KR100973135B1 - Led fluorescent lamp - Google Patents

Abstract

The present invention relates to an LED fluorescent lamp operable in a variety of ballasts for fluorescent lamps. The LED fluorescent lamp includes an LED array including a plurality of LEDs connected in series or in parallel, first to fourth connecting pins, and first to fourth capacitors and cathodes having one end connected to the first to fourth connecting pins, respectively. A first diode connected to one end of the LED array, a second diode whose anode is connected to the other end of the LED array, an anode connected to the other end of the first capacitor and a cathode connected to the anode of the first diode, an anode Is a fourth diode connected to the cathode of the second diode and the cathode is connected to the other end of the second capacitor, the anode is connected to the other end of the third capacitor and the cathode is connected to the anode of the first diode, and the anode is the first diode. A sixth diode connected to the cathode of the second diode, a cathode connected to the other end of the fourth capacitor, an anode connected to the other end of the LED array, and a cathode connected to the first capacitor A seventh diode, and an anode connected to the other end of the emitter is connected to the other terminal of the second capacitor and the cathode comprises an eighth diode being connected to one end of the LED array. The LED fluorescent lamp according to the present invention can be used as it is to replace the existing fluorescent lamp without any additional device attachment or wiring changes.

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 ballasts installed in various fluorescent lamp mechanism.

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 LDC TV, a vehicle lamp, and general lighting. Accordingly, incandescent and fluorescent lamps, which have been used as the main light source for lighting for the last 100 years, are beginning to be 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. As a result, LED fluorescent lamps, which have many advantages in many respects, are still in the early stages of diffusion.

Accordingly, an object of the present invention is to provide an LED fluorescent lamp which can be driven using an existing ballast for a fluorescent lamp without changing a separate dedicated ballast or wiring.

LED fluorescent lamp according to the present invention for achieving the above object, the LED array including a plurality of LEDs connected in series, the first to fourth connecting pins, one end is connected to each of the first to fourth connecting pins First to fourth capacitors, a first diode having a cathode connected to one end of the LED array, a second diode having an anode connected to the other end of the LED array, an anode connected to the other end of the first capacitor, and a cathode A third diode connected to the anode of the first diode, an anode connected to a cathode of the second diode, a cathode connected to a fourth diode connected to the other end of the second capacitor, an anode connected to the other end of the third capacitor, The cathode is the fifth diode connected to the anode of the first diode, the anode is connected to the cathode of the second diode, the cathode is connected to the other end of the fourth capacitor A sixth diode, an anode connected to the other end of the LED array, a cathode connected to the other end of the first capacitor, and an anode connected to the other end of the second capacitor, and a cathode connected to the LED array And an eighth diode connected to the one end of the.

In addition, to ensure connection symmetry of the LED fluorescent lamp, an anode is connected to the other end of the fourth capacitor, a cathode is connected to the one end of the LED array, and an anode is connected to the other end of the LED array. The cathode may further include a tenth diode connected to the other end of the third capacitor.

According to the present invention, there is provided an LED fluorescent lamp that can be used as it is in a conventional fluorescent ballast without installing a separate dedicated ballast or changing the wiring inside the luminaire. Therefore, it is possible to use the high efficiency and eco-friendly lighting by replacing the existing fluorescent lamp without changing special wiring or circuit.

Hereinafter, with reference to the drawings will be described the present invention in more detail.

In general, a basic circuit of an electronic fluorescent ballast which is widely used includes an instant start method, a soft start method, and the like. A conventional iron core choke type ballast uses a starter lamp, a rapid start method, and the like. LED fluorescent lamp according to the present invention is configured to be applicable to all of these ballasts 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 110 according to the present embodiment includes an LED array 10 and capacitors C11, C12, C13, and C14, and the first to fourth connection pins 111, which are external connection pins. 112, 113, 114). According to the usage environment, only two connection pins among the first to fourth connection pins 111, 112, 113, and 114 may be used, and the LED array 10 may be used in a structure in which two or more are connected in parallel. This configuration can be equally applied to LED fluorescent lamps according to other embodiments described below.

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. The capacitor C11 is connected between the anode side terminal 10a of the LED array 10 and the first connection pin 111, and the capacitor C12 is connected to the cathode side terminal 10b and the second connection pin 112 of the LED array 10. ) Is connected between. The capacitor C13 is connected between the anode side terminal 10a of the LED array 10 and the third connection pin 113, and the capacitor C14 is connected to the cathode side terminal 10b and the fourth connection pin 114 of the LED array 10. ) Is connected between.

When the capacitors C11 to C14 are connected to the ballast circuits for fluorescent lamps of various methods described below through at least one of the first to fourth connection pins 111, 112, 113, and 114, the impedances in the ballast circuits for the fluorescent lamps according to the frequency change. Since it is possible to control the current flowing to the LED fluorescent lamp 110, it is possible to use the existing fluorescent ballast without changing.

 FIG. 2 is a diagram illustrating a configuration of the LED array shown in FIG. 1. As shown in FIG. 2A, the LED array 10 generally has 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. 2B, Zener diodes Z1 to Zn may be connected in parallel to each LED in reverse direction.

As described above, since a Zener diode is used in parallel with each LED, a current may flow through the D1 through Dn diodes in a positive period of the AC voltage, but a 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.

3 is a circuit diagram of an LED fluorescent lamp according to a second embodiment of the present invention. 3, in the LED fluorescent lamp 120 according to the present embodiment, diodes D21 and D22 connected in series to both terminals of the LED array 12 are added as compared to the LED fluorescent lamp 110 according to the first embodiment. do. Depending on the usage environment, only one of the diodes D21 and D22 may be added. Diodes D21 and D22 allow current only to flow through LED array 12 in the forward direction. Therefore, when a zener diode is connected in parallel in the LED array 12, current flows through the zener diode in a negative period to prevent power loss from occurring.

4 is a circuit diagram of an LED fluorescent lamp according to a third embodiment of the present invention. Referring to FIG. 4, the LED fluorescent lamp 130 according to the present embodiment has diodes D33 to D36 connected to capacitors C31 to C34 having one end connected to the first to fourth connection pins 131, 132, 133, and 134, respectively. Each is connected in series. Then, the anode is connected to the cathode side terminal 13b of the LED array 13, the diode is connected to the anode of the diode D33, the anode is connected to the cathode of the diode D34, and the cathode is connected to the anode of the LED array 13. Diode D38, which is connected to the side terminal 13a, is added.

The diodes D33 to D36 together with the diodes D37 and D38 allow the LED fluorescent lamp 130 according to the present embodiment to operate regardless of the phase of the AC voltage in various ballasts for fluorescent lamps.

5 is a circuit diagram of an LED fluorescent lamp according to a fourth embodiment of the present invention. In the LED fluorescent lamp 140 according to the present embodiment, diodes D49 and D50 are additionally used as compared to the LED fluorescent lamp 130 according to the third embodiment. Diode D49 has an anode connected to the cathode of diode D46, a cathode connected to the anode side terminal 14a of the LED array 14, and diode D50 has an anode connected to the cathode side terminal 14b of the LED array 14. The cathode is connected to the anode of diode D45. Diodes D49 and D50 allow the LED fluorescent lamp 140 to be symmetrical with respect to a voltage applied from the outside.

The LED fluorescent lamp of the above-described configuration can be used in connection with all conventional ballasts for fluorescent lamps without a separate circuit change. For convenience of description, an operation process of various fluorescent ballasts will be described using the LED fluorescent lamp described with reference to FIG. 4 or 5 as an example.

FIG. 6 is a diagram showing the circuit configuration when the LED fluorescent lamp according to the third embodiment of the present invention is used for an electronic fluorescent ballast of an instant start method, and FIG. 7 is a fourth embodiment of the present invention. Fig. 1 shows a circuit configuration when the LED fluorescent lamp according to the present invention is used for an electronic fluorescent ballast of an instant start method.

Referring to FIG. 6, the instant start ballast for electronic fluorescent lamps has a self-oscillating operation of a circuit composed of transformers T1 and T2 and capacitor C, such that Q71 and Q72 of the switching elements continue the switching operation. The output of the switching point (A) to the primary winding T2-1 of the transformer T2 at the point (B), which is the midpoint of the series-connected capacitor Co, which is short in AC and 1/2 Vs in DC. In this connection, the fluorescent lamp is initially discharged with a high voltage induced in the secondary winding T2-2 of the transformer T2, and once discharged, the stabilizing lamp current is controlled by the capacitor C1 connected in series with the lamp load.

When the fluorescent ballast of this type is used, the basic operation when the output line of the electronic ballast is connected to the first connecting pin 131 and the second connecting pin 132 will be described. When a high frequency AC voltage is induced in the winding T2-2 and the point (C) is a positive potential with respect to the point (D), it is displaced by π / 2 with respect to the voltage by the capacitance component of the capacitors C31 to C34, (C) point-C1-C31-D33-D31-LED array (13)-D32-D34-C32-Main current flows in the path of (D) point, and also in the section where (C) point becomes (-) section By the capacitance component of the capacitors C31 to C34, they are displaced by π / 2 with respect to the voltage, and the main current in the path of the point (D)-C32-D38-LED array (13)-D37-C31-C1-(C) Will flow.

Therefore, the current value flowing in the LED array 13 is controlled by the series composite impedance of the current control capacitors C1, C31, and C32 contained in the electronic ballast and changes the values of the capacitors C51 and C52 inside the LED fluorescent lamp. By doing so, it is possible to control the current flowing in the LED array load.

In this case, if the values of the capacitors C31 and C32 are set to C2, the complex impedance Z may be expressed as follows.

As shown in FIG. 7, when the LED fluorescent lamp 140 according to the fourth embodiment of the present invention is used for an electronic fluorescent lamp ballast of an instant start method, the third connecting pin 143 and the fourth The connection pin 144 is a terminal for symmetry, and the basic operation is the same as described above.

8 is a circuit diagram illustrating a circuit configuration when the LED fluorescent lamp according to the fourth exemplary embodiment of the present invention is used in a soft start ballast for electronic fluorescent lamps.

The ballast for electronic fluorescent lamps 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 lamps to both ends of the resonant capacitor C1. It becomes the structure to say. In this method, in order to maximize the life of the fluorescent lamp, the T3 secondary preheating windings T3-a and T3-b are wound around the resonant transformer, and the filament of the fluorescent lamp is produced by the secondary voltage generated in the preheating winding when the lamp is initially turned on. After sufficiently preheating, by applying a high voltage to the lamp, it is intended to maximize the lifetime of the fluorescent lamp by minimizing the oxide scattering of the fluorescent lamp filament at the time of lighting.

In this case, if the switching frequency of the switching elements Q81 and Q82 is matched with the inductance value L1 of the inductor T3 and the series resonant frequency of the capacitor C1, the operating frequency f can be expressed as have.

Therefore, the AC voltage of frequency f is induced across the capacitor C1. In operation, the current flowing through the filament heating winding T3-a coupled to the inductor T3 is blocked by diodes D53 and D55 because the voltage induced by T3-a in the actual ballast is less than 10V. Since no current flows, there is no power loss, and the opposite filament preheating winding T3-b is also blocked by diodes D54 and D56.

Referring to FIG. 8, since the main current flowing through the LED fluorescent lamp 130 has a very small current flowing through the LED array 15 by the windings of the preheating windings T3-a and T3-b, T3-a and T3-b. Neglecting the winding of, the potential at point (B) is displaced by π / 2 with respect to the voltage by the capacitance component of capacitors C41 to C44 in the period (+) relative to point (C), and at point (B)-C43- D45-D41-LED array (14)-D42-D46-C44-Main current flows through the path of (C) point, and the potential of (B) is also capacitor C41- By the capacitance component of C44, it is displaced by π / 2 with respect to the voltage, and vice versa, the main current flows through the path of points (C)-C44-D49-LED array 14-D50-C43-(B) . Therefore, the current flowing through the LED array 14 at this time, if the value of the capacitors C41 to C44 is set to C2, the composite impedance of the capacitor becomes 2 / jwC2, and the current flowing to the LED array 14 is controlled by changing the value of C2. You can do it.

9 is a circuit diagram illustrating a circuit configuration when the LED fluorescent lamp according to the fourth embodiment of the present invention is used in the choke type ballast of the starter lamp type.

9, when the input voltage is applied, unlike the general fluorescent lamp, since the impedance of the LED fluorescent lamp 150 does not appear to be infinite, the starter lamp 200 may be considered to be in an open state, and thus, the main current may be ignored. In the path, the voltage applied to the third connection pin 143 is displaced by π / 2 with respect to the voltage in the (+) period as before, so that C43-D45-D41-LED array 14-D42-D46-C44 In the negative period, it is also displaced by π / 2 with respect to the voltage, and becomes C44-D49-LED array 14-D50-C43, and the complex impedance Z controlling the current at this time is the value of inductance L. L and put the value of capacitors C41 to C44 to C2,

Becomes

At this time, the flowing current is in the form of a pulse with a frequency of 100/120 Hz, which is twice the frequency of commercial input power 50/60 Hz. Therefore, flickering, which may occur when driving the LED fluorescent lamp 140 at low frequency, may be significantly reduced.

FIG. 10 is a circuit diagram illustrating a circuit configuration when an LED fluorescent lamp according to a third exemplary embodiment of the present invention is used in a fluorescent ballast of an iron core type rapid start method, and FIG. 11 is a fourth exemplary embodiment of the present invention. Is a circuit configuration when the LED fluorescent lamp according to the present invention is used in a fluorescent ballast of the iron core type rapid start method.

Referring to FIG. 10, when a positive voltage is applied to the (A) side of the transformer winding based on the point (B), the voltages applied to the preheating windings n1 and n2 for preheating the filament of the fluorescent lamp are referred to as Vn1 and Vn2, respectively. In this case, as in the soft start electronic ballast of FIG. 8, diodes D33 and D35 and diodes D34 and D36 are connected to each other in a reverse direction, so that the load appears to be in an open state, thereby reducing power loss due to preheating windings. .

If you see the path of the main current flowing in the LED fluorescent lamp, if you set the input power voltage to Vo,

Vo is higher than the initial discharge start voltage of several hundred volts sufficient to induce the initial discharge of the fluorescent lamp. When the main current flowing through the LED array 13 is seen, the point (A) is shifted by π / 2 with respect to the voltage by the capacitance component of the capacitors C31 to C34 in the period of the (+) period based on the point (B). The main current flows through the path of point (C)-C31-D33-D31-LED array (13)-D32-D34-C32-(D), and point (A) based on point (B) In the minus period, the capacitance component of the capacitors C31 to C34 is also displaced by π / 2 with respect to the voltage, so that the points of (D)-C32-D38-LED array (13)-D57-C31-(C) Main current flows through the path.

Also in this case, similar to the choke ballast of the starter method of FIG. 9, the current flowing through the LED fluorescent lamp 130 has a pulse current form having a frequency of 2f, which is twice the input power frequency f. Therefore, there is an advantage that can significantly reduce the flickering phenomenon when driving the LED fluorescent lamp at f at a commercial frequency of 50/60 Hz.

In addition, as shown in FIG. 11, even when the LED fluorescent lamp 140 according to the fourth embodiment of the present invention is used in an iron ball type rapid start type fluorescent ballast, the basic operation process is also described above. Same as bar.

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, the LED fluorescent lamp according to the present invention is not limited to the configuration and method of the embodiments described as described above, the embodiments are all or part of each embodiment so that various modifications can be made It may alternatively be configured in combination.

In addition, although the preferred embodiment of the present invention has 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.

1 is a circuit diagram of an LED fluorescent lamp according to a first embodiment of the present invention,

2 is a view showing the structure of the LED array of FIG.

3 is a circuit diagram of an LED fluorescent lamp according to a second embodiment of the present invention;

4 is a circuit diagram of an LED fluorescent lamp according to a third embodiment of the present invention;

5 is a circuit diagram of an LED fluorescent lamp according to a fourth embodiment of the present invention;

6 is a circuit diagram illustrating a circuit configuration when an LED fluorescent lamp according to a third exemplary embodiment of the present invention is used in an instant start type electronic fluorescent ballast.

7 is a view showing a circuit configuration when the LED fluorescent lamp according to the fourth embodiment of the present invention is used in the electronic fluorescent lamp ballast of the instant start method,

8 is a circuit diagram illustrating a circuit configuration when the LED fluorescent lamp according to the fourth embodiment of the present invention is used in a soft start ballast for an electronic fluorescent lamp.

9 is a view showing a circuit configuration when an LED fluorescent lamp according to a fourth embodiment of the present invention is used in a choke type ballast using a starter lamp;

10 is a view showing a circuit configuration when the LED fluorescent lamp according to the third embodiment of the present invention is used in the fluorescent ballast of the iron core type rapid start method; and

11 is a circuit diagram illustrating a circuit configuration when the LED fluorescent lamp according to the fourth embodiment of the present invention is used in a fluorescent ballast of the iron core type rapid start method.

Explanation of symbols on the main parts of the drawings

14: LED array 140: LED fluorescent lamp

Claims (3)

An LED array comprising a plurality of LEDs connected in series; 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 a cathode connected to one end of the LED array; A second diode having an anode connected to the other end of the LED array; A third diode having an anode connected to the other end of the first capacitor and a cathode connected to an 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 an anode of the first diode; A sixth diode having an anode connected to the cathode of the second diode and a cathode connected to the other end of the fourth capacitor; A seventh diode having an anode connected to the other end of the LED array and a cathode connected to the other end of the first capacitor; And And an anode connected to the other end of the second capacitor and a cathode connected to the one end of the LED array. The method of claim 1, A ninth diode having an anode connected to the other end of the fourth capacitor and a cathode connected to the one end of the LED array; And An anode is connected to the other end of the LED array, the cathode further comprises a tenth diode connected to the other end of the third capacitor LED fluorescent lamp. The method according to claim 1 or 2, The LED array is characterized in that a plurality of LED fluorescent lamps are connected in parallel.

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