KR101377038B1 - LED lighting apparatus - Google Patents

Abstract

The present invention relates to an LED lighting device, and more particularly, in the existing lighting using the wall switch, without dividing wiring and additional configuration, the dimming is made through the turn off-turn on operation of the wall switch, The present invention relates to a multi-level dimmable LED lighting device that can be adjusted in various levels.
The present invention generates a constant current from the rectified DC voltage through the full-wave rectifier 102 to receive the AC power input through the wall switch 98 to the rectified DC voltage to supply to the LED lamp 99, the voltage supply The LED lighting driver 80 provides multi-level dimming according to the count value of the counter 96 which receives the output voltage VDD1 of the circuit 90 and counts the number of turn-off / turn-on times of the wall switch 98. Characterized in that the configuration.

Description

LED lighting device {LED LIGHTING APPARATUS}

The present invention relates to an LED lighting device, and more particularly, in the existing lighting using the wall switch, without dividing wiring and additional configuration, the dimming is made through the turn off-turn on operation of the wall switch, The present invention relates to a multi-level dimmable LED lighting device that can be adjusted in various levels.

In general, dimming dims'; [Eye, etc.] is blurred [faint] ', and on the luminaire side as part of the luminaire to adjust to the desired brightness of the user, this device is called dimmer do.

This dimming or dimmer is an indispensable technology in recent lighting equipment. (It is used to improve the quality of lighting such as creating a pleasant lighting environment in recent lighting design, eliminating glare, adjusting the illumination to create an atmosphere, and saving energy.) This dimming to dimmer is mainly provided in the ballast to provide the above functions.

The ballast serves to maintain a constant lighting of the lamp by continuously supplying a constant voltage to the lighting device (lamp) to interrupt the discharge of the lamp. That is, since the lamp has a negative voltage-current characteristic, when the initial lamp is turned on, the voltage continuously decreases while the voltage increases, and eventually the lamp is destroyed. A ballast is required to prevent such a phenomenon. After the ballast serves to limit the current by supplying a constant voltage to the lamp.

) 값을 결정한다. R23은 가변저항이다. 사용자는 R23을 변경하여 지연시간을 조절할 수 있다. 이때, 트라이악(25)이 턴온하기 전에는 R23을 거쳐 C24에 충전되는 전류를 제외한 다른 전류는 없다. 이 작은 전류는 백열등에 흐르게 된다. 보통 백열등은 수백옴 정도의 저항 성분으로 되어 있다. 지연시간이 지난 후에는 C24의 전압은 다이악(26)을 도통시키기에 충분히 높은 상태로 되어야 한다. 다이악이 도통되면 트라이악의 GT에 짧은 전류 펄스가 유입되고, 트라이악은 턴온 된다. Conventionally, a dimming circuit of a lamp may be exemplified by a conventional triac dimming circuit used in the incandescent lamp 10 shown in FIG. 1. The dimming circuit 20 is connected between the wall switch 98 of the AC power line. Resistor R23 and capacitor C24 have a delay time after the AC voltage crosses 0V.

) To determine the value. R23 is a variable resistor. The user can adjust the delay time by changing R23. At this time, before the triac 25 turns on, there is no current other than the current charged to C24 via R23. This small current flows through the incandescent lamp. Incandescent lamps are usually made up of hundreds of ohms. After the delay has elapsed, the voltage at C24 must be high enough to allow the diaak 26 to conduct. When the Diac becomes conductive, a short current pulse flows into the Triac's GT, and the Triac is turned on.

In addition, Figure 2 shows some waveforms that are important in a conventional triac dimming circuit. As the delay increases, the conduction angle of the triac decreases. Therefore, the amount of power or current of the incandescent lamp can be controlled. The method of changing the delay time to adjust the available power of the load is called phase control.

However, a lighting apparatus using a triac dimmer such as the conventional dimming circuit 20 does not have a good power factor. For example, when set to very low brightness, the power factor drops below 0.2.

Triac dimmers also generate EMI and noise. That is, EMI filter is generally composed of C21 and L22.

Triac dimmers are also designed to be used to control resistive loads, such as incandescent lamps. If the dimming level is set low while using the triac method, the temperature of the tungsten filament is lowered, causing a reddish light.

Also, triac dimmers are not compatible with most fluorescent lights. In addition, Triac dimmers are not compatible with most LED luminaires. That's because LEDs emit light by flowing forward current, so the light disappears immediately when the current flows off (using some blocking of the AC voltage makes the LED light flicker).

The LED lighting device has advantages such as high brightness, low power consumption, small size, light weight, and long life compared to the existing incandescent lamps or fluorescent lamps, and is spurring efforts to develop and use such LEDs as lighting devices. The demand for this is also increasing steadily.

Therefore, the LED lighting equipment, as in the case of incandescent and fluorescent lamps, requires not only to turn on / off the LED lighting but also a dimming function (shopping mall, shop, school, hospital, office, subway, factory, etc. Requires dimming instead of turning off all lights at the end of work or at night in public places.)

However, the lighting dimmer including the dimming circuit has to be installed separately in the luminaire, which incurs additional costs, and thus, most fluorescent lamps, energy-saving lamps and general LED lamps do not include a dimming device. Since only the function of turning on or turning off the maximum, improvement is required.

The present invention was created to solve the problems of the prior art as described above and to meet the requirements, and in the existing lighting using the wall switch without the need for additional wiring and additional configuration, turn-on-turn operation of the wall switch It aims to provide a multi-level dimmable LED lighting device that can be dimmed through, and the dimming level can be adjusted in various ways.

The present invention for achieving the above object is to generate a constant current from the rectified DC voltage through the full-wave rectifier 102 receives the AC power through the wall switch 98 to supply a rectified DC voltage LED lamp (99) Multi-level according to the turn-on-turn-count count value of the counter 96 that stores and provides the turn-on-turn-on time of the wall switch 98 by receiving power from the voltage supply circuit 90. It is characterized in that it comprises a LED lighting driver 80 to provide dimming.

The present invention by the above problem solving means is to make the dimming through the turn-on-turn operation of the wall switch without additional wiring work and additional configuration in the existing lighting using the wall switch, switching the dimming function By incorporating it into the controller, the effect of enabling dimming at low cost is obtained.

1 is a circuit diagram showing the configuration of a conventional triac dimming circuit.
2 is a waveform diagram showing an operating state of a conventional triac dimming circuit.
3 is a circuit block diagram schematically showing a configuration according to an embodiment of the present invention.
4 is a circuit diagram showing in more detail the configuration according to an embodiment of the present invention.
5 is a waveform diagram showing an operating state of the present invention.
6 is a circuit diagram showing a configuration according to another embodiment of the present invention.

The present invention will now be described with reference to the accompanying drawings.

First, the present invention is a constant from the DC voltage rectified through the full-wave rectifier 102 to receive the AC power input to the rectified DC voltage through the wall switch 98, as shown in Figure 3 and 4 of the accompanying drawings A current is generated and supplied to the LED lamp 99, and the power is supplied from the voltage supply circuit 90 to store and provide the turn-off and turn-on times of the wall switch 98. It may be configured to include an LED lighting driver 80 to provide a multi-level dimming according to the count value.

Here, in the present invention, the voltage supply circuit 90 rectifies the AC voltage induced in a transformer formed while the inductor 81 and the bias winding 93 are provided on a common magnetic core while the wall switch 98 is turned on. This may be to supply a DC voltage ripple is removed.

Meanwhile, the LED lighting driver 80 includes an inductor 81 connected to the LED lamp 99; An anode connected to the inductor 81 and a cathode connected to a stage to which a rectified DC voltage is supplied and a reflux diode 82 connected to an LED lamp 99; A power MOSFET 83 connected between the anode of the reflux diode 82 and GND; A switching controller 85 which is driven at the output voltage VDD1 of the voltage supply circuit 90 and controls the duty cycle of the power MOSFET 83 according to the count value of the counter 96 to provide multi-level dimming. It can be configured to include. In addition to the Buck structure, the LED lighting driver 80 may also have a flyback and forward structure.

In this case, the power MOSFET 83 may stop the switching operation when the wall switch 98 is turned off.

When the switching operation of the power MOSFET 83 is stopped, the supply of energy to the power capacitor 92 is stopped from the bias winding 93, after which the power capacitor 92 starts to discharge, and the voltage VDD1 is previously set. When the voltage falls below a predetermined voltage, the switching controller 85 is shut down, and when a reset trigger signal is generated at the switching controller 85, the RS flip-flop 78 connected to the output terminal of the switching controller 85 is an EN signal. The counter 96 may count the EN signal (Enable signal) of the RS flip-flop 78.

In this case, the counter 96 may store a count value for a predetermined time until all of the energy of the power capacitor 92 is discharged.

In addition, the switching controller 85 includes a UVLO1 stage for detecting that the VDD1 voltage is above a predetermined voltage and generating a set trigger signal; And a UVLO2 stage that detects that the VDD1 voltage is discharged below a predetermined voltage and generates a reset trigger signal. The RS flip-flop 78 receives the reset trigger signal and outputs an EN signal to the counter 96. It may be configured to include more.

In this case, the switching controller 85 may further include a control logic circuit which receives the EN signal of the RS flip-flop 78 and shuts down the switching controller 85 except for the counter 96. The switching controller 85 may further include a MUX 79 that selects one of a plurality of preset voltages with reference to the count value of the counter 96 and transmits the selected voltage to Vref, which is a reference voltage. . At this time, when the count value of the counter 96 increases, Vref decreases and the switching duty cycle of the power MOSFET 83 decreases.

In addition, the MUX 79 may be alternatively configured as a digital-to-analog converter (DAC) for converting a count value into a Vref voltage.

The operation of the present invention, which can be configured as described above, is as follows.

First, the present invention, as described above, the full-wave rectifier 102 receives the AC power source 101 through the wall switch 98 to provide a full-wave rectified voltage. The voltage supply circuit 90 supplies a VDD1 voltage which is a DC voltage.

In addition, the counter 96 is usually 2 bits, and uses the VDD1 voltage as a power source, and stores the counted value and supplies it to the switching controller 85.

In addition, the LED lighting driver 80 operates by receiving the VDD1 voltage, generates a current from the rectified DC voltage to drive the LED lamp 99, and corresponds to the value counted by the counter 96. The brightness of the LED lamp 99 is adjusted from various levels.

In this case, the LED lighting driver 80 includes an inductor 81, a free-wheeling diode 82, a power MOSFET 83, a current sensing resistor 84, and a switching controller 85.

The inductor 81 is connected to the LED lamp, the anode of the reflux diode 82 is connected to the inductor 81, and the cathode is connected to the rectified DC voltage supply terminal and the LED lamp 99.

In addition, the power MOSFET 83 is connected to the anode of the inductor 81 and the flyback diode 82.

In addition, the current sensing resistor 84 is connected between the source of the power MOSFET 83 and GND.

At this time, when the power MOSFET 83 is turned on, the voltage applied to the inductor 81 becomes positive, and the current flows through the LED lamp 99 and the inductor 81 while increasing, and is caused by the current sensing resistor 84. When the voltage of the ISEN node is increased to reach Vref, the power MOSFET 83 is turned off.

As such, when the power MOSFET 83 is turned off, the voltage applied to the inductor 81 becomes negative since the voltages of the LED lamp 99 and the flyback diode 82 are constant. At this time, the current flowing through the LED lamp 99 and the inductor 81 decreases. In the above, since the power MOSFET 83 switches quickly, the current flowing in the LED lamp 99 is kept constant.

In addition, the switching controller 85 operates with the VDD1 voltage generated from the voltage supply circuit 90, and changes the PWM of the power MOSFET 83 according to the value provided by the counter 96 to change the LED lamp 99. Adjust the brightness.

The voltage supply circuit 90 includes a bias winding 93, a rectifying diode 91, a power capacitor 92, and a startup resistor 95.

In the above, the startup resistor 95 supplies the VDD1 voltage capable of sufficiently driving the power MOSFET 83 at the initial startup.

In addition, the inductor 81 and the bias winding 93 are electromagnetically coupled by a transformer using a common magnetic core. When the power MOSFET 83 switches, AC is connected to the inductor 81. A voltage is generated, which induces an AC voltage proportional to the bias winding 93, and the rectifying diode rectifies the induced AC voltage.

In addition, the power capacitor 92 filters the ripple of the rectified voltage, resulting in a VDD1 voltage, which is a direct current voltage. As such, when the wall switch 98 is initially turned on, the full-wave rectified voltage VDC charges the power capacitor 92 through the start-up resistor 95. At this time, when the VDD1 voltage reaches a predetermined voltage, the Set trigger signal is generated in the UVLO1, and the trigger signal is generated by the RS flip-flop 78 to generate the EN signal.

The EN signal starts switching by operating the switching controller 85. If the wall switch 98 is temporarily turned off, the switching of the power MOSFET 83 is stopped. At this time, the bias winding 93 can no longer supply power to the power capacitor 92. When the voltage VDD1 of the power capacitor 92 discharges below a specific voltage (ex. 6V), the UVLO2 generates a reset trigger signal.

At this time, the counter 96 counts the trigger signal, and the reset trigger signal shuts down the switching controller 85 except the counter 96 by the RS flip-flop 78.

Since the power consumption of the counter 96 is very small, after the LED light driver 80 stops operating, the counter 96 may have a count value as a voltage charged in the power capacitor 92.

Therefore, when the user turns off the wall switch 98 and turns on within about 2 seconds, the dimming level of the LED lamp 99 can be adjusted. If the off state continues for more than about 2 seconds, the count value disappears, and the dimming level of the LED lamp 99 is reset to the initial state. This time is described as an example, and may vary with time constant.

In addition, the MUX 79 selects a corresponding dimming voltage among preset voltages and sends the count value to Vref. At this time, when the count value increases, the dimming voltage decreases.

By the control mechanism of the conventional switching controller 85, the switching controller 85 controls the duty cycle of the power MOSFET 83 to be proportional to the dimming voltage Vref. Therefore, when the count value increases, the LED light driver 80 gives a low output.

Instead of MUX, it converts digital signal such as DAC into analog voltage and changes the circuit.

5 is a waveform diagram showing an operating state of the present invention, in which the counter value is initialized to 00 when the wall switch 98 is first turned on. In this state, the switching controller 85 drives the PWM dimming level at 100%.

Subsequently the turn off-turn on of the wall switch 96 increases the counter value by one. After the first turn-off, the count value is 01. At this time, the switching duty cycle of the power MOSFET is reduced to 50%. After the second turn off-turn on, the count value becomes 10.

At this time, the switching duty cycle is 25%, and after the third turn off-turn on, the switching duty cycle is 12.5%. After the fourth turn off-turn on, the count value returns to 00 and the switching duty cycle returns to 100%.

However, if the wall switch 96 is turned off for a few seconds or more, VDD1 discharges to a very low voltage and the counter 96 loses the count value. At this time, when the wall switch 98 is turned on again, the counter 96 is reset to 00 so that the switching controller operates at 100% duty cycle.

Although the count is composed of 2 bits in the present invention, more bits can be configured to allow fine dimming level adjustment. In addition, the switching controller 85 may be configured as a PWM or PFM converter, and the LED lighting driver 80 may be configured as a flyback converter or a forward converter, as shown in FIG. 6.

In the circuit shown in FIG. 6, when the power MOFET 83 is turned on, current flows to the primary winding of the inductor 81, and the inductor 81 is induced with an input voltage. On the other hand, the secondary winding of the inductor 81 is induced a voltage of a polarity opposite to the primary side in the direction of the black spot to conduct a diode, the energy stored in the magnetizing inductance of the inductor 81 to the output side By discharging, the LED lamp 99 is operated.

In addition, the present invention utilizes a low power counter to store the dimming level, that is, when the wall switch 98 is turned off momentarily, only the switching controller 85 except for the counter 96 is shut down, and the low power counter Is made possible by maintaining the count value using the energy stored in the power capacitor 92.

In addition, UVLO (Under Voltage Lockout) is a function that all switching controllers have, and it utilizes this UVLO function as it can be applied as an easily integrated switching controller simply by adding a counter and a simple digital logic circuit.

In addition, the LED lighting of the present invention is adapted to A19, PAR30, PAR38, and the like, which are ordinary lighting equipment.

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. In addition, those skilled in the art will appreciate that many modifications and variations of the present invention are possible without departing from the spirit and scope of the appended claims. Accordingly, all such appropriate modifications and changes, and equivalents thereof, should be regarded as within the scope of the present invention.

80: LED lighting driver 81: inductor
82: reflux diode 83: power MOSFET
84: current sensing resistor 85: switching controller
90: voltage supply circuit 91: rectifier diode
92: power capacitor 93: bias winding
95: start-up resistor 96: counter
98: wall switch 99: LED lamp
101: AC power supply 102: full-wave rectifier

Claims (12)

In the LED lighting device that controls the on / off of the LED lamp by turning on / off the power through the wall switch operation,
A constant current is generated from the rectified DC voltage through the full-wave rectifier 102 that receives AC power through the wall switch 98 and supplies the rectified DC voltage to the LED lamp 99, and supplies the voltage to the LED lamp 99. It is configured to include an LED lighting driver 80 that provides a multi-level dimming according to the count value of the counter 96 for counting the turn-off-turn-on times of the wall switch 98 by receiving the output voltage of VDD1) ,
The counter 96
LED lighting device, characterized in that for storing a count value for a predetermined time until all the energy of the power capacitor 92 is discharged.
The method of claim 1, wherein the voltage supply circuit 90
While the wall switch 98 is turned on, the inductor 81 and the bias winding 93 are provided on a common magnetic core to rectify the AC voltage induced in the transformer, thereby supplying the DC voltage without the ripple. LED lighting device.
The method of claim 1, wherein the LED light driver 80
An inductor 81 connected to the LED lamp 99;
An anode connected to the inductor 81 and a cathode connected to a stage to which a rectified DC voltage is supplied and a reflux diode 82 connected to an LED lamp 99;
A power MOSFET 83 connected between the anode of the reflux diode 82 and GND;
A switching controller 85 which is driven at the output voltage VDD1 of the voltage supply circuit 90 and controls the duty cycle of the power MOSFET 83 according to the count value of the counter 96 to provide multi-level dimming. LED lighting device, characterized in that configured to include.
4. The power MOSFET of claim 3, wherein
LED lighting device, characterized in that the switching operation is stopped when the external wall switch 98 is turned off.
The method of claim 3, wherein
When the switching operation of the power MOSFET 83 is stopped, the supply of energy to the power capacitor 92 is stopped from the bias winding 93 constituting the voltage supply circuit 90, and then the power capacitor 92 is stopped. When the discharge is started and the VDD1 voltage, which is the output voltage of the voltage supply circuit 90, falls below the preset voltage, the switching controller 85 is shut down, and together with the reset trigger signal generated by the switching controller 85, The LED lighting device, characterized in that the RS flip-flop (78) connected to the output terminal of the switching controller (85) outputs the EN signal, the counter 96 counts the EN signal of the RS flip-flop (78).
delete The method of claim 3, wherein the switching controller 85
A UVLO1 stage that detects that the VDD1 voltage is above a predetermined voltage and generates a Set trigger signal; And a UVLO2 stage that detects that the VDD1 voltage is discharged below a predetermined voltage and generates a reset trigger signal. The RS flip-flop 78 receives the reset trigger signal and outputs an EN signal to the counter 96. LED lighting device, characterized in that further comprises.
The method of claim 7, wherein the switching controller (85)
LED lighting device, characterized in that it further comprises a control logic circuit for receiving the EN signal output from the RS flip-flop (78), the switching controller (85) except for the counter (96).
The method of claim 3, wherein the switching controller 85
LED lighting device further comprises a MUX (79) for selecting one of a plurality of preset voltages with reference to the count value of the counter (96), and transmits it to the reference voltage Vref.
The method of claim 3, wherein
The LED lighting apparatus according to claim 1, wherein Vref decreases as the counter value increases and the switching duty cycle of the power MOSFET decreases.
10. The apparatus of claim 9, wherein the MUX 79 is
LED lighting device, characterized in that the alternative configuration to the DAC converts the count value to the Vref voltage.
The method of claim 3, wherein the switching controller 85
When the power MOSFET 83 is turned on, current flows to the primary winding of the inductor 81, the inductor 81 induces an input voltage, and the secondary winding of the inductor 81 has a black dot in the direction of the black spot. It is a flyback converter or forward converter that operates the LED lamp 99 by inducing a voltage of opposite polarity to the primary side, conducting the diode, and releasing energy accumulated in the magnetization inductance of the inductor 81 to the output side. LED lighting device.

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