-pressure
The 10A controller
The present invention
10 transformers
102 first windings
104 second windings
106 tertiary windings
20 first rectifiers
30 second rectifiers
40 LED light strings
50 voltage detection units
Vp first alternating voltage
Vs second alternating voltage
Va the 3rd alternating voltage
Np first umber of turn
Ns second umber of turn
The Na tertiary winding number of turn
The Vdri driving voltage
Vsen detects voltage
The Vnd normal drive voltage
Vns normally detects voltage
The T1 very first time is interval
T2 second time interval
T3 the 3rd time interval
S100～S700 step
Summary of the invention
Technical matters to be solved by this invention is; A kind of voltage detecting circuit and detection method thereof of LED light string are provided; Utilize turn ratio relation between the winding of many winding types transformer simply; Judge whether this driving DC voltage that drives this LED light string takes place unusually, and then the protection of this LED light string is provided.
In order to reach above-mentioned purpose, the present invention provides a kind of voltage detecting circuit of LED light string, and the voltage of driven for emitting lights diode lamp luster is detected.Voltage detecting circuit comprises transformer, first rectifier, second rectifier and voltage detection unit.
Transformer comprises first winding, second winding and the tertiary winding.First winding receives first alternating voltage.Second winding is according to the turn ratio relation of first winding and second winding, and changing first alternating voltage is second alternating voltage.Tertiary winding system is according to the turn ratio relation of first winding and the tertiary winding, and changing first alternating voltage is the 3rd alternating voltage.
First rectifier is electrically connected at second winding and LED light string, is driving DC voltage with rectification second alternating voltage, and utilizes driving DC voltage driven for emitting lights diode lamp luster.Second rectifier is electrically connected at the tertiary winding, serves as to detect voltage with rectification the 3rd alternating voltage.
Voltage detection unit electrically connects second rectifier, and the turn ratio relation according to second winding and the tertiary winding detects voltage swing through direct measurement, to detect the driving DC voltage size of driven for emitting lights diode lamp luster.
In order to reach above-mentioned purpose, the present invention also provides a kind of voltage detection method of LED light string, and the voltage of driven for emitting lights diode lamp luster is detected.The step of voltage detection method comprises: at first, transformer is provided, comprises first winding, second winding and the tertiary winding that are coupled to each other.Then, utilize first winding to receive first alternating voltage.Then, utilizing second winding to change first alternating voltage is second alternating voltage; And utilizing the tertiary winding to change first alternating voltage is the 3rd alternating voltage.Then, rectification second alternating voltage is a driving DC voltage, with the driven for emitting lights diode lamp luster; And rectification the 3rd alternating voltage is for detecting voltage.At last, measure the size that detects voltage, to learn the driving DC voltage size of driven for emitting lights diode lamp luster.
Describe the present invention below in conjunction with accompanying drawing and specific embodiment, but not as to qualification of the present invention.
Description of drawings
Fig. 1 is the divider resistance circuit framework of existing LED light string voltage detecting;
Fig. 2 is the circuit block diagram of the voltage detecting circuit of LED light string of the present invention;
Fig. 3 is the exemplary waveforms figure of this driving voltage of the present invention and this detection voltage; And
Fig. 4 is the process flow diagram of the voltage detection method of LED light string of the present invention.
Wherein, Reference numeral
Embodiment
Below in conjunction with accompanying drawing structural principle of the present invention and principle of work are done concrete description:
See also the circuit block diagram of Fig. 2 for the voltage detecting circuit of LED light string of the present invention.The voltage detecting circuit of this LED light string is that the voltage that drives a LED light string 40 is detected.This voltage detecting circuit comprises a transformer 10, one first rectifier 20, one second rectifier 30 and a voltage detection unit 50.
This transformer 10 comprises one first winding 102, one second winding 104 and a tertiary winding 106.This first winding 102 is to receive one first alternating voltage Vp.This second winding 104 is according to turn ratio (turn ratio) relation of this first winding 102 with this second winding 104, and changing this first alternating voltage Vp that this first winding 102 received is one second alternating voltage Vs.This tertiary winding 106 is according to the turn ratio relation of this first winding 102 with this tertiary winding 106, and changing this first alternating voltage Vp that this first winding 102 received is one the 3rd alternating voltage Va.Wherein, this transformer 10 can be a three-winding transformer (three-winding transformer).
If this first winding 102 of this transformer 10 has one first umber of turn Np, this second winding 104 has one second umber of turn Ns and this tertiary winding 106 has a tertiary winding number of turn Na.Therefore; When received this first alternating voltage Vp of this first winding of this transformer 10 102; Then this second winding 104 utilizes the turn ratio relation of this first winding 102 and this second winding 104 (also be Np: Ns), therefore, convertible to obtain this first alternating voltage Vp is this second alternating voltage Vs; Wherein, Vs=Vp * Ns/Np.In like manner; When received this first alternating voltage Vp of this first winding of this transformer 10 102; Then this tertiary winding 106 utilizes the turn ratio relation of this first winding 102 and this tertiary winding 106 (also be Np: Na), therefore, convertible to obtain this first alternating voltage Vp is the 3rd alternating voltage Va; Wherein, Va=Vp * Na/Np.
Simultaneously; Because this second winding 104 is Ns: Na with the turn ratio relation of this tertiary winding 106; Therefore; This second alternating voltage Vs then is Vs: Va=Ns: Na with the ratio of the 3rd alternating voltage Va, that is the ratio of this second alternating voltage Vs and the 3rd alternating voltage Va is the turn ratio of this second winding 104 and this tertiary winding 106.
This first rectifier 20 electrically connects this second winding 104 and this LED light string 40 of this transformer 10, and Vs is a direct current driving voltage Vdri with this second alternating voltage of rectification, and utilizes this driving DC voltage Vdri to drive this LED light string 40.This second rectifier 30 electrically connects this tertiary winding 106 of this transformer 10, is a detection voltage Vsen with rectification the 3rd alternating voltage Va.Wherein, this first rectifier 20 can be a full wave rectifier (full-wave rectifier) or a half-wave rectifier (half-wave rectifier).Likewise, this second rectifier 30 can be a full wave rectifier (full-waverectifier) or a half-wave rectifier (half-wave rectifier).Be worth mentioning, if this first rectifier 20 is the use of full wave rectifier, then this second rectifier 30 uses full wave rectifier similarly; Otherwise if this first rectifier 20 is the use of half-wave rectifier, then this second rectifier 30 uses half-wave rectifier similarly.
In addition, this first rectifier 20 can further electrically connect one first wave filter (not shown), with the harmonic wave composition of this driving DC voltage Vdri of this first rectifier of filtering 20 outputs.Likewise, this second rectifier 30 can further electrically connect one second wave filter (not shown), detects the harmonic wave composition of voltage Vsen with this of this second rectifier of filtering 30 outputs.
This voltage detection unit 50 electrically connects this second rectifier 30, through measuring this detection voltage Vsen to judge whether this driving DC voltage Vdri takes place unusually.That is; Utilize and exist a proportionate relationship (being the turn ratio of this second winding 104 and this tertiary winding 106) between this second alternating voltage Vs and the 3rd alternating voltage Va; So; Can directly measure the size that this detects voltage Vsen, promptly can directly obtain driving this driving DC voltage Vdri size of this LED light string 40 through this voltage detection unit 50.Suppose this second umber of turn Ns of this tertiary winding number of turn Na of this tertiary winding 106 less than this second winding 104; Then under this circuit framework; Then can be directly through detecting this detection voltage Vsen size of small voltage current potential, to obtain this driving DC voltage Vdri size of higher voltage potential.So, the voltage detecting circuit of this LED light string can provide convenience and the high reliability to this driving DC voltage Vdri detection of this LED light string 40.
So; Utilize this voltage detection unit 50 to measure the size of this detection voltage Vsen; This driving DC voltage Vdri judge to drive this LED light string 40 whether take place unusually (that is; And then the protection of this LED light string 40 is provided when this LED light string 40 is short-circuited or opens a way, unusual this driving DC voltage Vdri that is produced).
See also the waveform synoptic diagram of Fig. 3 for this driving voltage of the present invention and this detection voltage.When supposing that this LED light string 40 is operated for driven; This driving DC voltage Vdri size is a normal drive voltage Vnd, therefore, and under this driven operation; The size of this voltage detection unit 50 measured this detection voltage Vsen then is a normal voltage Vns that detects; And the relation of this normal voltage Vns of detection and this normal drive voltage Vnd of detecting then is the turn ratio relation of this second winding 104 with this tertiary winding 106, that is Vns=Vnd * Na/Ns.So when this LED light string 40 operates in interval T1 of a very first time (also being the driven operation); Then can be directly through detecting this detection voltage Vsen size of small voltage current potential, to obtain this driving DC voltage Vdri size of higher voltage potential.
Yet; If this LED light string 40 is when driving for abnormal voltage, that is, as shown in the figure when operating in one second time interval T2 or one the 3rd time interval T3; Wherein, When the second time interval T2 operates, represent that this LED light string 40 operates in unusual short-circuit condition, make this voltage detection unit 50 measured this detection voltage Vsen less than this normal voltage Vns that detects; In addition, when the 3rd time interval T3 operates, represent that this LED light string 40 operates in unusual open-circuit condition, make this voltage detection unit 50 measured this detection voltage Vsen greater than this normal voltage Vns that detects.
Therefore; Can be directly big or small through this detection voltage Vsen that detects the small voltage current potential, with this driving DC voltage Vdri size of acquisition higher voltage potential, and; Judge whether this driving DC voltage Vdri takes place unusually, and then the protection of this LED light string is provided.
See also the process flow diagram of Fig. 4 for the voltage detection method of LED light string of the present invention.The voltage detection method of this LED light string is that the voltage that drives a LED light string is detected.The step of this voltage detection method comprises: at first, a transformer (S100) is provided, this transformer comprises one first winding, one second winding and a tertiary winding that is coupled to each other.Wherein, this transformer can be a three-winding transformer (three-winding transformer).Then, utilize this first winding to receive one first alternating voltage (S200).Then, utilizing this this first alternating voltage of second winding conversion is one second alternating voltage (S300), and utilizing this this first alternating voltage of tertiary winding conversion is one the 3rd alternating voltage (S400).Then; Utilizing a full wave rectifier or this second alternating voltage of a half-wave rectifier rectification is a direct current driving voltage; Driving this LED light string (S500), and utilizing a full wave rectifier or a half-wave rectifier rectification the 3rd alternating voltage is one to detect voltage (S600).In addition, in this step (S500) afterwards, also comprise the harmonic wave composition that utilizes this driving DC voltage of wave filter filtering.In this step (S600) afterwards, also comprise the harmonic wave composition that utilizes this detection voltage of wave filter filtering.At last; Utilize a voltage detection unit to measure the size of this detection voltage; To learn this driving DC voltage size (S700) that drives this LED light string, judge whether this driving DC voltage takes place unusually, and then the protection of this LED light string is provided.
In sum, the present invention has following advantage:
1, need not use existing divider resistance circuit framework, utilize and high-tension light emitting diode driving voltage dividing potential drop to be delivered to extra controller after for low-voltage again judge;
2, utilize turn ratio relation between the winding of many winding types transformer simply; Can be directly through detecting this detection voltage Vsen size of small voltage current potential; Obtain this driving DC voltage Vdri size of higher voltage potential, make the voltage detecting circuit of this LED light string that convenience and high reliability to this driving DC voltage Vdri detection of this LED light string 40 can be provided; And
3, utilize to judge whether this driving DC voltage Vdri that drives this LED light string 40 takes place unusually, and then the protection of this LED light string 40 is provided.
Certainly; The present invention also can have other various embodiments; Under the situation that does not deviate from spirit of the present invention and essence thereof; Those of ordinary skill in the art work as can make various corresponding changes and distortion according to the present invention, but these corresponding changes and distortion all should belong to the protection domain of the appended claim of the present invention.
Claims (13)
1. the voltage detecting circuit of a LED light string detects the voltage that drives a LED light string; It is characterized in that this voltage detecting circuit comprises:
One transformer comprises: one first winding, one second winding and a tertiary winding, and this first winding receives one first alternating voltage; This second winding is according to the turn ratio relation of this first winding and this second winding, and changing this first alternating voltage is one second alternating voltage; This tertiary winding is according to the turn ratio relation of this first winding and this tertiary winding, and changing this this first alternating voltage is one the 3rd alternating voltage;
One first rectifier is electrically connected between this second winding and this LED light string, is a direct current driving voltage with this second alternating voltage of rectification, and utilizes this driving DC voltage to drive this LED light string;
One second rectifier is electrically connected at this tertiary winding, is a detection voltage with rectification the 3rd alternating voltage; And
One voltage detection unit electrically connects this second rectifier, and the turn ratio relation according to this second winding and this tertiary winding should detect voltage swing through direct measurement, to learn this driving DC voltage size that drives this LED light string.
2. the voltage detecting circuit of LED light string according to claim 1 is characterized in that, this transformer is a three-winding transformer.
3. the voltage detecting circuit of LED light string according to claim 1 is characterized in that, this first rectifier is a full wave rectifier or a half-wave rectifier.
4. the voltage detecting circuit of LED light string according to claim 1 is characterized in that, this second rectifier is a full wave rectifier or a half-wave rectifier.
5. the voltage detecting circuit of LED light string according to claim 1 is characterized in that, this first rectifier further electrically connects one first wave filter, with the harmonic wave composition of this driving DC voltage of this first rectifier output of filtering.
6. the voltage detecting circuit of LED light string according to claim 1 is characterized in that, this second rectifier further electrically connects one second wave filter, detects the harmonic wave composition of voltage with this of this second rectifier output of filtering.
7. the voltage detection method of a LED light string detects the voltage that drives a LED light string; It is characterized in that the step of this voltage detection method comprises:
(a) transformer is provided, comprises one first winding, one second winding and the tertiary winding that are coupled to each other;
(b) utilize this first winding to receive one first alternating voltage;
(c) utilizing this this first alternating voltage of second winding conversion is one second alternating voltage;
(d) utilizing this this first alternating voltage of tertiary winding conversion is one the 3rd alternating voltage;
(e) this second alternating voltage of rectification is a direct current driving voltage, to drive this LED light string;
(f) rectification the 3rd alternating voltage is a detection voltage; And
(g) measure the size of this detection voltage, to learn this driving DC voltage size that drives this LED light string.
8. the voltage detection method of LED light string according to claim 7 is characterized in that, in this step (e) afterwards, also comprises the harmonic wave composition that utilizes this driving DC voltage of wave filter filtering.
9. the voltage detection method of LED light string according to claim 7 is characterized in that, in this step (f) afterwards, also comprises the harmonic wave composition that utilizes this detection voltage of wave filter filtering.
10. the voltage detection method of LED light string according to claim 7 is characterized in that, this transformer is a three-winding transformer.
11. the voltage detection method of LED light string according to claim 7 is characterized in that, in this step (e), is to utilize a full wave rectifier or a half-wave rectifier to this second ac voltage rectifier.
12. the voltage detection method of LED light string according to claim 7 is characterized in that, in this step (f), is to utilize a full wave rectifier or a half-wave rectifier to the 3rd ac voltage rectifier.
13. the voltage detection method of LED light string according to claim 7 is characterized in that, in this step (g), is to utilize a voltage detection unit to measure this detection voltage, to learn this driving DC voltage size that drives this LED light string.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011100825000A CN102735909A (en) | 2011-04-01 | 2011-04-01 | Voltage detection circuit of light-emitting diode (LED) string light and detection method thereof |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011100825000A CN102735909A (en) | 2011-04-01 | 2011-04-01 | Voltage detection circuit of light-emitting diode (LED) string light and detection method thereof |
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| CN102735909A true CN102735909A (en) | 2012-10-17 |
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| CN2011100825000A Pending CN102735909A (en) | 2011-04-01 | 2011-04-01 | Voltage detection circuit of light-emitting diode (LED) string light and detection method thereof |
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5369355A (en) * | 1992-11-12 | 1994-11-29 | B/E Aerospace | Compensation circuit for transformer linearization |
| JPH07325114A (en) * | 1994-05-31 | 1995-12-12 | Okuma Mach Works Ltd | Voltage detection circuit |
| CN2227343Y (en) * | 1995-10-06 | 1996-05-15 | 杨大成 | Voltage measuring device for main frequency experimental |
| US5754421A (en) * | 1994-05-10 | 1998-05-19 | Load Controls, Incorporated | Power monitoring |
| CN2372691Y (en) * | 1999-05-28 | 2000-04-05 | 刘志生 | A. C. tester |
| CN201004076Y (en) * | 2006-08-10 | 2008-01-09 | 深圳市拓邦电子科技股份有限公司 | Power grid voltage detection circuit |
| CN101699922A (en) * | 2009-10-14 | 2010-04-28 | 友达光电股份有限公司 | Light emitting diode lamp driving circuit |
| CN201464607U (en) * | 2009-09-10 | 2010-05-12 | 保定天威集团有限公司 | Detection circuit for partial discharge of capacitor |
| CN201562001U (en) * | 2009-09-18 | 2010-08-25 | 哈尔滨九洲电气股份有限公司 | Direct current bus voltage sampler of intermediate-voltage transducer |
-
2011
- 2011-04-01 CN CN2011100825000A patent/CN102735909A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5369355A (en) * | 1992-11-12 | 1994-11-29 | B/E Aerospace | Compensation circuit for transformer linearization |
| US5754421A (en) * | 1994-05-10 | 1998-05-19 | Load Controls, Incorporated | Power monitoring |
| JPH07325114A (en) * | 1994-05-31 | 1995-12-12 | Okuma Mach Works Ltd | Voltage detection circuit |
| CN2227343Y (en) * | 1995-10-06 | 1996-05-15 | 杨大成 | Voltage measuring device for main frequency experimental |
| CN2372691Y (en) * | 1999-05-28 | 2000-04-05 | 刘志生 | A. C. tester |
| CN201004076Y (en) * | 2006-08-10 | 2008-01-09 | 深圳市拓邦电子科技股份有限公司 | Power grid voltage detection circuit |
| CN201464607U (en) * | 2009-09-10 | 2010-05-12 | 保定天威集团有限公司 | Detection circuit for partial discharge of capacitor |
| CN201562001U (en) * | 2009-09-18 | 2010-08-25 | 哈尔滨九洲电气股份有限公司 | Direct current bus voltage sampler of intermediate-voltage transducer |
| CN101699922A (en) * | 2009-10-14 | 2010-04-28 | 友达光电股份有限公司 | Light emitting diode lamp driving circuit |
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Application publication date: 20121017 |