KR100981854B1 - 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 is a LED array including a plurality of LEDs connected in series or in parallel, first to fourth connection pins, one end is connected to the first connection pin, the other end is connected to one end of the LED array A second capacitor connected to the other end of the LED array, the other end connected to the other end of the LED array, and one end connected to the third connection pin and the other end of the LED array to ensure connection symmetry of the fluorescent lamp. A third capacitor connected to the fourth capacitor, one end of which is connected to the fourth connection pin and the other end of which is connected to the other end of the LED array, between the connection point of the first capacitor and the third capacitor and one end of the LED array, and the second capacitor and the second capacitor. And at least one diode connected between the connection point of the four capacitors and the other end of the LED array to form a one-way current path in the LED array. LED fluorescent lamps according to the present invention can be used to replace the existing fluorescent lamps without the addition of additional equipment or wiring changes.

LED, Fluorescent Lamp, Ballast

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 to replace the existing fluorescent lamp in a variety of ballasts for fluorescent lamps.

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 mobile phone, 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 can be replaced in the case of E26 base compatible lamps, but when replacing fluorescent lamps that are the mainstream of general lighting, the lighting fixtures or a special ballast must be installed separately. . Therefore, there is a difficulty in changing the wiring inside the luminaire, so that the fluorescent LED lamp is not widely used.

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Accordingly, an object of the present invention is to provide an LED fluorescent lamp that can be used in a conventional ballast for a fluorescent lamp without changing a separate ballast or wiring.

LED fluorescent lamp according to the present invention for achieving the above object, an LED array including a plurality of LEDs connected in series, first and second connection pins, one end is connected to the first connection pin, the other end is the LED A first capacitor connected to one end of the array, one end connected to the second connection pin and the other end connected to the other end of the LED array; And at least one diode connected between the first connection pin and the second connection pin to form a one-way current path in the LED array.

Wherein the at least one diode is connected to the other end of the first capacitor, an anode of which is connected to an anode side terminal of the LED array, and an anode is connected to a cathode side terminal of the LED array, and a cathode May be at least one of the second diodes connected to the other end of the second capacitor.

In addition, in order to ensure the connection symmetry of the LED fluorescent lamp, the third and fourth connection pins, one end is connected to the third connection pin, the other end is connected to one end of the first diode, and one end is The fourth terminal may be connected to the fourth connection pin, and the other end may further include a fourth capacitor connected to the other end of the second diode.

According to the present invention, there is provided an LED fluorescent lamp that can be used by mounting the existing fluorescent ballast as it is without installing a separate dedicated ballast or changing the wiring inside the luminaire. Therefore, it is possible to use a high-efficiency 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 of the LED array 10 and the fourth connection pin ( 114).

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 parallel to capacitors C31 to C34 respectively connected to the first to fourth connection pins 131, 132, 133, and 134. Leads to. Such diodes D33 to D36 have a capacitor for maintaining the series resonance inside the electronic ballast when the output line of the electronic ballast of the series resonance type is connected to the first to fourth connection pins 131, 132, 133, and 134. When connected between the first connecting pin 131 and the second connecting pin 132 or between the third connecting pin 133 and the fourth connecting pin 134, the capacitor C31 connected in parallel according to the polarity of the voltage input from the ballast Through C34 to control the current flowing in the LED array 13 is possible. For example, a positive voltage is applied to the third connection pin 133 based on the fourth connection pin 134 and is connected between the first connection pin 131 and the second connection pin 132 in a series resonance circuit type. When the resonance holding capacitor inside the electronic ballast is connected, the capacitor C33 is shorted by the diode D35, the diodes D33 and D34 are opened, and the capacitor C34 is shorted by the diode D36, so that the combined capacitance of the resonance holding capacitor The value is shown as the series connection of capacitor C31, resonance holding capacitor C and capacitor C32. In a cycle in which a negative voltage is applied to the third connection pin 133 based on the fourth connection pin 134, the capacitor C32 is shorted by the diode D34 and the capacitor C31 is shorted by the diode D33. The complex capacitance value of the resonance holding capacitor in the negative period is shown as the series connection of the capacitor C34, the external capacitor C for holding the resonance, and the capacitor C33.

5 is a circuit diagram of an LED fluorescent lamp according to a fourth embodiment of the present invention. Diodes D47 to D50 are added to the LED fluorescent lamp 140 according to the present embodiment, so that the LED fluorescent lamp 140 according to the present embodiment is operated regardless of the phase change of the voltage applied to the terminal in various fluorescent ballasts. do.

6 is a circuit diagram of an LED fluorescent lamp according to a fifth embodiment of the present invention. In the LED fluorescent lamp 150 according to the present embodiment, diodes D53 to D56 are added in series to capacitors C51 to C54 respectively connected to the first to fourth connection pins 151, 152, 153, and 154. Diodes D53 to D56, together with diodes D57 to D60, allow the LED fluorescent lamp 150 to operate according to the present embodiment regardless of the phase of the AC voltage in various fluorescent ballasts.

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. 6 as an example.

FIG. 7 is a diagram illustrating a circuit configuration when an LED fluorescent lamp according to an embodiment of the present invention is used for an electronic fluorescent ballast of an instant start method. Referring to FIG. 7, the instant start type electronic fluorescent ballast stabilizes Q71 and Q72 of the switching element by the self-oscillation operation of a circuit composed of transformers T1, T2 and capacitor C. 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 151 and the second connecting pin 152 will be described. Induces AC voltage of high frequency to winding T2-2, and if (C) point is (+) potential based on (D) point, (C) point-C1-C51-D53-D51-LED array (15)-D52 -D54-C52-Current flows through the path of point (D), and point (D) in the area where point (C) becomes (-)-C52-D58-D51-LED array (15)-D52-D57-C51 -Current flows through the path of C1-(C) point.

Therefore, the current value flowing in the LED array 15 is controlled by the series composite impedance of the current control capacitors C1, C51 and C52 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.

At this time, if the values of the capacitors C51 and C52 are set to C2, the impedance Z can be expressed as follows.

The connecting pin 153 and the connecting pin 154 are terminals for symmetry, and the basic operation is the same as the case where the output line of the electronic ballast is connected to the connecting pin 151 and the connecting pin 152.

8 is a circuit diagram illustrating a circuit configuration when an LED fluorescent lamp according to an embodiment of the present invention is used in a soft start ballast for an electronic fluorescent lamp. 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 lifetime of the fluorescent lamp, T3 secondary preheating windings T3-a and T3-b are wound around the resonant transformer and the secondary voltage generated in the preheating winding at the initial lighting of the lamp After sufficiently preheating the filament, a high voltage is applied to the lamp 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 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.

Since the main current flowing through the LED fluorescent lamp 150 has a very small current flowing through the LED array 15 by the preheating windings T3-a and T3-b, the electric potential of the point (B) is (C) In the positive (+) period, current flows through the path of (B) point-C53-D55-D51-LED array (15)-D52-D56-C54-(C) point, and vice versa ) Point-C54-D59-D51-LED array 15-D52-D60-C53-(B) Current flows through the path. Therefore, when the current flowing in the LED array 15 is set to the value of capacitors C51 to C54 as C2, the composite impedance of the capacitor becomes 2 / jwC2, and the current flowing in the LED array 15 is controlled by changing the value of C2. You can do it.

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

9, when the input voltage is applied, unlike the fluorescent lamp, since the impedance of the LED fluorescent lamp 150 does not seem to be infinite, the starter lamp 200 may be regarded as an open state, and thus, the main current path may be ignored. The voltage applied to the third connection pin 153 becomes C53-D55-D51-LED array 15-D52-D56-C54 in the positive period, and C54-D59-D51-LED in the negative period. Array 15-D52-D60-C53, where the composite impedance for controlling the current at this time is Z, the value of inductance L is set to L, and the values of capacitors C1 to C4 are set to C2.

At this time, the flowing current shows the form of a pulse with a frequency of 2f, which is twice the input power frequency f, and thus significantly reduces the flickering phenomenon that may occur when driving the LED fluorescent lamp 150 at a commercial frequency f. Can be.

10 is a circuit diagram illustrating a circuit configuration when an LED fluorescent lamp according to an embodiment of the present invention is used in a fluorescent ballast of an 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 D53 and D55 and diodes D54 and D56 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 looking at the main current flowing through the LED array 15, the point (A) is based on the point (B) and the point (C) in the period of the (+) period-C51-D53-D51-LED array 15-D52 -The current flows through the path of D54-C52-(D), and in (-) cycle, (D)-C52-D58-D51-LED array (15)-D52-D57-C51-(C) 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 150 has a pulse current form having a frequency of 2f that 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.

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 of an LED fluorescent lamp according to a fifth embodiment of the present invention;

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

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

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

Explanation of symbols on the main parts of the drawings

15: LED array 150: LED fluorescent lamp

Claims (7)

In the LED fluorescent lamp connected to the ballast for electronic fluorescent lamp, An LED array comprising a plurality of LEDs connected in series; First and second connection pins connected to the electronic fluorescent ballast; A first capacitor having one end connected to the first connection pin and the other end connected to one end of the LED array; A second capacitor having one end connected to the second connection pin and the other end connected to the other end of the LED array; And And a diode unit connected between the first capacitor and the second capacitor, the diode unit including at least one diode to form a one-way current path in the LED array. The method of claim 1, The diode unit, A first diode having an anode connected to the other end of the first capacitor and a cathode connected to an anode side terminal of the LED array; And And an anode connected to a cathode side terminal of the LED array and a cathode connected to the other end of the second capacitor. The method of claim 2, Third and fourth connecting pins; A third capacitor having one end connected to the third connection pin and the other end connected to one end of the LED array; And One end is connected to the fourth connection pin, the other end LED fluorescent lamp further comprises a fourth capacitor connected to the other end of the LED array. The method of claim 3, The diode unit, 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 a cathode connected to the other end of the second capacitor and an anode connected to a cathode of the second diode; 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; And And a cathode connected to the other end of the fourth capacitor and an anode connected to the cathode of the second diode. The method of claim 4, wherein The diode unit, A seventh diode having an anode connected to an 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 comprises at least one of the tenth diode connected to the other end of the third capacitor. The method of claim 1, The diode unit, A first diode having an anode connected to the other end of the first capacitor and a cathode connected to an anode side terminal of the LED array; And And an anode is connected to the cathode side terminal of the LED array and the cathode comprises at least one of a second diode connected to the other end of the second capacitor. The method of claim 3, The diode unit, 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 a cathode connected to the other end of the second capacitor and an anode connected to a cathode of the second diode; 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; And The cathode is connected to the other end of the fourth capacitor, the anode comprises at least one of the sixth diode connected to the cathode of the second diode.

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