CN202889695U

CN202889695U - High-frequency AC LED lamp for illumination

Info

Publication number: CN202889695U
Application number: CN 201220158653
Authority: CN
Inventors: 刘晓博; 邱胜顺; 陈万昆
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-04-16
Filing date: 2012-04-16
Publication date: 2013-04-17
Anticipated expiration: 2022-04-16

Abstract

The utility model relates to a high-frequency AC LED lamp. An adopted circuit topology is formed by serially connecting one or more monolithic-chip AC LEDs or formed by serially connecting one or more groups each of which is formed by reversely connecting two bunches in a parallel way, wherein each bunch is formed by serially connecting one or more DC LEDs. The high-frequency AC LED lamp can be serially connected with a current-limiting inductor or accessed to a self-coupling transformer before being directly accessed to a high-frequency AC voltage. By serially connecting a small inductor, the LED lamp can obtain high impedance due to the fact that the operating frequency is far higher than the frequency of AC power. A large resistor is thus not required to be serially connected for current limiting. The current-limiting difficulties of common AC LEDs are thus overcome. The energy efficiency is further improved. The high operating frequency further makes the brightness alternation of the LED lamp alleviated. The high-frequency AC LED lamp is compatible with a traditional fluorescent lamp electronic ballast circuit. Meanwhile, control technologies of frequency modulation and bipolar pulse width modulation, etc. can be further adopted. A light-adjustable and intelligentized illumination system is easily achieved.

Description

The high-frequency ac LED lamp that is used for illumination

Technical field

The invention belongs to the led light source field, relate in particular to a kind of AC LED lamp for illumination.

Background technology

Direct-current LED is the research main flow of encapsulation industry, research direction is to improve thermal resistance between chip and the substrate (SLUG) as direction, as cover brilliant and substrate package etc., the chip part then is to promote inside and outside quantum efficiency or light extraction, generally with the angle of LED material as research direction, but direct-current LED has following shortcoming:

1. and present direct-current LED only can bear low-voltage direct, high pressure or exchange all may so that light-emitting diode damage, so all must cooperate DC converting circuit could be used for mains system on using.

2. low-voltage direct Light-Emitting Diode forward conduction is luminous, oppositely lowly is pressed with leakage current but not luminous.The Light-Emitting Diode Series Parallel Elements must be used and improve reverse breakdown voltage, to prevent the too high damage Light-Emitting Diode of reverse voltage.The single led damage of this structure will have a strong impact on the loop, cause the Light-Emitting Diode of same series connection group not work.For reducing this situation, need to reduce the series diode number, still relative meeting is so that circuit is elongated, and it is large that loss becomes, and often causes terminal voltage not enough, brightness irregularities.

3. the led chip of high-power low-voltage direct is easily because static (ESD) is so that moment revers voltage rising causes damage, for example AlInGaN.United States Patent (USP) 6547249B2 patent, the effect that utilizes the diode add a reverse parallel connection to produce protective circuit.

4. 220V can be directly received in a plurality of direct-current LED series connection and exchange, but only have monolateral volt-ampere characteristic; And because 2,3 described shortcomings seal in the interchange, easily be reversed puncture.

AC LED has the bilateral characteristic curve of bending over the desk, and energy incoming transport voltage is difficult for being reversed puncture.But present AC LED has following shortcoming:

1. direct-current LED is pressed the described series-parallel AC LED of Fig. 1, because LED forward equivalent resistance R _sLess, directly incoming transport voltage needs series reactance.If the employing inductance because operating frequency is that 50Hz is very low, needs high inductance value.If employing resistance, the higher series resistance of voltage is larger, and resistance can consume a large amount of electric energy, and simultaneously resistance can not afterflow, causes flicker and larger harmonic wave.

2. adopt a wafer is divided into a plurality of micromeritics, each intercrystalline insulation utilizes the series-parallel single-chip AC LED of electric conducting material.After a wafer is divided into micromeritics, forward equivalent resistance R _sImprove about h doubly (h is that wafer area is than upper micromeritics area), again by series connection, greatly improved the forward region operating resistance and (improved h ²Doubly).Utilize this special construction, directly be connected to high-voltage alternating.But this chip has high cost, intercrystalline insulation packaged type difficult, that too concentrate causes the shortcomings such as heat radiation difficulty.

Summary of the invention

The invention provides a kind of high-frequency ac LED lamp for illumination.To directly access high-frequency ac voltage behind this high frequency LED lamp series connection current-limiting inductance or the access autotransformer, because operating frequency is far above industrial frequency AC, the series connection small inductor can obtain large impedance, can directly access high voltagehigh frequency exchanges, large resistance need not to connect, solve common AC LED current limliting hard problem, improved efficiency; Operating frequency is high, and the light and shade of LED lamp is alternately fast especially, and because the afterflow effect of inductance and the afterglow effect of fluorescent material have slowed down the light and shade of LED lamp alternately.It is a kind of energy-conserving product.

A kind of high-frequency ac LED lamp.It is characterized in that described high-frequency ac LED has following feature:

Feature 1: it is a string adopting circuit topology or the extremely a plurality of direct-current LEDs series connection to a plurality of single-chip AC LED series connection, and two string reverse parallel connections are one group, one group of circuit topology of organizing at the most series connection.

Feature 2: operating frequency is higher than industrial frequency AC.

So-called feature 1 single-chip AC LED is that a wafer is divided into a plurality of micromeritics, and each intercrystalline insulation utilizes the series-parallel single-chip AC LED of electric conducting material.

So-called feature 1 AC LED is m among Fig. 1 _nIndividual direct-current LED series connection is for a string, and two string reverse parallel connections are one group, the AC LED of N group series connection.

Beneficial effect of the present invention is: solved common AC LED current limliting hard problem.The strategy of multi-chip series connection has solved the too concentrated encapsulation of single-chip high-voltage alternating LED and has caused heat radiation difficulty, intercrystalline insulation hard problem.Changed the DC driven pattern that led drive circuit is designed to the constant current and constant power circuit, not only can be compatible with the conventional fluorescent electronic ballast circuit, need not to change in the situation of any circuit, directly replace the conventional fluorescent lamps pipe, also can adopt the control technologys such as frequency modulation, bipolarity pulse-width modulation, realize easily tunable optical and intelligentized illuminator.

Description of drawings

Fig. 1 is the high-frequency ac led circuit topology that direct-current LED provided by the invention forms.

Fig. 2 is that Novel LED light provided by the invention is used for the circuit of fluorescent lamp electronic ballast schematic diagram.

Embodiment

The invention provides a kind of high-frequency ac LED lamp, below in conjunction with accompanying drawing, the course of work of this lamp is elaborated.Should be emphasized that following explanation only is exemplary, rather than in order to limit the scope of the invention and to use.

Fig. 1 is the high-frequency ac led circuit topology that direct-current LED forms.Among Fig. 1, the described high-frequency ac LED course of work and step are:

Step 1: when input terminal voltage is forward, Light-Emitting Diode D1, D2 ... Dm _n, n=0,1 ... N, conducting is luminous;

Step 2: when input terminal voltage is reverse, Light-Emitting Diode D1 ', D2 ' ... Dm _n', n=0,1 ... N, conducting is luminous;

As seen no matter input voltage is at positive half cycle or negative half period, and this lamp all the time conducting is luminous, so this structure has bilateral volt-ampere characteristic.The instantaneous light emission area is the conducting Light-Emitting Diode and the ratio 1/2 of total Light-Emitting Diode number.

Fig. 2 is the high-frequency ac led circuit topological diagram for electronic ballast for fluoresent lamp.Among Fig. 2, electric ballast inverter circuit output equivalent voltage source e _s, inverter circuit output equivalent reactance Zs, equivalent capacity Cs.e _sBe that frequency is the square wave of fHz, usually f is more than 20KHz.The reactance of current-limiting inductance L is j2 π fL, by transformer pressure-reducing or select suitable inductance value, utilize the threshold voltage step-down of LED self and distributed resistance current limliting with current limit in the rated operational current scope of high-frequency ac LED.

The above; only for the better embodiment of the present invention, but protection scope of the present invention is not limited to this, anyly is familiar with those skilled in the art in the technical scope that the present invention discloses; the variation that can expect easily or replacement all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection range of claim.

Claims

1. high-frequency ac LED lamp that is used for illumination based on the high-frequency ac LED of single-chip AC LED or based on the high-frequency ac LED of direct-current LED, is characterized in that described high-frequency ac LED has following feature:

Feature 1: it is a string adopting circuit topology or extremely a plurality of direct-current LEDs series connection of connecting to a plurality of single-chip AC LEDs, and two string reverse parallel connections are one group, one group of circuit topology of organizing at the most series connection, and it is equal or unequal that each organizes the LED number;

Feature 2: operating frequency is far above industrial frequency AC;

So-called single-chip AC LED is that a wafer is divided into a plurality of micromeritics, and each intercrystalline insulation utilizes the series-parallel single-chip AC LED of electric conducting material; So-called direct-current LED is one or more crystal grain or micromeritics series connection, the direct-current LED that reverse recovery time is extremely short.

2. the described high-frequency ac LED lamp for illumination of claim 1 is with behind high-frequency ac LED lamp series connection current-limiting inductance or the transformer for circuit of fluorescent lamp electronic ballast, directly accesses its circuit of electronic ballast, and does not change any circuit of its electric ballast.