LED lighting

I don't know about the smarter than part Shane - but osram and others make a range of products that are more efficent than the 50w standard downlights, and are direct replacements.

The CFL version are most cost effective and led ones are getting better but are still dearer.

Here is an example

http://www.todae.com.au/comersus2/store/comersus_viewItem.asp?idProduct=582

Have a look at Todae and especially LED Shop online. LED Shop Online has some good info on their site. Seems that typical 3W LEDs are only equivalent to about a 20W halogen although you can get some 5-7W LEDs (see below) which are claimed to be 85% the output of a 50W halogen. I haven't found a 50w equivalent LED yet.

I am running some 240v LEDs (warm white) at home but i would really need to double the number of light fittings before i put more LEDs in (and the cost of the LED globes is a limiting factor too!!). I have also used a single 12v MR16 "Galaxy 5-7W LED Down Light" from Todae in my Caravan annex & it is terrific (just so i had an 'overhead' light in addition to the van side light) .... it is claimed to be ".. the most powerful LED light on the market outputting about 85% of a 50w halogen". Cost me $90 just for the globe but it certainly is extremely bright & energy efficient.

Another consideration with LED lighting is that they typically don't achieve the beam spread that you get with incandescents & halogens.

LED Shop Online also has some good info about running LEDs from transformers

I have them all around the eaves of my house. Standard electronic switchmode or iron core trannys will run them no probs.

They put out bugger all light though. Might be better looking at a Nelson MR30 or MR50 compact fluro. Will fit into a standard halogen downlight fitting although they run on 240V not 12v and will require the base to be changed. Buy one LED before you blow your cash and have a look. You might be disappointed.

Craig

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thanks guys, looks like its not going to be that easy.

If the transformer is 12vDC it will run the LED's. Some transformers for halogens are 12vAC.

There are 7W LEDs coming out which are similar to 50W. $$$$$$
I heard that Nelson are currently testing 8W , 12V flouros that are MR16 and work with transformers. They are doing extended testing to make sure it works on most transformers. They are expected to be released later this year.

I would definitely wait for a while, it is too expensive now.

I replaced all the 50 W with 20 W at home and no one noticed!!

All very interesting.

I have been toying with the idea of changing our downlights to these low wattage LED's and running them from a 12v battery with a panel on the roof. It would also mean no more dark nights thanks to Energy Australia.

Shane,

Are we talking about downlights for a caravan, or home lighting?

I will assume home lighting as you have mentioned "off toplic"
If home lighting, get rid of those transformer based lights mate.

I was advised from my local Lighting Shop LED lights still have a way to go before they are as effective in brightness as the fluros.

I have replaced all of my 240/12 volt downlights with 240 volt fluorescent equivalents. The transformer type lights generate too much heat and are therefore potential fire hazards. They are also the most expensive to run in power consumption.
The 240/12 volt ones were rated at 50 watts each, compared with the 240 volt fluros of 14 watts each and don't generate much heat.
The best fluros to go for are the "warm light" ones. The others are just too harsh a light for indoors.

Bill.

Shane,

I have read somewhere that LED's are no more energy efficent than flouros. It was previously thought that led's put out more light per watt but this was due to the concentration of the light coming out of LED's and you are wasting energy in transormfers as well. Flouros, in my opinion, give a better all around light.

Okey Dokey....

First thing to specify is what colour temperature you want? Normal halogen lights run around 3000 K (Kelvin) which is that nice warm white we're used to. Most LEDs unless otherwise specified are going to be cool white, 6000K+, similar to standard fluorescent tubes. If cold white is ok then go for it, there are quite a few down lights out-there in cold white that will be similar output to 50W halogens, have a look at Soanar and their lighting division:

http://lighting.soanarplus.com/products.php?group=P26&product=DL-S-W-W-36

Now if you're interested in warm white then the efficiency of the LEDs is going to be much lower. In reality probably around the same as a good quality halogen, the lifetime will be 10 times as long at least but the efficiency will not be great with current technology. Give it 1-2 years and probably yes but right now no.

To answer the original question then yes there is a problem with so-called electronic power supplies designed for halogens (SMPS), these are design to regualte properly between 20W-50W output and below this some can fail to regulate and result in flicker on the LEDs. Not all it just depends on each individual unit. Two from the same manufacturer can exhibit different properties. Iron core transformers are fine - make sure the LED module has inbuilt current control however or you'll blow them up.

Couple of points to mention to those interested:

The efficiency of an LED as released by the LED manufacturer has nothing to do with the final lamp efficiency, a LED may output 70lm/w (lumens/watt) but one you heat it it reduces in output and then once you put it through a collimating optic it reduces again. Final system efficiency is more important.

If a light has a narrower beam angle (i.e. more of a spot) than another lamp but the light on the surface is the same then the lmp with the narrower beam angle has less output. If you focus something down you can get more perceived brightness but it will in fact not be brighter, just more focussed. What's really important is luminous flux output or lumens, which is the total lamp output.

A standard halogen will have around 1000lm +/- 100lm output, an LED would need to match this to be equivalent. Right now some systems are capable but only in cold white. Warm white still needs some work.


Cheers

Andrew