KR101222169B1 - Power apparatus for light emitting diode lighting - Google Patents

Abstract

According to an embodiment of the present invention, a power supply for LED lighting includes a current value register in which a first reference voltage is recorded for a rated current flowing in an LED array including a plurality of light emitting diode (LED) elements. And a voltage value register in which a second reference voltage for the output voltage applied to the LED array is written, and a data interface into which the first reference voltage and the second reference voltage are input.

Description

Power supply for light emitting diode lighting {POWER APPARATUS FOR LIGHT EMITTING DIODE LIGHTING}

The present invention relates to a power supply for light emitting diode lighting.

Light emitting diodes (LEDs) are semiconductor devices that emit light by passing a current through a compound such as gallium (Ga), phosphorus (P), or arsenic (As). LEDs are used in a variety of applications, such as electronic products, lighting, displays.

LED lighting is recognized as a next-generation light source because it is more energy-saving and semi-permanent than other light sources. LED lighting is a current drive element, the brightness is determined according to the amount of forward current.

1 is a graph showing light output with respect to the amount of forward current of LED lighting.

Referring to FIG. 1, there is a linear relationship between the forward current and the light output of the LED, but it exhibits nonlinear characteristics when the forward current exceeds a threshold level. If the LED has a forward current above the threshold, the power used for the light output is converted into thermal energy.

Thermal energy raises the temperature of the PN junction of the LED, which may result in the forward voltage drop as well as the destruction of the PN junction.

Therefore, when designing the LED lighting, there is a need for the consideration of heat dissipation and a technique that allows a constant current to flow. For this purpose, the voltage applied to the LED for lighting should vary according to the rated current value and the temperature of the PN junction according to the characteristics of the LED element used. Therefore, a constant current driving power source should be used for LED lighting. LED devices have different forward voltages and currents depending on the manufacturer or type of product. A large power LED lighting power supply composed of a plurality of LED elements has been designed and manufactured separately according to the LED element used, the arrangement method of the LED elements, and the total supply power supplied to the LED. Therefore, a very large variety of power supplies are needed.

In addition, the power supply for LED lighting must be separately obtained the verification test and certification in accordance with domestic and foreign electrical safety and related regulations. Therefore, it takes enormous cost and time to commercialize the LED lighting power supply.

In general, large output LED lighting is achieved by connecting a plurality of relatively small output LED elements in series and in parallel. Here, when one or several LED elements are destroyed, a problem arises in the distribution of balance for each element of the total current, so that the remaining elements may be serially destroyed. Therefore, a proper current control technique is needed to address this.

The problem to be solved by the present invention is simplified to several by the power used, by using a method to initially set the rated current value and the voltage value according to the individual LED device and device arrangement method to the power supply in the LED lighting manufacturing for LED lighting By simplifying the design and manufacture of power supplies, we provide power supplies for LED lighting that can increase reliability, reduce manufacturing costs, and dramatically reduce the costs and procedures of obtaining and securing international safety standards.

Another problem to be solved by the present invention is to provide a power supply for the LED lighting that can maintain the rated current value for the remaining devices by detecting the current runaway due to the destruction of one to several devices in the LED light consisting of a plurality of LED devices To provide.

According to an aspect of the present invention, a power supply for LED lighting includes a current value register in which a first reference voltage with respect to a rated current flowing in an LED array including a plurality of light emitting diode (LED) elements is recorded. And a voltage value register in which a second reference voltage for the output voltage applied to the array is written, and a data interface into which the first reference voltage and the second reference voltage are input.

At least one of the current value register and the voltage value register may be a nonvolatile memory.

A power supply for LED lighting includes a first digital-to-analog converter (DAC) for converting the first reference voltage recorded in the current value register into an analog value, and the second recorded in the voltage value register. The method may further include a second digital analog converter for converting the reference voltage into an analog value.

The power supply for the LED lighting is a current detection comparison unit for comparing the value output from the first digital analog converter with the current flowing in the LED array, and the value output from the second digital analog converter and applied to the LED array The apparatus may further include a voltage detection comparison unit configured to compare the output voltages.

A power supply for LED lighting uses a pulse width modulation (PWM) to control the current flowing through the LED array or the output voltage applied to the LED array using the output of the current detection comparison unit or the voltage detection comparison unit. The control unit may further include.

The power supply for LED lighting includes a primary coil and a secondary coil, one terminal of the primary coil is connected to the DC input unit, the other terminal of the primary coil is connected to the PWM control unit, the secondary One terminal of the coil is connected to the LED array, the other terminal of the secondary coil is grounded, and at least one of the primary coil and the secondary coil includes a switch, and the primary coil using the switch And a transformer for adjusting the turns ratio of the secondary coil.

The switch is connected to the data interface, and the winding ratio may be adjusted by varying the contact point of the data interface and the switch according to the rated current.

According to an aspect of the present invention, a power supply for LED lighting of a multi-LED array in which a series array in which a plurality of LED elements are connected in series is connected in parallel to each other may include data in which a reference voltage with respect to an output voltage applied to the multi-LED array is input. A change in the output voltage is monitored by monitoring an interface, a voltage value register storing the reference voltage, a voltage detection comparison unit comparing the reference voltage with an output voltage applied to the multiple LED array, and an output of the voltage detection comparison unit. And an operation unit for determining whether at least one LED element or at least one series array in the multiple LED array is abnormal.

The LED lighting power supply may further include a current value register in which a value for a rated current flowing in the multiple LED arrays is further input through the data interface, and a value for the rated current is stored.

The LED lighting power supply further includes a pulse width modulation (PWM) control unit for controlling a current flowing through the multiple LED array or an output voltage applied to the multiple LED array, wherein the operation unit determines whether an abnormality is detected. In this case, the PWM controller may adjust to reduce the rated current flowing in the multiple LED array.

According to one embodiment of the present invention, there is provided a power supply device capable of initially setting the rated current and power required in LED lighting. Since the power supply device according to an embodiment of the present invention can be applied to various LED lights, there is no need to develop, produce or authenticate a separate power supply device for each LED light. Therefore, the manufacturing cost of the LED lighting power supply can be reduced and the manufacturing period can be reduced. In addition, by adjusting the winding ratio of the transformer connected to the DC power supply of the power supply according to the rated current, it is possible to supply the necessary current and power while maintaining the efficiency of the power supply.

LED lighting power supply according to an embodiment of the present invention by controlling the amount of current based on a reference voltage recorded in advance in a multi-LED array structure in which a plurality of LED arrays are connected in parallel, as well as a single LED array connected in series It is possible to prevent chain breakage of the LED device.

That is, even when one LED element or one LED array is damaged, only the rated current flows through the remaining LED arrays, thereby preventing burnout of the entire LED lighting and reducing unnecessary power consumption. In addition, maintenance costs can be significantly reduced by replacing only faulty parts.

1 is a graph showing light output with respect to the amount of forward current of LED lighting.
2 is an example of an LED lighting power supply.
3 shows a current waveform controlled by PWM control logic.
4 is a view showing an LED lighting power supply according to an embodiment of the present invention.
5 is an example of a multiple LED array structure.
6 is another example of a multiple LED array structure with a current limiting resistor.
7 is a graph showing the output voltage and current waveform of the LED lighting power supply in the steady state.
FIG. 8 is a graph illustrating output voltage and current waveforms of an LED lighting power supply when a failure occurs in a part of an LED device.
9 is a flowchart illustrating a current limiting method of an LED lighting power supply according to an embodiment of the present invention.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise.

2 is an example of an LED lighting power supply.

Referring to FIG. 2, the LED lighting power supply 200 includes a LED array 210, a current detector 220, and a reference voltage provider 230 in which a plurality of light emitting diode (LED) devices are connected in series. ), A current detection comparison unit 240, a voltage detection comparison unit 250, a pulse width modulation (PWM) control logic 260, and a direct current (DC) power input unit 270.

The DC power input unit 270 of the LED lighting power supply 200 converts commercial alternating current (AC) power and supplies current to the LED array 210 through the transformer T. To this end, the PWM control logic 260 may convert the DC power input through the DC power input unit 270 into the required voltage and current. The PWM control logic 260 may be implemented, for example, as a buck mode converter of a step down method or a switching mode converter of a flyback method.

The current I _F flowing through the LED array 210 flows through the resistor R _s of the current detector 220. Voltage across resistor R _s V _Rs = R _s x I _F.

The current detection comparison unit 240 compares the voltage V _Rs obtained through the current detection unit 220 with the reference voltage V _Rv obtained through the reference voltage providing unit 230. Here, the reference voltage may be adjusted through the variable resistor R _v of the reference voltage providing unit 230.

As a result of the comparison of the current detection comparison unit 240, when the voltage V _Rs is lower than the reference voltage V _Rv , that is, when the current I _F flowing in the LED array 210 is lower than the predetermined reference, the PWM control logic 260 switches the switching element. Adjust Q to turn on. When the switching element Q is turned on, current flows continuously through the primary coil of the transformer T. Accordingly, the current I _F flowing in the LED array 210 is increased.

On the other hand, when the voltage V _Rs is higher than the reference voltage V _Rv , that is, when the current I _F flowing in the LED array 210 is higher than the predetermined reference, the PWM control logic 260 causes the switching element Q to be turned off. Adjust When switching element Q is turned off, the current flowing to the primary coil of transformer T is interrupted. Accordingly, the current I _F flowing in the LED array 210 is reduced.

As such, the PWM control logic 260 adjusts the turn-on and turn-off of the switching element Q according to the comparison result of the current detection comparison unit 240, so that the current I _F flowing in the LED array 210 is maintained at a constant level. Can be. 3 shows a current waveform controlled by PWM control logic. Here, I _L is a reference current controlled by the variable resistor R _v of the reference voltage providing unit 230.

As such, when the reference current I _L is adjusted by the variable resistor R _v , and the current I _F flowing through the LED array 210 is adjusted according to the reference current I _L , there is a limit to controlling the current in a wide range. That is, even in the case of LED lighting that consumes the same 40W, there may be a case of 2A, 20V ratings and 1A, 40V ratings, the range can not be adjusted simply by using only the variable resistor R _v . In addition, it is difficult to set the basic voltage corresponding to the rated current, and it is difficult to detect and control the current deviation between the LED arrays in a multiple LED array structure in which the LED arrays are connected in parallel. Hard to maintain quality In addition, it is difficult to maintain the waterproof and dustproof of the LED lighting power supply due to the exposure of the variable resistor.

In order to solve this problem, according to one embodiment of the present invention, a reference voltage value is directly input to adjust a current flowing in the LED array. Hereinafter, an LED lighting power supply device according to an embodiment of the present invention will be described in detail.

4 is a view showing the LED lighting power supply according to an embodiment of the present invention.

Referring to FIG. 4, the LED lighting power supply 400 includes an LED array 410, a current detector 420, a reference voltage provider 430, a current detection comparison unit 440, a voltage detection comparison unit 450, The operation unit 436, a PWM control logic 460, a DC power input unit 470, and a PWM transformer 480 are included.

The current detector 420 includes a resistor R _s . One end of the resistor R _s is connected to the LED array 410, and the other end of the resistor R _s is grounded.

The reference voltage provider 430 includes a data interface 431, a voltage value register 432, a DAC 433, a current value register 434, and a DAC 435. The data interface 431 is connected to the voltage value register 432 and the current value register 434, respectively, the voltage value register 432 is connected to the DAC 433, and the current value register 434 is connected to the DAC 435. Is connected to. The DAC 433 is connected to the negative input terminal of the voltage detection comparator 450, and the DAC 435 is connected to the negative input terminal of the current detection comparator 440.

The positive input terminal of the current detection comparison unit 440 is connected to the resistor R ₃ . One end of the resistor R ₃ is connected to the (+) input terminal of the current detection comparison unit 440, and the other end of the resistor R ₃ is connected to a node to which the LED array 410 is connected to the resistor R _s . Resistor R ₃ is much larger than resistor R _s .

The positive input terminal of the voltage detection comparison unit 450 is connected to a node to which the resistor R ₁ and the resistor R ₂ are connected. _One end of the resistor R ₂ is connected to the resistor R _1, and the other end of the resistor R ₂ is grounded. _One end of the resistor R ₁ is connected to the resistor R _2, and the other end of the resistor R ₁ is connected to the LED array 410.

The calculation unit 436 is connected to the output terminals of the current detection comparison unit 440 and the voltage detection comparison unit 450, respectively, and is connected to the PWM control logic 460.

PWM control logic 460 is connected to the switching element Q.

PWM transformer 480 includes a primary coil and a secondary coil. One terminal of the primary coil is connected to the DC power input unit 470, and the other terminal of the primary coil is connected to the PWM control logic 460 through the switch element Q. One terminal of the secondary coil is connected to the LED array 410, and the other terminal of the secondary coil is grounded. At least one of the primary coil and the secondary coil includes a switch to adjust the turns ratio of the primary coil and the secondary coil by using the switch. 4 shows an example in which the secondary coil includes a switch, and the winding ratio between the primary coil and the secondary coil is adjusted to N: n1 or N: n2 by using the switch of the secondary coil. However, the present invention is not limited thereto, and the primary coil may include a switch, and the winding ratio of the primary coil and the secondary coil may be adjusted by using a switch of the primary coil. The switch of the primary coil or the secondary coil is connected to the data interface 431 of the reference voltage provider 430. The winding ratio may be adjusted by varying the contact point of the data interface 431 and the switch according to the rated current. The switch may be composed of, for example, a MOSFET, which is a semiconductor element, or a general relay.

Now, the operation of the LED lighting power supply 400 will be described. The LED lighting power supply 400 operates as a constant current circuit in which the current is fixed and the voltage changes according to the load state.

The current setting reference voltage Vi _ref for the rated current flowing through the LED array 410 through the data interface 431 of the reference voltage providing unit 430 is recorded in the current value register 434 and applied to the LED array 410. The voltage setting reference voltage Vv _ref for the output voltage to be written is written to the voltage value register 432. The current value register 434 and the voltage value register 432 may be nonvolatile memories.

When the current setting reference voltage Vi _ref is recorded, the turns ratio that can supply the corresponding rated current is determined and the data interface can select the contact of the switch corresponding to the determined turns ratio.

The current setting reference voltage Vi _ref recorded in the current value register 434 is converted into an analog value through the DAC 435 and then input to the negative input terminal of the current detection comparison unit 440.

The voltage setting reference voltage Vv _ref recorded in the voltage value register 432 is converted into an analog value through the DAC 433 and then input to the negative input terminal of the voltage detection comparison unit 450.

The voltage value V _Rs = R _s x I _F by the current I _F detected through the resistor Rs of the current detector 420 is input to the positive input terminal of the current detection comparison unit 440.

The current detection comparison unit 440 compares the voltage V _Rs input through the current detection unit 420 with the current setting reference voltage Vi _ref input through the DAC 435 of the reference voltage providing unit 430.

The voltage detection comparison unit 450 compares the output voltage applied to the LED array 410 with the voltage setting reference voltage Vv _ref input through the DAC 433 of the reference voltage providing unit 430. Here, the output voltage applied to the LED array 410 may be an output voltage divided by the resistor R1 and the resistor R2.

The PWM control logic 460 controls the current flowing through the LED array 410 or the output voltage applied to the LED array 410 using the output of the current detection comparison unit 440 or the voltage detection comparison unit 450.

That is, as a result of the comparison between the calculation unit 436 and the current detection comparison unit 440, when the voltage V _Rs is lower than the current setting reference voltage Vi _ref , the current I _F flowing through the LED array 410 is lower than the reference current I _L. Judging, the PWM control logic 460 performs a control operation. That is, the PWM control logic 460 turns on the switching element Q, causes a current to flow in the primary coil of the transformer T, and increases the current I _F flowing in the LED array 410.

As a result of the comparison of the current detection comparison unit 440, when the voltage V _Rs is higher than the current setting reference voltage Vi _ref , it is determined that the current I _F flowing through the LED array 410 is higher than the reference current I _L , and the PWM control logic 460 is performed. Perform a control operation. That is, the PWM control logic 460 turns off the switching element Q and reduces the current I _F flowing through the LED array 410.

As described above, a constant level of current may flow in the LED array 410 according to the current setting reference voltage Vi _ref or the voltage setting reference voltage Vv _ref recorded in the reference voltage providing unit 430.

As such, by using a power supply device that initially sets the rated current and power required by the LED lighting, it is not necessary to develop a separate power supply device for each LED lighting having a different rated current or power.

In addition, it is possible to supply the necessary current and power while maintaining the efficiency of the power supply by appropriately selecting the turns ratio of the transformer for LED lighting having similar power consumption but largely different rated current values. For example, in the 40W, 1A class LED lighting, the rated current is 1A, so a voltage of 40V is required. However, a voltage of 27 V is required for 40 W, 1.5 A class LED lighting. It is possible to obtain a predetermined rated current by setting the initial rated current to 1.5A and adjusting the winding ratio of the transformer without having to prepare different power supplies for the two LED lights. Alternatively, the analog-to-digital conversion of the data recorded in the voltage value register is then performed by the current detection comparison unit or the voltage detection comparison unit. However, the present invention is not limited thereto. That is, after analog-to-digital conversion of the detected value of the current flowing through the LED light or the output voltage applied to the LED light, the operation unit 436 compares the digital value (for example, records the digital value of the detected current and the current value register). The measured data or compare the digital value of the detected output voltage with the data recorded in the voltage value register.

Meanwhile, although FIG. 4 illustrates one LED array 410 in which a plurality of LED elements are connected in series, the LED lighting power supply according to an embodiment of the present invention is also applicable to a multi-LED array structure in which a plurality of LED arrays are connected in parallel. can do.

5 is an example of a multiple LED array structure.

Referring to FIG. 5, in order to realize a predetermined brightness of the LED lighting, the LED array may have a multi-LED array structure in which the LED arrays connected in series are connected in parallel. The number of LEDs connected in series or in parallel can vary depending on the level of technology of the LED lighting manufacturer or the LED devices used.

The same current flows through each LED device in the LED array. Therefore, the brightness of the series connected LED array can be kept constant.

However, when a plurality of LED arrays are connected in parallel, the currents (I _f1 , I _f2 , ..., I _fn ) flowing in each LED array may vary, and flow in each LED array according to the temperature change of the PN junction. Unbalance current can result.

6 is another example of a multiple LED array structure.

Referring to FIG. 6, current limiting resistors R1, R2,..., And Rn are connected to each LED array. Accordingly, the currents I _f1 , I _f2 , ..., I _fn flowing through the respective LED arrays can be maintained at a constant level.

If one LED is defective or the junction is broken, the current I _f2 flowing to the LED array to which the LED belongs is cut off. The interrupted current I _f2 flows distributed to the remaining LED arrays. That is, each of the LED arrays is further flowed by I _f2 / (n−1).

The current increase for each LED array raises the voltage across the current limiting resistors R1, R2, ..., Rn. As a result, the voltage V _fa across each LED element is reduced, thereby reducing the current I _f1 , I _f2 , ..., I _fn flowing through each LED array, resulting in multiple LEDs of LED lighting. The total current I _F flowing through the array is also reduced.

According to a typical LED lighting power supply, when the total current I _F flowing through the multiple LED arrays of LED lighting is reduced, the voltage Vcc is increased due to the constant current circuit operation. As a result, the LED lighting power supply operates in the direction of continuously increasing the current until the initially set current value is reached. As a result, a current above the threshold level flows through each LED array, and the temperature rise may damage not only the LED device but also the entire LED lighting. 7 is a graph showing the output voltage and current waveform of the LED lighting power supply in the normal state, Figure 8 is a graph showing the output voltage and current waveform of the LED lighting power supply when a failure occurs in a part of the LED device.

In order to solve this problem, the LED lighting power supply according to an embodiment of the present invention can be used.

9 is a flow chart showing a current limiting method of the LED lighting power supply according to an embodiment of the present invention. Here, the LED lighting power supply 400 of FIG. 4 will be described as an example.

Referring to FIG. 9, when one LED device or one LED array is damaged in the multi-LED array structure (S900), the output voltage Vo increases due to the constant current circuit operation of the LED lighting power supply 400 (S910). .

At this time, the calculation unit 436 of the LED lighting power supply 400 detects the rising variation of the output voltage (S920). Specifically, the voltage setting reference voltage Vv _ref recorded in the voltage value register 432 of the reference voltage providing unit 430 is input to the negative input terminal of the voltage detection comparison unit 450, and the voltage detection comparison is performed. The output voltage Vo is input to the positive input terminal of the unit 450. The voltage detection comparison unit 450 compares the voltage setting reference voltage Vv _ref with the output voltage Vo and transfers the comparison result to the calculation unit 436. As a result, the calculator 436 may determine whether the LED device or the LED array is abnormal.

The calculating unit 436 controls the PWM control logic 460 to reduce the total current flowing to the multiple LED array (S930). That is, when the n-th LED array is broken, the PWM control logic 460 is controlled such that I _F ′ is obtained by subtracting the current I _f n flowing through the n-th LED array.

Accordingly, breakage of the cascaded LED elements in the multiple LED array is prevented (S940).

As described above, the LED lighting power supply according to an embodiment of the present invention is not only one LED array in which a plurality of LED elements are connected in series, but also in a multi-LED array structure in which a plurality of LED arrays are connected in parallel to a pre-recorded reference voltage. By controlling the amount of current based on this, chain breakage of the LED element can be prevented.

That is, even when one LED element or one LED array is damaged, only the rated current flows through the remaining LED arrays, thereby preventing burnout of the entire LED lighting and reducing unnecessary power consumption. In addition, maintenance costs can be significantly reduced by replacing only faulty parts.

The embodiments of the present invention described above are not implemented only by the apparatus and method, but may be implemented through a program for realizing the function corresponding to the configuration of the embodiment of the present invention or a recording medium on which the program is recorded.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It belongs to the scope of right.

Claims (11)

A current value register in which a first reference voltage is recorded for a rated current flowing in an LED array including a plurality of light emitting diode (LED) elements,
A voltage value register in which a second reference voltage is recorded for an output voltage applied to the LED array;
A data interface to which the first reference voltage and the second reference voltage are input;
A pulse width modulation (PWM) controller for controlling a current flowing through the LED array or an output voltage applied to the LED array, and
A transformer comprising a primary coil and a secondary coil,
One terminal of the primary coil is connected to the DC input unit, the other terminal of the primary coil is connected to the PWM control unit,
One terminal of the secondary coil is connected to the LED array, the other terminal of the secondary coil is grounded,
At least one of the primary coil and the secondary coil includes a switch, and adjusts the winding ratio of the primary coil and the secondary coil by using the switch,
The switch is connected to the data interface, and the winding ratio is adjusted by varying the contact point of the data interface and the switch according to the rated current.
Power supply for LED lighting. The method of claim 1,
At least one of the current value register and the voltage value register is a nonvolatile memory. The method of claim 1,
A first digital to analog converter (DAC) for converting the first reference voltage recorded in the current value register into an analog value, and
A second digital analog converter for converting the second reference voltage recorded in the voltage value register into an analog value
Power supply for LED lighting further comprising. The method of claim 3,
A current detection comparison unit for comparing the value output from the first digital-to-analog converter with the current flowing in the LED array; and
A voltage detection comparison unit comparing a value output from the second digital-to-analog converter with an output voltage applied to the LED array
Power supply for LED lighting further comprising. 5. The method of claim 4,
The PWM control unit uses the output of the current detection comparison unit or the voltage detection comparison unit to control the current flowing in the LED array or the output voltage applied to the LED array. delete delete In the power supply for LED lighting of a multiple LED array in which a series array in which a plurality of LED elements are connected in series are connected in parallel to each other,
A data interface to which a first reference voltage for a rated current flowing in the multiple LED array and a second reference voltage for an output voltage applied to the multiple LED array are input;
A current value register in which the first reference voltage is stored;
A voltage value register in which the second reference voltage is stored;
A voltage detection comparison unit comparing the second reference voltage with an output voltage applied to the multiple LED array;
An operation unit configured to monitor an output of the voltage detection comparison unit to detect a change in the output voltage, and determine whether at least one LED element or at least one series array in the multiple LED array is abnormal;
A pulse width modulation (PWM) controller for controlling a current flowing through the multiple LED array or an output voltage applied to the multiple LED array, and
A transformer comprising a primary coil and a secondary coil,
One terminal of the primary coil is connected to the DC input unit, the other terminal of the primary coil is connected to the PWM control unit,
One terminal of the secondary coil is connected to the multiple LED array, the other terminal of the secondary coil is grounded,
At least one of the primary coil and the secondary coil includes a switch, and adjusts the winding ratio of the primary coil and the secondary coil by using the switch,
The switch is connected to the data interface, and the winding ratio is adjusted by varying the contact point of the data interface and the switch according to the rated current.
Power supply for LED lighting. delete 9. The method of claim 8,
When it is determined that the abnormality by the operation unit, the PWM control unit for the LED lighting to adjust to reduce the rated current flowing in the multiple LED array. 9. The method of claim 8,
Each series array has its own current limiting resistor,
When an abnormality occurs in at least one LED element or at least one series array, the voltage applied to the current limiting resistor increases, and the total current flowing in the multiple LED array decreases, so that the output voltage increases. Device.

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