KR102070445B1 - LED Dimming Control Apparatus and Method for Reducing Flicker - Google Patents

Abstract

The present invention relates to an apparatus for controlling LED dimming for reducing flicker, which comprises: a pulse frequency modulation (PFM) control unit (110) generating a dimming control signal for controlling dimming; a power conversion device (130) modulating frequency according to the dimming control signal generated by the PFM control unit (110), and converting primary AC power into DC power to apply the power to the load; a voltage control unit (140) transmitting a voltage controlling signal to the PFM control unit (110); a dimming control signal-receiving circuit (210) receiving the dimming control signal generated by the PFM control unit (110) to transmit the same to a controller having a form of a comparator; an output current control unit (220) receiving the dimming control signal from the dimming control signal-receiving circuit (210) to control an output current according to a level of the dimming control signal; a switching stop (skip mode) activation circuit (230) generating a signal for activating a frequency amplification circuit when the level of the dimming control signal corresponds to a condition of a switching stop (skip mode) operation; and a whole frequency amplification circuit (240) of switching operation and switching stop, rapidly transmitting an operation signal of switching stop (skip) to the output current control unit (220) when the frequency amplification circuit is activated by the switching stop activation circuit (230) and the operation of switching stop (skip mode) is detected in the output.

Description

LED Dimming Control Apparatus and Method for Reducing Flicker

The present invention relates to an LED dimming control apparatus and method for reducing flicker at light load in LED, and more particularly, to light load through control of the speed of switching mode (Skip Mode). By reducing the time between switching stops and increasing the number of occurrences, that is, reducing the flicker phenomenon of LED flickering at light load by increasing the overall frequency of switching operation and switching stops. An apparatus and method are disclosed.

Recently, a lighting device using a high-efficiency LED (Light Emitting Diode) in place of the conventional fluorescent lamp has been applied in various fields of lighting. Compared to fluorescent lamps, LED lamps have the advantages of high energy efficiency, long life, and low power consumption.

These LED lamps usually have a dimming function that adjusts the illumination by controlling power to remove glare, create a pleasant atmosphere, and save energy. The problem is that in the case of LED lamp with dimming function, when dimming, the brightness of LED becomes weak at light load, but there is a need for a technical solution to prevent flicker, which is a phenomenon of flickering LED. .

The generation of flicker is known to be caused by the slow switching operation of the dimmer and the various types of dimmer operation, which generate a phase-cut signal at light load.

During the operation of the LED lamp, the polarity changes rapidly at the speed of energizing the alternating current, causing flickering of light flickering. This is called flicker, or flickering. The phenomenon of flicker that occurs during dimming causes problems such as fatigue when exposed for a long time.

In related prior documents, Republic of Korea Patent Publication No. 10-1080080, Announcement Date 2011. 11. 04. (hereinafter referred to as [Patent Document 1]) disclosed a LED dimming device through the power control. In [Patent Document 1], the first power line for connecting an existing LED lamp is detachably connected and compatible, and after setting the PWM duty ratio according to the amount of power set by the user, the LED on / through the set PWM duty ratio The LED dimming device is disclosed through a power amount control that can control the brightness of the LED lamp by adjusting the off time, and has a function of reducing the initial inrush current of the LED lamp.

In addition, as related prior documents, Korean Patent Publication No. 10-1644798, publication date 2016. 08. 02. (hereinafter referred to as [Patent Document 2]) discloses a device for controlling the excessive change of the flicker generated during dimming It was. [Patent Document 2] discloses that an excessive change in flicker generated during dimming can be adjusted to a reference value level through a combined control of a MCU (Micro Controller Unit) and a Passive Tunable Integrated Circuit (PTIC).

In addition, as related prior documents, Republic of Korea Patent Publication No. 10-1488682, Publication Date 2015. 02. 06. (hereinafter referred to as [Patent Document 3]) disclosed a dimming control circuit of the LED lighting. In [Patent Document 3], the initial starting current is adjusted until the amount of current capable of operating the LED at the initial operation, and the triac dimmer phase cut method is used to reduce the startup time of the LED light, so that the electrical characteristics do not change significantly. Has disclosed a dimming control circuit for LED lighting that enables stable dimming.

However, in [Patent Documents 1] to [Patent Document 3], even when the continuous mode limit low power operation is performed at light load dimming, when the power is high, the operation is stopped for a while. Large bending occurs, and as a result, there is a problem that the illumination flicker occurs.

Republic of Korea Patent Publication No. 10-1080080, Announcement Date 2011. 11. 04. Republic of Korea Patent Publication No. 10-1644798, Announcement Date 2016. 08. 02. Republic of Korea Patent Publication No. 10-1488682, Publication Date 2015. 02. 06.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to reduce flicker phenomenon in LED light sources and to increase dimming light load state switching operation and stop speed so as to enable dimming control. LED dimming control device and method for reducing flicker so that the circuit of the output part can be reduced by applying the method of reducing flicker, and the flicker phenomenon that user can not identify even at low current does not occur. To provide a solution to the problem.

According to an aspect of the present invention, there is provided an LED dimming control apparatus for reducing flicker, comprising: a frequency modulation (PFM) control unit generating a dimming control signal for dimming control; A power converter (130) for adjusting the frequency according to the dimming control signal generated by the frequency modulation control unit (110), converting the primary AC power into direct current, and applying the load to the load; A voltage controller 140 which transmits a signal for controlling the voltage to the frequency modulation controller 110; A dimming control signal receiving circuit 210 which receives a dimming control signal generated by the frequency modulation control unit 110 and transmits the dimming control signal to a controller of a comparator type; An output current controller 220 which receives a dimming control signal from the dimming control signal receiving circuit 210 and controls an output current according to a dimming control signal level; A switching mode-activation circuit 230 for generating a signal for activating a frequency amplification circuit when the dimming control signal level corresponds to a switching mode stop condition; And a frequency amplification circuit is activated by the switching operation-stop activating circuit 230, and when a switching mode stop operation is detected at an output, the switching current operation signal is quickly transmitted to the output current controller 220. It is characterized in that it comprises a full frequency amplification circuit 240 of the switching operation and switching stop to deliver.

Preferably, when it is determined that a flicker phenomenon occurs by the switching mode-activation circuit 230, the LED illuminance control device switches the switching operation to increase the total frequency of the switching operation and the switching stop. It is characterized in that the operation of the first transistor (U1) of the entire frequency amplification circuit 240 of the switching stop.

More preferably, the dimming control signal receiving unit 210 includes: a first controller 215 for varying an output level of a voltage output to a switching terminal according to an input dimming control signal; A compensator circuit comprising a fourth resistor (R4) and a sixth capacitor (C6) and voltage divider resistors (R6, R7); The output voltage of the dimming control signal is outputted through the seventh terminal of the first controller 215 and is transmitted to the switching operation stop activation circuit 230 through the third resistor R3 and the sixteenth resistor R16. ; The low value of the output current is output through the first terminal of the first controller 215 and is transmitted to the output current controller 220 through the ninth resistor (R9) and the fourth capacitor (C4).

Also preferably, the output current control unit 220 shares the switching operation stop activation circuit 230 and the second controller 225; Switching mode (Skip Mode) The flicker component of the switching ripple included in the output power through a control signal input to turn on / off the LED light source for operation and a dimming control signal input to turn on the LED light source to a desired brightness. It characterized in that to reduce.

Also, preferably, the dimming control circuit is input to terminal 5 of the second controller 225, and the dimming control signal received from the switching operation stop activation circuit 230 corresponds to a switching mode stop condition. In this case, the high signal is output from the first terminal of the second controller 225, and the high frequency amplification circuit 240 activates the switching operation and the switching stop.

Also preferably, the entire frequency amplification circuit 240 of the switching operation and the switching stop may include a first transistor U1, a first resistor R1, a second resistor R2, and a second capacitor C2. ; When the first resistor R1 and the second capacitor C2 detect the output voltage, a voltage is applied to the second resistor R2 so that the first transistor U1 is turned on, thereby activating the activated signal. 12 is transmitted to the resistor R12 and the third capacitor C3 to control the output current by increasing the control speed so that the frequency of the output power cannot be recognized by the on / off repetition of the first transistor U1. Characterized in that it can.

Also preferably, the first transistor U1 may be a P-type transistor.

On the other hand, LED dimming control method for reducing the flicker according to another aspect of the present invention for achieving the above object is an LED dimming control method for reducing the flicker using the LED dimming control device for reducing the flicker, (a) generating a dimming control signal for dimming control; (b) receiving the dimming control signal generated in the step (a) and transmitting it to the first controller 215 of the dimming control signal receiving circuit 210 in the form of a comparator; (c) in step (b), when the dimming control signal level corresponds to a switching mode operation condition, the switch operation stop activation circuit generates a signal for activating the entire frequency amplification circuit of the switching operation and the switching stop. ; (d) When the entire frequency amplification circuit of the switching operation and the switching stop is activated, and the switching mode stop operation is detected at the output, the switching stop operation signal is quickly transmitted to the output current controller 220, and the current It is characterized in that it comprises the step of reducing the flicker phenomenon by increasing the control circuit control speed.

In the present invention, first, the flicker phenomenon is minimized and lighting control is enabled. Second, the flicker is reduced through a method of controlling the speed of the switching operation in the dimming light load state, thereby reducing the manufacturing cost by simplifying the circuit. Third, there is an increased effect that the flicker does not occur even at a low current.

1 is a diagram illustrating a switching operation and a switching stop section in a dimming light load state.
2 is a circuit diagram of a dimming control device according to an embodiment of the present invention,
3 is an asymmetric half-bridge converter circuit diagram according to an embodiment of the present invention,
4 is a symmetric half bridge converter circuit diagram according to an embodiment of the present invention;
5 is a full-bridge converter circuit diagram according to an embodiment of the present invention,
6 is a detailed circuit diagram of a dimming control device according to an embodiment of the present invention,
7 is a detailed circuit diagram of a transformer secondary voltage controller according to an embodiment of the present invention;
8 is a view showing a photograph actually applied flicker reduction technology according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the LED dimming control apparatus and method for reducing the flicker according to the present invention. Specific structures or functions of the present invention described below are merely illustrated to describe embodiments in accordance with the concepts of the present invention, and embodiments according to the present invention may be implemented in various forms, and the embodiments described herein. It should not be construed as limited to the examples.

1 shows a switching operation and a switching stop section in a dimming light load state.

Referring to FIG. 1, FIG. 1 (a) shows a switching mode (Skip Mode) at the conventional dimming light load, and the switching mode (Skip Mode) is a power even when the continuous mode limit low power operation is performed at the dimming light load. If it is high, it means the function of stopping and reactivating the operation.If the switching skip period is long, the large sawtooth-shaped bend occurs in the output voltage.As a result, flicker occurs in the lighting. This will occur.

Therefore, if the switching stop interval occurs intermittently, the output voltage bending is large, and thus flicker occurs. Therefore, in order to prevent such a flicker phenomenon, the switching operation of the dimming light load state as shown in FIG. 1 (b) is stopped. (Skip Mode) shortens the time of the switching stop section during the switching mode stop operation, increases the repetitive frequency of the switching operation section and the switching stop section, which is the number of occurrences, and output voltage ripple. And flicker is reduced by reducing the size of the bend.

2 shows a circuit diagram of a dimming control device according to an embodiment of the present invention.

2, the dimming control circuit 10 includes a PFM (Pulse Frequency Modulation) control unit 110, a power converter 130, a voltage control unit 140, a dimming control signal receiving circuit 210, and an output current control unit ( 220, the switching operation stop activation circuit 230, the total frequency amplification circuit 240 of the switching operation and the switching stop, and the illuminance variable device 300 are included.

In general, PFM (Pulse Frequency Modulation) control increases the frequency at light load, the frequency drops at the full load, and the switching mode stops even if the frequency increases. Above all, at light loads, if the time of the switching stop section is long as shown in FIG. 1 (a), a problem occurs that the LED flickers due to a large sawtooth wave shape in the output voltage, causing inconvenience. do.

Thus, the speed control process of the switching operation stop according to the present invention is as follows. The illuminance variable device 300 can vary the illumination of the first to tenth stages (Zero-to-Ten), where the tenth stage is the brightest illuminance and the first stage is the state of the lowest illumination. Even the illuminance variable device 300 is characterized in that it is possible to control the illuminance more delicately, such as 0.5 step 1.2 step depending on the situation. First of all, when dimming is controlled to set the illuminance weakly, when the dimming control signal low voltage (low level) generated in the illuminance variable device 300 is generated, that is, in the first stage or the second stage, the first contact wire 1 and the second stage 2 are controlled. A small voltage is applied between the contacts Wire2. In this case, the switching operation stop (Skip Mode) occurs, the flicker of the LED flickers (Flicker) occurs. First of all, the voltage having the ripple reduced through the eighth resistor R8 and the eighth capacitor C8 is received by the dimming control signal receiving circuit 210 and transferred to the first controller 215 and IC1. Most of all, the contact between the third resistor R3 and the fourth resistor R4 generates a reference voltage to the comparator located on the right side of the first controller 215 and inputs it to the sixth terminal. In addition, the dimming control signal of the low voltage generated by the illuminance variable device 300 is input to the terminal 5 of the comparator located on the right side of the first controller 215 through the eighth resistor R8 and the sixth resistor R6. do. Accordingly, a dimming control signal of low voltage is compared to terminal 5 of the comparator located on the right side of the first controller 215 as the reference voltage, and below the reference voltage, the dimming control signal of the comparator located on the right side of the first controller 215 is compared. Low voltage is outputted through terminal 7. The low value output from No. 7 of the comparator located on the right side of the first controller 215 is input to the comparator located on the left side of the first controller 215 through the third resistor R3 and the sixteenth resistor R16. do. Accordingly, when the dimming control signal low voltage (low level) generated in the illuminance variable device 300 is generated, the first controller 215 finally outputs a low value and transmits the low value to the switching operation stop activation circuit 230. When a low value is output through the first terminal of the first controller 215 of the dimming control signal receiving circuit 210, the low value is input to the switching operation stop activation circuit 230 through the seventeenth resistor R17. The switching operation stop activation circuit 230 is input to a comparator located on the left side of the second controller 225, IC2. The comparator located on the left side of the second controller 225 (IC2) divides the transformer secondary control voltage (SEC_VCC) into a thirteenth resistor (R13) and a fourteenth resistor (R14) to generate a reference voltage. 225, IC2 is input to terminal 2 of the comparator located on the left side. In addition, when an output current of Low is output through the first terminal of the first controller 215 of the dimming control signal receiving circuit 210, the switching operation stop activating circuit 230 is transmitted through the fifteenth resistor R15. ) Is input to terminal 3 of the comparator located on the left side of the second controller 225 (IC2). When the dimming control signal low voltage (low level) generated in the illuminance variable device 300 is generated, a high value is output from the first terminal of the comparator located on the left side of the second controller 225 or IC2. Therefore, when the high value of the first terminal of the comparator located on the left side of the second controller 225 or IC2 is output, the first transistor U1 is turned on. Here, the first transistor is a P-type transistor. The low value output through the first terminal of the first controller 215 of the dimming control signal receiving circuit 210 is transmitted to the output current controller 220 through the ninth resistor R9, and output current controller ( It is input to terminal 5 of the second controller 225 of 220.

The high value output from the first terminal of the comparator located on the left side of the second controller 225 (IC2) of the switching operation stop activation circuit 230 is turned on through the first transistor U1. The reference voltage is changed at terminal 6 of the comparator located on the right side of the second controller 225 and IC2, and a low value is output from terminal 7 of the comparator located on the right side of the second controller 225 and IC2.

More than anything. When the low value is output from the terminal 7 of the comparator located on the right side of the second controller 225 or IC2, the first photo coupler P1, which is a current photocoupler, is operated to stop switching from the PFM controller 110. The biggest technical feature is to reduce the flickering of LEDs at light loads by shortening the time of the section and increasing the number of occurrences, that is, increasing the overall frequency of switching operation and switching stop. do.

FIG. 3 is an asymmetric half bridge converter circuit diagram according to an embodiment of the present invention, FIG. 4 is a symmetric half bridge converter circuit diagram according to an embodiment of the present invention, and FIG. 5 is a full bridge converter circuit diagram according to an embodiment of the present invention. Indicates.

3 to 5 show an embodiment of a circuit configuration of the power converter 130, the asymmetric half bridge 130-1 method, the symmetric half bridge 130-2 method, the full bridge 130-3 method Among the features that can be selectively applied by those skilled in the art as the greatest technical features.

In FIG. 3, the first and second switches 32 and 33 of the asymmetric half bridge converter 32 and 33 are positioned on the primary side of the asymmetric half bridge converter peripheral pressure transformer 30, and the first and second switches of the asymmetric half bridge converter peripheral pressure transformer 30 are positioned. On the vehicle side, asymmetric half bridge converter first and second diodes 34 and 35 and an output capacitor 36 are disposed. Above all, the duty ratio of each of the asymmetric half-bridge converter first and second switches 32 and 33 is different.

In FIG. 4, the symmetric half bridge converter first and second switches 43 and 44 and the symmetric half bridge converter first and second capacitors 41 and 42 are positioned on the primary side of the symmetric half bridge converter peripheral voltage transformer 40. In addition, on the secondary side of the symmetric half-bridge converter peripheral voltage 40, the symmetric half-bridge converter first and second diodes 46 and 47 and the output capacitor 48 are disposed.

Above all, the duty ratios of the symmetric half-bridge converters 1 and 2 switches 43 and 44 are the same.

In FIG. 5, full bridge converter first to fourth switches 51 to 54 are disposed at a primary side of the full bridge converter peripheral pressure receiver 50, and a full bridge converter is arranged at a primary side of the full bridge converter peripheral pressure receiver 50. First and second diodes 56 and 57 and an output capacitor 58 are disposed.

The full bridge converter has technical features that it is more suitable for large power conversion compared to the half bridge converter.

6 is a detailed circuit diagram of a dimming control device according to an embodiment of the present invention. The detailed operation of FIG. 6 has been described with reference to FIG. 2. Referring to FIG. 6, the dimming control signal receiving circuit 210 includes a compensator circuit and a voltage divider configured with a fourth resistor R4 and a sixth capacitor C6. And a dimming control signal through a terminal 1 of the first controller 215, and a low value is outputted to the third resistor R3 and the sixteenth resistor R16. Is transmitted to the switching operation stop activation circuit 230, and the output current is outputted through the first terminal of the first controller 215 so that the output current is output through the ninth resistor R9 and the fourth capacitor C4. The dimming control signal received from the switching controller 220 is input to the fifth terminal of the second controller 225 of the output current controller 220 and the switching operation stop activation circuit 230 stops the switching operation (Skip Mode). ) If the operating conditions, that is, the dimming signal is light, the terminal 1 of the second controller 225 High signal is output, and, an output signal is transmitted to the first transistor (U1) of the entire frequency amplifier circuit 240 of the switching operation and the switching is stopped.

The first transistor U1 is a P-type transistor (PNP transistor). When the voltage at the base is lower than the collector, the first transistor U1 is turned on. The first resistor R1 and the second capacitor C2 are configured to output the output voltage. Since the voltage of the second resistor R2 is increased due to the detection, the voltage is applied to the second resistor R2 so that the first transistor U1 is turned on, so that the entire frequency amplification circuit of the switching operation and the switching stop is turned on. The signal activated at 240 is transmitted to the twelfth resistor R12 and the third capacitor C3, and the output current controller 220 controls the voltage to be a constant voltage and controls the current to be reduced to control the output current. It is a technical feature.

Accordingly, when the activation signal generated by the switching operation battery activation circuit 230 is received and the entire frequency amplification circuit 240 of the switching operation and the switching stop is activated, the switching stop period is shortened and the number of occurrences is increased. That is, the biggest technical feature is to reduce the flicker phenomenon of LED flickering at light load by increasing the overall frequency of switching operation and switching stop.

7 is a detailed circuit diagram of a secondary voltage controller according to an embodiment of the present invention.

The output voltage Vout is divided by the voltage controller first and second voltage divider resistors 73 and 74 and input to the voltage controller comparator 70. The voltage controller comparator 70 generates a control voltage Vc by comparing the output voltage divided by the reference voltage Vref and the first and second voltage divider resistors 73 and 74. The control voltage transmits a control signal to the feedback terminal 111 on the primary side through the second photocoupler P2 and transmits a signal to the PFM controller 110 through the feedback terminal 111.

8 is a view showing a photograph actually applied flicker reduction technology according to an embodiment of the present invention.

Referring to FIG. 8, when the switching mode is stopped by controlling the frequency through the entire frequency amplification circuit of the switching operation and the switching stop in the dimming light load state to reduce the flicker phenomenon to the LED light source to enable dimming control. By reducing the size of output curvature by increasing the generation speed of the switching stop section, the method of reducing flicker is applied, which reduces the manufacturing cost by simplifying the circuit diagram of the DC output unit and prevents flicker from occurring even at low current. Technical features that can implement a circuit of the LED dimming control device to reduce the.

Accordingly, in the present invention, an LED dimming control apparatus for reducing flicker, comprising: a pulse frequency modulation (PFM) control unit 110 for generating a dimming control signal for dimming control; A power converter (130) for adjusting a frequency according to a dimming control signal generated by the PFM controller (110), converting a primary AC power into a direct current, and applying the load to a load; A voltage controller 140 which transmits a signal for controlling the voltage to the PFM controller 110; A dimming control signal receiving circuit 210 which receives a dimming control signal generated by the PFM control unit 110 and transmits the dimming control signal to a controller of a comparator type; An output current controller 220 which receives a dimming control signal from the dimming control signal receiving circuit 210 and controls an output current according to a dimming control signal level; A switching mode-activation circuit 230 for generating a signal for activating a frequency amplification circuit when the dimming control signal level corresponds to a switching mode stop condition; And a frequency amplification circuit is activated by the switching operation stop activation circuit 230, and when a switching mode stop operation is detected at an output, a switching stop signal is quickly transmitted to the output current controller 220. The dimming control device for reducing the flicker, characterized in that it comprises a full frequency amplification circuit 240 of the switching operation and the switching stop.

In addition, the present invention provides a dimming control method for reducing flicker, comprising: (a) generating a dimming control signal for dimming control; (b) receiving the dimming control signal generated in the step (a) and transmitting it to the first controller 215 of the dimming control signal receiving circuit 210 in the form of a comparator; (c) in step (b), when the dimming control signal level corresponds to a switching mode operation condition, the switch operation stop activation circuit generates a signal for activating the entire frequency amplification circuit of the switching operation and the switching stop. ; (d) The entire frequency amplification circuit of the switching operation and the switching stop is activated, and when the switching mode stop operation is detected at the output, the switching stop operation signal is quickly transmitted to the output current control circuit. An object of the present invention is to propose a dimming control method for reducing flicker, which includes reducing a flicker phenomenon by increasing a control speed.

The above description is merely illustrative of the technical idea of the present invention, the present invention can be applied to LED dimming control apparatus and method for reducing the flicker by various modifications having ordinary skill in the art, It should also be recognized that the scope of technology that is easily technically modified falls within the scope of the present patent.

30: Asymmetric Half-Bridge Converter Peripheral Voltage
31: Asymmetric Half Bridge Converter First Capacitor
32: asymmetric half-bridge converter first switch
33: Asymmetric Half-Bridge Converter Second Switch
34: Asymmetric Half-Bridge Converter, First Diode
35: Asymmetric Half-Bridge Converter Second Diode
36: Asymmetric Half-Bridge Converter Output Capacitors
40: symmetric half-bridge converter peripheral voltage
41: symmetric half bridge converter first capacitor
42: symmetric half-bridge converter second capacitor
43: symmetric half bridge converter first switch
44: symmetric half-bridge converter second switch
45: Symmetric Half-Bridge Converter Resonant Capacitor
46: symmetric half-bridge converter first diode
47: symmetric half-bridge converter second diode
48: Symmetric Half-Bridge Converter Output Capacitors
50: full bridge converter
51: full bridge converter first switch
52: full bridge converter second switch
53: full bridge converter third switch
54: fourth bridge of a full bridge converter
55: full bridge converter resonant capacitor
56: full-bridge converter first rectifier diode
57: full-bridge converter second rectifier diode
58: full-bridge converter output capacitor
60: LOAD
70: voltage control comparator
71: voltage controller first resistor
72: voltage controller second resistor
73: voltage divider first voltage divider resistance
74: voltage divider second voltage divider resistance
75: voltage control capacitor
110: pulse frequency modulation (PFM) control unit
111: Feedback terminal
130: power converter
130-1: Asymmetric Half Bridge Converter
130-2: Symmetric Half Bridge Converter
130-3: Full Bridge Converter
140: voltage control unit
210: dimming control signal receiving circuit
215: first controller IC1
220: output current control unit
225: second controller (IC2)
230: switching operation-stop mode activation circuit
240: full frequency amplification circuit of switching operation and switching stop
300: illuminance variable
C1: first capacitor
C2: second capacitor
C3: third capacitor
C4: fourth capacitor
C5: fifth capacitor
C6: sixth capacitor
C7: seventh capacitor
C8: eighth capacitor
GND: Ground Terminal
P1: first photocoupler
P2: second photocoupler
R1: first resistance
R2: second resistor
R3: third resistance
R4: fourth resistor
R5: fifth resistor
R6: sixth resistor
R7: seventh resistor
R8: eighth resistor
R9: ninth resistor
R10: tenth resistance
R11: eleventh resistance
R12: 12th resistor
R13: thirteenth resistor
R14: 14th resistance
R15: 15th resistance
R16: 16th resistor
R17: 17th resistance
U1: first transistor
SEC_VCC: Transformer Secondary Control Voltage
VC: control voltage
VCC: Transformer Primary Control Voltage
VDD: Input Supply Voltage
Vout: Output voltage
VR1: first variable resistor
VREF: reference voltage
WIRE1: 1st contact
WIRE2: 2nd contact

Claims (8)

In the LED dimming control device for reducing flicker,
A pulse frequency modulation (PFM) control unit 110 generating a dimming control signal for dimming control;
A power converter (130) for adjusting the frequency according to the dimming control signal generated by the frequency modulation control unit (110), converting the primary AC power into direct current, and applying the load to the load;
A voltage controller 140 which transmits a signal for controlling the voltage to the frequency modulation controller 110;
A dimming control signal receiving circuit 210 which receives a dimming control signal generated by the frequency modulation control unit 110 and transmits the dimming control signal to a controller of a comparator type;
An output current controller 220 which receives a dimming control signal from the dimming control signal receiving circuit 210 and controls an output current according to a dimming control signal level;
A switching mode-activation circuit 230 for generating a signal for activating a frequency amplification circuit when the dimming control signal level corresponds to a switching mode stop condition; And
The frequency amplification circuit is activated by the switching operation-stop activating circuit 230. When a switching mode stop operation is detected at an output, a frequency of a switching stop operation signal is quickly transmitted to the output current controller 220. LED dimming control device for reducing the flicker, characterized in that it comprises a full frequency amplification circuit 240 of the switching operation and switching stop.
The method of claim 1,
If it is determined that a flicker phenomenon occurs by the switching mode-activation circuit 230, the LED illuminance control device may increase the total frequency of the switching operation and the switching stop in order to increase the overall frequency of the switching operation and the switching stop. LED dimming control device for reducing the flicker, characterized in that the operation of the first transistor (U1) of the frequency amplification circuit (240) On.
The method of claim 1,
The dimming control signal receiving unit 210 includes: a first controller 215 for varying an output level of a voltage output to a switching terminal according to an input dimming control signal;
A compensator circuit comprising a fourth resistor (R4) and a sixth capacitor (C6) and voltage divider resistors (R6, R7);
The output voltage of the dimming control signal is outputted through the seventh terminal of the first controller 215 and is transmitted to the switching operation stop activation circuit 230 through the third resistor R3 and the sixteenth resistor R16. ;
The flicker is characterized in that the output current is outputted through the first terminal of the first controller 215 and is transmitted to the output current controller 220 through the ninth resistor R9 and the fourth capacitor C4. LED dimming control unit to reduce.
The method of claim 1,
The output current controller 220 shares a switching operation stop activation circuit 230 with a second controller 225;
Switching operation (Skip Mode) Flicker component of the switching ripple included in the output power through a control signal input to turn on / off the LED light source for operation and a dimming control signal input to turn on the LED light source to a desired brightness. LED dimming control device for reducing the flicker, characterized in that to reduce.
The method of claim 4, wherein
The dimming control circuit is input to terminal 5 of the second controller 225, and if the dimming control signal received from the switching operation stop activation circuit 230 corresponds to a switching mode stop condition, the second controller LED signal dimming control device for reducing the flicker, characterized in that the high signal is output from the terminal 1 of (225), and activated in the entire frequency amplifier circuit 240 of the switching operation and switching stop.
The method of claim 1,
The total frequency amplification circuit 240 of the switching operation and the switching stop is composed of a first transistor U1, a first resistor R1, a second resistor R2 and a second capacitor C2;
When the first resistor R1 and the second capacitor C2 detect the output voltage, a voltage is applied to the second resistor R2 so that the first transistor U1 is turned on, thereby activating the activated signal. 12 LED to reduce the flicker, which is transmitted to the resistor (R12) and the third capacitor (C3) to control the output current by increasing the control speed through the on / off repeat of the first transistor (U1) Dimming Control.
The method of claim 2,
LED dimming control device for reducing the flicker, characterized in that the first transistor (U1) is a P-type transistor.
In the LED dimming control method for reducing the flicker using the LED dimming control device for reducing the flicker of claim 1,
(a) generating a dimming control signal for dimming control;
(b) receiving the dimming control signal generated in the step (a) and transmitting it to the first controller 215 of the dimming control signal receiving circuit 210;
(c) in step (b), when the dimming control signal level corresponds to a switching mode operation condition, the switch operation stop activation circuit generates a signal for activating the entire frequency amplification circuit of the switching operation and the switching stop. ;
(d) When the entire frequency amplification circuit of the switching operation and the switching stop is activated, and the switching mode stop operation is detected at the output, the switching stop operation signal is quickly transmitted to the output current controller 220, and the current Reducing the flicker phenomenon by increasing the control circuit control speed;
LED dimming control method for reducing the flicker characterized in that it comprises a.

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