LED-lambi valgusvoo intensiivsuse reguleerimine

Kaasaegsed LED-tehnoloogia lahendused valgustuses pakuvad mitmeid eeliseid nii elektrienergia säästus kui ka kujunduses, kuid sellega kaasnevad ka mitmed komplikatsioonid. Kuigi tehnoloogia on alles arengujärgus võimaldab leedvalgustite efektiivsus, pikk eluiga ja paindlikud kasutamisvõimalused neid juba praegu ekspluateerida peaaegu kõikjal. Selleks, et LED-lampide valgustootlikust optimeerida tuleb arvestada nende unikaalsete omadustega. Teoorias on leedid täies ulatuses hämardatavad, kuna erinevalt teistest valgusallikatest ei ole neil omaseid tunnuseid, mis takistaksid hämardamis protsessi. Kuid teatavasti ei pea kõik teooriad tegelikkuses paika, reaalsuses jätab valgusdioodlampide käitumine hämardamisel soovida. Magistritöös tuuakse välja erinevaid probleeme, mis tekivad valgusdioodlampide hämardamisel ning leitakse probleemide põhjused. Selleks kasutatakse simuleerimistarkvara Multisim, kus teostatakse hämardi ja LED-lambi simulatsioonid.

Modern solid-state lighting (SSL) is already bringing energy-efficiency, excellent colour, long life, controllability, unique optics and forms to architectural lighting. To optimise SSL, a number of unique properties must be taken into account. One of the unpleasant aspects of SSL is its behaviour whilst dimming. Dimming lights makes them use less energy and lengthens their lifespan; this effect is achieved by phase-cut dimmers. Phasecut dimmers are historically meant for incandescent bulbs for which they work perfectly, but it is a different story with LED lamps. LED lamps are more complex than incandescent bulbs, for they need a driver to operate and they react very quickly to changes in current. Even a slight incompatibility with the dimmer could significantly affect the light output. Flicker has been shown to induce photosensitive epilepsy, migraines and headaches, and increased autistic behaviours in certain people. Reduced task performance, stroboscopic or phantom array motion effects, distraction, and annoyance are other possible consequences. In this paper the issues that occur whilst dimming are brought out and the causes are explained. Simulations of the driver and the dimmer circuits are performed in Multisim 14.0 to analyze the performance.