TWI522004B - Variable power of the light-emitting diode lighting device and set the power output control method - Google Patents

Description

Constant power LED illuminating device and control method for constant power output

The invention relates to the driving of a light-emitting diode, and more particularly to a lighting device for a constant power and a control method for a constant power output.

According to the illuminating device, the illuminating device includes a illuminating diode chip and a driving unit for supplying the electric energy required for the illuminating diode chip. At present, the specifications of the LED chips on the market are numerous. For the LEDs with the same power, the combination of the working voltage and the operating current is various. Taking the 28W LED chip as an example, the working voltage is The combination with the operating current is 80V/350mA, 56V/500mA, 40V/700mA, etc. Therefore, in order to drive such a combination of light-emitting diode chips, the current method is to develop a light-emitting diode wafer for each type. Light-emitting diode wafer drive unit. However, for lighting device manufacturers of light-emitting diodes, each type of power LED chip needs to manufacture several kinds of driving units, which not only increases the pressure of the driving unit inventory, but also cannot be priced, resulting in manufacturing cost. Stay high. If a driving unit suitable for a combination of different operating voltages and operating currents can be developed, the pressure on the inventory of the driving unit of the LED chip can be reduced, and the manufacturing cost can be effectively reduced.

In view of this, the main object of the present invention is to provide a constant power The light diode device and the control method of the constant power output can be applied to the LED chip with the same power but different working voltage and working current, and the power supplied to the LED chip is maintained at a preset. The range of power.

In order to achieve the above object, the illuminating diode device of the constant power provided by the present invention is electrically connected to a power source, and includes a light emitting diode chip, a driving unit, a voltage detecting unit and a feedback control. unit. The driving unit is electrically connected to the power source and the LED chip for receiving power of the power source and outputting an operating voltage and an operating current to the LED chip; the voltage detecting unit is electrically connected The driving unit is configured to detect a voltage value of the working voltage; the feedback control unit is electrically connected to the voltage detecting unit and the driving unit, and the feedback control unit is pre-configured with at least two different reference voltage values. Forming a voltage section between the two reference voltage values, the voltage section corresponding to a slope parameter, the feedback control unit corresponding to the voltage value of the working voltage measured by the voltage detecting unit and the voltage value of the working voltage The slope parameter of the voltage section outputs a current control signal to the driving unit to control a current value of an operating current outputted to the LED chip, wherein the current value of the operating current and the voltage value of the operating voltage The product of is within a range of preset power.

The present invention further provides a method for controlling a constant power output for maintaining power supplied to a light emitting diode chip within a predetermined power range. The method is provided with at least two different reference voltage values. Forming a voltage section between the two reference voltage values, the voltage section corresponding to a slope parameter The method includes the steps of: detecting a voltage value of an operating voltage supplied to the LED chip; selecting a voltage value of the operating voltage corresponding to a slope parameter of the voltage segment; and selecting according to the selected The slope parameter and the voltage value of the working voltage output a corresponding operating current to the LED chip, wherein the product of the current value of the operating current and the voltage value of the operating voltage is within the range of the preset power Inside.

Therefore, the light-emitting diode lighting device and the method for controlling the power consumption of the light-emitting diode can be applied to the LED chip having the same power but different working voltages and operating currents, and can be maintained and supplied to the LED device. The power of the light emitting diode chip is within a range of preset power. The illumination device for effectively improving the conventional light-emitting diode can only be applied to the inconvenience of the LED of a single working voltage and working current.

10‧‧‧Power supply

20‧‧‧Light Diode Wafer

30‧‧‧Drive unit

40‧‧‧Fixed power adjustment module

42‧‧‧Voltage detection unit

44‧‧‧current detection unit

46‧‧‧Return control unit

462‧‧‧ comparator

464‧‧‧Signal Generator

V1, V2, V3, V4‧‧‧ reference voltage values

Vmax‧‧‧ upper limit voltage value

Imax‧‧‧ upper limit current value

S‧‧‧Voltage section

C‧‧‧ Curve

1 is a block diagram of a light-emitting diode lighting device of a preferred embodiment of the present invention; FIG. 2A is a graph showing a relationship between operating voltage and operating current according to a preferred embodiment of the present invention; 2B is a partial enlarged view of FIG. 2A, showing a voltage section formed between two reference voltage values; and FIG. 3 is a flow chart of a control method for the constant power output of the present invention.

In order to explain the present invention more clearly, the following examples are set forth in the accompanying drawings in detail. FIG. 1 is a light-emitting diode lighting device with a constant power according to a preferred embodiment of the present invention, electrically connected to a power source 10, including a light-emitting diode chip 20, a driving unit 30 and a certain power adjustment mode. Group 40. The driving unit 30 is electrically connected to the power source 10 and the LED chip 20 for receiving the power of the power source 10 and outputting an operating voltage and an operating current to the LED chip 20; Unit 30 is controllably varying the voltage value of the operating voltage and the current value of the operating current. In practice, the drive unit 30 can be designed based on circuits of the PWM, half bridge, Buck, Boost, and the like.

The constant power adjustment module 40 includes a voltage detecting unit 42 , a current detecting unit 44 and a feedback control unit 46 . The voltage detecting unit 42 is electrically connected to the driving unit 30 for detecting the voltage value of the driving voltage of the driving unit 30 for the operating voltage of the LED chip 20. The current detecting unit 44 is electrically connected to the driving unit 30 for detecting the working power of the driving unit 30 for the light emitting diode chip 20 The current value of the flow.

The feedback control unit 46 includes a comparator 462 and a signal generator 464 that are electrically connected to each other. The comparator 462 is electrically connected to the voltage detecting unit 42. The signal generator 464 is electrically connected to the driving unit 30. . As shown in FIG. 2A and FIG. 2B, in the embodiment, the comparator 462 is pre-configured with four different reference voltage values V1, V2, V3, and V4, and each of the reference voltage values corresponds to a current of a working current. value. A voltage section S is formed between adjacent two reference voltage values, and the three straight lines formed by the three voltage sections S are close to an ideal working voltage-operating current relationship C, the ideal working voltage - The product of the operating current is a preset power. The reference voltage value V1 (the largest of the reference voltage values) is defined as an upper limit voltage value Vmax; and the current value of the operating current corresponding to the reference voltage value V4 (the smallest of the reference voltage values) is an upper limit. Current value Imax. The straight line of each of the voltage segments S has a slope, and the absolute values of the slopes of the voltage segments S are sequentially decreased according to the order of the reference voltage values V1, V2, V3, and V4, that is, The absolute value of the slope of the voltage section S of the reference voltage value V1 - the reference voltage value V2 is the largest, and the absolute value of the slope of the voltage section S of the reference voltage value V3 - the reference voltage value V4 is the smallest. Each of the slopes has a slope parameter, and the slope parameters are preset in the comparator 462. The comparator 462 can output a corresponding slope signal corresponding to each of the slope parameters.

The signal generator 464 is configured to receive the slope signal, and calculate the voltage value of the slope signal and the working voltage to output a current control signal. The driving unit 30 receives the current control signal, and accordingly changes the current value of the operating current output to the LED chip 20 according to the current control signal.

In addition, the comparator 462 can further output a voltage limiting signal and a current limiting signal to the signal generator 464. After receiving the current limiting signal, the signal generator 464 controls the driving unit 30 to limit the voltage value of the working voltage. Or the current value of the working current, to avoid abnormality of the output working voltage or working current, and cause damage of the LED chip 20.

Thereby, the above-mentioned constant power LED lighting device can perform the control method of the constant power output of the present invention, and the method includes the following steps as shown in FIG. 3:

A. Connect the light emitting diode chip 20 having the same power as the preset power to the driving unit 30.

B. The voltage detecting unit 42 detects the voltage value of the working voltage, and detects the current value of the working current through the current detecting unit 44.

C. The comparator 462 determines whether the voltage value of the operating voltage is higher than the upper limit voltage value Vmax: if yes, the operating voltage is abnormal, and the comparator 462 sends the voltage limiting signal to the signal generator 464. After receiving the voltage limiting signal, the signal generator 464 outputs a highest voltage control signal to the driving unit 30 to limit the voltage value of the operating voltage outputted to the LED chip 20 to be equal to the reference voltage value V1, and return to the step. B.

If no, proceed to step D.

D. The comparator 462 determines whether the current value of the operating current is higher than the upper limit current value Imax: if yes, the operating current is abnormal, and the comparator 462 sends the current limiting signal to the signal generator 464, the signal The generator 464 receives the current limiting signal and outputs a highest current control signal to the driving unit 30 to limit the voltage flow of the operating current output to the LED chip 20 to be equal to the upper limit current value Imax, and returns to step B. .

If no, proceed to step E.

E. The comparator 462 determines the voltage segment S to which the voltage value of the working voltage belongs according to the voltage value of the operating voltage measured by the voltage detecting unit 42, and obtains the voltage segment to which the voltage value corresponding to the operating voltage belongs. The slope parameter of S is used to output the corresponding slope signal. The signal generator 464 outputs a corresponding current control signal to the driving unit 30 according to the voltage value of the working voltage and the received slope signal, so that the driving unit 30 outputs the operating current to the LED chip 20 . The product of the current value and the voltage value of the operating voltage is within the range of the preset power. That is, the current value of the operating current required for the preset power is calculated by using the voltage value of the operating voltage and the slope of the line of the associated voltage segment S. Preferably, the preset power ranges from 90% to 110% of the preset power (ie, between the preset powers and ±10%). For example, the preset power is 28W, and the working current is The product of the current value and the voltage value of the operating voltage is between 25.2W and 30.8W.

F. Repeat step B to step E to continuously maintain the power supplied to the LED chip 20 within the range of the preset power.

In the above, the relationship between the plurality of voltage segments S and the operating current is used to form an ideal working voltage-operating current curve C. Even if the LEDs 20 of different operating voltages are replaced, the constant-emitting LEDs are used. The illuminating device can change the operating current supplied to the illuminating diode chip 20 accordingly, so that the power supplied to the illuminating diode chip 20 is maintained within a preset power range. When the preset voltage segment S is more, the range of the preset power output is closer to the ideal value.

The method for controlling the power of the LED and the method for controlling the power of the LED can be applied to the LED chip having the same power but different working voltages and working currents, and is not limited to a single working voltage and working. A light-emitting diode chip of current. The illumination device for effectively improving the conventional light-emitting diode can only be applied to the inconvenience of the LED of a single working voltage and working current. The above description is only a preferred embodiment of the present invention, and is not all embodiments of the present invention. Variations in the equivalent structures and methods of the present invention and the scope of the claims are intended to be included within the scope of the invention.

10‧‧‧Power supply

20‧‧‧Light Diode Wafer

30‧‧‧Drive unit

40‧‧‧Fixed power adjustment module

42‧‧‧Voltage detection unit

44‧‧‧current detection unit

46‧‧‧Return control unit

462‧‧‧ comparator

464‧‧‧Signal Generator

Claims (13)

A method for controlling a constant power output for maintaining a power supply to a light emitting diode chip within a predetermined power range, wherein the method is pre-configured with at least two different reference voltage values, the two reference voltages Forming a voltage section between the values, the voltage section corresponding to a slope parameter, the method comprising the steps of: detecting a voltage value of an operating voltage supplied to the LED chip; selecting a voltage of the operating voltage a value corresponding to the slope parameter of the voltage section; and outputting an operating current corresponding to the voltage value of the operating voltage to the LED chip according to the selected slope parameter, wherein the current value of the operating current is The product of the voltage value of the operating voltage is within the range of the preset power. The control method for determining the power output according to claim 1, wherein when the voltage value of the working voltage is higher than an upper limit voltage value, the voltage value of the working voltage outputted to the LED chip is limited to be equal to the reference voltage values. The biggest of them. The control method for determining the power output according to claim 1 or 2, comprising detecting a current value of an operating current supplied to the LED chip, when the current value of the operating current is higher than an upper limit current value, The current value that limits the operating current output to the LED chip is equal to the upper current value. The method for controlling the power output according to claim 1, wherein the preset power ranges between 90% and 110% of the preset power. The control method for determining the power output according to claim 1, wherein at least three different reference voltage values are pre-set, and the voltage segment is formed between adjacent two reference voltage values. The method for controlling the power output according to claim 5, wherein the absolute values of the slopes of the voltage sections are sequentially decreased in descending order of the reference voltage values. A light-emitting diode lighting device for electrically connecting a power source, comprising: a light-emitting diode chip; a driving unit electrically connecting the power source and the light-emitting diode chip for receiving the power source And outputting a working voltage and an operating current to the LED chip; a voltage detecting unit electrically connected to the driving unit for detecting a voltage value of the operating voltage; and a feedback control unit, Electrically connecting the voltage detecting unit and the driving unit, the feedback control unit is pre-set with at least two different reference voltage values, and a voltage segment is formed between the two reference voltage values, and the voltage segment corresponds to a slope a feedback control unit outputs a current control signal to the driving unit to control according to a voltage value of the operating voltage measured by the voltage detecting unit and a slope parameter of the voltage section corresponding to the voltage value of the working voltage a current value of the operating current outputted to the light emitting diode chip, wherein a product of the current value of the operating current and the voltage value of the operating voltage is between a predetermined power Around inside. The illuminating diode illuminating device of claim 7, wherein when the feedback control unit determines that the voltage value of the operating voltage is higher than an upper limit voltage value, the feedback control unit outputs a voltage control signal to the The voltage value of the driving unit to control the output voltage of the output to the LED chip is equal to the largest of the reference voltage values. The illuminating diode device as claimed in claim 8 includes a current detecting unit electrically connected to the driving unit and the feedback control unit for detecting a current value of the working current; When the control unit determines that the current value of the working current is higher than an upper limit current value, the feedback control unit outputs a highest current control signal to the driving unit to control the current value of the working current outputted to the LED chip to be equal to The upper limit current value. The illuminating diode illuminating device of claim 7, wherein the feedback control unit comprises a comparator electrically connected to the signal generator, and the comparator is electrically connected to the voltage detecting unit. The signal generator is electrically connected to the driving unit, and the comparator pre-sets the reference voltage value and the slope parameter. When the comparator determines that the voltage value of the working voltage belongs to the voltage segment, the output corresponds to the voltage segment. A slope signal of the slope parameter, after receiving the slope signal, the signal generator outputs the current control signal according to the slope signal and the voltage value of the working voltage. The illuminating diode lighting device of claim 7, wherein the preset power ranges between 90% and 110% of the preset power. The illuminating diode illuminating device of claim 7, wherein the feedback control unit presets at least three different reference voltage values, and a voltage is formed between adjacent two reference voltage values. Section. The illuminating diode illuminating device of claim 12, wherein the absolute values of the slopes of the voltage sections are sequentially decreased in descending order of the reference voltage values.