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Re: [microhydro] Re: how many capacity i need to have for 20 houses

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  • Nando
    Manfred: Heck, When I wrote about the 8 footed lamps I did not re-adjust my brain to just say FL= Fluorescent Lamps, instead of the CFL= Compact Fluorescent
    Message 1 of 3 , Jul 1, 2011
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      Heck, When I wrote about the 8 footed lamps I did not re-adjust my brain to just say FL= Fluorescent Lamps, instead of the CFL= Compact Fluorescent Lamps I was referring initially.

      Remembering those times trying to make 18 kHz electronic ballasts with SCRs = Silicon Controlled Rectifiers which was a pain , virtually, to make them to switch off at high rate,and it was reported that the industry was not ready to accept the high cost of those ballasts when compared to the simple magnetic ballast available then; it was a waste of time and effort, as what General Electric discovered as well,

      The initial heating of the CFLs for fast Light stability levels is done by increasing the power level for a short time ( indirectly the heating filaments) -- though, still the time needed to put maximum light level is somewhat too long.

      Some ballast had or have a separated circuitry for lamp filament preheating , I have some large FLs electronic ballasts that I acquired just to see how the technology has advanced that now include PFC= Power Factor Correction and Variable input Voltage ranges to avoid the logistic of having several types, then the availability of new types of CFLs and FLs of high intensity and life with light output levels to replace high Mercury-Resistive lamps with several times the light output and with a dramatic reduction in power usage plus longer lamp life.


      ----- Original Message -----
      From: Manfred Mornhinweg
      To: microhydro@yahoogroups.com
      Sent: Thursday, June 30, 2011 4:43 PM
      Subject: [microhydro] Re: how many capacity i need to have for 20 houses


      > I wonder what are the testing procedures utilized here to evaluate
      > the 4 light generating devices.

      Normally the total light output is measured, regardless of the spatial
      distribution, and the output is calibrated according to the spectral

      > Normally a Standard Incandescent generate light speeded
      > omnidirecctionally producing an Spherical light source with the
      > exception of the area needed to mount the lamp and to supply the
      > electrical power.
      > The Halogen lamp, often includes a reflector to-re direct some of the
      > light to cover hemispherical volumetric area . Though basically the
      > lamp is close to the incandescent light spherical source shape.
      > CFL, due to the diverse types of tube, straight, short and long, or
      > even twisted to conform into a shape close to an incandescent shape
      > or a long small diameter tube folded in two to present a light source
      > close to such incandescent shape.
      > LEDs produce their POINT light sources and often requiring additional
      > shapes send the light in defined areas of coverage.

      This doesn't matter, as long as the testing correctly considers ALL
      light emitted by the lamp.

      There are other tests often done, that measure the light density over
      area. These give higher values for lamps that produce beams, like many
      LEDs. These values are normally stated in candela. The unit Lumen is not
      usable for light intensity over area, but only for total amount of light.

      Probably someone here can illustrate us about the exact
      technical/scientific terms!

      > In the long past, I have played with CFL lamps , specially the 8 foot
      > long --

      WOW, Nando! An 8 foot long COMPACT Fluorescent Lamp? How long are the
      non-compact ones, then? ;-)

      By the way, those long fluorescent tubes sometimes achieve over 100
      lumen per watt overall efficiency!

      > CFLs need to have a preheating time to have a much greater longevity
      > -- but most people do not want to wait for the lamp to be pre-heated
      > to attain high hours of life than some of the 8 to 10,000 hours often
      > quoted.

      I understand that modern CFLs actually do preheat the filaments, but
      VERY quickly, at high power. Then the lamp ignites, and the filament
      power is drastically reduced. They often do it by shifting the frequency
      of the oscillator, and using separate resonances in the power circuit to
      control the power applied to the filaments and then to the gas discharge.
      Of the CFLs I have in my home, the slowest ones take almost one second
      to ignite. The fastest ones seem instantaneous, but surely they too are
      taking a small time for preheating!

      > All 4 types of light sources have their place in society.

      Yes. And sodium lamps, metal halide lamps, and many others, too! Each
      has its niche in terms of power level, light type, life span, cost,
      efficiency, and lots of other characteristics.

      But also some shifting happens. It's pretty clear that household
      lighting has shifted from mostly incandescent bulbs and a few long
      fluorescent tubes until a few years ago, to mostly CFLs today, and is
      now trying to move toward LEDs. Flashlights have largely shifted from
      incandescents to LEDs. Street lamps have shifted from open arc lamps and
      incandescents, mostly to sodium. Stage lighting has partially shifted
      from incandescents including halogen, to metal halide. Projectors are
      shifting from halogen to metal halide too (many of them outrageously
      expensive, by the way). Car lighting used to be 100% incandescent,
      including a few halogen lamps, and now contains lots of LEDs and
      sometimes some metal halides. Display backlighting is shifting from cold
      cathode fluorescents to LEDs. And so on...

      And microhydro turbine lighting? Well, my turbine house has an 18 watt
      CFL in it! So we are back on topic.. ;-)


      Visit my hobby homepage!

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