KR101988807B1 - Converter for controlling led lighting - Google Patents

Abstract

The present invention reduces a flicker phenomenon by having a flicker free circuit in a converter and, particularly, not only minimizes power waste by increasing efficiency of the flicker free circuit, but also supplies uniform current to an LED module by allowing an inductor to stabilize voltage supplied to the LED module. Particularly, the present invention allows the inductor to filter direct current (DC) voltage obtained by removing current ripples, which is included when converting voltage into current, from a smoothing circuit so as to obtain the voltage to be used in the LED module, thereby providing the stable DC voltage to the LED module. Moreover, the present can accumulate energy in the inductor when a reflux diode is switched on, and a reverse electromotive force can be suppressed when the reflux diode is switched off, thereby minimizing damage to a circuit or generation of odd signals and the like.

Description

CONVERTER FOR CONTROLLING LED LIGHTING [0002]

The present invention relates to a converter for LED lighting control, and more particularly to a converter for LED lighting control, which comprises a smoothing circuit, a flicker circuit, two reflux diodes, two inductors, and a blocking diode sequentially connected to a secondary side of a DC transformer, Flicker), and even when several converters are connected, they do not collide with each other, thereby increasing the efficiency of the converter and stabilizing the DC output by stabilizing the current.

Generally, it is known that the lighting using LED is more energy saving than the incandescent lamp, and the brightness and the lifetime are also excellent. These LED lights are designed to be able to select the color to emit light or adjust the brightness according to the purpose of use. In the following Patent Documents 1 and 2, a technique related to a control technique for driving and controlling an LED is disclosed.

(Patent Document 1) Korean Patent No. 1276961

An LED driving apparatus for driving an LED (Light Emitting Diode), comprising: an EMI filter connected to an input power source for eliminating electromagnetic noise of an input / output signal; a power factor compensation unit connected to an output terminal of the EMI filter, A DC-DC converter for transforming an output voltage of the power factor correction circuit, a sensor input for receiving a sensor signal, a transceiver for transmitting and receiving a communication signal, and a DC- DC converter, and a DSP (digital signal processor) for controlling the illuminance according to the sensor signal input from the sensor input unit or the communication signal input from the transmission / reception unit. According to the present invention, by implementing an LED driving circuit using a low-cost DSP, it is possible to reduce the manufacturing cost of a circuit for implementing an apparatus for driving LED lighting, and it is possible to miniaturize the circuit size and increase price competitiveness.

(Patent Document 2) Korean Patent No. 1601607

The present invention relates to an LED lighting device for integrated extension control, comprising: a plurality of first to N converters for receiving an AC current and converting the AC current into a DC current; An LED module that receives a direct current from the first to N converters and emits light; And a plurality of first to N on-off switches (1, 2, 3, ..., N) connected to the first to N converters, respectively, for controlling the application of power; And the first to N-th converters are configured such that the output converters do not collide with each other when they are coupled to each other. In the present invention, a constant-current constant voltage source is directly made in the primary-side auxiliary winding, so that it is basically switched to a plurality of first to N-th converters capable of constant current driving required for LED driving and at the same time, So that a separate dimming circuit is not needed, thereby reducing the equipment cost and also reducing standby power consumption.

However, there are the following problems in the method of controlling the LED lighting by having a converter for each of the existing switches one by one.

(1) In order to control the LED lighting more precisely, the number of switches must be increased so much. So, you need to have more converters than the number of switches. This requires additional configuration of the converter, which not only requires a lot of manufacturing cost, but also causes the total weight of the LED lighting to be large.

(2) In addition, the LED lighting control through the converter must control the intensity of the LED light according to the intensity of the current applied to the converter, that is, the number of the converters to which the current is applied through the switch.

(3) Thus, the number of converters operating according to the illumination control is changed, and the flicker phenomenon may occur because the LED lighting does not output a uniform current.

(4) In particular, since each converter performs a simple conversion function, there is a limit in stably controlling the LED lighting. Therefore, a flicker phenomenon occurs or a current is not stably supplied, which causes a waste of electric power.

(5) To solve such a problem, a separate circuit must be formed in the converter or the LED control device, so that the size of the control device for controlling the LED lighting becomes large, and it becomes difficult and difficult to manufacture.

Korean Registered Patent No. 1276961 (Registered on March 23, 2013) Korean Registered Patent No. 1601607 (Registered on Feb. 2016)

The present invention takes this point into consideration and reduces flicker phenomenon by providing a flicker-free circuit inside the converter. Especially, it improves the efficiency of the flicker-free circuit, minimizes power consumption, and supplies the LED module with an inductor And to supply a uniform current to the LED module by stabilizing the voltage to be applied to the LED module.

Particularly, the present invention can provide a stable DC voltage to the LED module by filtering the DC voltage obtained by removing the current ripple included in the direct current converted from the voltage to DC into the smoothing circuit by using the inductor to obtain the voltage to be used in the LED module There is another purpose of providing a converter for LED lighting control.

Further, the present invention constitutes a reflux diode to accumulate energy in the inductor when the switch is in the ON state, and to suppress the reverse directional electromotive force generated when the switch is turned off, so that the circuit is broken, The present invention also provides a converter for LED lighting control,

According to an aspect of the present invention, there is provided a converter for LED lighting control, including: a DC transformer; A smoothing circuit (10) connected to the secondary terminals (2, 4) of the DC transformer (T); A flicker-free circuit 20 connected to both ends of the smoothing circuit 10 to reduce current ripple (flicker); Two reflux diodes (D3, D4) connected in parallel between both ends of the output side of the flicker-free circuit (20); Two inductors L1 and L2 connected to opposite ends of the reflux diode D4 and connected in opposite polarity; And a blocking diode (30) connecting the inductors (L1, L2) and the LED module (M).

In particular, the smoothing circuit 10 includes two diodes D1 and D2 connected in parallel to the secondary terminal 2 of the DC transformer T; RC circuits (R4, C1) connected in series to each other and connected in parallel to the diodes (D1, D2); And two resistors R1 and R2 and capacitors EC1 and EC2 connected in parallel between the secondary terminals 2 and 4 of the DC transformer T. [

The flicker-free circuit 20 includes a flicker improvement circuit U1 connected in parallel to both ends of the smoothing circuit 10, and is connected to receive a voltage through the current limit resistor R3. .

Lastly, the blocking diode 30 is four diodes D5, D6, D7, and D8 connected in parallel to the inductors L1 and L2 in forward and reverse directions, respectively.

The LED lighting control converter according to the present invention has the following effects.

(1) One or several converters can control the LED module according to one or several switch operations.

(2) Especially, by having a flicker-free circuit in the converter, it is possible to eliminate eye fatigue by reducing the current ripple (flicker) phenomenon that the illuminance changes periodically like an adult in the LED module.

(3) At this time, the voltage output from the DC transformer is removed by a smoothing circuit and then filtered by the inductor to supply the LED module with a stable voltage. Thus, stable voltage can be supplied .

(4) Thus, the voltage supplied to the LED module can be stabilized and a uniform current can be supplied to the LED module.

(5) Further, since the present invention constitutes a reflux diode, it is possible to suppress the reverse directional electromotive force generated when the switch is turned off, thereby minimizing the occurrence of a circuit break or a noise signal.

(6) Even if several converters are connected, stable current can be stabilized without colliding with each other through a blocking diode.

(7) Since it is controlled on the secondary side of the DC transformer, it can be used without any circuit such as CC (Constant Current) circuit and CV (Constant Voltage) circuit. Therefore, it becomes possible to control the converter regardless of the type of the converter.

FIG. 1 is a block diagram showing an example of LED lighting using a converter for LED lighting control according to the present invention.
2 is a circuit diagram showing a configuration of a converter for LED lighting control according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms, and the inventor should properly define the concept of the term to describe its invention in the best possible way The present invention should be construed in accordance with the spirit and scope of the present invention.

Therefore, the embodiments described in the present specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and are not intended to represent all of the technical ideas of the present invention. Thus, various equivalents And variations may be present.

(Configuration)

The converter C for LED lighting control according to the present invention includes a DC transformer T, a smoothing circuit 10, a flicker-free circuit 20, two reflux diodes D3 , D4, two inductors L1 and L2, and a blocking diode 30.

In particular, the flicker-free circuit reduces the occurrence of flicker within the converter (C), and also improves the efficiency of the flicker-free circuit, stabilizes the voltage supplied to the LED module by the inductor while minimizing power dissipation, So that current can be supplied to the LED module.

The smoothing circuit removes the current ripple to obtain a DC voltage and filters the DC voltage with an inductor to obtain a voltage to be used in the LED module, thereby providing a stable DC voltage to the LED module.

In addition, the reflux diode allows energy to be stored in the inductor when the switch is in the ON state, and suppresses the reverse directional electromotive force generated when the switch is turned OFF, thereby minimizing the occurrence of circuit breakage or occurrence of work noise.

Finally, since the blocking diode 30 for preventing the reverse current is used, the circulating power between the circuits is cut off in a multi-parallel circuit in which a plurality of circuits are connected in parallel, thereby improving the efficiency of the entire converter, Thereby enabling the supply to be made.

Hereinafter, this configuration will be described in more detail with reference to the accompanying drawings. Here, the LED lighting to which the converter C for LED lighting control according to the present invention is applied will be briefly described, and the LED lighting control converter C will be described in detail.

LED lighting

As for the LED illumination, a commercial power source is used as shown in Fig. In this case, the commercial power source is a power source used for lighting in a home or an office, and the power source of AC 220V / 60㎐ is converted into DC.

Here, the commercial power source is a protection circuit that can be shut off when the converter C is not operating normally due to a failure of the converter C, which will be described later, and can be protected when an overload such as a surge voltage occurs due to external factors, Protect the product with a varistor. In addition, EMC filter operation is performed by using X-CAP (across-the-line capacitor) and line filter, and the neutral point of Y-CAP (line-bypass capacitor) connected in parallel with line filter is connected to ground, Reduces the conductive noise contained in the power supply so that it can be used safely and electrically.

The commercial power source that has been filtered so that it can be safely used is full-wave rectified by a bridge diode to obtain a DC voltage (220 V x 1.414). The DC voltage is stabilized via an LC filter, .

The commercial power supply switches an AC power source to a DC power source while passing through an SMPS (Switched Mode Power Supply) for LED power supply as the switch S is turned on / off to adjust the illuminance, .

At this time, current ripple (flicker) of 120 Hz occurs due to the characteristics of the full-wave rectification when the AC power is converted into the DC power. Here, the flicker refers to a phenomenon in which the LED illumination is blinking as the illuminance generated by the LED module is not constant and varies periodically with time.

The DC voltage obtained through the SMPS is supplied to the LED lighting control converter (C) to be described later.

<Converter for LED lighting control>

The LED lighting control converter C includes a DC transformer T, a smoothing circuit 10, a flicker-free circuit 20, two reflux diodes D3 and D4, two inductors L1 , L2), and a blocking diode (30).

DC transformer

The DC transformer T receives the DC converted by the SMPS to the primary side and converts the DC to the secondary side and supplies it to the secondary side as shown in Fig. 1 and Fig.

As such a DC transformer T, for example, a flyback transformer may be used. A flyback transformer is a conventional single-phase transformer used in a television receiver or the like to obtain a high voltage for a watercraft using a pulse generated during a retrace period of a horizontal deflection output.

Smoothing circuit

The smoothing circuit 10 is connected to the secondary side 2 and 4 of the above-described DC transformer T as shown in Fig. The smoothing circuit 10 may be any circuit that can remove the ripple included in the direct current when converting to a direct current such as a direct current generator or a rectifier. For example, the smoothing circuit 10 may be a low-pass filter composed of an iron core coil or a capacitor.

In the preferred embodiment of the present invention, the smoothing circuit 10 includes two diodes D1 and D2, RC circuits R4 and C1, and two resistors R1 and R2 And condensers EC1 and EC2. The two diodes D1 and D2 are connected in parallel to the secondary terminal 2 of the DC transformer T and the RC circuits R4 and C1 are connected in parallel with the diodes D1 and D2. Connect. The two resistors R1 and R2 and the capacitors EC1 and EC2 are connected in parallel to the secondary terminals 2 and 4 of the DC transformer T, respectively.

The smoothing circuit 10 thus formed removes the ripple included in the DC converted through the DC transformer T to make it close to the DC power source. In addition, the RC circuits R4 and C1 can obtain a stable DC voltage through the two diodes D1 and D2.

At this time, the DC voltage obtained through the smoothing circuit 10 has 120 Hz current ripple of a predetermined intensity. Thus, the flicker-free circuit 20 is used to remove the current ripple.

Flicker free  Circuit

The flicker free circuit 20 is connected to both ends of the smoothing circuit 10 as shown in Fig. 2, and any circuit capable of reducing the current ripple occurring in the smoothing circuit 10 Can be used.

2, the flicker-free circuit 20 includes a flicker improvement circuit U1 for reducing current ripple at a voltage converted to DC, and a current limiter for protecting the flicker improvement circuit U1, And a resistor R3. At this time, the current limit resistor R3 can protect the flicker improvement circuit U1 at the VCC voltage and protect the flicker improvement circuit U1 even when a high output voltage fluctuation occurs in the blocking diode 30 And the DC voltage supplied to the LED module (M).

2, the output voltage VCC of the flicker improvement circuit U1 is connected to the cathode (LED +) side of the LED module M. The GND of the output voltage is connected to the anode of the LED module M (LED-) side to reduce current ripple.

In the preferred embodiment of the present invention, the flicker-free circuit 20 is a flicker-free circuit in which the current ripple generated when the voltage is converted from the smoothing circuit 10 to DC is about 120 Hz, Can also be used.

Reflux diode

The reflux diodes D3 and D4 are connected in parallel to the output side of the above-described flicker-free circuit 20 as shown in Fig.

Here, the reflux diodes D3 and D4 refer to a diode manufactured by a conventional technique in which the load is connected in parallel with the load to prevent damage to the device due to an inductor charge current or the like.

Such reflux diodes D3 and D4 are used when the energy accumulated in the inductors L1 and L2 in the switch ON state forms a reverse direction electromotive force by switching OFF, as shown in Fig. 1 and Fig. 2 It emits a directional electromotive force to prevent damage to the equipment.

Inductor

As shown in Fig. 2, the inductors L1 and L2 are connected to two ends of the above-described reflux diode D4, one at each end.

Particularly, the inductors L1 and L2 are connected in such a manner that their polarities are opposite to each other, as shown in FIG. In other words, one of the inductors L1 is connected to the reflux diode D4 with a "+" pole and the other inductor L2 is connected to the reflux diode D4 with a "-" Connect them.

These inductors L1 and L2 are formed by a conventional technique using a filter that induces a voltage proportional to the amount of current change to prevent a sudden change in current and filters electrical noises and the like.

Blocking diode

The blocking diode 30 is connected to each of the above-described inductors L1 and L2 and the LED module M as shown in Fig. 2 to prevent a reverse current use.

In particular, as shown in FIG. 2, the blocking diode 30 is connected in parallel to two inductors L1 and L2, respectively, in a direction opposite to the forward direction, So that each converter voltage can safely be controlled without collision. That is, the blocking diode 30 cuts off the circulating power between the circuits in the multi-parallel circuit in which the respective circuits are connected in parallel, so that the efficiency of the entire converter can be increased and the power supply can be stably performed.

The diode capacity used for such a blocking diode 30 is selected to have a current intensity of 4 to 5 times the current flowing therethrough and a voltage having a sufficient margin so as to generate a voltage abnormality at both ends is used.

In the present invention as described above, the pulsating current output from the rectifying circuit is converted into a DC transformer, the converted power is made similar to the DC power by using a smoothing circuit, and then a smoothing process is performed using a flicker- Even if multiple converters are connected after reducing the generated current, the circulating power is cut off through the blocking diode, so that the efficiency of the converter can be increased and the power supply can be stably performed.

C: Converter for LED lighting control
D3, D4: Reflux diode
T: DC transformer
U1: flicker improvement circuit
10: Smoothing circuit
20: Flicker-free circuit
30: blocking diode

Claims (4)

DC transformer (T);
A smoothing circuit (10) connected to the secondary terminals (2, 4) of the DC transformer (T);
A flicker-free circuit 20 connected to both ends of the smoothing circuit 10 to reduce current ripple (flicker);
Two reflux diodes (D3, D4) connected in parallel between both ends of the output side of the flicker-free circuit (20);
Two inductors L1 and L2 connected to opposite ends of the reflux diode D4 and connected in opposite polarity; And
And a blocking diode (30) connected to each of the inductors (L1, L2) and the LED module (M).
The method of claim 1,
The smoothing circuit (10)
Two diodes D1 and D2 connected in parallel to the secondary terminal 2 of the DC transformer T;
RC circuits (R4, C1) connected in series to each other and connected in parallel to the diodes (D1, D2); And
And two resistors (R1 and R2) and capacitors (EC1 and EC2) connected in parallel between the secondary terminals (2 and 4) of the DC transformer (T).
The method of claim 1,
The flicker-free circuit (20)
And a flicker improvement circuit (U1) connected in parallel to both ends of the smoothing circuit (10), wherein a voltage is supplied through the current limit resistor (R3).
The method of claim 1,
The blocking diode (30)
D5, D6, D7, and D8 connected in parallel to the inductors L1 and L2 in forward and reverse directions, respectively.

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