CN114205965A - Circuit for preventing LED from flickering during starting - Google Patents
Circuit for preventing LED from flickering during starting Download PDFInfo
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- CN114205965A CN114205965A CN202111404608.7A CN202111404608A CN114205965A CN 114205965 A CN114205965 A CN 114205965A CN 202111404608 A CN202111404608 A CN 202111404608A CN 114205965 A CN114205965 A CN 114205965A
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- resistor
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/50—Circuit arrangements for operating light-emitting diodes [LED] responsive to malfunctions or undesirable behaviour of LEDs; responsive to LED life; Protective circuits
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/30—Driver circuits
- H05B45/37—Converter circuits
Abstract
The invention discloses a circuit for preventing LED from flickering when being started, which comprises an anti-flickering circuit, wherein the anti-flickering circuit comprises a third resistor, a fourth resistor and a third capacitor; the dimming circuit is connected with a DIM pin of the direct current converter; and the anode of the LED lamp is connected with one end of the first capacitor, and the other end of the LED lamp is connected with the SW pin of the direct current converter. Increase third electric capacity and fourth resistance through the EN pin at direct current converter to set up the resistance value of third resistance and fourth resistance rationally, can guarantee that the voltage of VO does not start up before rising certain voltage for prevent the problem of LED lamp scintillation, and this scheme design is simple and practical, low cost.
Description
Technical Field
The invention relates to the field of power circuits, in particular to a circuit for preventing an LED from flickering when being started.
Background
The reference CN201620331750.1 discloses a power circuit for an LED light modulation panel, which includes a power chip UP, a voltage input pin IN of the power chip UP is connected to a first common point, an enable pin EN of the power chip UP is connected to the first common point through a first resistor R1, and the first common point is connected to a working power supply; the feedback pin FB of the power supply chip is grounded through a fifth resistor R5; a switch power supply output pin SW of the power supply chip UP is connected with a first end of an inductor L1, and a second end of an inductor L1 is respectively connected with an output end of a power supply circuit and one end of a second resistor R2; a boosting pin BS of the power chip UP is connected between the SW and the first end of the inductor L1 through a seventh capacitor C7; the other end of the R2 is connected between the FB and the R5 through a third resistor R3 and a fourth resistor R4 which are connected in parallel; three grounded capacitors are arranged between the second end of the inductor L1 and the output end of the power circuit.
However, in LED lamp applications, an application of AC/DC constant voltage driving plus post-stage DC-DC band dimming is often adopted. In this application, since the AC/DC has a certain starting time, and the subsequent DC-DC step-down constant current has a fast starting speed, especially when the difference between VO and VLED is large, the AC/DC is difficult to start, sometimes the AC/DC needs to be started several times to succeed, or the AC/DC cannot be started, which may cause the LED flashing phenomenon.
Disclosure of Invention
The present invention is directed to solving at least one of the problems of the prior art, and to this end, the present invention provides a circuit for preventing flicker when an LED is turned on, which can be effectively solved by improving a DC-DC circuit.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:
according to an embodiment of the first aspect of the invention, a circuit for preventing LED from flickering when being started comprises: the first capacitor is connected with the AC/DC chip; a voltage conversion circuit connecting the first capacitor and the AC/DC chip, the voltage conversion circuit including a DC converter; the anti-flicker circuit is connected with the direct current converter and comprises a third resistor, a fourth resistor and a third capacitor, an EN pin of the direct current converter is connected with one end of the third resistor through one end of the third capacitor and one end of the fourth resistor, the other end of the third resistor is connected with one end of the first capacitor, and the other ends of the third capacitor and the fourth resistor are grounded; the dimming circuit is connected with a DIM pin of the direct current converter; and the anode of the LED lamp is connected with one end of the first capacitor, and the other end of the LED lamp is connected with the SW pin of the direct current converter.
The circuit for preventing the LED from flickering when being started according to the embodiment of the invention at least has the following beneficial effects: through the EN pin at DC converter increase resistance R3 and resistance R4 to set up resistance R3 and resistance R4's resistance value rationally, can guarantee that the voltage of VO does not start before rising certain voltage, with the problem that is used for preventing LED lamp scintillation, and this scheme design simple and practical, low cost.
According to some embodiments of the present invention, the dimming circuit includes a fifth resistor, a sixth resistor, a voltage follower, and a first diode, wherein a non-inverting input terminal of the voltage follower is connected to one end of the first capacitor through the fifth resistor, an inverting input terminal and an output terminal of the voltage follower are connected to each other and to a cathode of the first diode, a positive electrode of the first diode is connected to a DIM pin of the dc converter and one end of the sixth resistor, and another end of the sixth resistor is connected to a power source VCC.
According to some embodiments of the invention, the dimming circuit further comprises a resistor-capacitor circuit, the resistor-capacitor circuit comprises a seventh resistor and a fourth capacitor, one end of the seventh resistor and one end of the fourth capacitor are connected with each other and the non-inverting input end of the voltage follower, and the other end of the seventh resistor and the other end of the fourth capacitor are both grounded.
According to some embodiments of the present invention, the dimming circuit further comprises an eighth resistor, one end of the eighth resistor is connected to the DIM pin of the dc converter, and the other end of the eighth resistor is grounded.
According to some embodiments of the invention, the dimming circuit further comprises a second diode, a cathode of the second diode is connected to the dimming signal input, and an anode of the second diode is connected to the DIM pin of the dc converter.
According to some embodiments of the invention, the LED lamp further comprises an inductor for filtering and a third diode for freewheeling, wherein one end of the inductor is connected to the SW pin of the dc converter IC and the anode of the third diode, the other end of the inductor is connected to the cathode of the LED lamp, and the cathode of the third diode is connected to one end of the first capacitor.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Drawings
The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
fig. 1 is a circuit schematic of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention are further described below with reference to the accompanying drawings.
The technical solutions in the embodiments of the present invention will be fully described below, and it should be apparent that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
According to some embodiments, as shown in fig. 1, a circuit for preventing flickering of an LED when activated, includes: the LED driving circuit comprises an AC/DC constant-voltage power supply, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a diode D1, an inductor 1 lamp, a voltage follower U and a direct-current converter IC, wherein an output end of an AC/DC chip is connected with a cathode of the capacitor C1, a cathode of the resistor R1, a cathode of the diode D1 and an anode of the LED lamp D1, the other end of the capacitor C1 is grounded for filtering, the other end of the resistor R1 is connected with a pin VDD of the direct-current converter IC, the other end of the resistor R1 is connected with one end of the resistor R1, one end of the capacitor C1 and an EN pin of the converter IC, and the other ends of the resistor R1 and the capacitor C1 are grounded. The anode of the diode D1 is connected to the SW pin of the dc converter IC and to the cathode of the LED lamp D2 via the inductor L. The GND pin and the VSS pin of the dc converter IC are grounded, the CS pin is grounded through the resistor R2, the Toff pin is connected to one end of the capacitor C2, and the other end of the capacitor C2 is grounded. Furthermore, the other end of the resistor R5 is connected to one end of the capacitor C4, one end of the resistor R7, and the non-inverting input terminal of the voltage follower U, and the other ends of the capacitor C4 and the resistor R7 are grounded. The output end of the voltage follower U is connected with the cathode of a diode D3, the anode of a diode D3 is connected with one end of a resistor R6, one end of a resistor R8, the anode of a diode D4 and a DIM pin of a direct current converter IC, the other end of a resistor R6 is connected with a power supply VCC, the other end of a resistor R8 is grounded, and the cathode of a diode D4 is connected with a dimming signal.
The working principle of the embodiment is as follows:
the output voltage of the AC/DC is attenuated through the voltage division of the resistor R3 and the resistor R4 and then is added to an EN pin of the DC converter IC, the capacitor C3 has the function of improving the anti-interference capacity, and the DC converter IC can be ensured not to be started before the voltage of the VO rises to a preset threshold value through reasonably designing the resistor R3 and the resistor R4. Meanwhile, the VO is divided by the resistor R5 and the resistor R7 and then is added to the non-inverting input end of the voltage follower U, the voltage follower U is used for proportionally following the VO (attenuated) output by the AC/DC chip, and meanwhile, the voltage follower U plays a role in isolating the output voltage VO and the dimming circuit, so that the anti-interference capability is improved. After the voltage V0 rises to a preset threshold, the DC converter IC starts, the output voltage VO of the AC/DC continues to rise, and the output voltage VO of the voltage follower U rises accordingly, that is, the voltage of the DIM pin of the DC converter IC increases linearly after the DC converter IC starts, and the output current of the DC converter IC also increases linearly until another dimming signal is active or the voltage V0 is 2V lower than the rated voltage (at this time, it is considered that the AC/DC constant voltage power supply has started and is 100% of the rated current output when the dimming is not performed), which can effectively ensure the smooth start of the AC/DC chip and the DC converter IC, and avoid the phenomenon of flashing during starting.
It will be evident to those skilled in the art that the invention is not limited to the exemplary embodiments described above, but that the present solution is capable of being embodied in other specific forms without departing from the essential characteristics thereof. Accordingly, the embodiments should be considered as exemplary and non-limiting.
Claims (6)
1. A circuit for preventing flashing of an LED when activated, comprising:
an AC/DC constant voltage power supply connected to an AC power supply, and a first capacitor (C1) connected to an output terminal of the AC/DC constant voltage power supply;
connecting the first capacitor (C1) and the DC converter;
the anti-flicker circuit is connected with the direct current converter and comprises a third resistor (R3), a fourth resistor (R4) and a third capacitor (C3), an EN pin of the direct current converter IC is connected with one end of the third resistor (R3) through one ends of the third capacitor (C3) and the fourth resistor (R4), the other end of the third resistor (R3) is connected with one end of the first capacitor (C1), and the other ends of the third capacitor (C2) and the fourth resistor (R3) are grounded;
the dimming circuit is connected with a DIM pin of the direct current converter IC;
and the anode of the LED lamp is connected with one end of the first capacitor (C1), and the other end of the LED lamp is connected with the SW pin of the DC converter IC.
2. The circuit of claim 1, wherein the dimming circuit comprises a fifth resistor (R5), a sixth resistor (R6), a voltage follower (U) and a first diode (D3), a non-inverting input terminal of the voltage follower (U) is connected to one end of the first capacitor (C1) through the fifth resistor (R5), an inverting input terminal and an output terminal of the voltage follower (U) are connected to each other, a cathode of the first diode (D3) is connected, an anode of the first diode (D3) is connected to the DIM pin of the dc converter IC and one end of the sixth resistor (R6), and the other end of the sixth resistor (R6) is connected to a power source VCC.
3. The circuit of claim 2, wherein the dimming circuit further comprises a resistor-capacitor circuit, the resistor-capacitor circuit comprises a seventh resistor (R7) and a fourth capacitor (C4), one end of the seventh resistor (R7) and one end of the fourth capacitor (C4) are connected to each other and to the non-inverting input of the voltage follower (U), and the other end of the seventh resistor (R7) and the fourth capacitor (C4) are both connected to ground.
4. The circuit of claim 2 or 3, wherein the dimming circuit further comprises an eighth resistor (R8), one end of the eighth resistor (R8) is connected to the DIM pin of the DC converter IC, and the other end is connected to ground.
5. The circuit of any one of claims 2 to 4, wherein the dimming circuit further comprises a second diode (D4), a cathode of the second diode (D4) is connected to the dimming signal input, and an anode of the second diode is connected to the DIM pin of the DC converter IC.
6. The circuit for preventing LED from flickering during starting of claim 1, further comprising an inductor (L) for filtering and a third diode (D1) for freewheeling, wherein one end of the inductor (L) is connected to the SW pin of the DC converter (IC) and the anode of the third diode (D1), the other end of the inductor (L) is connected to the cathode of the LED lamp (D3), and the cathode of the third diode (D1) is connected to one end of the first capacitor (C1).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111404608.7A CN114205965B (en) | 2021-11-24 | 2021-11-24 | Circuit for preventing LED from flickering during starting |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111404608.7A CN114205965B (en) | 2021-11-24 | 2021-11-24 | Circuit for preventing LED from flickering during starting |
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| CN114205965A true CN114205965A (en) | 2022-03-18 |
| CN114205965B CN114205965B (en) | 2022-10-11 |
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Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6218787B1 (en) * | 1998-04-20 | 2001-04-17 | Jrs Technology Inc. | Remote dimming control system for a fluorescent ballast utilizing existing building wiring |
| JP2002117990A (en) * | 2000-10-11 | 2002-04-19 | Ushio Inc | Feeder system for discharge lamp |
| JP2006252907A (en) * | 2005-03-10 | 2006-09-21 | Matsushita Electric Works Ltd | Electrodeless discharge lamp lighting device an illumination apparatus using the same |
| US20110001434A1 (en) * | 2009-07-06 | 2011-01-06 | Kuo-Ching Hsu | LED Device and Method for Preventing Soft-Start Flicker |
| CN102026451A (en) * | 2010-11-26 | 2011-04-20 | 深圳市聚作实业有限公司 | Dimmable light-emitting diode (LED) driving power supply |
| CN203167355U (en) * | 2013-03-06 | 2013-08-28 | 广州凯盛电子科技有限公司 | LED driver preventing LED from flickering |
| CN103346684A (en) * | 2013-07-18 | 2013-10-09 | 南京理工大学 | Alternating current/direct current (AC/DC) converter adopting active energy-storage capacitance converter |
| CN105554963A (en) * | 2016-02-05 | 2016-05-04 | 江苏力行电力电子科技有限公司 | Alternating current input detection and starting circuit for LED (Light Emitting Diode) driver and LED driving method |
| CN105722272A (en) * | 2016-02-15 | 2016-06-29 | 深圳迈睿智能科技有限公司 | Initial voltage adaptive method for constant-voltage dimming power supply |
| JP2017084702A (en) * | 2015-10-30 | 2017-05-18 | 三菱電機株式会社 | Lighting device and luminaire |
| CN109195272A (en) * | 2018-10-26 | 2019-01-11 | 广东新昇电业科技股份有限公司 | One kind can turn off the three-in-one light adjusting circuit of formula |
| US10602597B1 (en) * | 2012-06-15 | 2020-03-24 | Aleddra Inc. | Solid-state lighting with a reduced temporal light artifact |
| CN212211443U (en) * | 2020-05-20 | 2020-12-22 | 禧荣电器(深圳)有限公司 | double-PWM dimming circuit |
-
2021
- 2021-11-24 CN CN202111404608.7A patent/CN114205965B/en active Active
Patent Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6218787B1 (en) * | 1998-04-20 | 2001-04-17 | Jrs Technology Inc. | Remote dimming control system for a fluorescent ballast utilizing existing building wiring |
| JP2002117990A (en) * | 2000-10-11 | 2002-04-19 | Ushio Inc | Feeder system for discharge lamp |
| JP2006252907A (en) * | 2005-03-10 | 2006-09-21 | Matsushita Electric Works Ltd | Electrodeless discharge lamp lighting device an illumination apparatus using the same |
| US20110001434A1 (en) * | 2009-07-06 | 2011-01-06 | Kuo-Ching Hsu | LED Device and Method for Preventing Soft-Start Flicker |
| CN102026451A (en) * | 2010-11-26 | 2011-04-20 | 深圳市聚作实业有限公司 | Dimmable light-emitting diode (LED) driving power supply |
| US10602597B1 (en) * | 2012-06-15 | 2020-03-24 | Aleddra Inc. | Solid-state lighting with a reduced temporal light artifact |
| CN203167355U (en) * | 2013-03-06 | 2013-08-28 | 广州凯盛电子科技有限公司 | LED driver preventing LED from flickering |
| CN103346684A (en) * | 2013-07-18 | 2013-10-09 | 南京理工大学 | Alternating current/direct current (AC/DC) converter adopting active energy-storage capacitance converter |
| JP2017084702A (en) * | 2015-10-30 | 2017-05-18 | 三菱電機株式会社 | Lighting device and luminaire |
| CN105554963A (en) * | 2016-02-05 | 2016-05-04 | 江苏力行电力电子科技有限公司 | Alternating current input detection and starting circuit for LED (Light Emitting Diode) driver and LED driving method |
| CN105722272A (en) * | 2016-02-15 | 2016-06-29 | 深圳迈睿智能科技有限公司 | Initial voltage adaptive method for constant-voltage dimming power supply |
| CN109195272A (en) * | 2018-10-26 | 2019-01-11 | 广东新昇电业科技股份有限公司 | One kind can turn off the three-in-one light adjusting circuit of formula |
| CN212211443U (en) * | 2020-05-20 | 2020-12-22 | 禧荣电器(深圳)有限公司 | double-PWM dimming circuit |
Non-Patent Citations (2)
| Title |
|---|
| IGNACIO CASTRO: "An Electrolytic Capacitorless Modular Three-Phase AC–DC LED Driver Based on Summing the Light Output of Each Phase", 《IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONICS》 * |
| 程新华: "一种带调光功能的LED均流驱动电路设计", 《信息技术》 * |
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| CN114205965B (en) | 2022-10-11 |
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