Re: Re: 100 watt light bulbs

[Kevin Hawkins <yahoogroupskh@xxxxxxxxxxxxxx>]

I'm the first to agree that old incandesent is inefficient however we
need a transition replacement that provides the same role, and I have
yet to find it..  Something that physically looks ok, has same
brightness/colour temperature output, similar angles of radiation, come
on instantly without a warm up period and most importantly can be dimmed
in the same way, retrofittable to existing control.

Last couple of years has seen good progress in some of these aspects but
AFAIK the dimmability is still a problem.    A solution advocating 'yes
they are dimmable but you must have had them on for a few minutes at
full brightness first and you must dim downwards' - oh and you can't go
below 30%  isn't acceptable and seems like a retro nod to X10 !  The
cospmetics are simply not approriate in some fittings eg chandeliers
either.   As Mal says heat output from incandescents is not wasted
either and might have to be supplemented from elsewhere. Not so useful
in Aus but always welcome here.  But needless inefficency and wastage is
obviously a bad thing

As soon as I'm offered such a replacement I'm happy to adopt and change
my control if needed.   I do agree that PWM is likley to be the way
forward for LED brightness control, albeit that is simply waveform
chopping similar to current dimmers but using a square waveform and
variable frequency, and is not a simple retrofit either. Square edge
high current waveforms have RFI issues too.

I've used 100W in a  lot of places I used 60 W but at a dimmed
brightness and my bulb life has been amazing. However the lower
efficieny of dimmers cf relays or full on dimmers is likely considerable

So many technology advances nowadays seem to be advocating improvement
but impacting performance  eg DAB radio, digital television, low bitrate
audio compression etc

K

PS Some of these look nice (in Aus)
http://brightgreen.net.au/products_features.php



Ian Lowe wrote:
> --- In ukha_d@xxxxxxx, "Peter and Jane"
<pandj.munnoch@...> wrote:
>
>> Ian
>> Are they dimmable?
>> Rgds
>> Peter
>>
>
> Peter
> Yes.
> Rgds
> Ian
>
>
>
> If you mean, 'are they dimmable using the same crappy voltage chopping
dimmers that you use with incandescent bulbs', then the answer is still
yes, just not as well.
>
> Clearly, a system which slices the 240V AC into thin chunks really
quickly to vary the power delivered is as old fashioned as heating a bit of
wire until it glows. When LED lighting (or the next big thing again) takes
off properly, we'll be dimming on the low voltage side, or using some
inherent property of the material to do it.
>
> Personally though, I don't use dimmers. I hate the bloody things - not
least of all because of the insistence of some folks (which included my
grandparents) to sit in near darkness rather a nicely lit room.
>
> I get the light level I want (which is a very pleasant mix of point
and room effects) with a mix of small lamps and large floor standers. My PC
room has 5 lights - 11W CFLs in the 2 floor standers, 7W CFL in the splash
lights behind the monitors, and a 1.1W rated Blue LED strip under the desk
for effect. It looks gorgeous.
>
> the sooner we ditch incandescents and move on to new technologies (and
yes, new dimmer technologies as well) the better.
>
> I.
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>
>
>



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