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4 watt CF bulb?

Discussion in 'Lighting' started by Nick Hull, Feb 5, 2005.

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  1. Nick Hull

    Nick Hull Guest

    I've been using a 4 watt flourescent bulb as a night light in my house,
    it is just right for my purposes except the bulbs don't last long
    enough; I keep it on 24/7. Does anyone make a very low wattege CF bulb?
    I tried a 13 watt one and kept it on for over a year, it's still working
    fine but is too bright.
  2. TKM

    TKM Guest

    A CFL is not a particularly good choice if you need just a bit of light
    since both the efficacy and life of CFLs are reduced at low wattage
    operation. In my experience, the 9 or 13 watt lamps are about the minimum
    for reliability. Night lights are one application where neon glow lamps or
    LEDs are a better match and are inexpensive as well. Both types of lamps
    last a long time (several years) and then slowly dim down rather than fail
    abruptly. Neon glow lamps emit an orange-tinted light, so go with LED
    sources if you want white light.

    Terry McGowan
  3. Ken

    Ken Guest

    My own experience is that 7 Watt is the lowest to go.
    Lower watts don't last very long.
  4. Nick Hull

    Nick Hull Guest

    Not only does hidher power waste electricity, it puts a load on the air
    conditioning in summer. Waste heat is fine in winter.
  5. 8760 hours in a normal year. 8784 in leap year.

    Vic Roberts
    To reply via e-mail:
    replace xxx with vdr in the Reply to: address
    or use e-mail address listed at the Web site.
  6. Yes, I understand :)
    OK, if you insist

    8765.81277 hours to be more exact :)))))

    Vic Roberts
    To reply via e-mail:
    replace xxx with vdr in the Reply to: address
    or use e-mail address listed at the Web site.
  7. JM

    JM Guest


    I know exactly what you're describing. Basically, a Japaneese company called
    "Hybec" manufactures much of the miniature T5 tubes imorted into America.
    They have been long been low quality and frequently have early failures.

    This company has good quality 4 watt t5. I've had some in service 1-2 years.


    The low wattage CFLs are here.

  8. I've got a few 4W CF's from IKEA in the UK which are nearly 5 years
    old, and one of them is used many evenings for perhaps 6 hours, the
    others less often. These do have a long preheat time -- around 3-5
    seconds. Of course, IKEA no longer do this style -- by the time you
    know you have a good lamp, it's no longer available;-).
  9. Nick Hull

    Nick Hull Guest

    Could you expand on that last item a bit? What is a VFD?
  10. Regular fluorescent lamps are phosphorescent, not fluorescent due to
    the decay time of the phosphors.

    Vic Roberts
    To reply via e-mail:
    replace xxx with vdr in the Reply to: address
    or use e-mail address listed at the Web site.
  11. R.Lewis

    R.Lewis Guest

    Vacuum fluorescent display

    Men who like to keep slaves own guns
  12. gudmundur

    gudmundur Guest

    If you have one of the 4,6,8 watt universal ballasts, it wont last
    very long. Find a true 4 watt ballast. My 4 watter in the barn runs
    24/7 for years at a time!! Might also want to try a radio shack 120/12
    power transformer wired in a 'buck' configuration to drop the line
    voltage to about 100, then just use the ballast you have now.
  13. Zak

    Zak Guest

    5 watt is the lowest I have seen, though there are 3 watt CF bulbs 'for
    decorative lighting only'.

  14. Ioannis

    Ioannis Guest

    I've got a desk luminaire which connects to my laptop's USB and it sez
    2.5W below its base. I believe it is a cold cathode one.
  15. Ken

    Ken Guest

  16. Zak

    Zak Guest

    But not very good: not for continuous use and only 33 lumen/watt.
    Their 5 watt is rated for continuous use and is 48 lumen/watt.
    BTW Philips Genie is 44 lm/w for the 5 watt model and 53 lm/watt for the
    8 watt model. The Osram numbers I have calculated by division, so
    rounding may play a big part. If the 3 watt lamp really is 2.55 watt...

  17. Depends how you start them. CFL's operated in rapid start mode are
    normally rated for 10,000 hours with a 3 hour on, 20 minute off cycle.
    Some Instant start CFLs are rated for only 6,000 hours on the same
    cycle. I would expect that switch start (pre-heat start) CFLs would
    have life as short as instant start or worse. The life of CFLs on the
    very best programmed start (or programmed rapid start) ballasts is
    virtually independent of operating cycle. Osram has one self-ballasted
    CFL they rate for 500,000 starts.

    Vic Roberts
    To reply via e-mail:
    replace xxx with vdr in the Reply to: address
    or use e-mail address listed at the Web site.
  18. You're talking about CCFL's (Cold Cathode Fluorescent Lamps.) As sold
    in kits at Maplins for about a fiver at the moment including the power

    As far as the life expectancy is concerned, that's all down to
    manufacturing quality. It could last 50,000hrs or it could last

    I've got one of the Maplin white tubes lighting my keyboard right now
    and it's doing just fine.
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