CN202474845U - Short circuit protection circuit and LED power supply circuit used for active PFC circuit output terminal - Google Patents
Short circuit protection circuit and LED power supply circuit used for active PFC circuit output terminal Download PDFInfo
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- CN202474845U CN202474845U CN2011205749460U CN201120574946U CN202474845U CN 202474845 U CN202474845 U CN 202474845U CN 2011205749460 U CN2011205749460 U CN 2011205749460U CN 201120574946 U CN201120574946 U CN 201120574946U CN 202474845 U CN202474845 U CN 202474845U
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Abstract
The utility model provides a short circuit protection circuit and an LED power supply circuit used for an active PFC circuit output terminal. Owing to short circuit protection circuit, an active PFC circuit of the LED power supply circuit can be directly connected with the output terminal, and the anti-short circuit protection to the active PFC circuit can be realized, so the power supply circuit is simplified, and the cost is greatly reduced. The short circuit protection circuit includes a unidirectional silicon controlled rectifier Q, a photoelectric coupler U, a resistor R1, a resistor R2, a resistor R3, and a resistor R4. The photoelectric coupler U includes a light-sensitive element D2 and a light emitting diode D1. The two terminals of the resistor R1 are connected with the anode A and the control electrode G of the unidirectional silicon controlled rectifier Q respectively. One terminal of the resistor R2 is connected with the anode A of the unidirectional silicon controlled rectifier Q, and the other terminal is connected with the control electrode G of the unidirectional silicon controlled rectifier Q via the light-sensitive element D2 in the photoelectric coupler U. The two terminals of the resistor R3 are connected with the cathode K and the control electrode G of the unidirectional silicon controlled rectifier Q. The two terminals of the resistor R4 are connected with the cathode K of the unidirectional silicon controlled rectifier Q and the light emitting diode D1 in the photoelectric coupler U.
Description
Technical field
The utility model belongs to the electronic circuit technology field, refers in particular to the short-circuit protection circuit and the LED power circuit that are used for the active PFC circuit output.
Background technology
LED; A kind of solid state light emitter of novel concept; With its impayable energy-saving and environmental protection, long-life, controllability high-technology advantage; Become in recent years one of new and high technology of the tool development prospect in the whole world, formally draw back the prelude that comprehensively substitutes traditional lighting, it is historical that the semiconductor lighting technological innovation is changing the century-old tradition illumination.Along with the application of LED technology at lighting field, the LED product has started the green storm of energy-conserving and environment-protective in the whole world, is described as " green illumination " product by industry.
In the prior art, active PFC circuit is made up of inductance capacitance and electronic devices and components, and volume is little, can reach very high power factor, often adopts the IC of high integration in the active PFC circuit, adopts the PC power source of active PFC circuit, has following characteristics at least:
1) input voltage can be from 90V to 270V;
2) be higher than 0.99 line power factor, and have low-loss and advantage such as highly reliable;
3) PFC of IC also can be used as accessory power supply, therefore in using active PFC circuit, does not often need the standby transformer;
4) output does not change with input voltage fluctuation, therefore can obtain high stability output voltage;
5) active PFC output dc voltage ripple is very little, and is the sine wave of 100Hz/120Hz (2 times of power frequencies), therefore adopts the power supply of active PFC need not adopt very jumbo filter capacitor.
The LED power circuit that has active PFC circuit; Generally not directly to electric; Mainly be because when short circuit appears in load; It can't realize self is prevented short-circuit protection that the therefore existing general employing of the LED power circuit power circuit shown in Figure 1 that has active PFC circuit comprises the ac input end, current rectifying and wave filtering circuit, active PFC circuit, pwm circuit and the dc output end that connect successively.Be used to regulate and the balance voltage and current between phase difference, improve the active PFC circuit of the power factor of LED power circuit and prevent short-circuit protection, to prevent when short circuit appears in the load led light source, to the protection of active PFC circuit through pwm circuit.As shown in Figure 2, be the LED power supply pwm circuit schematic diagram of prior art, be not difficult to find out pwm circuit because the element of the pattern of wants is more, complex circuit and cost are higher.Secondly pwm circuit also needs the LED power circuit to provide electric energy to keep its normal work for it, has increased the power consumption of LED power circuit simultaneously again, has reduced the efficient of LED power circuit.
Therefore can remove pwm circuit, utilize the LED power supply of active PFC circuit directly to be the LED electric, realize power circuit simplify, with low cost and can also improve power-efficient and become the important topic that people need to be resolved hurrily.
Summary of the invention
The purpose of the utility model is to provide a kind of short-circuit protection circuit and LED power circuit that is used for the active PFC circuit output; Can realize that the active PFC circuit on the LED power circuit directly is connected with output; The more important thing is and to realize active PFC circuit is prevented short-circuit protection that power circuit obtains simplifying, practicing thrift cost.
The utility model is realized through following technical scheme:
Be used for the short-circuit protection circuit of active PFC circuit output, include: an one-way SCR Q, a photoelectric coupling circuit U and resistance R 1, resistance R 2, resistance R 3 and resistance R 4; Photoelectric coupling circuit U includes light-sensitive element D2 and light-emitting diode D1; The two ends of said resistance R 1 are connected with control utmost point G with the anode A of said one-way SCR Q respectively; One end of said resistance R 2 is connected with the anode A of said one-way SCR Q, and the other end is connected with the control utmost point G of said one-way SCR Q through the light-sensitive element in the said photoelectrical coupler; The two ends of said resistance R 3 are connected with control utmost point G with the negative electrode K of said one-way SCR Q respectively, and the two ends of said resistance R 4 are connected with light-emitting diode D1 in the said photoelectrical coupler U with the negative electrode K of said controllable silicon Q respectively; Light-emitting diode D1 one end in the said photoelectrical coupler U connects resistance R 4, and the other end connects said negative input and the cathode output end that is used for the short-circuit protection circuit of active PFC circuit output; The anode A of said one-way SCR Q connects the said electrode input end that is used for the short-circuit protection circuit of active PFC circuit output, and the negative electrode K of said one-way SCR Q connects the said cathode output end that is used for the short-circuit protection circuit of active PFC circuit output.
The LED power circuit; Comprise the ac input end 10, current rectifying and wave filtering circuit 11, active PFC circuit 12, short-circuit protection circuit 13 and the dc output end 14 that connect successively; Wherein, Said short-circuit protection circuit 13 adopts the above-mentioned short-circuit protection circuit that is used for the active PFC circuit output, the said electrode input end of the short-circuit protection circuit of active PFC circuit output, the output that negative input connects active PFC circuit 12 respectively of being used for.
The beneficial effect of the utility model is following:
The short-circuit protection circuit that is used for the active PFC circuit output of the utility model; Different and prior PWM circuit; Can realize that not only the active PFC circuit on the LED power circuit directly is connected with output, the more important thing is and can also realize active PFC circuit is prevented short-circuit protection.The LED power circuit of the utility model because the main a kind of anti-short circuit current that adopts one-way SCR and photoelectrical coupler to form is used for linking to each other with the active PFC circuit output, is realized the active PFC circuit on the LED power circuit is prevented short-circuit protection.Its circuit is formed simply, the formation original paper is few, with low cost; Power consumption is few and safe and reliable, and the LED power supply that is well-suited for various dissimilar active PFC circuit provides anti-short-circuit protection.
Description of drawings
Fig. 1 is the LED power circuit principle block diagram that has the active PFC circuit of pwm circuit in the prior art;
Fig. 2 is a LED power supply pwm circuit schematic diagram in the prior art;
Fig. 3 is the circuit theory diagrams of the short-circuit protection circuit that is used for the active PFC circuit output of the utility model;
Fig. 4 is the theory diagram of the utility model LED power circuit.
Description of reference numerals:
10, ac input end, 11, current rectifying and wave filtering circuit, 12, active PFC circuit, 13, short-circuit protection circuit, 14, dc output end.
Embodiment
Ask for an interview Fig. 3 to Fig. 4, the utility model discloses a kind of short-circuit protection circuit that is used for the active PFC circuit output, include: an one-way SCR Q, a photoelectric coupling circuit U and resistance R 1, resistance R 2, resistance R 3 and resistance R 4; Photoelectric coupling circuit U includes light-sensitive element D2 and light-emitting diode D1; The two ends of said resistance R 1 are connected with control utmost point G with the anode A of said one-way SCR Q respectively; One end of said resistance R 2 is connected with the anode A of said one-way SCR Q, and the other end is connected with the control utmost point G of said one-way SCR Q through the light-sensitive element D2 in the said photoelectrical coupler U; The two ends of said resistance R 3 are connected with control utmost point G with the negative electrode K of said one-way SCR Q respectively, and the two ends of said resistance R 4 are connected with light-emitting diode D1 in the said photoelectrical coupler U with the negative electrode K of said controllable silicon Q respectively; Light-emitting diode D1 one end in the said photoelectrical coupler U connects resistance R 4, and the other end connects said negative input and the cathode output end that is used for the short-circuit protection circuit of active PFC circuit output; The anode A of said one-way SCR Q connects the said electrode input end that is used for the short-circuit protection circuit of active PFC circuit output, and the negative electrode K of said one-way SCR Q connects the said cathode output end that is used for the short-circuit protection circuit of active PFC circuit output.
Further, also connect between the light-emitting diode D1 in said resistance R 4 and the said photoelectrical coupler U one be used for indicative function light-emitting diode D3.
Further; Light-emitting diode D1 in the said photoelectrical coupler U goes up the voltage stabilizing didoe D4 that also parallel connection one is used to prevent said light-emitting diode D1 voltage fluctuation; Said voltage stabilizing didoe D4 one end links to each other with the input of said light-emitting diode D3, and an end is connected with cathode output end with the said negative input that is used for the short-circuit protection circuit of active PFC circuit output.
The resistance size order of said resistance R 1, resistance R 2, resistance R 3 is: resistance R 1＞resistance R 2 and resistance R 1＞resistance R 3.
The LED power circuit; Comprise the ac input end 10, current rectifying and wave filtering circuit 11, active PFC circuit 12, short-circuit protection circuit 13 and the dc output end 14 that connect successively; Wherein, Said short-circuit protection circuit 13 adopts the above-mentioned short-circuit protection circuit that is used for the active PFC circuit output, the said electrode input end of the short-circuit protection circuit of active PFC circuit output, the output that negative input connects active PFC circuit 12 respectively of being used for.
Embodiment:
As shown in Figure 4; Schematic block circuit diagram when a kind of short-circuit protection circuit that is used for the active PFC circuit output of the utility model uses on the LED of active PFC circuit power circuit comprises the ac input end 10, current rectifying and wave filtering circuit 11, active PFC circuit 12, short-circuit protection circuit 13 and the dc output end 14 that connect successively.Said short-circuit protection circuit 13 is used for linking to each other with active PFC circuit 12 outputs, is used for when short circuit appears in the load of said dc output end 14, and said active PFC circuit 12 is played a protective role.As shown in Figure 3, said short-circuit protection circuit 13 comprises an one-way SCR Q, a photoelectrical coupler U and resistance R 1, resistance R 2, resistance R 3 and resistance R 4 compositions.The two ends of said resistance R 1 are connected with control utmost point G with the anode A of said one-way SCR Q respectively; One end of said resistance R 2 is connected with the anode A of said one-way SCR Q, and the other end is connected with the control utmost point G of said one-way SCR Q through the light sensor D2 on the said photoelectrical coupler U; The two ends of said resistance R 3 are connected with control utmost point G with the negative electrode K of said one-way SCR Q respectively, and the two ends of said resistance R 4 are connected with light-emitting diode D1 in the said photoelectrical coupler U with said negative electrode K respectively.
The resistance size order of said resistance R 1, resistance R 2, resistance R 3 is resistance R 1＞resistance R 2 and resistance R 1＞resistance R 3; When the direct voltage from said active PFC circuit puts on the anode A of said one-way SCR Q; Because the interior light-sensitive element D2 of photoelectrical coupler U this moment also is not excited; Belong to off state,, form and set up initial conducting electric current through resistance R 3 so above-mentioned direct voltage can only be applied on the series circuit that said resistance R 1, resistance R 3 and light-emitting diode D3 formed; Because said resistance R 1 is greater than resistance R 3; So make and set up forward voltage between said control utmost point G and the negative electrode K, because the ratio that preestablishes between said resistance R 1 and the resistance R 3 is bigger, the forward voltage between said control utmost point G and the negative electrode K is not enough to excite said one-way SCR Q conducting.And after initial electric current is through R4 and the said light-emitting diode D1 of conducting; Said light-sensitive element D2 in the said photoelectrical coupler U will be excited and connect; Thereby so that 2 conductings of said resistance R because the resistance of said resistance R 1 is greater than the resistance of resistance R 2, and the resistance of resistance R 3 is near resistance R 2; Event makes the forward voltage between said control utmost point G and the said negative electrode K raise and reaches the magnitude of voltage that makes said anode A and negative electrode K conducting; Be said one-way SCR Q conducting, and give described dc output end 14, use to supply with the led light source load with voltage transmission.
When the DC load short circuit of its output; Because said light-emitting diode D1 two ends can't be switched on by short circuit; Said light-sensitive element D2 will quit work; Be that photoelectrical coupler quits work; Cause the loop at said resistance R 2 and resistance R 3 places can't conducting, make and keep the said control utmost point G of said one-way SCR Q conducting that said one-way SCR Q entering is by state with the forward voltage between the said negative electrode K can't arrive predetermined value; Will be applied between said resistance R 1, resistance R 3 and the negative pole V from the voltage of said active PFC circuit and to keep above-mentioned initial current, prevent that effectively said active PFC circuit from short circuit occurring and cause the damage of the LED power circuit of the utility model.
Said short circuit current 13 is also connected between the light-emitting diode D1 in said resistance R 4 and the said photoelectrical coupler U and one has been used for the light-emitting diode D3 of indicative function, so that show whether the LED power circuit of the utility model is in running order.
Because load voltage exists inevitably unusual; Cause and occur fluctuation on the light-emitting diode D1 in the said photoelectrical coupler U thereupon; Thereby make the voltage of said one-way SCR Q output occur unusual; The voltage that finally has influence on supply load fluctuation occurs and causes the load cisco unity malfunction; The utility model is gone back the said voltage stabilizing didoe D4 that parallel connection one is used to prevent said light-emitting diode D1 voltage fluctuation on the light-emitting diode D1 of said short circuit current 13 in said photoelectrical coupler U for this reason, and said voltage stabilizing didoe D4 one end links to each other with the input of said light-emitting diode D3, and an end is connected with negative pole V.
The utility model case study on implementation to the utility model details and explains; Though it has certain particularity on form and structure; But these are special only to be in order to describe and to explain the utility model, can't having influence on any restriction to the utility model.Above-mentioned listed concrete implementation is nonrestrictive, and to one skilled in the art, in the scope that does not depart from the utility model, various improvement and the variation carried out all belong to the protection range of the utility model.
Claims (7)
1. be used for the short-circuit protection circuit of active PFC circuit output, it is characterized in that: include: an one-way SCR Q, a photoelectric coupling circuit U and resistance R 1, resistance R 2, resistance R 3 and resistance R 4; Photoelectric coupling circuit U includes light-sensitive element D2 and light-emitting diode D1; The two ends of said resistance R 1 are connected with control utmost point G with the anode A of said one-way SCR Q respectively; One end of said resistance R 2 is connected with the anode A of said one-way SCR Q, and the other end is connected with the control utmost point G of said one-way SCR Q through the light-sensitive element D2 in the said photoelectrical coupler U; The two ends of said resistance R 3 are connected with control utmost point G with the negative electrode K of said one-way SCR Q respectively, and the two ends of said resistance R 4 are connected with light-emitting diode D1 in the said photoelectrical coupler U with the negative electrode K of said controllable silicon Q respectively; Light-emitting diode D1 one end in the said photoelectrical coupler U connects resistance R 4, and the other end connects said negative input and the cathode output end that is used for the short-circuit protection circuit of active PFC circuit output; The anode A of said one-way SCR Q connects the said electrode input end that is used for the short-circuit protection circuit of active PFC circuit output, and the negative electrode K of said one-way SCR Q connects the said cathode output end that is used for the short-circuit protection circuit of active PFC circuit output.
2. the short-circuit protection circuit that is used for the active PFC circuit output as claimed in claim 1 is characterized in that: also connect between the light-emitting diode D1 in said resistance R 4 and the said photoelectrical coupler U one be used for indicative function light-emitting diode D3.
3. the short-circuit protection circuit that is used for the active PFC circuit output as claimed in claim 2; It is characterized in that: the light-emitting diode D1 in the said photoelectrical coupler U goes up the voltage stabilizing didoe D4 that also parallel connection one is used to prevent said light-emitting diode D1 voltage fluctuation; Said voltage stabilizing didoe D4 one end links to each other with the input of said light-emitting diode D3, and an end is connected with cathode output end with the said negative input that is used for the short-circuit protection circuit of active PFC circuit output.
4. the short-circuit protection circuit that is used for the active PFC circuit output as claimed in claim 1 is characterized in that: the resistance size order of said resistance R 1, resistance R 2, resistance R 3 is: resistance R 1＞resistance R 2 and resistance R 1＞resistance R 3.
5. the short-circuit protection circuit that is used for the active PFC circuit output as claimed in claim 2 is characterized in that: the resistance size order of said resistance R 1, resistance R 2, resistance R 3 is: resistance R 1＞resistance R 2 and resistance R 1＞resistance R 3.
6. the short-circuit protection circuit that is used for the active PFC circuit output as claimed in claim 3 is characterized in that: the resistance size order of said resistance R 1, resistance R 2, resistance R 3 is: resistance R 1＞resistance R 2 and resistance R 1＞resistance R 3.
7.LED power circuit; Comprise the ac input end (10), current rectifying and wave filtering circuit (11), active PFC circuit (12), short-circuit protection circuit (13) and the dc output end (14) that connect successively; It is characterized in that: said short-circuit protection circuit (13) adopts like any one described short-circuit protection circuit that is used for the active PFC circuit output in the claim 1 to 6, the said electrode input end of the short-circuit protection circuit of active PFC circuit output, the output that negative input connects active PFC circuit (12) respectively of being used for.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011205749460U CN202474845U (en) | 2011-12-31 | 2011-12-31 | Short circuit protection circuit and LED power supply circuit used for active PFC circuit output terminal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011205749460U CN202474845U (en) | 2011-12-31 | 2011-12-31 | Short circuit protection circuit and LED power supply circuit used for active PFC circuit output terminal |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202474845U true CN202474845U (en) | 2012-10-03 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011205749460U Expired - Fee Related CN202474845U (en) | 2011-12-31 | 2011-12-31 | Short circuit protection circuit and LED power supply circuit used for active PFC circuit output terminal |
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| Country | Link |
|---|---|
| CN (1) | CN202474845U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103187720A (en) * | 2011-12-31 | 2013-07-03 | 广东德豪润达电气股份有限公司 | Short-circuit protective circuit and light-emitting diode (LED) power source circuit used for output end of active power factor correction (PFC) circuit |
| CN106487059A (en) * | 2016-10-27 | 2017-03-08 | 江苏科技大学 | A kind of power protection system |
-
2011
- 2011-12-31 CN CN2011205749460U patent/CN202474845U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103187720A (en) * | 2011-12-31 | 2013-07-03 | 广东德豪润达电气股份有限公司 | Short-circuit protective circuit and light-emitting diode (LED) power source circuit used for output end of active power factor correction (PFC) circuit |
| CN106487059A (en) * | 2016-10-27 | 2017-03-08 | 江苏科技大学 | A kind of power protection system |
| CN106487059B (en) * | 2016-10-27 | 2018-08-07 | 江苏科技大学 | A kind of power protection system |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20171103 Address after: Zhuhai City, Guangdong province high tech Zone 519000 1 science and Technology Innovation Coast Road No. 1 in a period of 2 -2 plant Patentee after: Yi Xun (Zhuhai) Photoelectric Technology Co., Ltd. Address before: 519000 Guangdong city of Zhuhai province tangjiewan Jinfeng Road No. 1 Patentee before: Guangdong Electech International Inc. |
|
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20121003 Termination date: 20181231 |