Characterization of Nepali solid-state lamps/Nepale pagamintu kietakuniu sviestuvu charakterizavimas

Two in-door solid-state lamps produced in Nepal for village illumination programs were investigated. The lamps, which are based on white phosphor-conversion LEDs and have different driving circuits (resistive ballast or switching converter), where characterized by measuring the input current, optical output, radiation pattern and chromaticity characteristics as functions of temperature. The variation of the output flux with input voltage was examined. The generated flux, chromaticity, and radiation pattern exhibited stability against temperature variation irrespectively of the driving circuit. The lamp based on the resistive ballast showed a high sensitivity of the output flux to input voltage. Also, for some models of the LEDs used, a noticeable variation of the correlated colour temperature within the viewing angel was observed. Ill. 9, bibl. 10 (in English; summaries in English, Russian and Lithuanian). [TEXT NOT REPRODUCIBLE IN ASCII] Istirti du vidaus apsvietimui skirti kietakuniai sviestuvai, pagaminti Nepale pagal kaimo apsvietimo programas. Jie pagristi baltais konversijos fosfore sviestukais (sviesos diodais) ir turi skirtingas maitinimo grandines (varzini balasta arba jungiklini keitikli). Itaisai charakterizuojami matuojant iejimo sroves, optinio isejimo, kryptingumo ir spalvio charakteristiku priklausomybe nuo temperaturos. Taip pat tirtas isejimo srauto kitimas sulig iejimo itampa. Parodyta, kad generuojamas srautas, spalvis ir kryptine diagrama pasizymi temperaturiniu stabilumu nepriklausomai nuo maitinimo grandines. Tuo tarpu sviestuvo su varziniu balastu isejimo srautas stipriai priklauso nuo iejimo itampos. Taip pat naudojant kai kuriu modeliu sviestukus, aptiktas pastebimas koreliuotosios spalvines temperaturos kitimas matymo kampo ribose. Il. 9, bibl. 10 (anglu kalba; santraukos anglu, rusu ir lietuviu k.).