Yes, it was sarcasm (or at least I hope it was), there's just nothing good about downlights really...
LED Lighting
(136 posts) (40 voices)-
Posted Friday 18 Mar 2011 @ 5:47:39 am from IP #
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Yes it was in Jest
Down lights aren't that bad (aside from cutting into the ceiling)its a personal opinion, if you want broad light coverage expect to use more power with a wider product. Most people are interested in light on the ground and not on the roof which is also the most efficient way of lighting.
From an environmental point of view its more the recessing that's the issue, Ive been testing some wide angle diffused lights which do look good, although efficiency is lost in the diffuser.
Its not just homes though all new technologies (louvred t5/LED) are getting more light on the ground and less on the roof to cut down energy usage.
In the end it really comes down to personal opinion as light is not wasted just because its low angle.
Posted Friday 18 Mar 2011 @ 7:02:18 am from IP # -
I've just purchased some LED lights with motion sensor for $10.43 at Woolies. Runs from 3 AA cells or 4.5V so I converted it to 12V operation with a 7905 regulator IC and it is very effective. Measured current was 61mA max for 30 secs duration when the detector senses movement. A built in light detector prevents day time operation. To be installed on the community garden solar system for long term test.
Posted Tuesday 29 Mar 2011 @ 2:12:03 am from IP # -
You realise a 7805 (7905 is the negative voltage version, not as commmon, was that just a typo?) is a linear reg and wastes the extra energy as heat? There are switchmode options available that are far less wasteful...
Posted Tuesday 29 Mar 2011 @ 3:35:27 am from IP # -
Yes I considered the energy waste but the short duration it runs at 61mA is not going to be an issue. I left it on full for an hour and could feel no warmth from the IC. I chose the 7905 because my nearest electronics shop in pedalling distance had run out of the 7805.
All up the modified light has cost $13 plus my time and it works great. Its in my kitchen for a few nights for a soak test and to see how it performs.
Posted Tuesday 29 Mar 2011 @ 3:41:48 am from IP # -
Just copied this, i posted it earlier in the week on the Who is the cheapest to get led light from post.
I have searched for the last six months finding well priced 50w halogen replacements for my shop, i spent several hundred dollars on different globes and came to one conclusion-you cannot get an mr16/gu10 replacement that will put out enough light. I eventually went with a 15w (tested consumption with driver 22w oh and a 50w halogen uses 63w with tranny) dedicated fitting 5x3w Cree xre's 60 deg (also avail in 120 deg)$60 a pop with driver. these are from ledcentral, and no i have no affiliation with them (wife and i own a florist shop). They were the cheapest replacements i could find they put out as much light as a 50w. compare that to Crompton, Osram and Brightgreen products. The have been in for 5 months or so, and only one problem- one chip overheated and melted the lens but the whole unit was replaced no questions asked.
I do agree standard battenholders are the best for all round lighting, but unfortunately many of us already have 90mm holes in our ceilings....
Posted Tuesday 29 Mar 2011 @ 11:30:29 am from IP # -
Was wondering if anyone sells Led fixtures that use Cree XP-G or XM-L leds. Seems the best used is the old XR-E.
Looking for either Gu-10 for a open fixture, integrated down-light or in an oyster style (Ceiling hung).
Hoping for 800+ lumen's per down-light or much more for an oyster.
How long would someone guess these sort of lights will become available to the public?
Posted Wednesday 30 Mar 2011 @ 2:23:24 am from IP # -
There's plenty of downlight fittings that do over 800 Lumens per fitting, they just use the less efficient LEDs. The XM-L devices should start appearing in fittings soon, there's already heaps of torches around using them and these are not expensive, indeed, XM-Ls are not expensive, I can retail them for $12 or so, at least in the daylight whites. The warms and neutrals are set to be out any time now, should be around the same price, so there's no reason a fitting using these should be much more expensive than one using XR-Es, given that one XM-L can replace 3 XR-E or 2 XP-G.
Posted Wednesday 30 Mar 2011 @ 3:30:50 am from IP # -
You can get some fittings with mc-e's, but this is still "old" tech. Either you jump in with XR-E's or wait...by the time the XM-l's come out in fittings Cree will have an even better chip in the works and you'll again have to decide whether to wait for it or just get whats available.
Posted Wednesday 30 Mar 2011 @ 8:43:58 am from IP # -
Hi thanks for the replies.
I'm building a house at the moment, will need to get lights in the next 2-3 months. So wondering to start getting them now or wait and hopefully some XM-L fixtures become available.
Do you think that it's possible to do a GU-10 at 800 lumens in a open fixture using XM-L's? I'm been thinking of getting track lighting - hence GU10.
Posted Wednesday 30 Mar 2011 @ 10:17:54 am from IP # -
you would still need 4 XM-L's to get to 800 fixture lumen's at 700mA which isn't that cheap.
There are not a lot of fittings getting over 800lm at least not within a viable price range.
Also why wait for XM-L there are plenty of 100lm/w modules out there for much cheaper, CREE are not known for their down light capabilities. If you are looking to build your own down light I would be looking towards Citizen/Sharp/Bridgelux.
Posted Wednesday 30 Mar 2011 @ 11:28:24 pm from IP # -
But why would you use 4, you only need one, the XM-L can handle up to 3 amps and can produce 1000 lumens at 10 watts in (so 100 lumens per watt), so at around 2.4 amps it will do the 800 lumens and it's still more efficient than most of the alternative LEDs, so will produce less heat for the same total power consumption. There's no point using a 10 watt LED and running at 2 watts, why would you do that?
However, Cree has a new array designed specifically for downlights, the MT-G, see http://mtg.cree.com
Posted Thursday 31 Mar 2011 @ 2:38:00 am from IP # -
3A is just a potential its not an intended operational current (I am happy to be told otherwise). Good luck finding a dimmable driver! You will also still need around 900-1000lm from the chip to get 800 fixture lumens. The footprint has also been reduced so heat will be just as much of an issue at higher currents.
The MTG on the other hand would be much more suited option as you have suggested. I think we will see XM-L modules in street lights, high bays etc. where the large heatsinks can deal with high currents.
There is no doubt its an awesome product I just think for similar money you can find products from other companies that would suit a down light application much better.
Posted Thursday 31 Mar 2011 @ 4:15:52 am from IP # -
I think 3A is the intended operational current, have you seen the size of the chips in those things? They are around 4 times the surface area of an XP-G, biggest single chip I've seen in any LED so far, I was amazed when I first got them and they were a single chip, thought they would be 4 paralleled chips like the SSC P7. And that large surface area also means 4 times the area to dissipate into the LED slug. So long as they are mounted properly on PCBs, they should dissipate heat well. After all, transistors around that size can be rated for much higher wattages and they work well, it's all a matter of getting the heatsink bonding right.
Posted Thursday 31 Mar 2011 @ 5:34:58 am from IP # -
Found this custom design for a MR-16 replacement. The guys is saying he used 4 and 7 XP-Gs with active cooling. Crazy lumens.
Is it easier to do MR-16 over Gu-10 as you shift the heat from the driver/transformer outside of the bulb?
Posted Thursday 31 Mar 2011 @ 6:09:56 am from IP # -
Those custom MR16 replacements look like they stick way out of the MR16 socket. In other words, not really an MR16.
Posted Thursday 31 Mar 2011 @ 10:58:29 pm from IP # -
Many MR16 fittings are backless, they have the socket on a flying lead and the lamp rests on the inside face of the retaining ring, so you can put in longer than standard bulbs without issue...
Posted Friday 1 Apr 2011 @ 12:05:36 pm from IP # -
Well then, you can see how much experience I have with MR16 halogens! I used to have one on the bicycle until LEDs became bright enough, and the other three are the garden lights in enclosed fittings.
Posted Saturday 2 Apr 2011 @ 5:20:07 am from IP # -
Ghost,
That is an inherent problem using the LED MR16 in enclosed fittings - very few of them will work (for long), due to them needing air circulating around them to let the heat sink work OR they are the too long to fit within the enclosure - i.e. replace the halogen MR16 in all dimensions.We have tried many different ones & we've only found 1, until they recently changed it (made it 5mm longer) & now will not fit into the fittings, unless that supplier (of the lamps & fittings) makes modifications to the fittings specifically for this LED MR16.
The Supplier is trying to source another factory (in China) to make them again as they are a reasonable lamp & worked well in many outdoor fittings.Posted Monday 4 Apr 2011 @ 2:48:38 am from IP # -
Just back from Autopro with a LED replacement for the interior light globe in my ute. A 4 x white LED array with adaptors and unbelievably a 13.5V 'test battery' with push button switch for $18. Brighter than the festoon globe which used 380mA the LED array used 40mA.
I removed the heatshrink from the battery to find 9 x 1.5V button cells in a holder which will now power my 12V digital volt meter.
A 9:1 reduction with more light. Transfer this to house lighting and you can light up 9 houses with the energy used by one. Added bonuses are they last longer, use less copper wire and run off your backup battery supply when the grid goes down. Transferred up you can turn off 8 out of 9 power stations.
Posted Tuesday 5 Apr 2011 @ 1:00:35 am from IP # -
I keep saying it, for this stuff, look online, such as http://www.dealextreme.com/c/car-led-light-bulbs-712
Posted Tuesday 5 Apr 2011 @ 1:49:16 am from IP # -
Lance I'm a seconds in the driveway consumer, I want it now. Besides the young lady who served me was grateful for the job. Of course if I wanted a quantity I might look at the online options.
Posted Tuesday 5 Apr 2011 @ 1:59:40 am from IP # -
Yep, true, sometimes the wait is just not worth the savings, but I've learned to be patient, can save a lot of money that way, and it still gives someone a job, after all, the order has to be processed, packed and shipped...
Posted Tuesday 5 Apr 2011 @ 2:48:30 am from IP # -
new to this thread and following with interest.
I purchased some 4W LED lights to swap out MR16s using my exist coil transformers. I have an issue (that has been discussed a bit here)in that they are emitting RF and interferring with set top box reception (mostly channels 7+9).
Has anyone got a proven working fix to stop the RF on these please?
I purchased 23 of these lights from china, and dont know if i have a chance to return them based on 'being faulty as emitting RF' etc.
Interesting to note I also tried another 4W LED MR16 via dealextreme that didnt interfere at all.
thanks, Nic.
Posted Friday 8 Apr 2011 @ 12:14:24 am from IP # -
Find out if the supplier claims any EMC testing, if so then that should be grounds for return otherwise you are probably out of luck.
Posted Friday 8 Apr 2011 @ 12:52:35 am from IP # -
Products sold in Australia must have a C-Tick compliance mark. This means it complies with Australian stds. Because you have imported directly this is unlikely and it is at your own risk.
http://www.acma.gov.au/scripts/nc.dll?WEB/STANDARD/1001/pc=PC_2676
Interference to TV reception is not unusual from this type of product. More info here.
Posted Friday 8 Apr 2011 @ 1:29:05 am from IP # -
thanks for the info.
i purchased the units via an ebay company - dreambestbuyau - so is it far to say it is an Oz company i have purchased from even though it comes from China?
I have sent them an email requesting to return them as faulty, given one i purchased as a test unit did not interfere, and the 23 of the same units i since got do interfere.if all else fails, do ferrite cores around the power feads fix it?
thanks.Posted Friday 8 Apr 2011 @ 3:07:10 am from IP # -
Yes they may help. It would be useful to know the signal levels you are receiving for your TV. If you don't have a good external antenna with quad shield RG6 cable it makes it harder. If you have an amplifier it may be worse also.
Posted Friday 8 Apr 2011 @ 3:21:00 am from IP # -
thanks. I dont have an Amp. The co-ax type will be basic (whatever trades people get away with over a decade ago), so will look at that.the antenna is good quality and sig/noise is good without the lights on! it is mounted inside a tiled roof with no foil insulation etc and line of site pretty much to transmitter.
Posted Friday 8 Apr 2011 @ 3:32:11 am from IP # -
You have to be really careful with imports from China, I got some LED GU10 lights from Ebay coming out of hong kong I put one in and it gave me a little zap, also if it is interfering that would be also cause it might not be approved under C-tick especially if the products do not have and CE accreditation. C-ticks ensure that there is no interference with transmitters i.e TV remote
So they all went in the bin and I bought some from an Australian shop TrimEnergy.com.au I got these GU10's http://www.trimenergy.com.au/shop-online/led-lights/led-gu10/9-watt-led-gu10-spotlight-cree-led-inside/ and they are really good with a pretty good light output and cheaper than other sites plus at least there are no shocks
Posted Saturday 30 Jul 2011 @ 2:45:53 am from IP #