KR20110088700A - Led fluorescent lamp - Google Patents

Abstract

PURPOSE: An LED fluorescent lamp is provided to obtain stable current features without severe influences due to a change of external operation conditions. CONSTITUTION: First to fourth capacitors(C101,C102,D103,D104) are connected to first to fourth connection pins respectively. One end of the first node s connected to the other end of the first capacitor and the other end of the third capacitor. The other end of an LED array circuit unit is connected to the other end of the second capacitor and the second node to which the other end of the fourth capacitor is connected. The LED array circuit unit includes a constant current circuit.

Description

LED fluorescent lamp

The present invention relates to an LED fluorescent lamp, and more particularly to an LED fluorescent lamp that can be used by replacing only the fluorescent lamp without replacing the ballast installed in a general fluorescent lamp fixture.

With the development of technology, the light efficiency of LEDs (Light Emitting Diodes), which have been used only for small power indicators such as indicators in the past, is being improved enough to be used in real life. In addition, unlike other light sources, LED is an environmentally friendly light source that does not contain mercury, and is widely used as a next-generation light source used for a backlight for a portable terminal, a backlight for an LCD TV, a vehicle lamp, and general lighting. Accordingly, fluorescent lamps containing environmental waste such as incandescent lamps or mercury lamps, which have been used as the main light source for lighting for the last 100 years, are being replaced by LED lamps.

However, in the case of LED lamps, incandescent lamps or halogen lamps can be replaced as they are, but when replacing fluorescent lamps that are the mainstream of general lighting, the internal wiring, the luminaire itself, or the dedicated ballast separately Installation has to be costly, both timely and economically. Accordingly, LED fluorescent lamps, which have many advantages in various aspects, are still in the early stages of diffusion.

Accordingly, an object of the present invention is to drive by using a variety of conventional electronic fluorescent ballasts as it is without changing a separate dedicated ballast or wiring, the change of the input voltage and the external operating conditions by using a variety of ballasts To provide an LED fluorescent lamp with a stable current characteristics without being greatly affected by the

LED fluorescent lamp according to the present invention for achieving the above object, the first to fourth connection pin, the first to fourth capacitor one end is connected to the first to fourth connection pin, respectively, and one end of the first The other end of the capacitor and the other end of the third capacitor are connected to the first node connected, the other end of the second capacitor and the other end of the fourth capacitor connected to the second node connected, at least one LED array and the And an LED array circuit portion having a constant current circuit for supplying a constant current to at least one LED array.

In addition, the LED fluorescent lamp according to the present invention for achieving the above object, the first to fourth connection pins, the first to fourth capacitors, one end of which is respectively connected to the first to fourth connection pins, the anode A first diode connected to the other end of the first capacitor, a second diode connected to the other end of the second capacitor, a third diode connected to the other end of the third capacitor, and an anode connected to the other end of the fourth capacitor. A fourth diode connected, and a second end of which is connected to a first node to which the cathode of the first diode and the cathode of the fourth diode are connected, and the other end of which is connected to an anode of the second diode and an anode of the third diode; And an LED array circuit portion connected to the node and having at least one LED array and a constant current circuit for supplying a constant current to the at least one LED array.

According to the present invention, LED fluorescent lamps can be installed in various kinds of existing fluorescent ballasts without installing a separate dedicated ballast or changing wiring inside the luminaire, and have a stable current operating characteristic for various kinds of electronic fluorescent ballasts. . Therefore, it is possible to simply replace the existing fluorescent lamps without incurring a special cost, making it easier to use the environment-friendly, high efficiency lighting.

1 to 3 are circuit diagrams of an LED fluorescent lamp according to a first embodiment of the present invention,
4 to 7 is a view showing the structure of the LED array circuit portion,
8 is a view showing the structure of an LED array;
9 is a circuit diagram of an LED fluorescent lamp according to a second embodiment of the present invention;
10 and 11 are circuit diagrams of an LED fluorescent lamp according to a third embodiment of the present invention;
12 and 13 are circuit diagrams of an LED fluorescent lamp according to a fourth embodiment of the present invention;
14 is a circuit diagram of an LED fluorescent lamp according to a fifth embodiment of the present invention;
FIG. 15 is a circuit diagram illustrating a circuit configuration when the LED fluorescent lamp according to the first embodiment of the present invention is used in an electronic fluorescent lamp ballast having a series resonance circuit connected to a half bridge inverter. FIG.
16 is a circuit diagram illustrating a circuit configuration when an LED fluorescent lamp according to a second exemplary embodiment of the present invention is used in an electronic fluorescent ballast of an instant starter type.
17 is a view showing a circuit configuration when the LED fluorescent lamp according to the first embodiment of the present invention is used in an electronic fluorescent ballast of a soft starter type, and
18 is a graph showing the results according to the experimental example of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in this specification and claims should not be construed in a common or dictionary sense, and the inventors will be required to properly define the concepts of terms in order to best describe their invention. Based on the principle that it can, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention.

Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, various equivalents may be substituted for them at the time of the present application. It should be understood that there may be water and variations.

The basic circuits of ballasts for electronic fluorescent lamps that are widely used generally include a half bridge method, an instant start method, a program start method, and the like. In addition, conventional iron core choke type ballasts include a starter ramp method, a rapid start method, and the like. LED fluorescent lamp according to the present invention is configured to be easily applicable to such a ballast for fluorescent lamps.

First, the configuration of the LED fluorescent lamp according to the present invention will be described, and next, the operation process when the LED fluorescent lamp according to the present invention is used for various fluorescent ballasts will be described.

1 is a circuit diagram of an LED fluorescent lamp according to a first embodiment of the present invention. Referring to FIG. 1, the LED fluorescent lamp 140 according to the present embodiment includes first to fourth connection pins 141, 142, 143, and 144, which are external connection pins, and basically, an LED array circuit unit 100. ) And capacitors C41, C42, C43, and C44, which are capacitive elements, one end of which is connected to the first to fourth connection pins 141, 142, 143, and 144.

If the connection point of the other end of the capacitor C41 and the other end of the capacitor C43 is defined as the first node, and the connection point of the other end of the capacitor C42 and the other end of the capacitor C44 is defined as a second node, the LED array circuit unit 100 is connected to the first node and the second node. It is connected between nodes. In this case, the LED array circuit unit 100 includes an LED array including a plurality of LEDs connected in series, and a constant current circuit for supplying a constant current to the LED array.

The LED fluorescent lamp 140 according to the present embodiment may further include diodes D41 to D44 connected in parallel to the capacitors C41 to C44, respectively. In addition, the LED fluorescent lamp 140 according to the present embodiment may further include diodes D45 to D48.

At this time, the cathode of the diode D45 is connected to the first connection pin 141, the anode is connected to the anode of the diode D42. The diode D46 has an anode connected to the second connecting pin 142 and a cathode connected to the cathode of the diode D41. In addition, diode D47 has an anode connected to the fourth connecting pin 144, a cathode connected to the cathode of the diode D43, a diode D48 connected to the third connecting pin 143, and an anode connected to the anode of the diode D44. Connected.

In the LED fluorescent lamp 140 configured as described above, the capacitors C41 to C44 are connected to ballast circuits for fluorescent lamps of various methods described below through at least one of the first to fourth connection pins 141, 142, 143, and 144. In this case, it is possible to control the current flowing through the LED fluorescent lamp 140 by changing the impedance in the fluorescent ballast circuit according to the frequency change, so that the existing fluorescent ballast can be used without change.

The diodes D41 to D44 are connected to the first to fourth connection pins 141, 142, 143, and 144, and the output line of the electronic ballast of the series resonance type is connected, and when the capacitor for maintaining the resonance inside the electronic ballast is C1, the capacitor C1 When connected between the first connecting pin 141 and the second connecting pin 142 or between the third connecting pin 143 and the fourth connecting pin 144, the parallel connection according to the polarity of the voltage input from the electronic ballast Capacitors C41 to C44 enable control of the current flowing in the LED array circuit unit 100. For example, a positive voltage is applied to the third connection pin 143 based on the fourth connection pin 144, and a series resonant circuit method is provided between the first connection pin 141 and the second connection pin 142. When the capacitor C1 for maintaining the resonance inside the electronic ballast is connected, the capacitor C43 is shorted by the diode D43, the diodes D41 and D42 are opened, and the capacitor C44 is shorted by the diode D44, and the resonance is performed. The complex capacitance of the holding capacitor is the series connection of capacitor C41, resonance holding capacitor C1, and capacitor C42. Also, in a cycle in which a negative voltage is applied to the third connection pin 143 based on the fourth connection pin 144, the capacitor C42 is shorted by the diode D42 and the capacitor C41 is shorted by the diode D41. Thus, the complex capacitance value of the resonance holding capacitor in the negative period becomes the series connection value of the capacitor C44, the resonance holding capacitor C1, and the capacitor C43.

The diodes D45 to D48 are configured to perform symmetrical operation with respect to a voltage applied from the outside, so that the LED fluorescent lamp 140 can be used immediately without covering the polarity in perfect symmetry like a general fluorescent lamp.

In addition, the LED fluorescent lamp 140 according to the present embodiment, as shown in Figure 2, the resistors R41 to R44 are added in parallel to each of the capacitors C41 to C44 to supply the current for the initial trigger drive to the inverter. Can be.

In addition, in the LED fluorescent lamp 140 according to the present embodiment, diodes D49 and D50 may be added in series to both terminals of the LED array circuit unit 100 as shown in FIG. 3. Diodes D49 and D50 allow current to flow only in the LED array circuit unit 100 in the forward direction. Depending on the usage environment, only one of the diodes D49 and D50 may be added.

In this way, a circuit configuration in which diodes are added in series to both terminals of the LED array circuit unit 100 may be applied to LED fluorescent lamps according to other embodiments described below.

4 to 7 are views showing an embodiment of the LED array circuit unit shown in FIG. Referring to FIG. 4, the LED array circuit unit 100 may include an LED array 10 including a plurality of LEDs connected in series, an inductor L1, an NPN transistor Q1, Q2, and resistors R1 and R2.

The inductor L1 is connected between the first terminal 100a of the LED array circuit unit 100 and one end 10a of the LED array 10. The collector of the NPN transistor Q1 is connected to the other end 10b of the LED array 10. The NPN transistor Q2 has a base connected to the emitter of the NPN transistor Q1, the collector connected to the base of the NPN transistor Q1, and the emitter connected to the second terminal 100b of the LED array circuit unit 100. The resistor R1 is connected between the one end 10a of the LED array 10 and the base of the NPN transistor Q1, and the resistor R2 is connected between the base of the NPN transistor Q2 and the second terminal 100b of the LED array circuit unit 100. Connected.

In this configuration, the inductor L1 serves to control the main current flowing through the LED circuit unit 100 by changing the impedance of the LED array 10 at the time of lighting, and is a constant current composed of NPN transistors Q1, Q2 and resistors R1, R2. The circuit portion allows a constant current to be supplied to the LED array 10.

The constant current circuit section includes bipolar transistors Q1 and Q2 and resistors R1 and R2, and is a circuit used as a constant current source by applying negative feedback to the NPN transistors Q1 and Q2. In other words, when the NPN transistor Q1 is biased by the base resistor R1 and conducts with it, a voltage is applied to the emitter resistor R2. When this voltage is applied to the base-emitter of the NPN transistor Q2, the NPN transistor Q2 conducts and the base current of the NPN transistor Q1 is sorted, resulting in a negative feedback in which the current of the NPN transistor Q1 decreases, thereby providing a constant current source through which the current flows constantly.

In the constant current circuit, when the voltage applied to the anode point 10a of the LED array changes from 50V to 100V based on the end point 100b, the current flowing in the transistor Q2 is doubled, but the base of the transistor Q2 is increased. Since the emitter voltage Vbe (Q2) changes only 30mV from 0.66V to 0.69V, a change in the current I flowing through the LED array 10 to the transistor Q1 is dI, and dI is expressed as follows.

Therefore, even when the power supply voltage changes by 100%, the current of the LED array 10 flowing through the transistor Q1 changes by about 30 mV / 660 mV, showing a relatively stable constant current characteristic of only about 4.66%.

The base resistor R1 is determined in consideration of the H _FE of the NPN transistor Q1 and the required constant current, and the magnitude of the constant current of the entire circuit is determined by the value of the emitter resistor R1.

If it is assumed that the pulsatin DC voltage applied to the LED array 10 maintains a constant value, the current flowing through the LED array 10 is changed by changing the value of the inductor L1 connected in series with the LED array 10. Can be controlled. However, in the case of the actual electronic ballast, since the voltage itself applied to the LED array 10 may vary according to the series resonance condition according to the load condition, there is a limit in controlling the current only by the value of the inductor L1.

Therefore, by connecting a constant current circuit composed of NPN transistors Q1, Q2 and resistors R1, R2 in series with the inductor L1, it is possible to control the amount of change of the current flowing in the LED array 10 more stably. Accordingly, as the voltage of the power applied to the electronic ballast is increased or the characteristics of the ballast used are changed, the power consumed by the LED fluorescent lamp 140 is prevented from being greatly changed, so that the LED fluorescent lamp 140 is stable in the region. It will work.

Meanwhile, as shown in FIG. 5, the constant current circuit may be freely positioned between the first terminal 100a and the second terminal 100b. In addition, as shown in Figs. 6 and 7, the PNP transistor may be used to configure a constant current circuit, and the operation principle thereof is basically the same as in the case of using an NPN transistor. In addition, various types of LED arrays and arrays of constant current circuits may be used to construct the LED circuit unit.

8 is a diagram illustrating a configuration of the LED array shown in FIGS. 4 to 7. As shown in FIG. 8A, the LED array 10 includes a plurality of LEDs connected in series, and includes an anode side terminal 10a and a cathode side terminal 10b. LED array 10 is generally a configuration in which a plurality of LEDs are connected in series. However, for the protection of LEDs connected in series, as shown in FIG. 8B, Zener diodes Z1 to Zn may be connected in parallel to each LED in reverse direction.

As such, when a Zener diode is used in parallel to each LED, current may flow through the diodes D1 through Dn during a positive period of the AC voltage, but current may flow through the Zener diodes Z1 through Zn in a negative period. . The flow of current through the zener diodes Z1 through Zn can be a reactive loss. Therefore, in order to prevent the flow of current through the Zener diodes Z1 to Zn to increase the efficiency, the LED fluorescent lamp according to the present invention can be changed as in the following embodiment.

In addition, the LED array 10 configured by the serial connection of the LED may be used in a structure in which two or more are connected in parallel, this configuration can be equally applied to the LED fluorescent lamp according to another embodiment described below.

9 is a circuit diagram of an LED fluorescent lamp according to a second embodiment of the present invention. 9, in the LED fluorescent lamp 150 according to the present embodiment, capacitors C51 to C54 having one end connected to the first to fourth connection pins 151, 152, 153, and 154, respectively, and diodes D51 to D54. Are each added in series. At this time, the additional diodes D51 to D54 together with the diodes D55 to D58 allow the LED fluorescent lamp 150 according to the present embodiment to operate regardless of the phase of the AC voltage in various types of electronic fluorescent ballasts.

10 and 11 are circuit diagrams of an LED fluorescent lamp according to a third embodiment of the present invention. Referring to FIG. 10, the LED fluorescent lamp 160 according to the present embodiment may further use diodes D65 to D67 between the diodes D61 to D64 and the LED array circuit unit 100, so that the first to first LEDs may be used in various electronic fluorescent ballasts. Regardless of the phase change of the AC voltage applied to the fourth connection pins 161, 162, 163, and 164, the LED fluorescent lamp 160 may be stably operated.

In addition, as shown in FIG. 11, capacitors C61 to C64 connected in parallel to the diodes D65 to D68 may be further used according to the number of LEDs used in the LED array circuit unit 100.

12 and 13 are circuits of the LED fluorescent lamp according to the fourth embodiment of the present invention. In the LED fluorescent lamp 180 according to the present embodiment, the inductor L81 is connected between the first connecting pin 181 and the third connecting pin 183, and the second connecting pin 182 and the fourth connecting pin 184 are connected to each other. The inductor L82 is connected in between. Inductors L81 and L82 act as a filament of a fluorescent lamp during the initial operation of the electronic ballast so that the filament detection protection circuit does not operate.In lighting, the inductance of L81 and L82 is added to the inductance of the resonant circuit, so that the power applied to the LED is reduced. It acts as a control. In addition, as shown in FIG. 13, the resistors R81 and R82 may be used instead of the inductors L81 and L82.

14 is a circuit diagram of an LED fluorescent lamp according to a fifth embodiment of the present invention. Referring to FIG. 14, the LED fluorescent lamp 200 according to the present embodiment includes capacitors C101 to C104 having one end connected to the first to fourth connection pins 201, 202, 203, and 204, and an LED array circuit unit ( In a circuit configuration in which diodes D101 and D102 are connected in series to both terminals of 100), diodes D103 to D108 are added.

In the LED fluorescent lamp 200 according to the present embodiment, diodes D103 and D104 are viewed regardless of the phase change of the voltage applied to the first to fourth connection pins 201, 202, 203, and 204 in various electronic fluorescent ballasts. LED fluorescent lamp 200 according to the embodiment is to be operated.

In addition, the diodes D105, D106, D107, and D108 connected in parallel to the capacitors C101, C102, D103, and D104, respectively, only have a different path through which current flows even when the polarities are reversed. Can be.

The LED fluorescent lamp of the configuration as described above can be used in connection with the electronic fluorescent ballast used in the past, without a separate circuit change. For convenience of description, an operation process in various ballasts for fluorescent lamps will be described using the LED fluorescent lamp described in FIG. 1 as an example.

FIG. 15 is a circuit diagram illustrating a circuit configuration when the LED fluorescent lamp according to the first embodiment of the present invention is used in an electronic fluorescent lamp ballast having a series resonance circuit connected to a half bridge inverter. The half-bridge type electronic fluorescent ballast is connected to a series resonant circuit consisting of an inductor Lo, a capacitor Co, and a C1 at a switching output point of a half-bridge inverter composed of switching elements, and discharged from a series resonance voltage induced at both ends of the resonant capacitor C1. After the phosphorescent lamp is initially turned on, the stabilizing current after lighting is controlled by the inductor Lo.

When the electronic fluorescent ballast of this type is used, when the LED fluorescent lamp 140 is connected, the operation is as follows. When the switching element Q61 is turned ON and the potential of the point (A) becomes Vs, The resonant current flows in the path of the inductors Lo-D43-C41-C1-C42-D44-2Co. On the contrary, when the switching element Q62 is turned on, the point (A) becomes the ground potential, and the initial resonance current flows to 2Co-C44-D42-C1-D41-C43-Lo.

Since the LED fluorescent lamp 140 should be symmetrical for versatility, the capacitors C41 to C44 inside the LED fluorescent lamp 140 should be set to C2 because they should not have polarity according to the LED fluorescent lamp 140 connecting pins. The composite capacitor Ca value in series of C1-C42 or C43-C1-C44 can be expressed as follows.

Therefore, in the case of C2 < C1, the value of Ca can be expressed as Ca ≒ C2 / 2, the main current flowing through the LED fluorescent lamp 140 is controlled by the impedance jωLo of the inductor of the ballast, and the operating frequency f is the inductance. It depends on the impedance of the LED array, which is determined by the value Lo, the composite capacitance Ca, and the number of LEDs in series.

16 is a circuit diagram illustrating a circuit configuration when the LED fluorescent lamp according to the second exemplary embodiment of the present invention is used in an instant start type electronic fluorescent ballast. Referring to FIG. 16 , the instant start type electronic fluorescent ballast stabilizes Q71 and Q72 of the switching element by the self-oscillating operation of a circuit composed of transformers T1 and T2 and capacitor C1, and the switching point is maintained. Connect the output of (A) to the point (B), which is the midpoint of the series-connected capacitor Co which is short in AC and 1/2 Vcc in DC, to the primary winding T2-1 of transformer T2, The fluorescent lamp is initially discharged with a high voltage induced in the secondary winding T2-2 of T2, and once discharged, the stabilization lamp current is controlled by a capacitor C1 connected in series with the lamp load.

In the case of using the electronic fluorescent ballast of this type, the basic operation is shown: Transformer T2 induces an AC voltage of high frequency to secondary winding T2-2 by self oscillation, and (C) points (+) ) In the case of potential, in the section where (C)-C1-C51-D51-LED array circuit section 100-D52-C52-(D), current flows and (C) is (-) Current flows to point (D)-C52-D56-LED array circuit unit 100-D55-C51-C1-(C).

Therefore, if the current value flowing through the LED array circuit unit 100 is set to the capacitance of the capacitors C51 to C54 as C2, the sum of the impedance 1 / jωC1 of the current control capacitor C1 of the ballast and the impedance 2 / jωC2 of the two capacitors C2 connected in series. Controlled by

17 is a circuit diagram illustrating a circuit configuration when the LED fluorescent lamp according to the first embodiment of the present invention is used in an electronic fluorescent ballast of a soft starter type. The electronic fluorescent ballast of this type connects a series resonant circuit composed of an inductor T3 and a capacitor C1 to the switching point (A) of switching elements Q81 and Q82, and connects one or more fluorescent lamps to both ends of the resonant capacitor C1. The basic operation is similar to the circuit configuration described with reference to FIG. In this method, however, in order to maximize the life of the fluorescent lamp, T3 secondary preheating windings T3-a and T3-b are wound around the resonant transformer, and the fluorescent lamp is generated by the secondary voltage generated in the preheating winding when the lamp is initially turned on. After sufficiently preheating the filament, by applying a high voltage to the lamp, it is to maximize the lamp life by minimizing the oxide scattering of the lamp filament during lighting.

In this case, if the switching frequency of the switching elements Q81 and Q82 matches the inductance value L1 of the inductor T3 and the series resonant frequency of the capacitor C1, as shown in FIG. 14, if the frequency f is Co '' C1, Co is ignored. If you do

An AC voltage of frequency f is induced across the capacitor C1. During operation, the current flowing through the filament heating winding T3-a coupled to the inductor T3 flows in the path of Ca-D41-C43 at the positive polarity period, and at D43-in the negative period. It flows through the path of C41-Ca. The current flowing in the winding T3-b flows in the path of C44-D42-Cb in the positive period, and flows in the path of Cb-C42-D44 in the negative period, and the value of the capacitor controlling the current is C41, If we put the values C42, C43, and C44 equal to C2,

Since the current Ca >> C2, the current flowing in the windings T3-a, T3-b is determined by C2, which is a value of C41 to C44, and the value of this capacitor is very small, about thousands of picoparades ( pF ), Since the voltage induced in the windings T3-a and T3-b is as low as a few volts, the current flowing through the inductors T3-a and T3-b can be almost ignored.

The main current flowing through the LED fluorescent lamp 140 is the path of the point (B) at the point (B) at the potential of the point (B) compared to the point (C). The current flows in the (-) cycle, and the current flows in the path of the point (C)-D47-LED array circuit unit 100-D48-(B) on the contrary.

Experimental Example

[Table 1] shows the constant current circuit when the 100KHz pulsating DC voltage obtained by full-wave rectification of 50KHz high frequency AC power is applied to the LED array circuit unit 100 including the constant current circuit shown in FIG. When the input voltage is applied in the absence of, the current value flowing through the LED array 10 at the input voltage of each step is shown. In the present experimental example, 32 6 chip LED packages were connected in series with the LED array of FIG. 4, and R1 was 30 kΩ and R2 was 5.6 Ω.

Input voltage (V) When only inductor (1mH) is inserted (mA) Inductor (1 mH ) + Constant current circuit  In use ( mA ) 70 10 10.9 72.5 13.9 13.9 75 17 18.6 77.5 22.1 22.2 80 26.5 26.8 82.5 33.1 33.4 85 38 38.4 87.5 43.8 42.6 90 48.5 46.8 92.5 54.7 51.9 95 63.6 49.2 97.5 72.4 47 100 79 46 102.5 84.4 45.6 105 90.1 45.8 107.5 103.4 46.1 110 121.2 46.7 112.5 139.5 47.4 115 160.5 49.1 117.5 186.9 51.5 120 207.9 55.3

The results of Table 1 are shown graphically in FIG.

18 is a graph showing a current flowing in the LED array 10 when the input voltage is changed from 70V to 120V. In FIG. 18, the curve 325 shows a case where only 1 mH main current control inductor L1 is used, and the curve 327 shows a case where a main current control inductor of 1 mH and a constant current circuit are used together.

As can be seen in FIG. 18, when the current flowing in the LED array 10 is controlled only by the main current control inductor, the current flowing rapidly increases beyond a predetermined voltage, thereby destroying the LED device. However, when the constant current circuit is used together with the inductor, it can be seen that the current flows stably in the LED array 10 even in a wide input voltage range.

For convenience of description, the operation of the LED fluorescent lamp 140 according to the first embodiment of the present invention has been described as an example, but in the case of the LED fluorescent lamp according to another embodiment, the basic operation may be the same as described above. have.

As described above, the LED fluorescent lamp according to the present invention can be directly mounted and used without changing a circuit in an electronic ballast which is generally used.

In addition, while the preferred embodiments of the present invention have been shown and described above, the present invention is not limited to the specific embodiments described above, but the technical field to which the invention belongs without departing from the spirit of the invention claimed in the claims. Of course, various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

100: LED array circuit unit 140: LED fluorescent lamp

Claims (22)

First to fourth connecting pins;
First to fourth capacitors having one end connected to the first to fourth connection pins, respectively; And
One end is connected to a first node connected with the other end of the first capacitor and the other end of the third capacitor, and the other end is connected with a second node connected with the other end of the second capacitor and the other end of the fourth capacitor, An LED fluorescent lamp comprising an LED array circuit portion having a LED array and a constant current circuit for supplying a constant current to the at least one LED array. The method of claim 1,
The LED array circuit unit,
An LED array comprising a plurality of LEDs connected in series;
An inductor coupled between the first node and one end of the LED array;
A first NPN transistor having a collector connected to the other end of the LED array;
A first resistor coupled between the one end of the LED array and the base of the first NPN transistor;
A second NPN transistor having a base connected to an emitter of the first NPN transistor, a collector connected to a base of the first NPN transistor, and an emitter connected to the second node; And
And a second resistor connected between the base of the second NPN transistor and the second node. The method of claim 1,
The LED array circuit unit,
An LED array comprising a plurality of LEDs connected in series;
An inductor coupled between the first node and one end of the LED array;
A first NPN transistor having a collector connected to the other end of the LED array;
A first resistor coupled between the other end of the LED array and the base of the first NPN transistor;
A second NPN transistor having a base connected to an emitter of the first NPN transistor, a collector connected to a base of the first NPN transistor, and an emitter connected to the second node; And
And a second resistor coupled between the emitter of the second NPN transistor and the base of the second NPN transistor. The method of claim 1,
The LED array circuit unit,
An LED array comprising a plurality of LEDs connected in series, one end of the LED array being connected to the second node;
A first PNP transistor having a collector connected to the other end of the LED array;
A first resistor having one end connected to a base of the first PNP transistor and the other end connected to one end of the LED array;
A second PNP transistor having a base connected to the emitter of the first PNP transistor and a collector connected to the base of the first PNP transistor;
A second resistor coupled between the base and emitter of the second transistor; And
An inductor having one end connected to the first node and the other end connected to the emitter of the second PNP transistor
LED fluorescent lamp comprising a. The method of claim 1,
The LED array circuit unit,
An LED array comprising a plurality of LEDs connected in series, one end of the LED array being connected to the second node;
A first PNP transistor having a collector connected to the other end of the LED array;
A first resistor connected between the base and the collector of the first PNP transistor;
A second PNP transistor having a base connected to the emitter of the first PNP transistor and a collector connected to the base of the first PNP transistor;
A second resistor coupled between the base and emitter of the second transistor; And
An inductor having one end connected to the first node and the other end connected to the emitter of the second PNP transistor
LED fluorescent lamp comprising a. The method of claim 1,
A first diode having an anode connected to the first connecting pin and a cathode connected to the first node;
A second diode having a cathode connected to the second connecting pin and an anode connected to the second node;
A third diode having an anode connected to the third connecting pin and a cathode connected to the first node; And
The cathode is connected to the fourth connection pin, the anode further comprises a fourth diode connected to the second node LED fluorescent lamp. The method of claim 1,
A first diode having an anode connected to the first node and a cathode connected to one end of the LED array circuit portion; And
An anode is connected to the other end of the LED array circuit portion, the cathode further comprises a second diode connected to the second node LED fluorescent lamp. The method of claim 7, wherein
A third diode having an anode connected to the first connecting pin and a cathode connected to an anode of the first diode;
A fourth diode having a cathode connected to the second connecting pin and an anode connected to a cathode of the second diode;
A fifth diode having an anode connected to the third connecting pin and a cathode connected to an anode of the first diode; And
The cathode is connected to the fourth connecting pin, the anode further comprises a sixth diode connected to the cathode of the second diode LED fluorescent lamp. The method of claim 8,
A seventh diode having a cathode connected to the first connecting pin and an anode connected to a cathode of the second diode;
An eighth diode having an anode connected to the second connecting pin and a cathode connected to an anode of the first diode;
A ninth diode having an anode connected to the fourth connecting pin and a cathode connected to an anode of the first diode; And
The cathode is connected to the third connecting pin, the anode further comprises a tenth diode connected to the cathode of the second diode LED fluorescent lamp. 10. The method of claim 9,
LED fluorescent lamp further comprises a first to fourth resistors connected in parallel to the first to fourth capacitors, respectively. The method of claim 7, wherein
A third diode having an anode connected to the other end of the first capacitor and a cathode connected to the anode of the first diode;
A fourth diode having an anode connected to the cathode of the second diode and a cathode connected to the other end of the second capacitor;
A fifth diode having an anode connected to the other end of the third capacitor and a cathode connected to the anode of the first diode; And
And an anode connected to the cathode of the second diode and a cathode connected to the fourth connection pin. The method of claim 11,
A seventh diode having an anode connected to the anode of the fourth diode and a cathode connected to the other end of the first capacitor;
An eighth diode having an anode connected to the other end of the second capacitor and a cathode connected to a cathode of the third diode;
A ninth diode having an anode connected to the other end of the fourth capacitor and a cathode connected to a cathode of the fifth diode; And
An anode is connected to the anode of the sixth diode, the cathode further comprises a tenth diode connected to the other end of the third capacitor LED fluorescent lamp. The method of claim 1,
A first diode having an anode connected to the first node and a cathode connected to one end of the LED array circuit portion;
A second diode having an anode connected to the other end of the LED array circuit portion and a cathode connected to the second node;
A third diode having an anode connected to the cathode of the second diode and a cathode connected to the one end of the LED array; And
And an anode connected to the other end of the LED array circuit portion and a cathode connected to the anode of the first diode. The method of claim 13,
A fifth diode having an anode connected to the first connecting pin and a cathode connected to an anode of the first diode;
A sixth diode having an anode connected to the second connecting pin and a cathode connected to a cathode of the second diode;
A seventh diode having an anode connected to the third connecting pin and a cathode connected to an anode of the first diode; And
And an anode connected to the fourth connecting pin and a cathode connected to the cathode of the second diode. The method of claim 13,
A fifth diode having a cathode connected to the first connecting pin and an anode connected to an anode of the first diode;
A sixth diode having a cathode connected to the second connecting pin and an anode connected to a cathode of the second diode;
A seventh diode having a cathode connected to the third connecting pin and an anode connected to an anode of the first diode; And
The cathode is connected to the fourth connecting pin, the anode further comprises an eighth diode connected to the cathode of the second diode LED fluorescent lamp First to fourth connecting pins;
First to fourth capacitors having one end connected to the first to fourth connection pins, respectively;
A first diode having an anode connected to the other end of the first capacitor;
A second diode having a cathode connected to the other end of the second capacitor;
A third diode having a cathode connected to the other end of the third capacitor;
A fourth diode having an anode connected to the other end of the fourth capacitor; And
One end is connected to a first node to which the cathode of the first diode and the cathode of the fourth diode are connected, and the other end is connected to a second node to which the anode of the second diode and the anode of the third diode are connected; An LED fluorescent lamp comprising an LED array circuit portion having a LED array and a constant current circuit for supplying a constant current to the at least one LED array. The method of claim 16,
The LED array circuit unit,
An LED array comprising a plurality of LEDs connected in series;
An inductor coupled between the first node and one end of the LED array;
A first NPN transistor having a collector connected to the other end of the LED array;
A first resistor coupled between the one end of the LED array and the base of the first NPN transistor;
A second NPN transistor having a base connected to an emitter of the first NPN transistor, a collector connected to a base of the first NPN transistor, and an emitter connected to the second node; And
And a second resistor connected between the base of the second NPN transistor and the second node. The method of claim 16,
The LED array circuit unit,
An LED array comprising a plurality of LEDs connected in series;
An inductor coupled between the first node and one end of the LED array;
A first NPN transistor having a collector connected to the other end of the LED array;
A first resistor coupled between the other end of the LED array and the base of the first NPN transistor;
A second NPN transistor having a base connected to an emitter of the first NPN transistor, a collector connected to a base of the first NPN transistor, and an emitter connected to the second node; And
And a second resistor coupled between the emitter of the second NPN transistor and the base of the second NPN transistor. The method of claim 16,
The LED array circuit unit,
An LED array comprising a plurality of LEDs connected in series, one end of the LED array being connected to the second node;
A first PNP transistor having a collector connected to the other end of the LED array;
A first resistor having one end connected to a base of the first PNP transistor and the other end connected to one end of the LED array;
A second PNP transistor having a base connected to the emitter of the first PNP transistor and a collector connected to the base of the first PNP transistor;
A second resistor coupled between the base and emitter of the second transistor; And
An inductor having one end connected to the first node and the other end connected to the emitter of the second PNP transistor
LED fluorescent lamp comprising a.
The method of claim 16,
The LED array circuit unit,
An LED array comprising a plurality of LEDs connected in series, one end of the LED array being connected to the second node;
A first PNP transistor having a collector connected to the other end of the LED array;
A first resistor connected between the base and the collector of the first PNP transistor;
A second PNP transistor having a base connected to the emitter of the first PNP transistor and a collector connected to the base of the first PNP transistor;
A second resistor coupled between the base and emitter of the second transistor; And
An inductor having one end connected to the first node and the other end connected to the emitter of the second PNP transistor
LED fluorescent lamp comprising a.
The method of claim 16,
A fifth diode having an anode connected to the first connecting pin and a cathode connected to an anode of the first diode;
A sixth diode having a cathode connected to the second connecting pin and an anode connected to a cathode of the second diode;
A seventh diode having a cathode connected to the third connecting pin and an anode connected to a cathode of the third diode; And
An anode is connected to the fourth connecting pin, the cathode further comprises an eighth diode connected to the anode of the fourth diode LED fluorescent lamp. The method of claim 21,
A ninth diode having a cathode connected to the first connecting pin and an anode connected to a cathode of the second diode;
A tenth diode having a cathode connected to the cathode of the first diode and an anode connected to the second connection pin;
An eleventh diode having a cathode connected to the fourth connecting pin and an anode connected to a cathode of the third diode; And
The cathode is connected to the anode of the fourth diode, the anode further comprises a twelfth diode connected to the third connecting pin.

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