Automotive headlights feem ntau yog tsim los ntawm peb qhov chaw: lub teeb pom kev zoo, reflector thiab daim iav sib xws (astigmatism mirror).
1. noob
Cov qhov muag teev uas siv nyob rau hauv lub tsheb headlights yog incandescent qhov muag teev, halogen tungsten qhov muag teev, tshiab high-brightness arc teeb thiab hais txog.
(1) Incandescent noob: nws filament yog ua los ntawm tungsten hlau (tungsten muaj lub siab melting point thiab lub teeb muaj zog). Thaum lub sijhawm tsim khoom, txhawm rau txhawm rau ua kom lub neej ua haujlwm ntawm lub teeb, lub noob tau ntim nrog cov roj inert (nitrogen thiab nws qhov sib xyaw ntawm cov roj inert). Qhov no tuaj yeem txo cov evaporation ntawm tungsten hlau, nce qhov kub thiab txias ntawm filament, thiab txhim khu lub luminous efficiency. Lub teeb los ntawm lub teeb incandescent muaj yellowish tinge.
(2) Tungsten halide teeb: tungsten halide lub teeb yog muab tso rau hauv cov roj inert rau hauv ib qho halide caij (xws li iodine, chlorine, fluorine, bromine, thiab lwm yam), siv lub hauv paus ntsiab lus ntawm tungsten halide recycling cov tshuaj tiv thaiv, uas yog, gaseous tungsten evaporating los ntawm filament reacts nrog lub halogen los tsim ib tug volatile tungsten halide, uas diffuses mus rau qhov kub ntawm qhov chaw nyob ze ntawm lub filament, thiab decomposed los ntawm tshav kub, yog li ntawd cov tungsten rov qab mus rau lub filament. Cov halogen tso tawm txuas ntxiv mus txuas ntxiv thiab koom nrog cov tshuaj tiv thaiv lub voj voog tom ntej, yog li lub voj voog txuas ntxiv, yog li tiv thaiv cov evaporation ntawm tungsten thiab blackening ntawm lub teeb. Tungsten halogen lub teeb me me yog me me, lub teeb lub plhaub yog ua los ntawm quartz iav nrog kub tsis kam thiab siab mechanical zog, nyob rau hauv tib lub hwj chim, lub brightness ntawm tungsten halogen teeb yog 1.5 npaug ntawm lub teeb incandescent, thiab lub neej yog 2 mus rau 3x ntev.
(3) Tshiab high-brightness arc teeb: Lub teeb no tsis muaj ib txwm filament nyob rau hauv lub teeb. Hloov chaw, ob lub electrodes tau muab tso rau hauv ib lub raj quartz. Lub raj yog ntim nrog xenon thiab kab hlau (los yog hlau halides), thiab thaum muaj txaus arc voltage ntawm lub electrode (5000 ~ 12000V), cov roj pib ionize thiab ua hluav taws xob. Cov roj atoms nyob rau hauv lub xeev zoo siab thiab pib emit lub teeb vim lub zog theem ntawm cov electrons. Tom qab 0.1s, me me ntawm mercury vapor yog evaporated nruab nrab ntawm cov electrodes, thiab lub hwj huam mov yog tam sim ntawd hloov mus rau mercury vapor arc tawm, thiab ces pauv mus rau lub halide arc teeb tom qab kub nce. Tom qab lub teeb ncav cuag qhov kub thiab txias ua haujlwm ntawm lub teeb, lub zog ntawm kev tswj cov arc tawm yog tsawg heev (txog 35w), yog li 40% ntawm lub zog hluav taws xob tuaj yeem txuag tau.
