KR101964681B1 - A free voltage led driving device with high uniformity ratio between LEDs - Google Patents

Abstract

The present invention discloses a high luminous uniformity prevoltage LED driving apparatus. This device includes: a rectifying device that receives an AC voltage from the outside to rectify and output a DC voltage; A plurality of LED arrays connected in series to each other to apply the direct current voltage to emit the light emitting diodes; A plurality of current drain switch elements positioned between each of the plurality of LED arrays and receiving a current outputted from each of the plurality of LED arrays and outputting a plurality of currents having a drain current value; A series type switch element which receives the plurality of currents and controls the transfer of current in accordance with opening and closing of a plurality of built-in transistors; A current control variable resistor connected to the series-type switching device and having a resistance variable when the applied AC voltage changes, so that power is constantly output; And a voltage sensing circuit part connected to one end of the rectifying device to sense the direct current voltage and the other end of the current sensing device connected to the current control variable resistor part to control the variation of the resistance value.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a free voltage LED driving device,

The present invention relates to an AC voltage direct-coupled LED driving apparatus, and more particularly, it relates to an LED lighting apparatus which detects an external supply AC voltage when an external AC voltage is changed and varies a resistance value, So that it can be driven with a high light emission uniformity.

Conventional general lighting devices have incandescent lamps that generate light due to high temperature, and fluorescent lamps that generate light by high voltage discharge. Since the lamps operate at high temperature and high voltage, their service life is not long.

LEDs developed in recent years generate light by the combination of electrons and holes in the semiconductor as the current flows, and operate at a low voltage and a low current.

In order to drive these LEDs, a constant voltage and a constant current method are commonly used.

Among them, the constant current driving method is widely used, and the voltage of the LED array is usually driven to 48V or less.

Therefore, a transformer is mainly used to obtain a low voltage from a high AC voltage power source of about 100V to 277V.

If a low-frequency AC power source is applied to a transformer as it is, the transformer must be very large. Therefore, the transformer is switched to a high frequency and uses a relatively small transformer.

At this time, noise, harmonics, and power factor control due to high frequency are difficult to implement, resulting in a very complicated circuit.

For these reasons, the price is high, the reliability is low, and the life span is short, causing problems in repairing or replacing within several years.

In recent years, an AC voltage direct type LED driving method capable of solving these problems has been implemented in a compact, economical, and highly reliable manner and is widely used.

However, there is still a lot of improvement in the function of direct current type LED driving method of AC voltage.

In general, an AC voltage direct LED drive device is composed of an AC power source, a rectifier, an LED, a switching device, and a current control resistor.

The control of the electric power is performed by the current control resistor.

As the magnitude of the current control resistor increases, the power decreases and as the magnitude of the current control resistor decreases, the power increases.

There are three types of switch elements for constituting the direct current type LED driving apparatus according to the connection method with the LED, that is, the series type, the parallel type, and the current drain type.

The series type switch element which is the first type switch element is connected in series to the (-) terminal of the LED array. When the switch is on, the LED is on. When the switch is off, the LED is off.

The second type switch element, a parallel type switch element, is connected in parallel at both ends of the LED array. When the switch is on, the LED is off. When the switch is off, the LED is on.

And is off when the AC voltage is lower than the voltage of the first LED array.

When the AC voltage becomes higher than the voltage of the first LED array, the LED is turned on.

When the AC voltage is higher than the sum of the first and second LED array voltages, the first and second LED arrays are turned on.

As the ac voltage increases further, the LED arrays turn on sequentially.

As described above, when the series-connected and parallel-connected switch elements are arranged by the number of LED arrays by a general method, there is a problem that they are sequentially turned on.

In order to solve this problem, it is possible to arrange all the LED arrays at the AC voltage equal to or more than the LED array voltage by appropriately arranging more switch elements than the number of LED arrays.

Such a simultaneous lighting method has a very good luminous uniformity characteristic at the time of dimming.

In such a simultaneous lighting mode, there are cases where only parallel type switching elements are used and a case where parallel type and series type switching elements are used in combination.

However, in the case of using a series type switch element, it is possible to arrange the current control resistor only in one place, but when a parallel type switch element is used, a current control resistor should be arranged for each switch element.

In order to solve the problem of placing current control resistors in such a plurality of places, there is a current drain switch element which is a third type switch element.

A current drain switch element is a device that senses when the current in the LED array flows into a series switch element and allows a desired drain current to flow from the (+) terminal of the LED array to the (+) terminal of the next LED array to be.

This current drain switch element allows the current to be diverted into each LED array to be proportional to the current controlled in the series switch element by a resistor placed to control the current in the series switch element.

However, when the alternating voltage fluctuates or the voltage differs for each country or region, the device should be newly designed and manufactured considering the voltage.

Since more than two voltages are usually used in each country, two or more products with different rated voltages are required.

The typical AC voltage range for each country is in the range of 100V to 277V.

However, when installing the LED light emitting device, the electronic device, and the electric equipment using the triac (TRIAC) dimmer or the 0-10V dimmer equipped with the LED, it is difficult to prevent safety problems such as overheat, There was a risk that it could occur.

KR 10-1217063 B1

It is an object of the present invention to provide an LED lighting device which is directly connected to an AC voltage and which can be driven with a high luminance uniformity by adjusting the resistance value so that the power is constantly outputted when the AC voltage supplied from the outside is changed, Emitting diode (LED) drive device capable of driving at a constant power irrespective of a different AC rated voltage.

According to an aspect of the present invention, there is provided a high-emission-level pre-volt LED driving apparatus including: a rectifier for rectifying a rectified voltage by receiving an AC voltage from an external source to output a DC voltage; A plurality of LED arrays connected in series to each other to apply the direct current voltage to emit the light emitting diodes; A plurality of current drain switch elements positioned between each of the plurality of LED arrays and receiving a current outputted from each of the plurality of LED arrays and outputting a plurality of currents having a drain current value; A series type switch element which receives the plurality of currents and controls the transfer of current in accordance with opening and closing of a plurality of built-in transistors; A current control variable resistor connected to the series-type switching device and having a resistance variable when the applied AC voltage changes, so that power is constantly output; And a voltage sensing circuit part connected to one end of the rectifying device to sense the direct current voltage and the other end of the current sensing device connected to the current control variable resistor part to control the variation of the resistance value.

상기 P는 상기 LED 구동장치의 전력이고, 상기 V_AC는 외부로부터 인가되는 상기 교류 전압이며, 상기 V_C는 상기 전류제어 가변저항부의 최대 전압값인 것을 특징으로 한다. In order to achieve the above object, the current control variable resistor unit of the high luminous intensity uniform pre-bolt LED driving apparatus of the present invention is characterized in that an equivalent resistance (R _S ) is calculated by the following equation,

The P is the power of the LED driving device, V _AC is the AC voltage applied from the outside, and V _C is the maximum voltage value of the current control variable resistor.

In order to achieve the above object, the voltage sensing circuit part of the high-emission-level pre-bolt LED driving device of the present invention has one side connected to the (+) terminal of the rectifying device and receiving the DC voltage, First to third branching resistors connected in series for branching a DC voltage; A DC voltage charging unit connected in parallel to the second and third branch resistors to charge the branched DC voltage; And a first switching unit connected in parallel to the DC voltage charging unit to open and close according to the magnitude of the DC voltage branched to the third branching resistor to adjust the magnitude of the charged DC voltage and output to the output voltage port .

In order to achieve the above object, the DC voltage charging unit of the high-emission-level pre-bolt LED driving apparatus of the present invention includes a first capacitor having one side connected to a second DC voltage terminal and receiving the DC voltage and the other side grounded; And a zener diode connected in parallel to the first capacitor to prevent an overvoltage of the charged DC voltage.

In order to achieve the above object, the first switching unit of the high luminous intensity pre -bolted LED driving apparatus of the present invention includes a first field effect transistor in which a gate terminal is connected to a third DC voltage terminal and a source terminal is grounded; A drain resistor having one side connected to the first DC voltage terminal and the other side connected to the drain terminal of the first field effect transistor; A source resistor having one side connected to the source terminal of the first field effect transistor and the other side grounded; And a second capacitor having one side connected to the drain terminal and the output voltage port of the first field effect transistor and the other side grounded.

In order to attain the above object, the plurality of LED arrangements of the high-emission-level pre-bolt LED driving apparatus according to the present invention are characterized in that the basic driving voltage is 53 to 79 V when the number of LED array units is four.

In order to achieve the above object, the LED array of the high-emission-level pre-bolt LED driving apparatus of the present invention is characterized in that the number of LEDs connected in parallel is 3: 1: 1: 1.

In order to achieve the above object, the present invention provides a high-emission-level pre-bolt LED driving apparatus, wherein the plurality of LED array units have a number of LEDs connected in parallel at a ratio of 4: 2: 1: 1.

In order to achieve the above object, the plurality of LED arrangements of the high-emission-level pre-bolt LED driving apparatus according to the present invention are characterized by having a basic driving voltage of 40 to 60 V when the number of LED arrangements is five.

In order to accomplish the above object, the present invention provides a high-emission-level pre-bolt LED driving apparatus, wherein the plurality of LED array units are formed in a ratio of 4: 1: 1: 1: 1 in number of LEDs connected in parallel.

In order to achieve the above object, the plurality of LED arrangements of the high-emission-level pre-bolt LED driving apparatus of the present invention are configured such that the number of LEDs connected in parallel is 6: 2: 2: 1: 1.

In order to achieve the above object, the plurality of LED arrangements of the high-emission-level pre-bolt LED driving apparatus according to the present invention are characterized by having a basic driving voltage of 36 to 54 V when the number of LED array portions is six.

In order to achieve the above object, the LED array of the high-emission-level pre-bolt LED driving apparatus of the present invention has a number of LEDs connected in parallel at a ratio of 3: 3: 2: 2: 1: 1.

In order to achieve the above object, the current control variable resistor unit of the high luminous uniformity prevoltage LED driving device of the present invention has a drain terminal connected to the series type switch element to receive a current, and a gate terminal connected to the output voltage port A second field effect transistor opened and closed according to an intensity of an applied output voltage; A first control resistor having one side connected to the drain terminal of the field effect transistor and the other side grounded; And a second control resistor having one side connected to the source terminal of the field effect transistor and the other side grounded.

In order to achieve the above object, the current control variable resistor unit of the high-emission-level pre-volt LED driving apparatus of the present invention can be replaced with an analog dimming terminal.

In order to achieve the above object, the present invention is characterized in that the current control variable resistor portion of the high-emission-level pre-bolt LED driving device of the present invention can be replaced with a reference voltage generator.

In order to achieve the above object, the series type switch element of the high luminous uniformity prevoltage LED driving apparatus of the present invention has a drain terminal connected to each of the plurality of current drain switch elements and a source terminal connected to the current control variable resistor And a plurality of field effect transistors connected to the gate terminal and opened and closed in response to a voltage applied to the gate terminal.

Specific details of other embodiments are included in the " Detailed Description of the Invention " and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and / or features of the present invention and the manner of achieving them will be apparent by reference to various embodiments described in detail below with reference to the accompanying drawings.

However, it is to be understood that the present invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

According to the present invention, one AC direct LED drive device operating from the low voltage to the high voltage operates at the same power, and the change in the brightness of the drive device due to the instantaneous voltage fluctuation is also reduced.

In addition, safe driving is possible even when a high voltage higher than the rated voltage is used, and brightness control is good even when the dimmer is used.

In addition, when installing electronic devices or electric equipments equipped with LEDs having different rated voltages in different countries, it is possible to prevent the risk of overheating, destruction, and fire due to malfunction, thereby improving the performance of the product.

1 is a circuit diagram of a high luminous uniformity prevoltage LED driving apparatus according to an embodiment of the present invention.
FIG. 2 is a waveform diagram showing a drive waveform and a drive voltage according to time of an LED array and a quarter cycle waveform according to time of an AC voltage when the circuit shown in FIG. 1 is driven.
3 is a waveform diagram showing an equivalent resistance value (R _S ) of the current control variable resistance portion required for each applied AC voltage in order to realize a constant power of 17 W in the circuit shown in FIG.
4 is a circuit diagram of the voltage sensing circuit portion and the current control variable resistance portion in the LED driving apparatus shown in FIG.
5 is a graph showing a result of simulating the voltage of each node of the current control variable resistor through the LED driving device shown in FIG.
FIG. 6 is a graph illustrating a result of simulating power according to an AC driving voltage applied to the LED driving apparatus shown in FIG. 1, and comparing the result with a target power value.
Fig. 7 is a photograph of the LED driving device shown in Fig. 1, which is constituted by an actual circuit on a printed circuit board.
FIG. 8 is a graph comparing power values measured through the LED real circuit of the present invention shown in FIG. 7 with simulation results and target power values shown in FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Before describing the present invention in detail, terms and words used herein should not be construed as being unconditionally limited in a conventional or dictionary sense, and the inventor of the present invention should not be interpreted in the best way The concepts of various terms can be properly defined and used.

Furthermore, it should be understood that these terms and words are to be construed in light of the meanings and concepts consistent with the technical idea of the present invention.

In other words, the terminology used herein is for the purpose of describing preferred embodiments of the present invention, and is not intended to specifically limit the contents of the present invention.

It should be understood that these terms are defined terms in view of the various possibilities of the present invention.

Further, in this specification, the singular forms "a", "an," and "the" include plural referents unless the context clearly dictates otherwise.

Also, it should be understood that the present invention can include a single meaning even if it is similarly expressed in plural.

Where an element is referred to as " comprising " another element throughout this specification, the term " comprises " does not exclude any other element, It can mean that you can do it.

Furthermore, in the case where a component is described as being "inside or connected to another component", the component may be directly connected or in contact with another component.

In addition, there may be a third component or means for fixing or connecting the component to another component when the component is spaced apart from the first component by a predetermined distance .

On the other hand, it should be noted that the description of the third component or means may be omitted.

On the other hand, it should be understood that there is no third component or means when an element is described as being "directly connected" or "directly connected" to another element.

Likewise, other expressions that describe the relationship between the components, such as "between" and "immediately", or "neighboring to" and "directly adjacent to" .

In this specification, terms such as "one side", "other side", "one side", "other side", "first", "second", and the like refer to one component It is used to make it clearly distinguishable from element.

It should be understood, however, that such terms do not limit the meaning of the component.

It is also to be understood that terms related to positions such as "top", "bottom", "left", "right" in this specification, if used, refer to relative positions in the drawings for the respective components.

Further, it should not be understood that these position-related terms refer to absolute positions unless an absolute position is specified for these positions.

Furthermore, in the specification of the present invention, the terms "part", "unit", "module", "apparatus" and the like mean units capable of handling one or more functions or operations, if used.

It should be appreciated that this may be implemented in hardware or software, or a combination of hardware and software.

In the drawings attached to the present specification, the size, position, coupling relationship, and the like of each constituent element of the present invention may be partially or exaggerated or omitted or omitted for the sake of clarity of description of the present invention or for convenience of explanation May be described, and therefore the proportion or scale may not be rigorous.

Further, in the following description of the present invention, a detailed description of a configuration that is considered to be unnecessarily blurring the gist of the present invention, for example, a known technology including the prior art may be omitted.

1 is a circuit diagram of a high luminous uniformity prevoltage LED driving apparatus according to the present invention and includes a bias voltage supply unit 50, a rectifying device 100, four LED array units 210 to 240 indicated by LA1 to LA4, Three current drain switch elements P1 to P3, one serial switch element 400 indicated by m, a current control variable resistor section 500 and a voltage sensing circuit section 600. [

FIG. 2 is a waveform diagram showing a drive waveform and a drive voltage according to time of the LED array units 210 to 240 according to the time of the AC voltage when the circuit shown in FIG. 1 is driven.

3 is a waveform diagram showing a resistance value R _S of the current control variable resistance unit 500 required for each applied AC voltage in order to realize a constant power of 17 W in the circuit shown in FIG.

The structure and function of each component of the high-emission-level pre-bolt LED driving apparatus according to the present invention will be described with reference to FIGS. 1 to 3. FIG.

The rectifying element 100 receives an AC voltage from the outside and rectifies it to output a DC voltage.

The four LED arrays 210 to 240 are connected in series to each other to receive a DC voltage from the rectifying device 100 to emit light.

Each of the three current drain switch elements P1 to P3 is disposed between each of the four LED arrays 210 to 240 and receives a current output from each of the four LED arrays 210 to 240, And outputs a plurality of currents having drain current values in response to the control of the device 400.

One series-connected switch element 400 has a drain terminal connected to each of the three current drain switch elements P1 to P3 and a source terminal connected to the current control variable resistor section 500 through a common node CN NMOS transistors NM1 to NM4 and is opened / closed in response to the intensity of the voltage applied to the gate terminal.

The current control variable resistor unit 500 is connected to the series type switch element 400 so that the resistance value is varied according to the operation of the built-in transistor so that the power is constantly output even when the alternating voltage supplied from the outside changes.

One end of the voltage sensing circuit unit 600 is connected to the rectifying element 100 and the other end of the voltage sensing circuit unit 600 is connected to the current control variable resistance unit 500 to sense the DC voltage output from the rectifying element 100, 500). ≪ / RTI >

Although the four LED arrangement units 210 to 240 are illustrated as being connected in series in FIG. 1, the LED array units 210 to 240 may be configured in any number of L. In this case, The ratio of the number of connected LEDs can be set differently.

For example, if the number of LED arrays is four, each voltage of the LED arrays has a basic driving voltage of 66V? 20%, that is, 53 to 79V.

In this case, the ratio of the number of parallel-connected LEDs constituting the plurality of LED array units can be set to 3: 1: 1: 1 or 4: 2: 1: 1.

Further, when the number of LED array portions is five, each voltage of the LED arrays has a basic driving voltage of 50V20%, that is, 40 to 60V.

In this case, the ratio of the number of parallel-connected LEDs constituting the plurality of LED array units can be set to 4: 1: 1: 1: 1 or 6: 2: 2: 1: 1.

Further, when the number of LED array portions is six, each voltage of the LED arrays has a basic driving voltage of 45V20%, that is, 40 to 60V.

In this case, the ratio of the number of parallel-connected LEDs constituting the plurality of LED array units can be set to 3: 3: 2: 2: 1: 1.

Meanwhile, when the number of LED array units 210 to 240 is L, the number of NMOS transistors in the series-type switching device 400 is also L, but the number of current drain switch elements P1 to P3 is L-1.

The operation of the high-emission-level prebolted LED driving apparatus according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 3. FIG.

The LED array units 210 to 240 shown in FIG. 1 are constituted by a 24-series and a 72-V LED array in a normal operation mode according to an embodiment of the present invention.

The first LED array LA1 is composed of three parallel LEDs, and the second to fourth LED arrays LA2 to LA4 are formed of one parallel structure.

The operation characteristics of the current drain switch elements P1 to P3 in FIG. 1 are as follows.

When the applied AC voltage becomes equal to or higher than about 72 V corresponding to the voltage of the basic LED arrangement parts 210 to 240, N times the current flowing to terminal 5 flows from terminal 2 to terminal 8, and all of LA1 to LA4 are turned on.

When the applied voltage is higher than the voltage of the basic LED array units 210 to 240 by a factor of two to four times and a current higher than the corresponding channel current of the series type switching device 400 flows to the next channel, The current flowing into the second terminal of the elements P1 to P3 also becomes zero.

As a result, the voltage increases from P1 to P3, which is the current drain switch element, and the current flows directly from terminal 1 to terminal 8 as the terminals are sequentially cut off.

1, the ratio of the currents flowing from the first to fifth terminals to the second to eighth terminals is set to 1: 1, 1: 2, and 1: 1 respectively in P1 to P3.

When the current drain switch elements P1 to P3 are set at the above ratios, the current is driven in two stages when driven at an AC voltage of 120 V. When driven by the channel current value of the first channel, the LED array parts 210 to 240 are arranged in six parallel .

LA2 ~ LA4 are connected in parallel when driven by channel 2 current value, and LA2 ~ LA4 connected in series are connected in series with LA1, and they are driven in parallel with two rows and three columns of the basic arrangement so that the current flowing through each LED is equalized, Is driven at 100%.

When the AC power source is driven at a voltage higher than that, the magnitude of the current flowing through each of the LED array units 210 to 240 is changed. However, the light efficiency is substantially constant with respect to 120V,

Structural characteristics of the series type switching device 400, the voltage sensing circuit part 600, and the current control variable resistance part 500 shown in FIGS. 1 and 4 are as follows.

The series switch element 400 has a drain terminal connected to each of the plurality of current drain switch elements P1 through P3 and a source terminal connected to the current control variable resistance section 500 through a common node CN, And a plurality of field effect transistors (NM1 to NM4) that open and close in response to the intensity of the applied voltage.

At this time, a voltage applied to the gate terminal of each of the plurality of field effect transistors (NM1 to NM4) is supplied from the bias voltage supplier 50.

That is, the bias voltage supply unit 50 includes a bias voltage branching resistance unit 52, a power supply voltage drop resistor R ₁ , a DC supply voltage stabilization unit C ₁ , and an overvoltage prevention unit Z ₂ .

The bias voltage branching resistance unit 52 includes first to fifth voltage dividing resistors R ₂ to R ₆ , one side of which is connected to the (+) terminal of the rectifying device 100 to receive the DC voltage, Is grounded to branch the applied DC voltage.

_One side of the power supply voltage drop resistor R ₁ is connected to the (+) terminal of the rectifying element 100, and the other side thereof is connected to one side of the bias voltage drop resistor section 52 to drop the power supply voltage.

The DC power supply voltage stabilizing part C ₁ is connected in parallel to the bias voltage branching resistor part 52 to stabilize the DC power supply voltage.

Over-voltage protection unit (Z ₂₎ is to prevent the direct-current power supply voltage stabilizing part (C ₁₎ is parallel-connected to the inlet of the over-voltage of the DC power supply voltage from a surge voltage or the like is suddenly introduced into the lightning strike or the like.

Therefore, the bias voltage that is branched through the second to fifth voltage dividing resistors R ₃ to R _{6 in the} bias voltage branching resistance section 52 is applied to the gate terminal of the fourth field effect transistor NM 4, To the fifth voltage dividing resistors R ₄ to R ₆ is applied to the gate terminal of the third field effect transistor NM3.

Further, the fourth to the fifth voltage branch bias voltage branch via a resistor (R ₅ to R ₆₎ is applied to the gate terminal of the second field effect transistor (NM2), via a fifth voltage branch resistor (R ₆₎ The biased voltage that is branched is applied to the gate terminal of the first field effect transistor NM1.

The voltage sensing circuit part 600 includes first to third branching resistors 610 and 610 which are connected to the (+) terminal of the rectifying element 100 to receive the DC voltage, and the other terminal is grounded to branch the applied DC voltage. ), A DC voltage charging unit 620 connected in parallel to the second and third branch resistors R _{v2 and} R _v3 to charge the branched DC voltage, and a DC voltage branching to the third branch resistor R _v3 And a first switching unit 630 that adjusts the magnitude of the DC voltage charged to the DC voltage.

At this time, the DC voltage charging unit 620 is connected in parallel to the first capacitor C _V1 and the first capacitor C _V1 , one side of which is connected to the second DC voltage terminal V2 to receive the DC voltage, is provided with a zener diode (Z ₁₎ to prevent the over-voltage of the DC voltage to be charged.

The first switching unit 630 includes a first field effect transistor T1 having a gate terminal connected to a third DC voltage terminal V3 and a source terminal connected to ground, a first field effect transistor T1 having a first terminal connected to the first DC voltage terminal V1, A drain resistor R _VD whose one end is connected to the drain terminal of the first field effect transistor T 1 and a source resistor whose one end is connected to the source terminal of the first field effect transistor T 1 and whose other end is grounded, And a second capacitor C _V2 whose one side is connected to the drain terminal and the output voltage port V _O of the first field effect transistor T 1 and whose other side is grounded.

The current control variable resistor 500 has a drain terminal connected to a common node CN of the series type switching device 400 to receive a current and a gate terminal connected to the output voltage port V _O A first control resistance R _S1 having one side connected to the drain terminal of the second field effect transistor T2 and the other side grounded and a second control resistance R _S1 having one side connected to the drain terminal of the second field effect transistor T2, And a second control resistor R _S2 connected to the source terminal of the field effect transistor T2 and grounded on the other side.

The operational characteristics of the series type switching device 400, the voltage sensing circuit part 600 and the current control variable resistance part 500 shown in FIGS. 1 and 4 are as follows.

The gate voltages of the field effect transistors (FETs) connected to the drain terminals of the first to fourth terminals of the series-type switching device 400 are set to be sequentially increased.

1) in accordance with the voltage of the LED array portions 210 to 240 of the current drain switch elements P1 to P3 in accordance with the increase of the DC voltage outputted from the rectifying element 100 To 4th terminal, and the field effect transistor in the previous stage is cut off when driven by the next step current value.

Although the detailed operation is different depending on the type of the switching device, the circuit of FIG. 1 also basically includes four LED arrangement parts 210 to 210, depending on the value of the current control variable resistance part 500 of the series- The current drainage switch elements P1 to P3 connected in parallel to the LEDs in the LEDs 240 to 240 are operated and the current waveform and the LED lights as shown in FIG.

However, the channels that are not cut-off due to the operation of the current drain switch elements P1 to P3 are divided into currents.

 Figure 2 shows a portion of the period when the circuit of Figure 1 is driven at 277V.

In this case, v _L (t) is a voltage applied to the LEDs in the four LED arrays 210 to 240 by an alternating voltage varying with time, and i _L (t) is a current varying with time.

V _AC is the RMS AC voltage value, and I _L is the maximum current flowing through the circuit.

v _C (t) is the voltage of the current control variable resistance unit 500 and is expressed as the product of the equivalent resistance R _S of the current control variable resistance unit 500 and the current i _L (t).

N means the number of steps up to the maximum current according to the applied AC voltage.

For example, in the circuit of FIG. 1, N is 2 when the RMS voltage is 120 V, and N is 4 when applied at 277 V, as in FIG.

1, V _C is the maximum voltage of v _C (t) of the current control variable resistor unit 500 at the drive AC voltage, and is calculated as the voltage value at the last step of v _C (t) according to the applied voltage do.

When the AC voltage is applied, the power P of the LED lighting apparatus is expressed by the following equation (1).

Here, T is one cycle time of the AC power supply voltage, V _AC (t) is an AC voltage varying with time, and i _L (t) is a current varying with time.

V _AC is an AC voltage value applied from the outside, and I _L is a maximum current value flowing in the circuit.

V _C is the maximum voltage of the voltage v _C (t) of the current control variable resistor unit 500 and R _S is the equivalent resistance of the current control variable resistance unit 500.

Then, the value of the equivalent resistance (R _S ) of the current control variable resistor unit 500 for making the power P constant is obtained by the following equation (2).

Here, P is the electric power of the LED driving apparatus, V _AC is the AC voltage value applied from the outside, and V _C is the maximum voltage of the voltage v _C (t) of the current control variable resistance unit 500.

When the four LED arrays 210 to 240 of FIG. 1 are used, the graph of the equivalent resistance (R _S ) of the current control variable resistor unit 500 in one embodiment is calculated to be 'R _S 'constant power'.

As the AC voltage increases, the equivalent resistance (R _S ) of the current control variable resistor unit 500 must increase. As the voltage increases, the series-connected LED voltage increases and the channel current of the series IC increases Therefore, V _C also increases in a step form, so that the current control resistance must be increased in a step form to obtain a constant power.

5 is a graph showing a result of simulating the voltage of each node of the current control variable resistor through the LED driving device shown in FIG.

FIG. 6 is a graph illustrating a result of simulating power according to an AC driving voltage applied to the LED driving apparatus shown in FIG. 1, and comparing the result with a target power value.

Fig. 7 is a photograph of the LED driving device shown in Fig. 1, which is constituted by an actual circuit on a printed circuit board.

FIG. 8 is a graph comparing power values measured through the LED real circuit of the present invention shown in FIG. 7 with simulation results and target power values shown in FIG.

The operation of the high-emission-level prebolted LED driving apparatus according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 8. FIG.

4, the voltage sensing circuit part 600 has three external connection ports SP1, SP2 and SP3 and the current control variable resistance part 500 also has three external connection ports CP1, CP2 and CP3, .

The external connection port SP1 of the voltage sensing circuit unit 600 is connected to the (+) terminal of the rectifying element rectification voltage of FIG.

The external connection port CP1 of the current control variable resistor unit 500 is connected to the external connection port MP5 of the series type switch element 400 of FIG.

The external connection port SP2 of the voltage sensing circuit unit 600 is connected to the external connection port CP2 of the current control variable resistance unit 500 and the external connection port SP3 of the voltage sensing circuit unit 600 and the current control variable The external connection port CP3 of the resistor 500 is grounded as the (-) terminal of the rectified voltage of the rectifying element 100. [

The three branching resistors R _v1, R _v2 and R _v3 are connected in series to the external connection port SP1 of the voltage sensing circuit part 600. The first branch resistor R _v1 reduces the voltage, Allows connected components to operate at low voltages.

The second and third branch resistors R _v2 and R _v3 branch the voltage with the first branch resistor R _v1 and are proportional to the ac voltage. The capacitor C _v1 connected in parallel to the first branch resistor R _v1 , It becomes a DC voltage proportional to the voltage.

The second DC voltage V ₂ supplies power to the drain resistor R _vD connected to the drain of the transistor T 1 and the third DC voltage V ₃ is connected to the gate of the transistor T 1.

In Figure 1, when the AC voltage is increased to be supplied from outside the second DC voltage (V ₂₎ increases, and the transistor (T2) of the current control variable resistor unit 500 is fully turned on (Turn-on) current control variable The resistance between the external connection port CP1 and the external connection port CP3 of the resistor section 500 is driven by the parallel resistance value of the control resistor Rs1 and the control resistor Rs2.

A second transistor (T1) of the direct current voltage (V ₂₎ is increased and at the same time the third direct-current voltage a voltage sensing circuit 600, while (V ₃₎ is increased gradually turned on, as AC voltage is increased to be supplied from the outside.

As a result, a voltage drop occurs as a current flows through the resistor RvD and the output voltage Vo decreases.

Further, the current control transistor (T2) of the variable resistor unit 500 is completely is turned on state a second control resistor (Rs ₂₎ the resistance across the transistor (T2) increases as the current decreases in series with the resistance is increased in the When the AC drive voltage increases, the current decreases and the power becomes constant.

Therefore, the current control variable resistor unit 500 of the present invention can be replaced with an analog dimming terminal or a reference voltage generator.

As shown in FIG. 6, when the AC voltage is 100 V, 120 V, 200 V, 220 V, 230 V, 245 V, and 277 V, it is driven within 11% of the target power and within 16% .

When the main voltage of interest is set to 120V (USA), 220V (Asia, part of Europe) and 277V (USA), the error rate of target power is within 1%.

As shown in FIG. 8, the power consumption was -1.7%, -1.7%, -1.7%, and -1.7%, respectively, based on the 17 W power of 16.7 W, 17.7 W, and 17.8 W at 120 V and 277 V, 4.8% Good results show constant power.

As described above, according to the present invention, when the alternating voltage supplied from the outside is changed, it is sensed and the resistance value is changed so that the power is controlled to be constantly output, so that the LED lighting device, which is directly connected to the AC voltage, The present invention provides a highly luminous uniformity pre-bolt LED driving device which can be driven with a constant power irrespective of the AC rated voltage which varies from country to country.

Through this, one AC direct LED drive device operating from the low voltage to the high voltage operates at the same power, and the change of the brightness of the driving device due to the instantaneous voltage fluctuation is also reduced.

In addition, safe driving is possible even when a high voltage higher than the rated voltage is used, and brightness control is good even when the dimmer is used.

In addition, when installing electronic devices or electric equipments equipped with LEDs having different rated voltages in different countries, it is possible to prevent the risk of overheating, destruction, and fire due to malfunction, thereby improving the performance of the product.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

In addition, since the present invention can be embodied in various other forms, the present invention is not limited by the above description, and the above description is intended to be a complete description of the present invention, It will be understood by those of ordinary skill in the art that the present invention is only provided to fully inform the person skilled in the art of the scope of the present invention and that the present invention is only defined by the claims of the claims.

100: rectifying element
210 to 240: LED array portion
P1 to P3: Current drain switch element
400: series switch element
500: current control variable resistor section
600: voltage sensing circuit part

Claims (17)

A rectifying element for receiving an AC voltage from the outside to rectify and output a DC voltage;
A plurality of LED arrays connected in series to each other to apply the direct current voltage to emit the light emitting diodes;
A plurality of current drain switch elements positioned between each of the plurality of LED arrays and receiving a current outputted from each of the plurality of LED arrays and outputting a plurality of currents having a drain current value;
A series type switch element which receives the plurality of currents and controls the transfer of current in accordance with opening and closing of a plurality of built-in transistors;
A current control variable resistor connected to the series-type switching device and having a resistance variable when the applied AC voltage changes, so that power is constantly output; And
A voltage sensing circuit part having one side connected to the rectifying element to sense the direct current voltage and the other side connected to the current control variable resistance part to control variation of the resistance value;
And,
The voltage sensing circuit part
First to third branch resistors connected in series, one side of which is connected to the (+) terminal of the rectifying element to receive the DC voltage and the other of which is grounded to branch the applied DC voltage;
A DC voltage charging unit connected in parallel to the second and third branch resistors to charge the branched DC voltage; And
A first switching unit connected in parallel to the DC voltage charging unit to open and close according to a magnitude of a DC voltage branched to the third branching resistor to adjust the magnitude of the charged DC voltage to output to the output voltage port;
And a control unit
High luminous uniformity pre-bolt LED driver.
The method according to claim 1,
The current control variable resistor portion
The equivalent resistance R _S is calculated by the following equation,

Wherein P is the power of the LED driving device, V _AC is the AC voltage applied from the outside, and V _C is the maximum voltage value of the current control variable resistor portion.
High luminous uniformity pre-bolt LED driver.
delete The method according to claim 1,
The DC voltage charging unit
A first capacitor having one side connected to the second DC voltage terminal to receive the DC voltage and the other side grounded; And
A zener diode connected in parallel to the first capacitor to prevent an overvoltage of the DC voltage to be charged;
And a control unit
High luminous uniformity pre-bolt LED driver.
The method according to claim 1,
The first switching unit
A first field effect transistor having a gate terminal connected to a third DC voltage terminal and a source terminal grounded;
A drain resistor having one side connected to the first DC voltage terminal and the other side connected to the drain terminal of the first field effect transistor;
A source resistor having one side connected to the source terminal of the first field effect transistor and the other side grounded; And
A second capacitor having one side connected to the drain terminal and the output voltage port of the first field effect transistor and the other side grounded;
And a control unit
High luminous uniformity pre-bolt LED driver.
The method according to claim 1,
The plurality of LED arrays
And when the number of the LED array portions is four, the basic driving voltage is set at 53 to 79 V,
High luminous uniformity pre-bolt LED driver.
The method according to claim 6,
The plurality of LED arrays
Characterized in that the number of LEDs connected in parallel is configured in a ratio of 3: 1: 1: 1.
High luminous uniformity pre-bolt LED driver.
The method according to claim 6,
The plurality of LED arrays
Characterized in that the number of LEDs connected in parallel is configured in a ratio of 4: 2: 1: 1.
High luminous uniformity pre-bolt LED driver.
The method according to claim 1,
The plurality of LED arrays
And when the number of LED array portions is five, the basic driving voltage is set to 40 to 60 V. [
High luminous uniformity pre-bolt LED driver.
10. The method of claim 9,
The plurality of LED arrays
Characterized in that the number of LEDs connected in parallel is configured in a ratio of 4: 1: 1: 1: 1.
High luminous uniformity pre-bolt LED driver.
10. The method of claim 9,
The plurality of LED arrays
The number of parallel-connected LEDs is configured at a ratio of 6: 2: 2: 1: 1,
High luminous uniformity pre-bolt LED driver.
The method according to claim 1,
The plurality of LED arrays
And when the number of the LED array portions is 6, 36 to 54 V is set as the basic driving voltage.
High luminous uniformity pre-bolt LED driver.
13. The method of claim 12,
The plurality of LED arrays
The number of parallel-connected LEDs is configured in a ratio of 3: 3: 2: 2: 1: 1,
High luminous uniformity pre-bolt LED driver.
The method according to claim 1,
The current control variable resistor portion
A second field effect transistor having a drain terminal connected to the series switch element to receive a current and a gate terminal connected to the output voltage port to be opened or closed according to an intensity of an applied output voltage;
A first control resistor having one side connected to the drain terminal of the field effect transistor and the other side grounded; And
A second control resistor having one side connected to the source terminal of the field effect transistor and the other side grounded;
And a control unit
High luminous uniformity pre-bolt LED driver.
The method according to claim 1,
The current control variable resistor portion
Analog dimming terminal. ≪ RTI ID = 0.0 >
High luminous uniformity pre-bolt LED driver.
The method according to claim 1,
The current control variable resistor portion
Characterized in that it is replaceable by a reference voltage generator,
High luminous uniformity pre-bolt LED driver.

The method according to claim 1,
The series-type switch element
A plurality of field effect transistors connected in series between the drain terminal of each of the plurality of current drain switch elements and the source terminal of the field effect transistor in response to an intensity of a voltage applied to the gate terminal through a common node;
And a control unit
High luminous uniformity pre-bolt LED driver.

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