rough service bulbs

[sm_jamieson]

All this talk about stockpiling bulbs ... Any use in storing rough service bulbs? - are these more likely to work 10 years down the line, or to last longer in normal use ? Simon.

[Graham.]

IIRC they are effectively under-run and give out fewer lumens per watt.

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember sm_jamieson saying something like:

I wonder if it's worthwhile stockpiling a few of those. I don't go through many, by their very nature, but it would be a bit of a pisser if I couldn't get any at all. I haven't tried CFLs in handlamps yet, so maybe it's moot.

[Reentrant]

That's "long life" or "extended life". Rough service bulbs have more support loops for the filament, to help survive vibration or shock.

[Andy Champ]

CFLs are worryingly heavy for something that's attached by a couple of little pins in the BC connector, and is going to get bounced about.

I suspect LEDs may be the way to go for handlamps. not heavy, and no glass.

I also suspect they aren't good enough - yet.

Andy

[Huge]

My local MOT place uses a LED inspection lamp. Seems to suit them...

[Dave Plowman (News)]

Rough service types are designed to more withstand vibration. But are far less efficient than GLS types so their use should be confined to the above.

For most, the only domestic use would be in an inspection light etc - and a low voltage one would be more efficient and less prone to vibration damage too, as well as safer.

[gazz]

electric garage door openers specify rough service bulbs in the light fitting,

non rough service ones last about 10 open and close cycles before blowing, and a cfl dosent work due to the light being flashed in certian sequences to show faults/what stopped the motor (on mine 3 short one long flash is the beam break sensor interupted/knocked out of alignment)

[Andrew Gabriel]

This is a case where an ES lampholder would be better.

There are some in use in the US (where sharp cut-off on dip beam isn't required like it is in Europe).

[jim]

this talk about stockpiling bulbs ...

No.

ISTR - from decades ago - that there are 2 types of filament used in GLS lamps (ie the normal lamp bulbs Broon is busy banning), viz Single- Coiled (SC) and Coiled-Coil (CC). In SC bulbs the filament is wound round a former, the former is dissolved away in acid and the filament mounted in the bulb. For CC bulbs the process is repeated, treating the coiled first stage as if it were a length of wire - hence Coiled- Coil.

Sometimes bulbs are stamped SC or CC - depends on source.

Coiled Coil are far more susceptible to vibration failure because the double wound coil can short across windings.

CC bulbs used in lamp battens screwed direct to a downstairs ceiling or staircase may fail for just that reason (ie vibration from foot traffic above).

yes something like 10% less would be typical SC reduction, IIRC. But for either type lamp designers have wide latitude to vary light output & life (& reliability!) by varying the design parameters. Using Krypton(?) for the envelope gas instead of Argon can double the life of a bulb.

As for storage, regret I have no info as to likely failure rate in storage though the cautious *might* (1) consider storing them in the expected installation orientation to counter possible gravity induced deformation of the filaments & (2) store in a vibration proof location. Amongst other possible problems that may occur long term are (3) argon gas leakage from the bulb envelope seals (& ?? through the glass itself); & (4) discolouration of the glass bulb.

I hope to be able to post news of those aspects in 20 years time ;-)

HTH

[John]

I guess this is due to vibration in the motor unit - why not take a lead from the unit and mount it separately

[Huge]

*Hand*lamps, not *head*lamps. :o)