"CARAMEL CANDY" LIGHT BULBS
"Caramel candy" incandescent light bulbs. Fun project in which I have tested colored glass envelopes. Light bulbs are relatively big in size - amber color section diameter is 80mm and the transparent base is 50mm.
- Year: 2016
- Project: Incandescent light bulb
Lamp glass envelopes are made of 3 components. Main section is a color tube. Top thin tube is the evacuation tube (vacuum and gas filling). Bottom transparent tube is for connecting the stem
Next step is preparing glass stem blanks. Afrer sealing electrodes stem would be connected to the lower section of the main body.
Glass metal seal - wires vacuum sealed into the glass. Additional wires are spot welded to hold the filament.
Tungsten filament is attached to lead in wires. (I wanted the filament of those lamps look like U shaped Edison lamps).
The stem and filament were inserted into an envelope, then glass edges are melted and connected. The place of the connection is annealed in a soft flame of Bunsen burner.
Lamps are connected to vacuum pumping station. Now bulbs will pass several procedures - pumping to low vacuum, envelope and filament outgassing, pumping to high vacuum, outgassing, activating filaments, flushing and inert gas filling.
Coil light - "Caramel Candy" incandescent light bulb is glowing (still attached to a vacuum post)
"Caramel Candy" Finished one
Bulb variation in blue glass