Energy saving lamp, lamp Type ARC 3U, 4U

Long time wide use of the standard luminescent lamps (LL) in house conditions (for illumination of housing) was limited because of own overall dimensions of LL. In the early eighties last century numerous types of compact luminescent lamps (KLL, in the English CFL option - Compact Fluorescent Lamps) with power from 5 to 25 W with light returns from 30 to 60 Lm/W and service life from 3 to 10 thousand h appeared.
Development of KLL became possible only as a result of creation of the highly stable narrow-band phosphors activated by rare-earth materials which can work at higher area densities of radiation, than in standard LL. At the expense of it it was succeeded to reduce diameter of a digit tube considerably. As for reduction of dimensions of lamps in length, this task was solved by division of the tubes into several shorter sites located in parallel and connected among themselves by either curved sites of a tube, or vvarenny glass branch pipes.