KR101108094B1 - Bidirectional lighting emitting diode module device to drive with constant current - Google Patents

Abstract

The present invention provides a constant current driving bidirectional LED module device that can suppress the flicker phenomenon due to the AC LED operating characteristics according to the application of the AC power, can improve the light efficiency, and improve the power factor.

According to an aspect of the present invention, there is provided a constant current driving bidirectional LED module device comprising: a rectifying unit configured to receive and rectify AC power; A constant current unit connected between the read leg and the leg leg of the rectifier to provide a constant current; And a bidirectional LED module unit connected between the other end of the rectifying unit and the other end of the AC power supply.

LED, AC, Constant Current, Bidirectional, Power Factor

Description

Constant Current Drive Bidirectional LED Module Device {BIDIRECTIONAL LIGHTING EMITTING DIODE MODULE DEVICE TO DRIVE WITH CONSTANT CURRENT}

The present invention relates to a constant current drive bidirectional LED module device, and more particularly, to a bidirectional LED module device driven with a constant current.

LED (Luminescent Diode) can operate when a constant current is supplied to the current driving device. In particular, LEDs that require high power generate a lot of heat in the LEDs themselves because of their large driving current (typically 350mA or more), which results in a higher degradation rate of luminance than LEDs at low power. This is directly linked to the lifetime of the LED and is very important in the lighting market. Accordingly, all LEDs at high power are driven with a constant current, and are driven in a pulse width modulation (PWM) scheme to more efficiently use the power of the SMPS used as the constant current power source.

However, this method requires an electronic component, which increases the manufacturing cost. Therefore, recently, a method of rectifying AC power and applying the same to an LED module connected in series has been applied.

1 is a bidirectional LED module device according to the prior art.

The bidirectional LED module device according to the prior art includes a bidirectional LED module 120 coupled through an applied AC power source 110 and a resistor (R1).

Here, the resistor R1 determines the magnitude of the current flowing in the bidirectional LED module 120.

2 is a waveform diagram of applied voltage and driving current in a bidirectional LED module according to the related art, where v is a voltage waveform to be applied and i is a current waveform flowing to the bidirectional LED module 120 according to an applied AC voltage.

When the positive half-cycle voltage of the AC power source 110 is applied, current flows when the magnitude of the voltage is greater than or equal to the forward threshold voltage of the forward LED module 121 and the forward LED module 120 emits light. Similarly, in the negative half cycle of the AC power supply 110, when the magnitude of the voltage is equal to or greater than the forward threshold voltage of the reverse LED module 122, current flows and the reverse LED module 122 emits light. That is, as shown in Figure 2, the load current does not flow in the section a and b.

As such, when the magnitude of the applied voltage is greater than or equal to the forward threshold voltage, an operating characteristic of the bidirectional LED module 120 that operates only, that is, when the forward threshold voltage is greater than or equal to the forward threshold voltage of the bidirectional LED module 120 connected by the application of AC power. The power factor is low and the total harmonic distortion is due to the fact that the current suddenly flows through the current and the LED module operates within a period of the applied AC power. THD) increases, and there is a problem that excessive flicker occurs. In addition, there is also a problem that the light efficiency is lowered due to this.

Disclosure of Invention The present invention devised to solve the above problems is an object of the present invention to provide a constant current driving bidirectional LED module device that can suppress the flicker phenomenon due to the AC LED operating characteristics according to the application of the AC power.

In addition, another object of the present invention is to provide a constant current driving bidirectional LED module device that can improve the light efficiency degradation due to the AC LED operating characteristics according to the application of the AC power.

In addition, another object of the present invention is to provide a constant current driving bidirectional LED module device that can improve the power factor decrease due to the AC LED operating characteristics according to the application of the AC power.

According to an aspect of the present invention, there is provided a constant current driving bidirectional LED module device comprising: a rectifying unit configured to receive and rectify AC power; A constant current unit connected between the read leg and the leg leg of the rectifier to provide a constant current; And a bidirectional LED module unit connected between the other end of the rectifying unit and the other end of the AC power supply.

Preferably, the constant current unit, the switching unit is connected between the lead leg and the lag leg of the rectifying unit for switching using the pulse flow outputted by the rectifier; A control voltage output unit for detecting a load current flowing through the bidirectional LED module unit and converting a switching voltage output from the switching unit into a driving voltage of a saturation region operating level and an active region operating level according to the detected load current; And a constant current driver configured to provide a constant current by controlling the driving voltage of the saturation region operating level and the active region operating level.

Preferably, the constant current unit detects a load current flowing through the bidirectional LED module unit and adjusts the voltage between the read leg and the lag leg of the rectifying unit according to the detected load current. A control voltage output unit converting the driving voltage; And a constant current driver configured to provide a constant current by controlling the driving voltage of the saturation region operating level and the active region operating level.

Preferably, the battery module may further include a charge / discharge unit including a resistor-capacitor connected in parallel with the bidirectional LED module unit.

Preferably, the constant current driver may be any one of a field effect transistor (FET), a bipolar junction transistor (BJT), and an insulated gate bipolar transistor (IGBT).

Preferably, the control voltage output unit, the detection resistor disposed on the path of the load current; And a zener voltage that is a driving voltage of the saturation region operating level when the control voltage applied to the detection resistor is less than or equal to a set value, and maintains a short circuit state between an anode and a cathode when the control voltage exceeds the set value. It may include a three-terminal zener diode for outputting a drive voltage of the level.

Preferably, when the applied voltage of the AC power source fluctuates in the range of 10% of the rated voltage, the load current flowing in the bidirectional LED module unit varies in the range of 5 to 20%.

Preferably, when the applied voltage of the AC power source fluctuates in the range of 10%, the light quantity of the bidirectional LED module unit varies in the range of 9 to 20%.

According to the present invention, it is possible to suppress the flicker phenomenon caused by the AC LED operating characteristics according to the application of the AC power supply is suitable for use as an illumination device. Since the flicker phenomenon is suppressed, there is an effect of extending the life of the lighting device. Further, according to the present invention, it is possible to improve the light efficiency drop and to improve the power factor drop.

In addition, compared with the prior art, the LED operating period is wider, and thus, the effective power is increased to improve the power factor (PF), and the effective value of the fundamental wave is larger, so that the total harmonic distortion (THD) is improved.

Hereinafter, exemplary embodiment (s) of the present invention will be described in detail with reference to the accompanying drawings. First, in adding reference numerals to the elements of each drawing, it should be noted that the same elements are denoted by the same reference numerals as much as possible even if they are displayed on different drawings. In addition, many specific details are shown in the following description, which is provided to help a more general understanding of the present invention, and the present invention may be practiced without these specific details. Will be self-evident. In describing the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

3 is a circuit diagram of a constant current driving bidirectional LED module device according to a first embodiment of the present invention.

Bidirectional LED module device driven by a constant current according to an embodiment of the present invention, the rectifier 320 for receiving and rectifying the commercial AC power source 310; The other end of the constant current unit 330 and the rectifier 320 connected to the lead legs D1 and D2 and the lag legs D3 and D4 of the rectifier 320 to provide a constant current, and a commercial AC power supply. It includes a bi-directional LED module unit 340 connected between the other end of (310).

The constant current unit 330 according to the exemplary embodiment of the present invention is connected between the lead legs D1 and D2 and the lag legs D3 and D4 of the rectifier 320 so that the rectifier 320 is connected. Detects the load current flowing through the switching unit 331 and the bidirectional LED module unit 340 using the output pulses, and saturates the switching voltage output from the switching unit 331 according to the detected load current. And a control voltage output unit 332 for converting the operating level and the active region operating level into driving voltages, and a constant current driver 333 controlled to the saturation region operating level and the active region operating level to provide a constant current.

The switching unit 331 includes a first resistor R1 and a first zener diode ZD1 connected in series between the lead legs D1 and D2 and the lag legs D3 and D4 of the rectifier 320. ), A second FET Q2 turned on and off at the zener voltage of the first zener diode ZD1, and a second resistor R2 having one end coupled to a source terminal of the second FET Q2.

The control voltage output unit 332 is coupled between the detection resistor Rsen disposed in the path of the load current, the other end of the second resistor R2, and the lower end of the rectifier 320, and the control voltage Vcon applied to the detection resistor. And a three-terminal zener diode (3p-ZD) which is controlled at and outputs driving voltages of the saturation region operating level and the active region operating level.

The constant current driver 333 is composed of a first FET Q1 coupled between the upper end of the rectifier 320 and the detection resistor Rsen to vary the operation region according to the driving voltage of the saturation region operating level and the active region operating level.

Referring to the operation of the constant current driving bidirectional LED module device according to an embodiment of the present invention.

When the voltage applied between the upper end and the lower end of the rectifier 320 exceeds a predetermined level, both ends of the zener diode ZD1 maintain the zener voltage, and the second FET Q2 is turned on by the zener voltage.

The three-terminal zener diode (3p-ZD) has the same characteristics as the general zener diode characteristic when the control voltage (Vcon) applied to the detection resistance is lower than the set value, and outputs the zener voltage, and the anode when the control voltage (Vcon) exceeds the set value. Maintain a short between the and cathode.

The first FET Q1 operates in the saturation region according to the first driving voltage applied from the three-terminal zener diodes 3p-ZD, that is, the zener voltage, when the control voltage is less than or equal to the set value. On the other hand, if the control voltage exceeds the set value, the three-terminal zener diodes 3p-ZD operate in a short-circuit state, so that the control voltage applied to the detection resistor Rsen is reversed to the gate-source terminal of the first FET Q1. The first FET Q1 operates in the active region, so that the load current has a constant current characteristic.

FIG. 4 is a circuit diagram of a bidirectional LED module device driven with a constant current according to a second embodiment of the present invention, and most configurations are the same as those of the first embodiment of FIG.

However, the operation of the constant current unit 430 is identical except that the switching unit 431 for providing a constant current using two FETs instead of the switching unit 331 in FIG. 3 is different.

FIG. 5 is a circuit diagram of a bidirectional LED module device driven with a constant current according to a third embodiment of the present invention, and most configurations are the same as those of the first embodiment of FIG.

However, the operation of the constant current unit 530 is the same except that the switching unit 331 in the first embodiment of FIG. 3 is removed.

FIG. 6 is a circuit diagram of a bidirectional LED module device driven with a constant current according to a fourth embodiment of the present invention, and further includes a charge / discharge unit 350 in the circuit of the first embodiment of FIG.

The charging and discharging unit 350 includes a resistor R3 and a capacitor C1 coupled in parallel with the bidirectional LED module unit 340. The capacitor C1 charges energy of an AC power source and discharges energy to the bidirectional LED module unit 340.

Meanwhile, the charge / discharge unit 350 according to an embodiment of the present invention may be similarly applied to the second embodiment of FIG. 4 or the third embodiment of FIG. 5.

FIG. 7 is a voltage and current waveform diagram of a bidirectional LED module device driven with a constant current according to a fourth embodiment of the present invention. According to the present invention, the LED operating section is wider than the conventional circuit of FIG. Increased power improves power factor (PF), and the fundamental harmonic value is larger, which improves total harmonic distortion (THD).

8 is a light output waveform diagram according to the prior art compared to the light output according to the first to third embodiments of the present invention.

According to the present invention, it can be seen that there is no change in the light output since the change in the current peak can be minimized by limiting the increase in the AC peak storage even if the input power supply voltage changes.

In contrast, according to the related art of FIG. 1, since the current varies in proportion to the change in the AC power supply voltage, the light output also changes.

On the other hand, Figure 8 is to ignore the effect of the charging and discharging unit according to an embodiment of the present invention.

9 is a graph of current characteristics compared to applied voltages of the prior art and the present invention. In the present invention, the variation of the load current shows a very small constant current characteristic even if the applied voltage changes.

That is, according to the prior art, when the applied voltage is reduced by 10% compared to the rated voltage and 200 volts is applied, the load current is reduced (41.66-29.30) / 41.66 * 100 = 29.7%, the applied voltage is 10 compared to the rated voltage When 240 volts is applied in% increase, the load current increases by (54.22-41.66) /41.66*100 = 30.1%.

On the other hand, according to an embodiment of the present invention, the load current is reduced (39.23-36.09) / 39.23 * 100 = 8% when applying 200 volts, the load current is increased by (41.50-39.23) / 39.23 = 5.8% when applying 240 volts do. Here, the circuit of the prior art and the circuit of the present invention are implemented for an 8-watt LED lamp.

FIG. 10 is a graph of light quantity characteristics versus applied voltages of the prior art and the present invention, and it can be seen that the increase in the amount of light is not significant even if the applied voltage is increased in the present invention compared to the prior art.

That is, according to the prior art, when the applied voltage is reduced by 10% compared to the rated voltage and 200 volts is applied, the amount of light is reduced (299-215) / 299 * 100 = 28.1%, the applied voltage is 10% compared to the rated voltage When 240 volts is applied, the amount of light increases (383-299) / 299 * 100 = 28.1%.

On the other hand, according to an embodiment of the present invention, the amount of light applied at 200 volts is reduced by (277-239) / 277 * 100 = 13.7%, and the amount of light applied at 240 volts is increased by (304-277) / 277 = 9.7%. Here, the circuit of the prior art and the circuit of the present invention are implemented for an 8-watt LED lamp.

As described above, although the specific embodiment (s) have been described in the detailed description of the present invention, various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiment (s), but should be defined by the appended claims and equivalents thereof.

1 is a bidirectional LED module device according to the prior art,

2 is a waveform diagram of applied voltage and driving current in a bidirectional LED module according to the related art;

3 is a circuit diagram of a constant current driving bidirectional LED module device according to a first embodiment of the present invention;

4 is a circuit diagram of a bidirectional LED module device driven with a constant current according to a second embodiment of the present invention;

5 is a circuit diagram of a bidirectional LED module device driven with a constant current according to a third embodiment of the present invention;

6 is a circuit diagram of a bidirectional LED module device driven with a constant current according to a fourth embodiment of the present invention;

7 is a voltage and current waveform diagram of a bidirectional LED module device driven with a constant current according to a fourth embodiment of the present invention,

8 is a light output waveform diagram according to the prior art compared to the light output according to the first to third embodiments of the present invention,

9 is a graph of current characteristics versus current applied voltage of the prior art and the present invention, and

Figure 10 is a graph of the light quantity characteristics compared to the applied voltage of the prior art and the present invention.

DESCRIPTION OF THE RELATED ART [0002]

310: commercial AC power source 320: rectifier

330: constant current unit 331: switching unit

332: control voltage output unit 333: constant current drive unit

340: bidirectional LED module unit 350: charging and discharging unit

Claims (8)

Rectifying unit for receiving rectified AC power; A constant current unit connected between the read leg and the leg leg of the rectifier to provide a constant current; And And a bidirectional LED module unit connected between the other end of the rectifying unit and the other end of the AC power source. The constant current unit, A switching unit connected between a lead leg and a lag leg of the rectifying unit to switch using a pulse current output by the rectifying unit; A control voltage output unit for detecting a load current flowing through the bidirectional LED module unit and converting a switching voltage output from the switching unit into a driving voltage of a saturation region operating level and an active region operating level according to the detected load current; And A constant current driver configured to provide a constant current by controlling the driving voltage of the saturation region operating level and the active region operating level Constant current drive bidirectional LED module device comprising a. delete Rectifying unit for receiving rectified AC power; A constant current unit connected between the read leg and the leg leg of the rectifier to provide a constant current; And It includes a bidirectional LED module connected between the other end of the rectifier and the other end of the AC power, The constant current unit, A control voltage output for detecting a load current flowing through the bidirectional LED module unit and converting a voltage between the read leg and the lag leg of the rectifying unit into a driving voltage of a saturation region operating level and an active region operating level according to the detected load current. part; And A constant current driver configured to provide a constant current by controlling the driving voltage of the saturation region operating level and the active region operating level Constant current drive bidirectional LED module device comprising a. The method according to claim 1 or 3, And a charge / discharge unit comprising a resistor-capacitor connected in parallel with the bidirectional LED module unit. 5. The method of claim 4, And the constant current driver is any one of a field effect transistor (FET), a bipolar junction transistor (BJT), and an insulated gate bipolar transistor (IGBT). The method of claim 4, wherein the control voltage output unit, A detection resistor disposed on the path of the load current; And When the control voltage applied to the detection resistor is less than or equal to a set value, a zener voltage that is a driving voltage of the saturation region operating level is output. When the control voltage exceeds the set value, an active region operating level that maintains a short circuit between an anode and a cathode. -Terminal zener diodes outputting drive voltage Constant current drive bidirectional LED module device comprising a. 5. The method of claim 4, When the applied voltage of the AC power supply fluctuates in the range of 10% of the rated voltage, the load current flowing in the bidirectional LED module unit varies in the range of 5 to 20%, characterized in that the constant current drive bidirectional LED module device. 5. The method of claim 4, When the voltage applied to the AC power supply fluctuates in the range of 10%, the light quantity of the bidirectional LED module unit varies in the range of 9 to 20%.

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