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Posted by willshak on September 19, 2007, 4:31 pm
on 9/19/2007 3:28 PM Jeff Wisnia said the following:
> willshak wrote:
>
>> on 9/18/2007 2:22 PM Jeff Wisnia said the following:
>>
>>> RickH wrote:
>>>
>>>>
>>>>> RickH wrote:
>>>>>
>>>>>> On Sep 18, 9:18 am, "dan" <> wrote:
>>>>>
>>>>>
>>>>>>> I posted a message earlier about light bulbs in my kitchen failing
>>>>>>> prematurely (lasting roughly 1 month). I received some good
>>>>>>> suggestions
>>>>>>> but did not find anything. Since then, I have paid particular
>>>>>>> attention
>>>>>>> to the lights (there are two on the same switch). When I turn
>>>>>>> them on,
>>>>>>> I have noticed a slight delay for the second bulb to light up.
>>>>>>> Could
>>>>>>> this be the issue? I would think both would instantaneously
>>>>>>> light up at
>>>>>>> the same time. I have not checked the connections, but will do
>>>>>>> so this
>>>>>>> weekend.
>>>>>
>>>>>
>>>>>>> --
>>>>>
>>>>>
>>>>>> I assume you switched bulb brands a few times to determine it's not
>>>>>> just a batch of bad bulbs. If you switch the two bulbs, does the
>>>>>> delay problem follow the same bulb? Are they ceiling cans? If so,
>>>>>> the thermal switch might be causing a delay due to carboned
>>>>>> contacts.
>>>>>> Need more info. Temperature change is the hardist thing on a bulb,
>>>>>> thats why bulbs dont last long outdoors, especially in winter. Slow
>>>>>> start dimmers can extend bulb life a little.
>>>>>
>>>>>
>>>>> Rick, can you offer a cite confirming that temperature change is the
>>>>> hardest thing on a bulb.
>>>>>
>>>>> I'd think that given the huge difference between ambient temperatures
>>>>> and the bulb filament's white hot operating temperature less than a
>>>>> hundred degree swing in its starting temperature wouldn't mean
>>>>> diddly.
>>>>>
>>>>> Do automobile light bulbs fail more frequently in Minnesota than in
>>>>> California? I think not.
>>>>>
>>>>> Did you maybe mean to say that it's the outside weather conditions
>>>>> which
>>>>> cause bulb failures, stemming from moisture induced corrosion of
>>>>> sockets
>>>>> and bulb bases, which can cause all sorts of bulb failures?
>>>>>
>>>>> Jeff
>>>>>
>>>>> --
>>>>> Jeffry Wisnia
>>>>> (W1BSV + Brass Rat '57 EE)
>>>>> The speed of light is 1.8*10^12 furlongs per fortnight.- Hide
>>>>> quoted text -
>>>>>
>>>>> - Show quoted text -
>>>>
>>>>
>>>>
>>>> By temperature change I mean sudden temp change, the sudden in rush
>>>> current to a cold filament going hot causes it to flex and eventually
>>>> break. Slow start dimmers bring the filament to temperature slowly
>>>> and avoid some of the sudden flex and resulting metal fatigue.
>>>
>>>
>>> Thanks, the inrush current part I agree with. I mistakenly thought
>>> you were referring to outdoor ambient temperature changes as
>>> contrasted with the generally smaller range of indoor temperature
>>> changes.
>>>
>>>
>>>> For a cite I would have to google around, but google for how slow
>>>> start
>>>> dimmers help bulb life and that will probably explain more, I read it
>>>> myself years ago. My outdoor bulbs never lasted long, so I started
>>>> using CFL's outdoors in the carriage lights.
>>>
>>>
>>> Ans did I. The lights on either side of our front door had three
>>> candelabra based flame shaped bulbs in each of them when we bought
>>> the place. I don't think we could go for more than a month without
>>> one of those six bulbs burning out, and it required a stepladder and
>>> some serious arm twisting to replace a bulb, usually accompanied by
>>> my cussing when I dropped one of the little decorative nuts which
>>> held the tops on those fixtures.
>>>
>>> Shortly after CFs became available I replaced the three sockets in
>>> each of those fixtures with a single edison base one and stuck in
>>> CFs. That was probably close to ten years ago now ant the original
>>> CFs are still going strone here in Red Sox Nation.
>>>
>>> ***********
>>>
>>> I've seen "bulb life extenders" for incandescents which were just
>>> NTC (negative temperature coefficient) thermistors housed in a
>>> housing you could stick into a socket before screwing the bulb in.
>>>
>>> Don Klipstein's work describes that application thusly:
>>>
>>> http://members.misty.com/don/bulb1.html#ss
>>>
>>> Jeff
>>>
>> One of the complaints against using CFLs is that they are slow to
>> start. The extender would cause the same complaints for an
>> incandescent as a CFL, but using more energy than a CFL.
>>
>
> The "extenders" I've see just slow the start by a second or two, no
> where near as long as the CFLs in my outside front door lights take to
> come up when it's cold outside.
>
> But you are correct on the energy usage.
>
> I can't wait for LED bulbs to get down to a reasonable price. From
> what I've read they'll last nearly forever and won't be a serious
> hazardous waste. LEDs seem to have already "taken over" in many of of
> the traffic signals around here.
>
> Jeff
>
Yes, and the auto industry has been using them in taillights, but
there's about 20 LEDs in each lamp. LEDs have to be used in large groups
to be useful enough for home lighting. The light from one LED bulb is
little better than a candle.
--
Bill
In Hamptonburgh, NY
To email, remove the double zeroes after @
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