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Long life lights

T

Tim Williams

Jan 1, 1970
0
I've got a problem. I happen to carry the distinction of being the one
responsible for changing lights. Much as that's a problem in itself, the
biggest problem is.....the front porch light (surprisingly, it's not a
stairway light, eh?), which happens to be a hanging, upside-down, enclosed
fixture. And they put two screws in the thing, so it's almost impossible
for a single person to replace the bulb thus inserted. Really quite
remarkable how no one thought of this.

Besides modifying it, which I may consider because it's just that bad, in
the mean time I need something that'll last. We've already tried the "ten
gajillion hour" CFLs, which died in all of, you know it, three months. I'm
guessing something high voltage (130V+?) and incandescent. Any
recommendations?

Tim
 
D

Don Klipstein

Jan 1, 1970
0
I've got a problem. I happen to carry the distinction of being the one
responsible for changing lights. Much as that's a problem in itself, the
biggest problem is.....the front porch light (surprisingly, it's not a
stairway light, eh?), which happens to be a hanging, upside-down, enclosed
fixture. And they put two screws in the thing, so it's almost impossible
for a single person to replace the bulb thus inserted. Really quite
remarkable how no one thought of this.

Besides modifying it, which I may consider because it's just that bad, in
the mean time I need something that'll last. We've already tried the
"ten gajillion hour" CFLs, which died in all of, you know it, three
months. I'm guessing something high voltage (130V+?) and incandescent.
Any recommendations?

1. How about CFLs suitable for such things?

a) - wide temperature range, outdoor: Philips 15 watt "Outdoor". My
experience is that they mosty last more than a year in outdoor enclosed
fixtures in/near Philadelphia.

b) - as far as I know, the "ultimate" high temperature environment CFL:
Philips 15 watt "Marathon" triple-arch

That one may run dim in cold weather, even if it is enclosed.

Be patient with warmup times for wide temperature range CFLs,
especially in weather cold enough to depend on an enclosure. That can be
quite a few minutes.

2. The longest life common variety of incandescent I know of (other than
indicator lamps for electronic equipment) is "traffic signal lamps". Most
are rated to last an average of 8,000 hours. Keep in mind that they
produce about 65% as much light as "standard" incandescents of the same
wattage. They also mostly come in oddball wattages such as 117 and 92
watts.

There are 130V versions of some of these - designed to last 8,000 hours
at 130V.

You may have to get them by the case.

Also, check the fixture's wattage rating. If there is none, it can
easily be 60 watts.

3. Incandescent with a series diode, preferably with the incandescent
of a vibration resistant / "Rough Service"/"industrial service" type.
And I would have some overkill choice of diode so that it lasts
through most of the line voltage surges - as in at least a 1KV one rated
a few amps.

Be prepared for low light output. Also, power consumption is reduced
about 40% rather than 50% since the filament's resistance has a positive
temperature coefficient.
Furthermore, it may be prudent to choose a lamp whose wattage does not
exceed the fixture's rating, without relying on the diode not failing
short to stay within the rating of the fixture.

- Don Klipstein ([email protected])
 
B

Blarp

Jan 1, 1970
0
Besides modifying it, which I may consider because it's just that bad, in
the mean time I need something that'll last. We've already tried the "ten
gajillion hour" CFLs, which died in all of, you know it, three months. I'm
guessing something high voltage (130V+?) and incandescent. Any
recommendations?

Most CFL's die prematurely because they are placed in a luminaire
designed for incandescants. I.e. with no cooling.

Incandescents can stand heat, CFL's respond very badly to (internal)
heat levels > 100C - mostly the caps die prematurely.

Solution:

- Extra cooling holes (and now spiders, insects etc. crawl in)

- Use a PL lamp with external ballast.

- 2 incandescents in series (long life, poor efficiency - some
soldering required?)
 
D

Don Klipstein

Jan 1, 1970
0
At Home Depot, i found FEIT Electric Maintenance Pack (24); lasts 3
times longer than standard bulbs when used on 120V.
They are also surge resistant (130V actual rating).
The brass base helps carry away the heat - which makes for a longer
life if compared to same bulb with aluminum base.
Seems to be available only in 60W clear bulb.
The dern things seem to last forever.
Probably longer outside due to more cooling?

Brass does not conduct heat better than aluminum.

- Don Klipstein ([email protected])
 
D

Don Klipstein

Jan 1, 1970
0
I do not think the diode will help much as the filament will be
thermally cycling over a much wider range, and the EM self-stress may
also shorten expected life.

My experience is that diodes do help a lot.

Keep in mind that the filaments in blinking marquee lights have a much
greater temperature swing than the filament of a lamp in series with a
diode.

- Don Klipstein ([email protected])
 
S

Spehro Pefhany

Jan 1, 1970
0
A 230 volt incandescent, or a 120 volt one with a diode in series.

Of course, a 120V incandescent with a diode in series is equivalent to
a 170VAC incandescent, so you'll get shorter life, but a less "red"
light, and better efficiency at creating visible light.

You used to be able to buy button diodes that screwed into the bottom
of a light socket.
I find that, in general, CFs last a long time if run continuously, but
die when cycled. So a 5 or 7-watt CF might be left on 24/7 and last
longer and use less net power than an incendescent run at lower
voltage.

There are some screw-in LEDs available now. I asume they're reliable.

John
Best regards,
Spehro Pefhany
 
R

Rich the Philosophizer

Jan 1, 1970
0
Evaporation kills filaments, not mechanical stress.

Diodes do greatly extend the life of an incandescent.
Wouldn't you use a pair in antiparallel?

Thanks,
Rich
 
D

David L. Jones

Jan 1, 1970
0
A 230 volt incandescent, or a 120 volt one with a diode in series.

I find that, in general, CFs last a long time if run continuously, but
die when cycled. So a 5 or 7-watt CF might be left on 24/7 and last
longer and use less net power than an incendescent run at lower
voltage.

Heat kills CFL's, they are not rated for use in enclosed housings.
No air flow in enclosed space = hot = short life.
The XXXXX hours rating on the box are usually free-air ratings.

I've started switching to Envirolux T5 circular fluro's with a
separate electronic ballast, they run much cooler.

Dave.
 
D

Don Klipstein

Jan 1, 1970
0
Heat kills CFL's, they are not rated for use in enclosed housings.
No air flow in enclosed space = hot = short life.
The XXXXX hours rating on the box are usually free-air ratings.

There are integral-electronic-ballast CFLs that are sufficiently
heat-resistant to be rated for use in recessed ceiling fixtures. My
experience suggests that enclosed fixtures don't get much worse than
recessed ceiling fixtures.

Examples of such CFLs: Philips "Marathon" triple arch, of wattages 15,
20 and 23 watts (but not 25), and only non-dimmable versions. I have seen
them at Home Depot. Use the 15 watt one when you can.

The hour rating is median life expectancy in a 25 degree C ambient at 3
hours per start.

- Don Klipstein ([email protected])
 
J

Jan Panteltje

Jan 1, 1970
0
Examples of such CFLs: Philips "Marathon" triple arch, of wattages 15,
20 and 23 watts (but not 25), and only non-dimmable versions. I have seen
them at Home Depot. Use the 15 watt one when you can.

The hour rating is median life expectancy in a 25 degree C ambient at 3
hours per start.

Right, this one is from my kitchen, failed early,
ftp://panteltje.com/pub/philips_9_watt.jpg

Sorry bad photograph, but if you look close you will see many soldering joints
sort of worked lose due to thermal stress.
This bulb was just upside down in in the ceiling, but in free air, like this.

--------------------
[ ]
||
||

Not sure what is wrong, or even if it is the soldering, it has 2 chips in it.
 
M

Mark

Jan 1, 1970
0
Sorry bad photograph, but if you look close you will see many soldering joints
sort of worked lose due to thermal stress.

no.... the solder joints were probably bad from the start

Mark
 

neon

Oct 21, 2006
1,325
Joined
Oct 21, 2006
Messages
1,325
This might require a little ingenuity and labor. LEXON lights are 7w dissipation or less the size of a dime LEDS that can make those 25 w lights brightness as very dim. I haven't actualy used them myself but my porch light is 25 LEDS superbrights that makes a 15 watts blush. run them directly from 120 ac diode resistor power dissipation about 2 watts total. break a bulb and have fun.
 
L

legg

Jan 1, 1970
0
Of course, a 120V incandescent with a diode in series is equivalent to
a 170VAC incandescent, so you'll get shorter life, but a less "red"
light, and better efficiency at creating visible light.
A shorter life?
You used to be able to buy button diodes that screwed into the bottom
of a light socket.

I found a sidac in one of these buttons. Claimed to reduce inrush.
Can't see how, as inrush is a simple function of cold element
impedance. Can't imagine the semiconductor - basically a self-firing
triac, would last long in that kind of thermal environment - one that
is not improved by extra crap shoved into the lamp base.

RL
 
S

Spehro Pefhany

Jan 1, 1970
0
A shorter life?

Shorter than a 230VAC bulb on 120VAC, of course.


See, for example, US 3617766, US 4229680

I found a sidac in one of these buttons. Claimed to reduce inrush.
Can't see how, as inrush is a simple function of cold element
impedance. Can't imagine the semiconductor - basically a self-firing
triac, would last long in that kind of thermal environment - one that
is not improved by extra crap shoved into the lamp base.

RL

Sounds like it would cause nasty RFI continuously.
Best regards,
Spehro Pefhany
 
S

Spehro Pefhany

Jan 1, 1970
0
Wouldn't you use a pair in antiparallel?

Thanks,
Rich

For really long life (and low efficiency), maybe two 120VAC bulbs in
series with a diode. Yeah, 2 bulbs 1 diode.

Best regards,
Spehro Pefhany
 
D

Don Klipstein

Jan 1, 1970
0
For really long life (and low efficiency), maybe two 120VAC bulbs in
series with a diode. Yeah, 2 bulbs 1 diode.

For 42 volts RMS across each lamp?

How extreme do you want to go? Put two 300W 120V lamps and a diode in
series, and power consumption will be about 170 watts. And light output
will be about 120 lumens. The light output exponent is more than 3.4-3.5
when voltage is that low.

A 230V lamp or two 120V ones in series should last long enough. I have
heard -13 and -14 for that life expectancy exponent, and at times worked
out -12 for myself. Even if it is -12, a 750 hour 230V lamp would have
median life of 210 years at 120V.

- Don Klipstein ([email protected])
 
D

Don Klipstein

Jan 1, 1970
0
For really long life (and low efficiency), maybe two 120VAC bulbs in
series with a diode. Yeah, 2 bulbs 1 diode.

For 42 volts RMS across each lamp?

How extreme do you want to go? Put two 300W 120V lamps and a diode in
series, and power consumption will be about 170 watts. And light output
of both combined will be about 200 lumens - about that of a "standard" 25W
120V lamp. The light output exponent is more than 3.4-3.5 when voltage is
that low - figure more like 4 for that hot-running lamp, 4.1 on average
for others.

A 230V lamp or two 120V ones in series should last long enough. I have
heard -13 and -14 for that life expectancy exponent, and at times worked
out -12 for myself. Even if it is -12, a 750 hour 230V lamp would have
median life of 210 years at 120V.

If you want really extreme, you don't need diodes - just put a few
lamps in series. 3 should be overkill, with mean life expectancy
(in the unlikely event filament evaporation is still the limiting factor)
in the 10's of millennia or more.

- Don Klipstein ([email protected])
 
J

Jan Panteltje

Jan 1, 1970
0
I do not think so :)

So, and since it was open anyways, I took the good old soldering
iron and soldered all the bad looking connections again.
Plugged it in, not expecting much.
Light!

So, the small coil that is in there, seemed to be the part that gets hottest,
and it's pins looked sort of lose, could have been it.
Could have been some of the other connections too.
That sort of breaking solder joints due to temp stresses I
have seen many times in TV repair, ofter with coils, sometimes
with connectors, like in the Philips K12 chassis.
Sometimes you get sparking at those joints, sometimes even burning holes in the PCB.
And that was with 60/40 solder.
So I am not blaming it on the new solder, merely on temperature.
Anyways, now I have a spare bulb :)
 
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