X ray of the Narva operations theatre lamp

While reading the description of the principle of operations and the inner construction of a lamp is intresting, it is always also interesting to see it up close. Sadly due to the lamp beeing frosted that is rather difficult. However I had the possibility to take this lamp with me when I last met james and we did an x ray on this lamp, allowing us to look at the inner construction. At the top you can see the lamp's main filament, the C-9 design. A bit lower you can see the low voltage Filament of C-6 design. Both filament have a common connection that goes to the screw part of the base. The Low voltage filament goes to the centre contact and the 220V filament to the outer contact. The Low voltage wire is shielded in the stem by and asbestos tube while the high voltage lead in wire is fused with a Ballotini fuse. This is important in order to limit/prevent arcing when the main filament fails which may lead to complete destruction of the lamp