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Timetable set to phase out high-energy light bulbs
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adam2
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PostPosted: Fri Oct 09, 2015 12:11 pm    Post subject: Reply with quote

Presuming that you require 12 or 24 volt DC lamps, then AFAIK LED "filament" bulbs are not available for these voltages.
Most of the mains ones will in fact work on DC but only at mains level voltages.
The LED "filaments" consist of numerous LEDs in series with a total voltage of about 40 to 60 volts. Operation from 12 or 24 volts would require an internal voltage increasing circuit, entirely doable with modern electronics but adds a little to the cost and complexity of a product with a limited market.
Warm white low voltage LED lamps can be obtained, but not AFAIK in decorative filament styles, and only in 3000K or at best 2700K and not warmer than that.
It might be worth use of mains voltage lamps from a small inverter ?these are now very cheap, though of course extra losses are introduced.

Edited many months after . The above was true AFAIK when I posted it, but technology moves on and LED "filament" lamps ARE now available for low voltage DC supplies. See following posts for details.
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Last edited by adam2 on Sun Aug 28, 2016 4:18 pm; edited 1 time in total
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clv101
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PostPosted: Fri Oct 09, 2015 2:28 pm    Post subject: Reply with quote

This bulb has been identified as ideal, very warm, even dimmable... only downside (other than cost) is that an inverter is needed:

http://www.brightgoods.co.uk/products/the-jane?variant=1365812289

Maybe I should look at very low power inverters? What's available in the 10-30W range?

Wonder if something like this could power a <10W LED 240V AC bulb?
http://www.ebay.co.uk/itm/Black-12V-DC-to-AC-Inverter-for-EL-Lamp-Wire-Electroluminescent-5M-Meters-/201428533601
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adam2
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PostPosted: Fri Oct 09, 2015 4:04 pm    Post subject: Reply with quote

Maplin have a 60 watt inverter for 23.
Probably Chinese watts, so perhaps about 30 real watts ?
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adam2
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PostPosted: Fri Oct 09, 2015 4:14 pm    Post subject: Reply with quote

clv101 wrote:
This bulb has been identified as ideal, very warm, even dimmable... only downside (other than cost) is that an inverter is needed:

http://www.brightgoods.co.uk/products/the-jane?variant=1365812289

Maybe I should look at very low power inverters? What's available in the 10-30W range?

Wonder if something like this could power a <10W LED 240V AC bulb?
http://www.ebay.co.uk/itm/Black-12V-DC-to-AC-Inverter-for-EL-Lamp-Wire-Electroluminescent-5M-Meters-/201428533601


I don't think so, it almost certainly produces an odd voltage and frequency that is optimised for working EL wire.
For an LED bulb you something more like mains.

Yet another option if you want decorative LED lighting in warm white from a 12 or 24 volt DC supply would be to use battery operated LED Christmas lights.
These are sold very cheaply on fleabay and elsewhere, in warm white and other colours. Usually powered by 3 AA cells. It is a fairly simple matter to wire 3 sets in series for 12 volts, or 6/7 sets in series for 24 volts.
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adam2
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PostPosted: Sun Aug 28, 2016 4:33 pm    Post subject: Reply with quote

LED "filament" lamps for low voltage DC supplies are now available from the supplier below. They are for any supply voltage between 12 volts and 36 volts, DC.
They also offer some other interesting LED lamps including some that work over the exceptionally wide voltage range of 12 volts to 85 volts DC.
I have no connection with the supplier, and cant specifically recommend them without any first hand experience regarding quality etc.
If anyone on here buys any, do please report your findings via this thread.
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adam2
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PostPosted: Sun Aug 28, 2016 7:52 pm    Post subject: Reply with quote

https://www.12vmonster.com/pages/about-us
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kenneal - lagger
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PostPosted: Tue Aug 30, 2016 5:58 am    Post subject: Reply with quote

emordnilap wrote:
adam2 wrote:
How many blank posts of mine do you see now ? Should be none now, though one post contains ONLY the link


For the past couple of years, I have previewed every post before submitting because something in the site software invokes a blank preview (and blank post if submitted) in some cases - not all. I'm not sure what the common denominator is.

Clicking the 'back' button from the blank preview takes me back to the draft and 'submit' works ok. I suspect the site software is getting past it, like me.


I suffer this occasionally too, Em. I can't work out what causes it either.
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Pepperman



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PostPosted: Sat Sep 03, 2016 4:05 pm    Post subject: Reply with quote

Can't remember whether I've posted about these guys before but for really high quality LED lamps check out https://well-lit.co.uk. Colour Rendering Index is key and they stock very high CRI lamps (90+, some up to 97). If anyone is moaning that LEDs don't put out a good quality of light, send them straight there. They're a bit more expensive than average but when your lighting is going to last tens of thousands of hours it's worth paying a few more quid for a really great quality of light.

Last edited by Pepperman on Sat Sep 03, 2016 4:08 pm; edited 1 time in total
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Pepperman



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PostPosted: Sat Sep 03, 2016 4:07 pm    Post subject: Reply with quote

Oh and of course there's stockpiling of halogens going on at the moment:

http://www.express.co.uk/news/uk/706646/EU-light-bulb-stockpile-shops-rules-ban-LED-halogen

Laughing

Appropriate byline for that piece...
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Little John



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PostPosted: Sat Sep 03, 2016 5:04 pm    Post subject: Reply with quote

Pepperman wrote:
Can't remember whether I've posted about these guys before but for really high quality LED lamps check out https://well-lit.co.uk. Colour Rendering Index is key and they stock very high CRI lamps (90+, some up to 97). If anyone is moaning that LEDs don't put out a good quality of light, send them straight there. They're a bit more expensive than average but when your lighting is going to last tens of thousands of hours it's worth paying a few more quid for a really great quality of light.
That shop only sells overpriced novelty LED lights and ridiculously low lumen normal LED lights.
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Pepperman



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PostPosted: Sat Sep 03, 2016 5:18 pm    Post subject: Reply with quote

What do you have in mind in particular?

You have to take a slight hit on the lumens in order to get a higher CRI but 810 lumens for a 60W GLS replacement and 345 lumens for a 50W halogen replacement is about right.
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adam2
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PostPosted: Sat Sep 03, 2016 6:26 pm    Post subject: Reply with quote

Pepperman wrote:
Can't remember whether I've posted about these guys before but for really high quality LED lamps check out https://well-lit.co.uk. Colour Rendering Index is key and they stock very high CRI lamps (90+, some up to 97). If anyone is moaning that LEDs don't put out a good quality of light, send them straight there. They're a bit more expensive than average but when your lighting is going to last tens of thousands of hours it's worth paying a few more quid for a really great quality of light.


Yes, good colour rendering is important and should be used whenever possible.
A CRI of at least 80 is desirable even for street lighting and the like, 90 or better for most interior applications.
Until recently the better types of fluorescent lamp tended to give improved colour rendering if compared to LED.
That has recently changed and LEDs with good colour rendering are now available

A bit doubtful though about the website linked too as it brings up a security warning on my PC.
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Little John



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PostPosted: Sat Sep 03, 2016 6:30 pm    Post subject: Reply with quote

Pepperman wrote:
What do you have in mind in particular?

You have to take a slight hit on the lumens in order to get a higher CRI but 810 lumens for a 60W GLS replacement and 345 lumens for a 50W halogen replacement is about right.
1000 to 2000 lumens. Which are equivalent to the lumen output of 100-150 watt incandescents. In LED terms, that's about 20 -25 watts

The highest wattage LED they sell is 11Watt. Which is in the late 100s to 1000 lumens at the most. Or, barely more than a 60 watt incandescent bulb.


Last edited by Little John on Sat Sep 03, 2016 6:35 pm; edited 1 time in total
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Pepperman



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PostPosted: Sat Sep 03, 2016 6:31 pm    Post subject: Reply with quote

Odd, I haven't had that on mine (Windows 10, Chrome & Firefox, Avast). I've placed three or four orders with them and the service has been excellent.

I'd say a CRI of 80 is definitely at the low end of what's acceptable. When you get into the 90s it's so close to incandescent you can't really tell it's an LED.
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Pepperman



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PostPosted: Sat Sep 03, 2016 6:40 pm    Post subject: Reply with quote

Little John wrote:
Pepperman wrote:
What do you have in mind in particular?

You have to take a slight hit on the lumens in order to get a higher CRI but 810 lumens for a 60W GLS replacement and 345 lumens for a 50W halogen replacement is about right.
1000 to 2000 lumens. Which are equivalent to ther lumen output of 100-150 watt incandescents. In LED terms, that's about 20 -25 watts


That's too bright for my taste. I'd prefer a couple of lower lumen lamps, maybe supplemented by a reading light, rather than one super bright one. Ikea do a decent one up at around 1000lm. Otherwise I think you're entering commercial / retail territory which will no doubt be expensive.
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