4 ms·
No bulb will last very long when hot. This isn't something new.
by adestefan 13y ago
No bulb will last very long when hot. This isn't something new.
- ars_technician 13y agoIncandescents will. They get very hot in normal operation and last the amount of time you would expect from an incandescent.
- Filligree 13y agoWhich is not, by any stretch of the imagination, "very long".
- DanBC 13y agoIncandescents die from thermal shock, not from being hot.
- neltnerb 13y agoThey die because over time the filament sinters causing grain growth and necking at the edges. The individual grains shift until due to the 1D constraint they each have grain boundaries with each other that stretch from the radial edges of the cylinder across. Once the grain boundary looks like that, you see increased surface diffusion at the grain boundary near the surface that forms a pit which weakens the filament. Perhaps you could argue that it requires cycling because the cooling causes increased axial stress and gradually pulls the filament apart, but it is most certainly more complicated than just thermal shock. I believe that so long as you're not shattering glass, it's more about how long it's been hot so far and how many times it's been completely cooled.
- jotm 13y agoBut they do last longer in lower ambient temps.