LED MR16 Transformer Compatibility

I have been looking at the Soraa LED MR16 and to a lesser extent the Cree LED MR16 options (reference design and LM16). You can get more info here:

http://www.ledsmagazine.com/article...-displace-halogen-in-mr16-lamps-magazine.html

Replacing a standard MR16 with one of these Soraa or Cree LEDs requires compatibility with existing transformers to avoid ripping them out of ceilings and walls. I have ELCO magnetic transformers (model EL-1499A). Soraa and Cree have tested their MR16s with some transformers, but not the widely used ELCOs. They surprisingly do not show HALO either which is also a very common low volt transformer brand. My feeling is, if its a widely used transformer and a LED MR16 manufacturer is mum on compatibility, then it probably isn't. Hoping that someone can prove otherwise.

Dimmers may not be compatible either, but those can be changed without ripping out the walls, so there is some flexibility there. However, at some point replacing standard bulbs and dimmers with LED replacements and compatibles will cause you to outspend any energy savings, say nothing about the time and energy invested.

My hope is that someone reading this has tested the Soraa or Cree MR16s with magnetic transformers and can report the results here, including the dimmer model use.

I am looking primarily at the Soraa Vivid 2 50 Watt (25° beam spread, 2700K Warm White, MR16) which appears to have a very good light with decent Center Beam Candle Power (CBCP = 2,320). There is some question as to whether the light produced has enough UV to be harmful to artwork, furniture, etc. Also, there is a question as to weather the bulb can last as long as its 35,000 hour rating given the intensity of the bulb. The company has a 3 year warranty however. The bulb uses 9.8 Watts.

Soraa Vivid 2 MR16 LED: Photo

All magnetic transformers should behave pretty much the same. Its the electronic transformers that have the huge variance.

Soraa by their own admittance when I asked said their could be an issue with art work.

Different LED tech so can't compare led directly and phosphor can withstand high power, its the power supply and phosphor binding materials that could be of concern.

Thanks Semi.

I just received the Cree LM16 50W 25 degree 3000K and a Soraa Vivid 2 50W 25 degree 2700K. CRI of Cree is 83 vs. 95 for Soraa. They both have a 3 year warranty.

The Soraa has a more halogen-like color to the light, and a harder beam which can be good or bad depending on desired effect. The Cree is 3000K and has a whiter light as you would expect, and whiter still than the halogen beam. They both work well with my ELCO magnetic transformer and 6 year old Lutron MALV-600 dimmer (for magnetic low volt transformer use only), except that the Soraa has a much narrower dimming range, bottoming out at an estimated to 30% to 40% to my eye. The Cree dims very much like a halogen, but has a noticeable hum/buzz. The Soraa is quiet/I hear no buzz. I am only testing single bulbs; using multiple bulbs on same dimmer may yield different results. I also am in the midst of testing the same bulbs with the Lutron MACL-153MR dimmer per Soraa's recommendation and will post results. Thus far in testing, the MACL-153 does not reduce the buzzing coming from Cree's LM16.

I am torn between the 2. After reading the Cree engineer's review of the Soraa bulb (October 2013 LEDs Magazine... he refers to GaN-on-GaN bulbs, and Soraa is the primary manufacturer if not the only manufacturer of GOG bulbs), I doubt whether the Soraa MR16 will last much longer than the 3 yr warranty given the hi temp of the bulbs. Will the hi heat undo the color and beam superiority as the bulb components and phospors degrade faster than on non-GaN-on-GaN bulbs? Cree is hardly an objective reviewer, though their arguments against the Soraa bulb technology make sense.

To complicate things, it looks like Soraa is about to release a new version of the MR16 (gen 3) very soon based on this article:

http://www.ledsmagazine.com/article...ion-gan-based-led-demos-larger-ssl-lamps.html

My hope is that Soraa uses the extra efficiency of the gen 3's to reduce the operating temp of the bulb (presumably also increasing longevity and longer term beam stability), and improve dimming, rather than increasing the already excellent beam strength and quality. Both this Soraa bulb and the Cree LM16 are rated for use in recessed fixtures (Cree says non-IC rated only), but with the higher operating temp of the Soraa my gut tells me the Cree will outlast the gen 2 Soraa's in a recessed fixture.

I wish Cree would update its aging LM16, but instead it keeps selling it, in addition to updating its reference design for LED MR16. For whatever reason, Cree seems content to let others manufacture improvements to the LM16 using its chips and specs, instead of doing it themselves.

I went into this in another post:

http://www.candlepowerforums.com/vb...-Performance&p=4425767&viewfull=1#post4425767

I completed testing of a second dimmer with my magnetic ELCO transformer and these 2 LEDs. The dimmer is the Lutron MACL-153. I do not see any difference between this newer dimmer and my older magnetic LV dimmer, the Lutron MALV-600. Dimming range on the bulbs appear to be same as tested prior, and the buzzing coming from the LM16 sounds the same to my ears.

[highlight]I plan to wait for the 3rd gen Soraa to be released (sometime before July 1, 2014 per Soraa). Hopefully the bulb runs significantly cooler, is less expensive, with a wider dimming range on my setup.[/highlight]

Also anxious to test multiple bulbs on same dimmer.

[highlight]If anyone gets ahold of the gen 3 Soraas, please post results.[/highlight]

While waiting for newer LED MR16's to emerge before taking the plunge, I bought several Eiko MR16 Halogen 50W bulbs for $2.50 each shipped to my door. Not certain about the quality of these bulbs but they seem to have good reviews. From a pure cost standpoint, paying $20 to $30 for an LED MR16 doesn't make a lot of sense by comparison. Hopefully Soraa can lower the cost on gen 3s and extend the warranty to at least 5 years, ensuring that the LED MR16 investment is at least a wash.

I don't think so there will be any issue with the transformers as far as the power rating is good to support the LED MR16 and even no compatibility issues with the transformers as all magnetic transformers of same ratings are almost same.

pcb layout

widmark said:

While waiting for newer LED MR16's to emerge before taking the plunge, I bought several Eiko MR16 Halogen 50W bulbs for $2.50 each shipped to my door. Not certain about the quality of these bulbs but they seem to have good reviews. From a pure cost standpoint, paying $20 to $30 for an LED MR16 doesn't make a lot of sense by comparison. Hopefully Soraa can lower the cost on gen 3s and extend the warranty to at least 5 years, ensuring that the LED MR16 investment is at least a wash.

Click to expand...

The Soraa gen 3 MR16s are being released later than announced by Soraa. They have a 3 year warranty not 5 as hoped. Not certain about cost yet. Sounds like 1000bulbs.com will be one of first to sell it when available.

widmark said:

While waiting for newer LED MR16's to emerge before taking the plunge, I bought several Eiko MR16 Halogen 50W bulbs for $2.50 each shipped to my door. Not certain about the quality of these bulbs but they seem to have good reviews. From a pure cost standpoint, paying $20 to $30 for an LED MR16 doesn't make a lot of sense by comparison. Hopefully Soraa can lower the cost on gen 3s and extend the warranty to at least 5 years, ensuring that the LED MR16 investment is at least a wash.

Click to expand...

Actually your statement is wrong.

MR16 at least in business may be run 12 hours a day/ 6-7 days a week. You would be surprised how quickly the payoff is in reduced electricity, can be <1 year.

SemiMan said:

Actually your statement is wrong.

MR16 at least in business may be run 12 hours a day/ 6-7 days a week. You would be surprised how quickly the payoff is in reduced electricity, can be <1 year.

Click to expand...

Its right for me... perhaps wrong for you.

Its easy math... yes, your 12 hours a day of running a bulb easily justifies a big bulb expense even if your electricity prices are under $.20/KWh. Buy a bunch of Soraa's if thats you.

For me, running Soraas a few hours a day at .$18 KWh makes little sense financially when you are paying $30/bulb with a 3 yr warranty vs. $2.50 for a 50W w/about the same life. Either way, its about $34 over 3 yrs. That calculation changes depending on the life of the Soraa bulb. If Soraa is willing to stand behind their brand new tech for 3 yrs only, than thats what I assume in my cost calculation, but some may choose to extend that out further.

A lot of folks have MR16s in their house that don't get lit up very often... call it weekend lighting. I have a bunch that get lit up only when we entertain. Those may never justify $30/bulb.

Hence why I qualified for business versus home use.

Personally for home it's GU10 I am more interested in as the halogen versions I have used including Osram, Globe and IKEA have all had poor life.

Does anybody know if the gen 3 Soraas can be bought anywhere/pricing? Gen 2s should be dropping in price.. might be the better buy of the two... they are only about 2 watts different in power use.

SemiMan said:

Hence why I qualified for business versus home use.

Click to expand...

(Its no big deal... but you replied to a remark about consumer use saying it was wrong, and then reasoned with your business use example. They call that conflation.)

I bought a gen3 Soraa MR16 (SM16-07-25D-927-03) 25 degree spot 2700K color, 50W equivalent burning 7.8W.

I am able to test this bulb against Halogen MR16s in same area. Dimming range is improved from Gen 2. I would estimate down to 5 or 10% now using my magnetic dimmer. The Soraa LED MR16 appeared slightly whiter than halogen MR16s over much of the dimming range. I do not hear buzzing from the Soraa at 100%, but in mid-range I can hear a slight almost unhearable buzzing. I don't think the buzzing would be a factor for most people. It may be a result of having mixed bulb types on the same dimmer.

At about $30 shipped per bulb, I am buying more for my heavy use fixtures. If this bulb could be found for about half that, I would buy many more for occasional use fixtures.

If anyone finds a sub-$20 price please share with the thread, as well if anyone hears if the UV/artwork bleaching rumor of prior versions of the Soraa bulbs is no longer a factor in gen 3.

widmark said:

Its right for me... perhaps wrong for you.

Its easy math... yes, your 12 hours a day of running a bulb easily justifies a big bulb expense even if your electricity prices are under $.20/KWh. Buy a bunch of Soraa's if thats you.

For me, running Soraas a few hours a day at .$18 KWh makes little sense financially when you are paying $30/bulb with a 3 yr warranty vs. $2.50 for a 50W w/about the same life. Either way, its about $34 over 3 yrs. That calculation changes depending on the life of the Soraa bulb. If Soraa is willing to stand behind their brand new tech for 3 yrs only, than thats what I assume in my cost calculation, but some may choose to extend that out further.

A lot of folks have MR16s in their house that don't get lit up very often... call it weekend lighting. I have a bunch that get lit up only when we entertain. Those may never justify $30/bulb.

Click to expand...

OK, did you do actual math, or just snap intuition? Because it's easy to do the math. You said "a few hours" per day, so let's take 3 hours per day, 7 days per week.

The Soraa at 25,000 hr life will last 22.8 years, costing, at a $35 rough bulb price, $1.50 a year. To that, add 10.7 kWh, at your 18 cents per kWh, for $1.90 a year in electricity. Total is $3.40 a year.

A 50w halogen (say Philips 247030) at 2000 hr life will last 1.8 years, costing, at a $3 bulb price ... $1.70 a year. Gee. To that, add 55 kWh, at your 18 cents per kWh, for $9.90 a year in electricity. Total is $11.60 a year.

Note that the warranty period has absolutely nothing to do with the expected life. That's where you went off the rails. But even if your superstition about the Soraa mysteriously burning out after only 3000 hours were to be borne out, the math still favors the Soraa. The total cost per year of the Soraa refigured based on throwing them away for no reason after 3 years is $13.60 - still more than the halogen.

It only gets better when you look forward to the cost of electricity skyrocketing in the coming years up due to various considerations (restrictions on coal, expensive fossil fuel emissions treatment, sky high cost for renewables, solid gold cost of nuclear, etc, etc).

I have two MR16s over the kitchen sink on a motion sensor. They come on for a couple of minutes at various points day and night when I come near the sink, and once or twice for maybe 15-30 minutes when I have something more to do than fill a glass with water. I just ordered two Soraa for this paltry use. I've been using cheap no-name $3 chinese MR16s, but I want to see what dramatically better CRI does for me. I wouldn't even dream of using halogens. For one thing, I'm running these lights off just a 2.5 amp Radio Shack DC supply, and the motion sensor is only rated up to 2 amps.

If you think you can run any MR16 for 22 years at 7.8w then you should buy it for $30. Neither of us can prove it will or won't work past its 3 yr warranty. Remember CFLs and their track record meeting their rated life? I don't think that will happen with Soraa... But I also don't think it will last 22+ yrs. Good luck with that.

widmark said:

If you think you can run any MR16 for 22 years at 7.8w then you should buy it for $30. Neither of us can prove it will or won't work past its 3 yr warranty. Remember CFLs and their track record meeting their rated life? I don't think that will happen with Soraa... But I also don't think it will last 22+ yrs. Good luck with that.

Click to expand...

Well, you're quite right, I can't prove it, but OTOH I have no reason to doubt it. I have a lot of experience with LEDs, and I have a Philips alien head 60-watt-equivalent A19 that has been burning 24x7 for two years now - that's 17,500 hr out of its claimed life of 25,000 so far, and no sign of trouble. Everybody told me it wouldn't last that long. I've had several CFLs that have lasted 2+ years running about 12x7 - that's well in excess of their rated life. I've had a whole lot of various things that outlasted both their warranties and their rated life.

12V Soraa lamps can work with AC and DC power supplies.
With AC - with some flicker, 28-32% and 0.1-0.12 for newest 3rd gen. (83%flicker for 1st gen.)
Simply connect lamps to good 12V DC source.

evgeniy said:

12V Soraa lamps can work with AC and DC power supplies.
With AC - with some flicker, 28-32% and 0.1-0.12 for newest 3rd gen. (83%flicker for 1st gen.)
Simply connect lamps to good 12V DC source.

Click to expand...

Any suggestions on a dimmable 12V DC power supply. It looks like PWM dimming is the only option for the Soraa. I've tried the Meanwell PWM-120-12 with 0-10V dimming but there is still some buzzing. My current setup with Hatch AC power supplies has noticeable buzzing in the middle of the dimming range.

I might try this product

http://www.digitallighting.com/animationfolder/AD110 PWM LED dimmer.htm, in particular the high-frequency version.

I wish there was a ELV/triac dimmable DC constant voltage driver that I could use.

This is also interesting

http://www.digitallighting.com/animationfolder/DT-AN10-PWM dimmer converter.htm

lgordon said:

Any suggestions on a dimmable 12V DC power supply. It looks like PWM dimming is the only option for the Soraa. I've tried the Meanwell PWM-120-12 with 0-10V dimming but there is still some buzzing.

Click to expand...

I received answer from Soraa engineer.
Unfortunately, current design of SOraa lamps isn't dimmable by constant current, only by PWM - but low-frequency PWM is bad idea for eyes (not only my eyes).

I currently use Soraa Vivid AR111 lamps, 2700 & 3000K.
Powered by constant current from good power source (Seasonic PSU - cheap, stable output and 87%+ efficiency) for zero pulsations.