KR102347770B1 - Ac direct led driver including micro controll unit - Google Patents

Abstract

A synchronous AC direct-coupled light emitting diode driving device is provided. A synchronous AC direct-coupled light emitting diode driving apparatus includes: a rectifying unit; a multi-channel light emitting diode unit including a first to Nth light emitting diode channel including at least one light emitting diode; a synchronous driver for mirroring the current flowing through the Mth light emitting diode channel (M<N, M is an integer greater than or equal to 1) and supplying it to the Nth light emitting diode channel; a sequential current driver controlling a path of a driving current flowing through the first to the Nth light emitting diode channel; a controller for controlling brightness or color temperature of the multi-channel light emitting diode unit; and a regulator connected to any one of the plurality of light emitting diodes included in the multi-channel light emitting diode unit to receive a power supply voltage of a preset level and provide a reference voltage to the controller.

Description

Synchronous AC direct-coupled light-emitting diode drive with controller {AC DIRECT LED DRIVER INCLUDING MICRO CONTROLL UNIT}

The present invention relates to a synchronous AC direct-coupled light-emitting diode driving device, and more particularly, to an AC direct-connected light-emitting diode driving device including a controller while having high efficiency and high current driving characteristics without using an inductor or a transformer.

When driving an LED, it is common to connect a controller for PWM dimming, analog dimming, or color temperature control to control the brightness of the LED lighting. A separate power supply, that is, a regulator, is required for the operation of such a controller.

1 shows a conventional converter-type light emitting diode driving device to which a controller and a regulator for supplying power to the controller are connected.

FIG. 1 is an LED driving device using a converter including a transformer or an inductor, in which the voltage of the input power is lowered by using the turns ratio of the transformer, and the voltage is supplied to the regulator. That is, the voltage of the input power is lowered to the level of the voltage of the power to be used by the controller with the turns ratio of the transformer, and the detailed appropriate voltage is adjusted using a separate regulator and then provided to the controller.

In the case of using the converter as described above, the system configuration is complicated and it is difficult to reduce the size and weight of the system. In addition, in order to improve the power factor, a separate power factor correction circuit must be used, and an additional circuit for suppressing the generation of electromagnetic waves generated during switching is required, so that the production cost is high.

2 illustrates a conventional AC direct-connected light emitting diode driving device to which a controller and a regulator for supplying power to the controller are connected.

In the case of an AC power direct-connected linear LED driving device that does not use a separate converter as shown in FIG. 2, since the current is directly controlled by using AC power, which is a commercial power, the circuit is simpler and power factor or electromagnetic waves are generated compared to the converter method. It shows excellent characteristics even without an additional compensation circuit for In addition, there is an advantage of a long lifespan and high reliability compared to the converter method, that is, SMPS (Switching Mode Power Supply).

However, a separate reference voltage source is required for various control of lighting through communication such as DALI (Digital Addressable Lighting Interface)　 or ZIGBEE. can make

However, since the AC direct connection type does not use a transformer or an inductor, there is a disadvantage in that the efficiency is very low as a general linear type reference voltage source that can be used compared to the switching type. Since the difference between the input voltage and the output voltage is large, the efficiency is very low when making a linear reference voltage source capable of driving a large current in a general way, or the THD (total harmonic distortion) characteristic deteriorates depending on the voltage forming method.

For example, in the case of converting AC 220V to a reference voltage of 12V, if the approximate efficiency is calculated, even at least 5.45% (12/220*100) is very low. In this case, it can be used when the current that can be supplied from the voltage regulator is very low (usually 12V/1mA or less) due to low efficiency and heat generation, etc. may not be suitable for

In order to drive a large current in an LED driving device that does not use a transformer or an inductor, as shown in FIG. 2 , a capacitor C having a large value is used to charge only in a low input voltage section, and in a high voltage section, a low section A method using the charged voltage is used.

When four LED channels are driven by receiving a low-level voltage as described above, a current waveform as shown in FIG. 3 may appear. Figure 3 shows the current waveform input to the LED channel when receiving low input power from the LED driving device for driving four LED channels,

When four LED channels are driven as shown in FIG. 2, the number of LED channels turned on and turned off is controlled according to the voltage level of the input power, and the current flowing through the LEDs is a step according to the number of LED channels turned on as shown in FIG. changed to brother

In addition, a high charging current is generated during a short charging time in a section in which the voltage level of the power supply is low. In the case of charging only in the low input voltage section and using the charged voltage in the low section in the high voltage section, the power factor decreases and THD increases significantly due to the high charging current generated during the short charging time, which is required for LED lighting. There is a problem in that the electrical characteristics of the product cannot be satisfied.

Therefore, it is necessary to develop an LED driving device capable of stably supplying power to the regulator while maintaining the advantages of an AC direct-connected light emitting diode driving device that does not use a separate SMPS and minimizing the degradation of power factor or THD characteristics. .

SUMMARY OF THE INVENTION An object of the present invention is to provide a synchronous AC direct-connected light emitting diode driving device capable of supplying stable power to a controller while having high efficiency and excellent power factor characteristics.

A synchronous light emitting diode driving apparatus according to an embodiment of the present invention includes: a rectifier for receiving and rectifying an AC power voltage; a multi-channel light emitting diode unit including a first light emitting diode channel to an Nth light emitting diode channel (N is an integer equal to or greater than 2) including at least one light emitting diode and receiving the rectified voltage from the rectifying unit to emit light; a synchronous driver for mirroring the current flowing in the Mth light emitting diode channel (M<N, M is an integer greater than or equal to 1) included in the multi-channel light emitting diode unit and supplying it to the Nth light emitting diode channel; a sequential current driver controlling a path of a driving current flowing through the first to the Nth light emitting diode channel according to different input voltage levels; a controller for controlling brightness or color temperature of the multi-channel light emitting diode unit; and a regulator connected to any one of the plurality of light emitting diodes included in the multi-channel light emitting diode unit to receive a power supply voltage of a preset level and provide a reference voltage to the controller.

According to an embodiment of the present invention, there is provided a synchronous AC direct-coupled light emitting diode driving device capable of supplying a stable power supply to a controller while having high efficiency and excellent power factor characteristics.

According to an embodiment of the present invention, a synchronous AC direct connection type capable of supplying stable power to the controller by adopting a multi-channel synchronous light emitting circuit capable of adjusting the connection state of the light emitting diode appropriately according to the level of the input voltage. A light emitting diode driving device is provided.

According to an embodiment of the present invention, there is provided a synchronous AC direct-connected light emitting diode driving device capable of easily connecting a voltage of a desired level to a regulator.

According to an embodiment of the present invention, since a high-frequency switching operation is not involved, there is no need for a noise filter such as an EMI filter, so the entire system is very simple and the manufacturing cost is reduced. do.

1 is a schematic diagram of a conventional converter-type light emitting diode driving device to which a controller and a regulator for supplying power to the controller are connected.
2 is a schematic diagram of a conventional AC direct-connected light emitting diode driving device to which a controller and a regulator for supplying power to the controller are connected.
FIG. 3 is a diagram illustrating an input current input to a light emitting diode according to an input voltage level in the AC direct-connected light emitting diode driving device of FIG. 2 .
4 is a view showing a synchronous multi-channel light emitting diode driving apparatus according to an embodiment of the present invention.
5 is a diagram illustrating a synchronous multi-channel light emitting diode driving device including a series current mirror unit according to an embodiment of the present invention.
6 is a diagram illustrating a synchronous multi-channel light emitting diode driving device including a parallel current mirror unit according to another embodiment of the present invention.
7 is a graph for explaining the operation of a synchronous multi-channel light emitting diode driving apparatus according to an embodiment of the present invention.
8 is a diagram illustrating a turn-on state of a light emitting diode channel for each section according to a synchronous multi-channel driving method according to an embodiment of the present invention.
9 is a graph illustrating a voltage applied to the last channel in an AC direct-connected light emitting diode driving device according to the related art and the present invention.
10 is a view showing a synchronous multi-channel light emitting diode driving apparatus according to another embodiment of the present invention.
11 is a graph illustrating a voltage applied to the regulator of FIG. 10 .
12 is a graph illustrating a current applied to a channel of the light emitting diode of FIG. 10 .
13 is a view showing a synchronous multi-channel light emitting diode driving apparatus according to another embodiment of the present invention.
14 is a diagram illustrating an example of a sequential current driver in the multi-channel light emitting diode driving apparatus of FIG. 13 .
15 is a diagram illustrating a form in which a current mirror unit is in parallel in another synchronous multi-channel light emitting diode driving device of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiment of the present invention may be modified in various other forms, and the scope of the present invention is not limited only to the embodiments described below. The shapes and sizes of elements in the drawings may be exaggerated for a clearer description, and elements indicated by the same reference numerals in the drawings are the same elements.

On the other hand, the meaning of the terms described in the present application should be understood as follows.

Terms such as “first” and “second” are for distinguishing one component from another, and the scope of rights should not be limited by these terms. For example, a first component may be termed a second component, and similarly, a second component may also be termed a first component.

And throughout the specification, when a part is "connected" with another part, it includes not only the case where it is "directly connected" but also the case where it is "electrically connected" with another element interposed therebetween. In addition, when a part "includes" or "includes" a certain component, it means that other components may be further included or provided without excluding other components unless otherwise stated. .

4 is a view showing a multi-channel light emitting diode driving apparatus according to an embodiment of the present invention.

As shown, the synchronous multi-channel light emitting diode driving apparatus according to an embodiment of the present invention includes a rectifying unit 100, a multi-channel light emitting diode unit 200, a synchronous driving unit 300, a sequential current driving unit 400, and a controller. 500 and a regulator 600 .

The rectifying unit 100 receives an AC power voltage from an AC power source (AC), rectifies the applied voltage, and supplies the rectified current to the multi-channel light emitting diode unit 200 . Here, the rectifier 100 may be a bridge diode, but is not limited thereto, and any circuit can be used as long as it can convert an alternating current that changes in both positive and negative directions into a current having only one direction. .

The multi-channel light emitting diode unit 200 receives the rectified voltage from the rectifier 100 and emits light, and the first light emitting diode channel 200-1 to the Nth light emitting diode channel N including at least one light emitting diode is an integer of 2 or greater, 200-N).

As described above, one light emitting diode channel includes at least one light emitting diode, and about 20 to 22 light emitting diodes may be connected in series to constitute one channel. The light emitting diodes included in the light emitting diode channel may be configured in parallel according to the current flowing through the light emitting diode or desired brightness.

In this embodiment, as an example, driving four light emitting diode channels (N=4) including all of the light emitting diodes connected in series. However, the connection state of the light emitting diode and the number of channels may be variously modified.

All of the light emitting diodes connected to one light emitting diode channel are turned on or off at the same time, and are driven as if one light emitting diode. Therefore, for convenience of description, a first light emitting diode channel including a plurality of light emitting diodes driven like one light emitting diode may be referred to as a first light emitting diode, and an N th light emitting diode channel may be referred to as an N th light emitting diode.

The synchronous driving unit 300 mirrors the current flowing in the M-th light-emitting diode channel (M<N, M is an integer greater than or equal to 1, 200-M) included in the multi-channel light-emitting diode unit 200 to mirror the N-th light-emitting diode channel ( 200-N). The synchronous driver 300 may include a current detector for detecting the current of the LED channel and a current mirror for mirroring the detected current. The current detection unit and the current mirror unit will be described in detail below with reference to FIGS. 5 to 6 .

The sequential current driver 400 may control a path of a driving current flowing through the first light emitting diode channel 200 - 1 to the Nth light emitting diode channel 200 -N according to different input voltage levels. In addition, the sequential current driving unit 400 activates the current detection unit according to the input voltage level, so that the current mirror unit mirrors the detected current, and through this, the mirrored current can be used as the driving current of the light emitting diode channel.

The controller 500 is connected between the sequential current driving unit 400 and the regulator 600 and corresponds to a control unit that performs control such as PWM dimming, analog dimming, or color temperature control with the multi-channel light emitting diode unit 200 . Typically, the controller 500 may be implemented as an external microcontroller unit (MCU), and the controller 500 is driven by receiving a separate power supply, not the power output from the rectifier 100 .

A control signal for PWM dimming, analog dimming, or color temperature control is input to the sequential current driving unit 400 , and the sequential current driving unit 400 is a multi-channel light emitting diode unit 200 according to a control signal input from the controller 500 . By controlling the turn-on period and turn-on time, the dimming and color temperature of the light emitting diode are controlled.

The regulator 600 is a power supply device for supplying power to the controller 500 , and generates a reference power of a level usable by the controller 500 by receiving power of a certain level.

The regulator 600 is connected to any one of the plurality of light emitting diodes included in the multi-channel light emitting diode unit 200 and receives a power supply voltage of a preset level from a corresponding node. As shown, the regulator 600 according to the present embodiment is connected to the Nth light emitting diode channel 200 -N, that is, the last fourth light emitting diode channel 200 - 4 , and the fourth light emitting diode channel 200 . It may be connected between any one of the light emitting diodes included in -4).

As in the present embodiment, when the multi-channel light emitting diode unit 200 is driven by the synchronous driving unit 300 rather than the general driving method shown in FIGS. 1 and 2 , power can be stably supplied without a reduction in power factor. Hereinafter, a method of synchronously driving the multi-channel light emitting diode unit 200 by the synchronous driving unit 300 will be described.

5 is a diagram illustrating a synchronous multi-channel light emitting diode driving device including a series current mirror unit according to an embodiment of the present invention.

As shown, the synchronous driving unit 300 according to the present embodiment includes current detection units 311 , 312 , 313 , current mirror units 321 , 322 , 323 , and diodes 331 , 332 , 333 .

The current detectors 311 , 312 , and 313 are connected to the first light emitting diode channel 210 to the N-1th light emitting diode channel, and in this embodiment, the third light emitting diode channel 230 to detect current flowing in each channel. .

The current mirror units 321 , 322 , and 323 generate a mirroring current by the current detected by the current detection units 311 , 312 , and 313 , and the diodes 331 , 332 , 333 form the M-th light emitting diode channel (M<N). , M is an integer greater than or equal to 1) receives the mirrored current and transmits it to the M+1th light emitting diode channel, and prevents the mirrored current from flowing back into the Mth light emitting diode channel.

The first light emitting diode channel 210 may have an anode connected to the positive (+) terminal of the bridge diode 110 and a cathode connected to the anode of the first diode 331 to emit light when current is conducted.

Meanwhile, the second light emitting diode channel 220 may have an anode connected to the cathode of the first diode 331 and a cathode connected to the anode of the second diode 332 to emit light when current is conducted.

In addition, the third light emitting diode channel 230 has an anode connected to the cathode of the current second diode 332 and a cathode connected to the anode of the third diode 333 to emit light when current is conducted.

Meanwhile, in the fourth light emitting diode channel 240 , an anode is connected to the cathode of the third diode 333 , and a cathode is sequentially connected to the current driver 400 to emit light when current is conducted. At this time, the cathode of the fourth light emitting diode channel 240 is a MOSFET (Metal Oxide Silicon Field Effect Transistor, not shown) in which the sequential current driver 400 receives the gate voltage and conducts the current input from the drain terminal to the source terminal. ), may be connected to the drain terminal of this MOSFET, but is not limited thereto.

In addition, one node between the light emitting diodes included in the fourth light emitting diode channel 240 is connected to the regulator 600 . Through this, a voltage of a specific level applied between the light emitting diodes may be supplied to the regulator 600 .

In the case of the 4-channel type as in the present embodiment, the synchronous multi-channel light emitting diode driving apparatus may include three current detection units 311 , 312 , and 313 .

First, the first current detector 311 has a first terminal connected to the cathode of the first light emitting diode channel 210 to detect a current flowing through the first light emitting diode channel 210 , and the second terminal is connected to the first current It is connected to the mirror 321 , and a third terminal is connected to the sequential current driver 400 to provide the detected current to the sequential current driver 400 . At this time, when the third terminal of the first current detection unit 311 includes a MOSFET that conducts the current I1 input from the drain terminal to the source terminal when the sequential current driver 400 receives the gate voltage, such a case It may be connected to the drain terminal of the MOSFET, but is not limited thereto.

The connection method and current detection of the second current detection unit 312 and the third current detection unit 313 may correspond similarly to the method of the first current detection unit 311 when referring to FIG. 5 , so the overlapping description will be is omitted.

The currents detected by the current detectors 311 , 312 , and 313 are generated as mirroring currents by the three current mirrors 321 , 322 , and 323 .

As shown, the first current mirror unit 321 has a first terminal connected to the anode of the first light emitting diode channel 210 , and a second terminal connected to the second terminal of the first current detection unit 311 , , a third terminal is connected to the cathode of the first diode 331 and the anode of the second light emitting diode channel 220 . Here, the first current mirror unit 321 mirrors the current detected by the first current detection unit 311 , that is, the current flowing through the first light emitting diode channel 210 to the second light emitting diode channel 220 . However, the mirrored current is not limited to the same magnitude as the current flowing through the first light emitting diode channel 210 and may have a proportional relationship with the current flowing through the first light emitting diode channel 210 .

In this case, the first diode 331 has an anode connected to the cathode of the first light emitting diode channel 210 , and the cathode is the anode of the second light emitting diode channel 220 and the third terminal of the first current mirror unit 321 . It is connected to and serves to prevent the current mirrored by the first current mirror unit 321 from flowing backward into the first light emitting diode channel 210 .

In addition, the connection method of the second current mirror unit 322, the third current mirror unit 323, the second diode 332 and the third diode 333, the current mirroring, the strength of the mirrored current, and the role of preventing the backflow are Referring to FIG. 5 , the method may be similar to that of the first current mirror unit 321 and the first diode 331 , and thus overlapping descriptions will be omitted.

In addition, the sequential current driver 400 includes a switching element therein, and conducts currents in different paths depending on the input voltage level. does not conduct, in section 1, the first input current I1 conducts only in the first path, in section 2, the second input current I2 conducts only in the second path, in section 3, only in the third path The input current I3 may conduct, and in section 4, the fourth input current I4 may conduct only on the fourth path.

6 is a diagram illustrating a synchronous multi-channel light emitting diode driving device including a parallel current mirror unit according to another embodiment of the present invention. The synchronous multi-channel light emitting diode driving device shown in FIG. 6 differs from the synchronous multi-channel light emitting diode driving device shown in FIG. 5 only in the connection structure of the current mirror units 321, 322, and 323, so that Components are given the same reference numerals as in FIG. 5, and a description thereof will be omitted for convenience.

First, the fourth current mirror unit 324 has a first terminal connected to the anode of the first light emitting diode channel 210 , and a second terminal connected to the second terminal of the first current detection unit 311 , The third terminal is the cathode of the first diode 331 and the anode of the second light emitting diode channel 220 , the fourth terminal is the anode of the third light emitting diode channel 230 and the third terminal of the fifth current mirror unit 325 . , a fifth terminal is connected to the anode of the fourth light emitting diode channel 240 , a fourth terminal of the fifth current mirror unit 325 , and a third terminal of the sixth current mirror unit 326 .

Here, the fourth current mirror unit 324 mirrors the current detected by the first current detection unit 311 , that is, the current flowing through the first light emitting diode channel 210 to the second light emitting diode channel 220 , the second The third light emitting diode channel 230 and the fourth light emitting diode channel 240 are transmitted, and the mirrored current is not limited to the same size as the current flowing through the first light emitting diode channel 210 and is not limited to the first light emitting diode channel. It may have a proportional relationship with respect to the current flowing in 210 .

In addition, the fifth current mirror unit 325 has a first terminal connected to the anode of the second light emitting diode channel 220 , and a second terminal connected to the second terminal of the second current detection unit 312 , The third terminal is the cathode of the second diode 332 , the anode of the third light emitting diode channel 230 , and the fourth terminal of the fourth current mirror unit 324 , and the fourth terminal is the fourth terminal of the fourth current mirror unit 324 . The fifth terminal is connected to the third terminal of the sixth current mirror unit 326 and the anode of the fourth light emitting diode channel 240 .

Here, the fifth current mirror unit 325 mirrors the current detected by the second current detection unit 312 , that is, the current flowing through the second light emitting diode channel 220 , and includes the third light emitting diode channel 230 and The current is transmitted to the fourth light emitting diode channel 240 , and the mirrored current is not limited to the same size as the current flowing through the second light emitting diode channel 220 , but with respect to the current flowing through the second light emitting diode channel 220 . They may have a proportional relationship.

Meanwhile, the sixth current mirror unit 326 has a first terminal connected to the anode of the third light emitting diode channel 230 and a second terminal connected to the second terminal of the third current detection unit 313 , 3 terminals are connected to the cathode of the third diode 333 , the anode of the fourth light emitting diode channel 240 , the fifth terminal of the fourth current mirror unit 324 , and the fourth terminal of the fifth current mirror unit 325 . do.

Here, the sixth current mirror unit 326 mirrors the current detected by the third current detection unit 313 , that is, the current flowing through the third light emitting diode channel 230 to the fourth light emitting diode channel 240 . However, the mirrored current is not limited to the same magnitude as the current flowing through the third light emitting diode channel 230 and may have a proportional relationship with the current flowing through the third light emitting diode channel 230 .

7 is a graph for explaining the operation of a synchronous multi-channel light emitting diode driving apparatus according to an embodiment of the present invention.

4 to 7, in the synchronous multi-channel light emitting diode driving device according to an embodiment of the present invention, the input voltage (V _IN ) slightly exceeds the _{driving voltage (V LED1} ) of the first light emitting diode channel 210 The operation of driving all the light emitting diode channels 210 , 220 , 230 , and 240 even when a low voltage corresponding to the degree is applied will be described below.

At this time, the voltage value and the current value on the graph are sufficient to indicate the transition in order to explain the operation of the present invention, and the detailed numerical values are not important. will be self-evident by

First, when the input voltage (V _{IN ) is less than the driving voltage (V LED1} ) of the first light emitting diode channel 210 (section 0), that is, when it is less than the minimum turn-on voltage, the driving current ( Since I _IN ) does not flow, all of the light emitting diode channels 210 , 220 , 230 , and 240 are turned off.

On the other hand, the input voltage (V _IN ) is equal to or greater than the driving voltage (V _LED1 ) of the first light emitting diode channel 210 and the driving voltage of the first light emitting diode channel 210 and the driving voltage of the second light emitting diode channel 220 . When the sum (V _LED1 + V _LED2 ) is less than or equal to (section 1), the first path of the sequential current driver 400 conducts and the first input current I1 flows through the first light emitting diode channel 210 .

At this time, the current flowing through the first light emitting diode channel 210 is detected by the first current detecting unit 311, and the detected current is mirrored by the first current mirroring unit 321 to the second light emitting diode channel ( 220) will flow.

In addition, the current flowing through the second light emitting diode channel 220 is detected by the second current detection unit 312, and the detected current is mirrored by the second current mirror unit 322 to the third light emitting diode channel ( 230) will flow.

On the other hand, the current flowing through the third light emitting diode channel 230 is detected by the third current detection unit 313, the detected current is mirrored by the third current mirror unit 323 to the fourth light emitting diode channel ( 240) will flow.

Accordingly, the input voltage V _IN is equal to or greater than the driving voltage V _LED1 of the first light emitting diode channel 210 and the driving voltage of the first light emitting diode channel 210 and the driving voltage of the second light emitting diode channel 220 . Even if the sum (V _LED1 + V _LED2 ) or less, the first driving current (I _LED1 ) _{A, a second driving current I LED2} is provided in the second light emitting diode channel 220 _{, a third driving current I LED3 is} provided in the third light emitting diode channel 230 , and a second driving current I LED3 is provided in the fourth light emitting diode channel 240 . 4 driving current (I _LED4 ) flows so that all of the four light emitting diode channels 210 , 220 , 230 , and 240 may be turned on.

In addition, the input voltage V _{IN is greater than the sum (V LED1} + V _LED2 ) of the driving voltage of the first light emitting diode channel 210 and the driving voltage of the second light emitting diode channel 220 and the first light emitting diode channel 210 ) to the sum of the driving voltages of the third light emitting diode channel 230 (V _LED1 + V _LED2 + V _LED3 ) or less (section 2), the first path in the sequential current driving unit 400 is blocked, Only the second path conducts so that the second input current I2 flows. Accordingly, the second input current I2 flows through the first light emitting diode channel 210 and the second light emitting diode channel 220 .

At this time, the current flowing through the second light emitting diode channel 220 is detected by the second current detection unit 312, and the detected current is mirrored by the second current mirror unit 322 to the third light emitting diode channel ( 230) will flow.

On the other hand, the current flowing through the third light emitting diode channel 230 is detected by the third current detection unit 313, the detected current is mirrored by the third current mirror unit 323 to the fourth light emitting diode channel ( 240) will flow.

Accordingly, the input voltage V _{IN is greater than the sum (V LED1} + V _LED2 ) of the driving voltage of the first light emitting diode channel 210 and the driving voltage of the second light emitting diode channel 220 and the first light emitting diode channel 210 . ) to the sum of the driving voltages of the third light emitting diode channel 230 (V _LED1 + V _LED2 + V _LED3 ) or less, the three light emitting diode channels 220 , 230 , 240 are in parallel, here As in the case where the first light emitting diode channel 210 is connected in series, the first driving current I _LED1 is applied to the first light emitting diode channel 210 and the second driving current I _{LED2 is supplied to the second light emitting diode channel 220 . ), the third driving current (I LED3} ) flows through the third light emitting diode channel 230 , and _{the fourth driving current (I LED4} ) flows through the fourth light emitting diode channel 240 , so that the four light emitting diodes 210 and 220 , 230 and 240) may all be turned on.

That is, according to the conventional circuit, even in the period in which the operation of the third light emitting diode channel 230 and the fourth light emitting diode channel 240 is impossible, the current of the second light emitting diode channel 220 is regenerated to the third light emitting diode channel 230 . ) and the fourth light emitting diode channel 240 may be operated.

In addition, the input voltage V _{IN is greater than the sum (V LED1} + V _LED2 + V _LED3 ) of the driving voltage of the first light emitting diode channel 210 to the driving voltage of the third light emitting diode channel 230 and the first light emitting diode _{When it is less than the sum (V LED1} + V _LED2 +V _LED3 + V _LED4 ) of the driving voltage of the channel 210 to the driving voltage of the fourth light emitting diode channel 240 (section 3), the sequential current driving unit 400 in the The first path and the second path are cut off, and only the third path conducts, so that the third input current I3 flows. Accordingly, the third input current I3 flows through the first to third light emitting diode channels 210 to 230 .

At this time, the current flowing through the third light emitting diode channel 230 is detected by the third current detecting unit 313, and the detected current is mirrored by the third current mirroring unit 323 to the fourth light emitting diode channel ( 240) will flow.

Accordingly, the input voltage V _{IN is greater than the sum (V LED1} + V _LED2 + V _LED3 ) of the driving voltage of the first light emitting diode channel 210 to the driving voltage of the third light emitting diode channel 230 and the first light emitting diode Even when the sum of the driving voltage of the channel 210 to the driving voltage of the fourth light emitting diode channel 240 (V _LED1 + V _LED2 + V _LED3 + V _LED4 ) or less, the two light emitting diode channels 230 and 240 are parallel Here, as in the case where the first light emitting diode channel 210 and the second light emitting diode channel 220 are connected in series, the first driving current I _LED1 is the first light emitting diode channel 210, and the second light emission The diode channel 220 has a second driving current I _LED2 , the third light emitting diode channel 230 has a third driving current I _LED3 , and the fourth light emitting diode channel 240 has a fourth driving current I _LED4 ) flows so that all four light emitting diode channels 210 , 220 , 230 , and 240 may be turned on.

That is, according to the conventional circuit, even in a section in which the operation of the fourth light emitting diode channel 240 is impossible, the current of the third light emitting diode channel 230 may be regenerated to operate the fourth light emitting diode channel 240 .

In addition, when the input voltage (V _IN ) is greater than _{the sum (V LED1} + V _LED2 + V _LED3 + V _LED1 ) of the driving voltage of the first light emitting diode channel 210 to the driving voltage of the fourth light emitting diode channel 240 ) In (section 4), the first to third paths in the sequential current driving unit 400 are cut off, and only the fourth path is conducted so that the fourth input current I4 flows. Accordingly, the fourth input current I4 flows through the first light emitting diode channel 210 to the fourth light emitting diode channel 240 , and all current detection units 311 , 312 , 313 and all current mirror units 321 , 322 and 323) do not work.

That is, as described above, the synchronous multi-channel light emitting diode driving apparatus according to an embodiment of the present invention may perform an operation similar to changing the connection state of the plurality of light emitting diodes according to the level of the input voltage.

On the other hand, when some of the plurality of light emitting diode channels operate as if they are connected in parallel, the magnitude of the currents (I _LED1 to I _LED4 ) flowing through each light emitting diode is determined by the plurality of current detectors 311 , 312 , 313 and the plurality of currents. This can be changed through adjustment of the mirrors 321 , 322 , 323 .

For example, when all the light emitting diode channels 210, 220, 230, 240 are connected in parallel according to the _{input voltage (V IN ), the first light emitting diode channel 210 to the second light emitting diode channel (} The mirroring current transferred to 220 is a current value that is three times the first input current I1, and the mirroring current transferred from the second light emitting diode channel 220 to the third light emitting diode channel 230 is the second 2 The current value is equal to twice the input current I2, and the mirroring current transferred from the third light emitting diode channel 230 to the fourth light emitting diode channel 240 is the same as the third input current I3. value can be

On the other hand, in the power factor characteristic of the synchronous multi-channel light emitting diode driving device according to an embodiment of the present invention, the sequential current driving unit 400 determines the finally flowing current, so the first input current set in the sequential current driving unit 400 ( It is determined by the magnitude of I1) to the fourth input current I4 and is not affected by the operations of the current detectors 311, 312, and 313 and the current mirrors 321, 322, and 323.

Accordingly, when the magnitudes of the first input current I1 to the fourth input current I4 set in the sequential current driver 400 are adjusted, the plurality of light emitting diode channels 210 , 220 , 230 , and 240 according to a change in the input voltage level. ) can adjust the size of the current (I _LED1 ~ I _LED4 ) flowing in, in this case, the power factor value is the first input current (I1) to the fourth input current (I4) set in the sequential current driving unit 400 will change accordingly.

8 is a diagram illustrating a turn-on state of a light emitting diode channel for each section according to a synchronous multi-channel driving method according to an embodiment of the present invention.

As described above, unlike the conventional AC direct-coupled light emitting diode driving, current may flow in the light emitting diode channels 210 , 220 , 230 , and 240 in all sections.

In section 1, only the first light emitting diode channel 210 is turned on, but the current is mirrored in the remaining light emitting diode channels 220, 230, and 240, so that the first light emitting diode channel 210 and the remaining light emitting diode channels 220, 230, 240 ) is driven as if they were connected in parallel.

In section 2, only the first light emitting diode channel 210 and the second light emitting diode channel 220 are turned on, but the current is mirrored in the remaining light emitting diode channels 230 and 240 to the second light emitting diode channel 220 and the remaining light emitting diodes. Channels 230 and 240 are driven as if they are connected in parallel.

In section 3, the first light emitting diode channel 210, the second light emitting diode channel 220, and the third light emitting diode channel 230 are turned on, but the current is mirrored in the fourth light emitting diode channel 240 to the third light emitting diode The channel 230 and the fourth light emitting diode channel 240 are driven as if they are connected in parallel.

As described above, when a plurality of light emitting diode channels are driven synchronously, a voltage of a predetermined level may be applied to the last light emitting diode channel as well.

9 is a graph illustrating a voltage applied to the last channel in an AC direct-connected light emitting diode driving device according to the related art and the present invention.

Typically, the voltage drop from the first light emitting diode channel to the fourth light emitting diode channel is about 80 to 85% of the peak voltage of the input power, and assuming that the voltage drop by each light emitting diode channel is the same, The voltage drop by (approximately 80-85% of the peak voltage) becomes /4. For example, when the input power is 220VAC, the peak voltage is about 311V and the voltage drop by the entire LED channel is about 260V, so the voltage drop (V _F ) by the fourth LED channel is about 65V.

After power is supplied to the third light emitting diode channel, the voltage V _A is applied to the point A of the last light emitting diode channel shown in FIG. 2 . When four LED channels are driven, _{it can be assumed that the voltage drop (V F} ) generated in one LED channel is about 65V as described above. As shown in FIG. 9 , the voltage at point A of the fourth light emitting diode channel is maintained at 0V when the first light emitting diode channel and the second light emitting diode channel are turned on, and then the third light emitting diode channel is turned on (t ₃ ) rise from When the voltage at point A becomes 65V, it can be seen that current starts to flow in the fourth light emitting diode channel.

On the other hand, in the case of a multi-channel LED driving device as in the present invention (the embodiment of FIG. 5), when the first LED channel 210 operates, all LED channels are operated, so even at point B of the last LED channel. _{A voltage (V F} =65V) according to the voltage drop of the first light emitting diode channel 210 may be applied. The voltage V B at point _B may increase when the fourth light emitting diode channel is turned on, and then maintain 65V after the fourth light emitting diode channel is turned off.

In summary, if the multi-channel light emitting diode is driven in a synchronous driving manner as in the present invention, the last light emitting diode channel of the plurality of light emitting diode channels can always maintain a turned-on state, which is always lower than the input voltage in the last light emitting diode channel. It means that more voltage is applied. The regulator 600 according to the present embodiment may generate a voltage having a level similar to a desired voltage by connecting one node inside the last light emitting diode channel as a power source. Since the difference between the high input voltage and the low voltage flows into the light emitting diode channel and is emitted as light, the efficiency does not decrease even if the voltage is changed from a high power supply to a low voltage unlike the existing method.

10 is a view showing a multi-channel light emitting diode driving apparatus according to another embodiment of the present invention.

As shown, the multi-channel light emitting diode driving apparatus according to the present embodiment may further include a peak resistor 700 connected between the multi-channel light emitting diode unit 200 and the regulator 600 .

The peak resistor 700 serves to reduce the charging current shown in FIG. 3 , that is, the peak current due to charging, and may be replaced by a current source or the like.

_{As shown, the voltage drop (V F} ) occurring in each of the four light emitting diode channels 210 , 220 , 230 , 240 is about 65V, and the power line of the regulator 600 is the fourth light emitting diode channel 240 . Among the light emitting diodes, it is connected to the node where the voltage drop is 55V. This indicates that the _{reference voltage V REF} desired to be input to the regulator 600 is 10V.

11 is a graph illustrating a voltage applied to the regulator of FIG. 10 , and FIG. 12 is a graph illustrating a current applied to a channel of the light emitting diode of FIG. 10 .

When the power of the regulator 600 is connected to a point where a voltage drop of 10V is expected among the plurality of light emitting diodes of the fourth light emitting diode channel 240 , the 10V reference voltage V _REF as shown in FIG. 11 is applied to the regulator 600 . can be

Since the peak current of FIG. 3 is reduced by the peak resistor 700, it can be confirmed through FIG. 12 that the waveforms of the current input to the multi-channel light emitting diode unit 200 and the current input by the regulator 600 are very similar. can

13 is a view showing a multi-channel light emitting diode driving apparatus according to another embodiment of the present invention.

The synchronous multi-channel light emitting diode driving apparatus according to another embodiment of the present invention performs all the functions of the current detection units 311 , 312 , 313 and the sequential current driving unit 400 of the synchronous multi-channel light emitting diode driving apparatus shown in FIG. 5 . It includes a sequential current driving unit 410 to perform. Here, except for the current detectors 311 , 312 , and 313 and the sequential current driver 400 , the rest of the configuration is similar to the configuration shown in FIG. 5 , and thus reference numerals and detailed descriptions will be omitted for convenience.

The sequential current driving unit 410 detects the current flowing through the multi-channel light emitting diode unit 200 and transmits it to the current mirror units 321 , 322 , 323 , and the function of the sequential current driving unit 410 has various types. It may be formed by combining with , which will be described below.

14 is a view showing an example of a sequential current driving unit 410 of a synchronous multi-channel light emitting diode driving device according to another embodiment of the present invention. It is a diagram illustrating an example.

The sequential current driver 410 receives the gate voltages V1, V2, V3, and V4, and conducts the currents I1, I2, I3, I4 input to the drain terminal to the source terminal. 410b), are connected in parallel to the gate and source terminals of the current driving MOSFET 410a to proportionally detect the current flowing in the first light emitting diode channel 210 (I1', I2', I3') ) may include a MOSFET 410b for current detection (in this case, the detection current corresponds to I1').

For example, the first current driving MOSFET 410a in the sequential current driving unit 410 receives an input voltage having an input voltage level as a gate, and a drain terminal is connected to the cathode of the first light emitting diode channel 210 . The source terminal is connected to the rectifier and turned on according to the first input voltage V1. For example, the input voltage level is equal to or greater than the driving voltage of the first light emitting diode channel 210. The first light emitting diode channel 210 When the sum of the driving voltage of , and the driving voltage of the second light emitting diode channel 220 is less than or equal to the sum of the driving voltage of , the first input current I1 may be conducted.

In addition, the first current detection MOSFET 410b, the gate is connected to the gate of the first current driving MOSFET 410a, the source terminal is connected to the source terminal of the first current driving MOSFET 410a, 1 is turned on according to the input voltage V1. For example, the input voltage level is equal to or greater than the driving voltage of the first light emitting diode channel 210, the driving voltage of the first light emitting diode channel 210 and the second light emitting diode channel 220 ), it may be turned on to conduct the detection current I1' when it is less than or equal to the sum of driving voltages.

Meanwhile, the second current driving MOSFET 410c receives an input voltage through a gate, a drain terminal is connected to the cathode of the second light emitting diode channel 220 , and a source terminal is connected to a rectifying unit, so that the second input voltage It is turned on according to (V2). For example, when the input voltage level exceeds the sum of the driving voltage of the first light emitting diode channel 210 and the driving voltage of the second light emitting diode channel 220, it is turned on and the second The input current I2 can be conducted.

In addition, the second current sensing MOSFET 410d has a gate connected to the gate of the second current driving MOSFET 410c, and a source terminal connected to the source terminal of the second current driving MOSFET 410c, 2 It is turned on according to the input voltage V2. For example, when the input voltage level exceeds the sum of the driving voltage of the first light emitting diode channel 210 and the driving voltage of the second light emitting diode channel 220 It may be turned on to conduct the detection current I2'.

15 is a diagram illustrating a form in which a current mirror unit is in parallel in another multi-channel light emitting diode driving device of the present invention.

Also in the synchronous multi-channel light emitting diode driving device according to another embodiment of the present invention as shown in FIG. 15 , the sequential current driving unit 410 in which the current detecting unit and the driving unit are merged as shown in FIGS. 13 and 14 is combined The structure may be applied, and since the rest of the configuration except for the sequential current driver 410 is similar to the configuration shown in FIG. 6 , reference numerals and detailed descriptions will be omitted for convenience.

As described above, the synchronous multi-channel light emitting diode driving device according to the present invention can achieve high efficiency without reducing characteristics such as power factor. In the case of the existing method, the power factor and THD characteristics are deteriorated, or the efficiency is very low. , inductors (transformers), etc., become very bulky. However, according to the present invention, if the connection line in the last channel is changed and a synchronous method is used, power supply having high efficiency and excellent characteristics such as power factor can be provided.

The present invention described above is not limited to the above-described embodiments and drawings, and it is common knowledge in the field to which the present invention pertains that any number of substitutions, changes and modifications are possible within the scope without departing from the technical spirit of the present invention. It will be clear to those who have

100: rectifying unit 200: multi-channel light emitting diode unit
300: synchronous driving unit 311, 312, 313: current detection unit
321, 322, 323, 324, 325, 326: current mirror unit
400, 410: sequential current driver
500: controller 600: regulator
700: peak resistance

Claims (11)

a rectifying unit for receiving and rectifying an AC power voltage;
a multi-channel light emitting diode unit including a first light emitting diode channel to an Nth light emitting diode channel (N is an integer equal to or greater than 2) including at least one light emitting diode and receiving the rectified voltage from the rectifying unit to emit light;
a synchronous driver for mirroring the current flowing in the Mth light emitting diode channel (M<N, M is an integer greater than or equal to 1) included in the multi-channel light emitting diode unit and supplying it to the Nth light emitting diode channel;
a sequential current driver controlling a path of a driving current flowing through the first to the Nth light emitting diode channel according to different input voltage levels;
a controller for controlling brightness or color temperature of the multi-channel light emitting diode unit;
and a regulator connected to any one of the plurality of light emitting diodes included in the multi-channel light emitting diode unit to receive a power supply voltage of a preset level and provide a reference voltage to the controller,
The regulator is connected to any one of the plurality of light emitting diodes included in the Nth light emitting diode channel included in the multi-channel light emitting diode unit and connected in series with each other,
When a voltage drop occurs in each of the first to Nth light emitting diode channels connected in series, the regulator is positioned at a point where a voltage drop to the reference voltage is expected among the plurality of light emitting diodes of the Nth light emitting diode channel connected,
The synchronous driver detects a current flowing in each of the first to N-1th light emitting diode channels, and the synchronous driver generates a mirroring current by the detected current, and mirrors in the Mth light emitting diode channel. A synchronous light emitting diode driving device, characterized in that the received current is transmitted to the M+1th light emitting diode channel. delete According to claim 1,
The synchronous light emitting diode driving apparatus according to claim 1, further comprising a peak resistor or a current source connected in series between the multi-channel light emitting diode unit and the regulator to reduce a peak current. According to claim 1,
The synchronous drive unit,
a current detection unit connected to the first to N-1th light emitting diode channels to detect a current flowing in each channel;
a current mirror unit for generating a mirroring current based on the current detected by the current detection unit;
A synchronous light emitting diode comprising a diode that receives the mirrored current from the Mth light emitting diode channel and transmits it to the M+1th light emitting diode channel, and prevents the mirrored current from flowing back into the Mth light emitting diode channel. drive device. 5. The method of claim 4,
The synchronous light emitting diode driving apparatus according to claim 1, wherein the current mirror unit includes a series mirror unit for mirroring the current detected in the Mth light emitting diode channel to the M+1th light emitting diode channel. 5. The method of claim 4,
The current mirror unit includes a parallel mirror unit for mirroring the current detected in the Mth light emitting diode channel to the M+1th light emitting diode channel to the Nth light emitting diode channel. a rectifying unit for receiving and rectifying an AC power voltage;
a multi-channel light emitting diode unit including a first light emitting diode channel to an Nth light emitting diode channel (N is an integer equal to or greater than 2) including at least one diode and receiving the rectified voltage from the rectifying unit to emit light;
a current mirror unit for mirroring the current flowing in the Mth light emitting diode channel (M<N, M is an integer greater than or equal to 1) included in the multi-channel light emitting diode unit and supplying it to the Nth light emitting diode channel;
Detecting the current flowing through the first light emitting diode channel to the N-1th light emitting diode channel, and controlling the path of the driving current flowing through the first light emitting diode channel to the N th light emitting diode channel according to different input voltage levels a sequential current driver;
a controller for controlling brightness or color temperature of the multi-channel light emitting diode unit;
and a regulator connected to any one of the plurality of light emitting diodes included in the multi-channel light emitting diode unit to receive a power supply voltage of a preset level and provide a reference voltage to the controller,
The regulator is connected to any one of the plurality of light emitting diodes included in the Nth light emitting diode channel included in the multi-channel light emitting diode unit and connected in series with each other,
When a voltage drop occurs in each of the first to Nth light emitting diode channels connected in series, the regulator is positioned at a point where a voltage drop to the reference voltage is expected among the plurality of light emitting diodes of the Nth light emitting diode channel connected,
A current detection unit for detecting a current flowing through each of the first to N-1th light emitting diode channels is provided,
The current mirror unit generates a mirroring current according to the detected current, and receives the mirrored current from the Mth light emitting diode channel and transmits the mirrored current to the M+1th light emitting diode channel. delete 8. The method of claim 7,
The synchronous light emitting diode driving apparatus according to claim 1, further comprising a peak resistor or a current source connected in series between the multi-channel light emitting diode unit and the regulator, and reducing a peak current. 8. The method of claim 7,
The synchronous light emitting diode driving apparatus according to claim 1, wherein the current mirror unit includes a series mirror unit for mirroring the current detected in the Mth light emitting diode channel to the M+1th light emitting diode channel. 8. The method of claim 7,
The current mirror unit includes a parallel mirror unit for mirroring the current detected in the Mth light emitting diode channel to the M+1th light emitting diode channel to the Nth light emitting diode channel.

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