Passed the time of incandescent lamp, LED lamp depends on its low price, less specific power consumption and macrobian life (can amount to 100 thousand hours) wait for an advantage to walk into popular gradually in the life, satisfied the many sided requirement of the illume of great majority person, recreation and even life.
(small make up beauty of division of lighting of lubricious harbour of illicit purplish blue to illuminate)
But small recently make up in labour (Mo) make (Yu) when, discovered the news that lamps and lanterns of a LED explodes accidentally, after that small make up get online one search discovery, this still is not a case really, LED lamp explosion happens from time to tome in the last few years. But, well why can a lamp explode?
Too long do not look edition:
LED won't explode commonly, although electric current is very big, also can appear only power is the local blowout of 0 basically. But if the drive circuit of LED is made non-standard, or the circumstance of short circuit of occurrence be affected with damp be affected with damp, appear very likely more serious blast is cracked.
Before studying LED lamp, let us see incandescent lamp first: Regard a kind of heat radiation as illuminant, when incandescent lamp is in working status, the electricity that filament is carried heats white-hot condition (right now filament temperature can amount to 3000 ℃ ) , can give out bright visible light through heat radiation.
But the issue that so high job temperature brings also is clearly: The Bo case that be made by Pyrex and becomes falls in heat radiation, its temperature is highest can amount to 100 ℃ left and right sides. Below this kind of circumstance, if you sprinkle a cold water toward the incandescent lamp that working (stem from safe consideration, small make up persuade you to be not spilled really) , bo carapace can bilge as a result of heat cold shrink the wall of inside and outside that create gets power not all and produce scamper probably to crack.
(when resistor two end brought to bear on after constant tension, the electron in resistor can be below the action of electric field, towards electromotive force elevatory place moves. But the electron will be inevitable in mobile process with resistor medium atom or element undertake colliding, produce heat energy, call joule heat. The Q in formula is joule heat, I is the electricity that carry, r is resistor, t is the time that tells electric current, u is resistor the voltage that two end bring to bear on) correct: The T in the U2/Rt in formula should be on the element
But when LED lamps and lanterns is working, its crust temperature is 50-60 ℃ only, average temperature suddenly Leng Shi is in to it compose does not become menace. Look, explosive reason was about to do it from other side.
LED lamp grows what sample
LED (Light Emitting Diode) , call glow diode again, it is a kind of electron component that can give off light, its main body is chip of a semiconductor actually. The basic structure of LED is the semiconductor chip an electroluminescence, park has the frame of down-lead to go up, one aspect of the matter is negative pole, another end is the anode of join power source, with epoxy resin sealed in order to protects in-house core line all around. When electric current has shed this kind of parts of an apparatus, electron and cavity are in semiconductor material interior is compound, the excess energy of generation causes photon to blast off, can give out monochromatic light, came true direct the process visible light of electric energy translate into. And smooth wavelengh, namely smooth color is decided by the material sort of semiconductor chip.
The cardinal principle of LED lamps and lanterns that we use daily can divide for component of the following parts:
Interface of 1. power source, use join power source and bulb;
2. crust, basically rise medicinal powder hot action, general by medicinal powder the aluminous material with very good heat is made, come loose goodly the service life that heats up the effect to be able to affect LED lamp directly;
3. chimney, the light that can give out LED gathers together, still can prevent get an electric shock;
4. drive circuit, the working voltage of individual LED lamp is very low, control in 2-4V commonly, and range of its job voltage is very narrow also. If direct link is on the 220V alternating current source that we use daily, LED can damage by instantaneous puncture. Must pass circuit design to undertake to inputting voltage constant voltage constant current is controlled so, 220V alternating current changeover is the dc of 12V, in order to make sure LED works normally.
LED lamp can explode for what
Actually, power source short circuit, bring to bear on quality of circuit of exorbitant, drive needs voltage, inside buy driver be affected with damp be affected with damp, medicinal powder the capacitance that the metropolis such as hot effect difference causes different level or life of other electronic parts are decreased short explode even. For instance the withstand voltage of lamp bead is in commonly 4V less than, the drive power source of LED lamp reachs 220V voltage drop more the low voltage of 12V, use in order to offer lamp bead. But if receive LED light directly,fall to 220V voltage, exorbitant voltage can make lamp bead polar a puncture blowout. This kind of explosion that because voltage is exorbitant,causes, more wiring is caused.
Then some people show very grievance: I also do not have random wiring, result well him lamp is shining to shining to explode, how is this to say? Actually, this boiler have to inferior drive circuit will carry on the back -- some businessmen to reduce the manufacturing cost of LED lamp, can play tricks on the material that make and craft. And because drive circuit is enclosed in bulb interior, cannot have immediate resolution, it is the heavy disaster area of perpetrate a gigantic fraud more.
The drive circuit of lamp of general and normal LED uses constant current drive, photograph comparing allows step-down drive circuit at the block of inferior lamp, the electricity that power source of constant current drive exports is stable, have very high safety factor, but apparent, its cost is relative also taller.
The working principle of circuit of drive of block look step-down is very simple, the capacitive reactance that uses capacitance to arise below certain communication signal frequency namely will restrict electric current of the biggest job. For example, below the labour frequency condition of 50Hz, the capacitive reactance that the capacitance place of F of a 1 μ produces is 3180 ohm about. Add in the two end of capacitor when the alternating voltage of 220V, the biggest electric current that has shed capacitance is 70mA about. But the work that this 70mA makes on capacitor is without result power, do not produce power comsumption.
And circuit of constant current drive uses transformer to turn into high pressure low pressure, have rectification filter wave, can achieve output to stabilize the purpose of low-pressure dc. When load current happening changes, manostat can change through feeling this to plant and carrying voltage to undertake adjustment to LED, make the electric current that sheds classics LED keeps constant thereby. So, won't fluctuate because of the voltage of electrified wire netting and power source of constant current drive outputs generation influence to its. Under photograph comparing, block allows drive power source to suffer voltage wave motion very easily to affect, cause the damage of in-house circuit element then.
Ten million vigilance is inferior lamps and lanterns
Besides meeting explosion, all the inferior LED lamps and lanterns of a few money still has price a lot of harms --
Dazzle harm, as a result of,be in namely in eye shot of brightness distributing or limits is unsuited, or existing on space or time extreme luminance contrast, down to is caused uncomfortable with the visual requirement that lowers object visibility. The eye to the person and the actinic harm that the skin can produce older rate, hot harm waits inferior LED lamp a moment.
Luminous environment harm, the frequency of inferior LED lamp shines, unreasonable spectrum distributings etc, the metropolis on the large-scale application such as illume of house is in the home, job illume, outdoors illume is right the eye ministry health of people causes a harm, make luminous environment safe the attention that causes people gradually.
...
Although,work overtime good, safety is more important. Here, small make up remind you: The LED product that selects normal manufacturer, standard is used, position of regular examination line, this dot nature meets LED light good Song, dare not explode.
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