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Cheap Energy Saving Bulbs
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sean
Downsizer Moderator


Joined: 28 Oct 2004
Posts: 42207
Location: North Devon
PostPosted: Wed Feb 09, 05 6:52 pm    Post subject: Reply with quote
    

Brilliant, I'll tell Mandy I'm waiting for them.

jema
Downsizer Moderator


Joined: 28 Oct 2004
Posts: 28098
Location: escaped from Swindon
PostPosted: Wed Feb 09, 05 7:44 pm    Post subject: Reply with quote
    

tahir wrote:
Pure white LED's in 2008 apparently:

https://tinyurl.com/4x8p8


From the piccie they look really nice.

jema

dougal



Joined: 15 Jan 2005
Posts: 7184
Location: South Kent
PostPosted: Wed Feb 09, 05 9:29 pm    Post subject: Reply with quote
    

tahir wrote:
Pure white LED's in 2008 apparently

Problem is that "pure white", on its own, is not technically meaningful.

The concept of "colour temperature" - Picture a blacksmith heating a horseshoe. Initially its a not glowing - in the range that the eye works in! When it starts glowing, its a dull red. The hotter it gets, the bluer the light given off - it gets "white hot". By measuring the 'colour', the temperature can be measured. Maplin will sell you a "non-contact" thermometer starting at about £20.
Note that the *colder* the source, the subjectively *warmer* the light!

Daylight is from a source at nearly 6000C (I know about K, but please recognise I'm simplifying!) No bulb can possibly run at such a temperature. Take a photograph (on a camera using ordinary colour *film*) by artificial light, and it will be a strange colour. Ordinary bulbs produce something that looks like candlelight!
Note that digital cameras typically try and adjust themselves to the colour of the light. Its because the eye and brain do this so well that we don't think we are living in candlelight!

However all fluorescent lights (inc "energy saving bulbs") don't give out a "continuous spectrum" - they give out a set of specific (pure) colours, which if well spread and carefully balanced give us the impression of 'white-ish' light... but it isn't!
To see what's missing look at a paint colour chart under different lights. The difference between halogen and "energy saving" bulbs is pretty dramatic.

Camera flashguns produce a simulation of daylight, good enough to satisfy ordinary film. Similarly "natural daylight" bulbs produce a simulation of daylight's blue/red balance - but this makes for a seemingly strangely "cold" light...

People doing colour critical work on computer screens not only need to "calibrate" their screens, but also to standardise their room lighting, (and be restrained in their decor), otherwise a 'real' colour that matches the screen colour at midday, will not match in late afternoon, let alone by artificial light in the evening!

jema
Downsizer Moderator


Joined: 28 Oct 2004
Posts: 28098
Location: escaped from Swindon
PostPosted: Wed Feb 09, 05 9:45 pm    Post subject: Reply with quote
    

Very clear explanation that. You need only to look at some of the optical illusions that fool you into thinking colour are different or the same to realise just how funky it all is.

jema

tahir



Joined: 28 Oct 2004
Posts: 45389
Location: Essex
PostPosted: Fri Feb 11, 05 5:35 pm    Post subject: Reply with quote
    

Some LED light fittings:

https://www.franklite.net/content/index.php?id=37

hardworkinghippy



Joined: 01 Jan 2005
Posts: 1110
Location: Bourrou South West France
PostPosted: Thu Nov 17, 05 1:08 pm    Post subject: Reply with quote
    

An update to this thread...

I've been off-line a lot recently because I'm busy rearranging and increasing my solar capacity (DOUBLE the power ) to have lots more light and loads more hours on the web, watching DVDs, charging power tools etc.

I've ordered 6 of these lights. I know they're not cheap to buy, but they're the best I've seen so far.

https://cgi.ebay.fr/AMPOULE-80-LEDs-12V-AMBREE-SUPERBE-AMBIANCE_W0QQitemZ4417273483QQcategoryZ20548QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

I'll let you know how they do once they're installed.

Irene

Bernie66



Joined: 14 Jan 2005
Posts: 13967
Location: Eastoft
PostPosted: Thu Nov 17, 05 1:12 pm    Post subject: Reply with quote
    

Being as it has been resurrected by someone else. B&Q have 11W energy saving standard baynet fitting for 98p(phillips) at the moment

tahir



Joined: 28 Oct 2004
Posts: 45389
Location: Essex
PostPosted: Thu Nov 17, 05 1:14 pm    Post subject: Reply with quote
    

Blimey, that's one huge bulb

jema
Downsizer Moderator


Joined: 28 Oct 2004
Posts: 28098
Location: escaped from Swindon
PostPosted: Thu Nov 17, 05 2:34 pm    Post subject: Reply with quote
    

Slight thread hijack, I was using all LEDs in the kitchen, but finally decided I wanted to be able to see in the dark and put some mains voltage Halogens back in, these were previously blowing on me at an inexcusable rate This time round I put dimmer switches in, and touch would not have blown since. Which is more than I can for the LED lights which have proved totally unreliable

hardworkinghippy



Joined: 01 Jan 2005
Posts: 1110
Location: Bourrou South West France
PostPosted: Sun Nov 20, 05 12:04 am    Post subject: Reply with quote
    

Well, I hear what everybody's saying, but in our search for more energy efficient lighting, we've spent the past few days wiring up LEDs to our 12v battery bank and I'd like to post a few pics of the kind of light they give.

We've got six lights plus a laptop running at the moment and that means we can move around the house without falling over dogs.

Here's one in the little room with the painting in it which uses less than one watt:



This one is a one watt bulb in the (unfinished ) bathroom:



Jema, have you any idea why your LEDs were unreliable? Here's hoping ours last for ages as they were very expensive.

So far, I'm pleased with the result.

HWH

jema
Downsizer Moderator


Joined: 28 Oct 2004
Posts: 28098
Location: escaped from Swindon
PostPosted: Sun Nov 20, 05 12:55 am    Post subject: Reply with quote
    

No idea at all but the dead lights speak for themselves... actually since LEDs are reliable, and as all the LEDs are dead, it is obviously the transformer that blows.

tahir



Joined: 28 Oct 2004
Posts: 45389
Location: Essex
PostPosted: Sun Nov 20, 05 8:35 am    Post subject: Reply with quote
    

That's a heck of an investment to lose just down to a dodgy tranny. Irene's on a 12v system though isn't she?

hardworkinghippy



Joined: 01 Jan 2005
Posts: 1110
Location: Bourrou South West France
PostPosted: Sun Nov 20, 05 9:11 am    Post subject: Reply with quote
    

Yep Tahir,

I use 12v straight from the batteries when I can to reduce power loss.

When I need to change to AC I use a transformer. I've been using a cheapo £35 car transformer for the laptop for four years with no problems. (There you go it'll probably blow up today because I said that !!! )

I've also got a 6OO watt tranformer for bigger things and it's been fine for six years (waits for explosion...)

Irene

tahir



Joined: 28 Oct 2004
Posts: 45389
Location: Essex
PostPosted: Sun Nov 20, 05 9:16 am    Post subject: Reply with quote
    

On a 12V system you shouldn't have a reliability problem.

dpack



Joined: 02 Jul 2005
Posts: 45376
Location: yes
PostPosted: Fri Nov 25, 05 8:48 pm    Post subject: Reply with quote
    

i have 1 ordinary 150 w .everything else is low energy exept a 12 v halogen which as it has its own transformer , it is probably not too good on energy but works well . my computer has an led from the usb but it is too dim to be of much use .if leds work as well as the snaps indicate im going to try some chunky ones .

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