# Philips L-Prize lamp



## jharkin (Dec 23, 2012)

Some of you might remember last year I reported trying out LED based down lights (Ecosmart/Cree CR6s and Ecosmart/Lighting Science PAR30 bulbs) when I was replacing all the can lights in my kitchen and dining room last year as part of an insulation/efficiency upgrade. Well a year later and I am *very *happy with the performance and light output of those units… soooo much better than CFL … that I decided to try out some more LEDs.


Presenting the *Philips L-Prize A19 bulb*!


​ 
I have a couple of fixtures where CFLs burn out often (bath) and the local electric company offers the Philips L-Prize bulb at a subsides price of $25 so I decided to try a couple.

My overall impression…. This is a VERY nice bulb. Brighter than CFL…maybe brighter than incandescent, minimal eyestrain, extremely low power consumption. The power savings is better than reported and in fact this bulb measured a 40% improvement even versus an equivalent CFL!

Even at the discounted $25 price it’s a bit of a luxury but I’d say worth it at this time for closed fixtures that get a lot of run time and eat CFLs, or maybe one or two around the house in your favorite reading lamp. I wouldn't shell out the full $49 for one.

For now I put in 3 – one in the bath vanity, and two in the table lamps in our den that get more use than any other lamp in the house. This is where I sit and read in the evening.


​ 
When the price comes under $10 I will seriously think about starting to swap them out around the house. The only question at this point is will something even better come along before these hit break even?

Since I know you all will appreciate it, I did some quick tests… read on to part 2.


----------



## jharkin (Dec 23, 2012)

First impressions: The bulb is a LOT brighter than the 13watt CFL we had in the same lamp. In fact it feels like going up a size. My wife’s first impression was “wow that’s bright” but after a day we really like the improved lighting, seems like the room was too dim before.

I am surprised thy omitted the big heat sink from the base, as it still gets quite hot… Not as hot as an incandescent obviously but still too hot to touch comfortably, I measured 127F on the white base with a cheap IR thermometer after an hour of run time.

To give you an idea of the relative brightness here are side by side shots of 3 roughly equivalent lamps – the L-Prize LED, a 13watt CFL and a 60watt incandescent (this one is a rough service bulb, it was all I had). All 3 bulbs are hooked up to the same power strip, and warmed up for 5 minutes. The voltage in my house is not great - fluctuating around 110-113vac at time of test.


​ 
Now looking at each lamp. I tested each on a kil-a-watt after a short (3-5 min) warmup.

*Incandescent: *GE 60 watt rough service (Hungary) $ a buck?
Rated at 60 watts, 500 lumens and 2000hours @ 130v (or 380 lumens & 5400h @ 120v)
Hooked up to a kil-a-watt I measured
· 46watt/46VA
· PF =* 1.0* (expected)
· @ 113.7vac





*CFL: *Westpointe 13 watt “60 watt equivalent” (China) $3
Rated at 13 watts, 900 lumens, ? CRI, 2700k color temperature and 12,000 hours
Measured:
· 12watt / 20VA
· PF = 0.58
· @ 112.2vac




*LED: *Phillips L-Prize bulb (USA) $35-50 on amazon or $25 subsidized
Rated at 9.5 watts, 940 lumens, 92 CRI, 2700k color temperature and 25,000 hour
Measured:
· *7watt / 8VA*
· PF = 0.85
· @ 110.0vac


----------



## begreen (Dec 23, 2012)

Nice comparison. What is with the declining voltage? We are usually at 120-122vac.

I'm hoping to see LEDs come down a lot in price. Right now they are just not cost competitive with CFLs for our electric rates. We stopped buying regular incandescents years ago. The 130v bulb is not a fair comparison for light output. A better comparison incandescent bulb would be an A-19, Philips EcoAdvantage 60w equiv (43w actual) halogen @ 790 lumens. Home Depot sells a 2 pack for $3.48, or $1.74 each. I prefer them in some locations like bathroom lights where they get switched on and off frequently.


----------



## velvetfoot (Dec 23, 2012)

I saw some interesting led bulbs last weekend in a restaurant.  The chandeliers and wall sconces had somewhat interesting looking bulbs, so I reached up there and it was cool!  I asked the waiter, and he said, yes, they were leds.  I think that is a great application for leds because there is no way a cf would work there and nice looking chandeliers can be used without suffering any pains of (misplaced?) guilt.  Of course, if you have those ritzy ditzy chandeliers, you can probably afford the price of all those led bulbs.


----------



## jharkin (Dec 23, 2012)

The power quality around here is not great... I rarely see anything over 120v.  Its not my house wiring as we have a new 200A service and Ive redone most of the circuits in the house...  While I was doing the test my wife was baking Christmas cookies so the voltage would bounce up and down as the oven element cycled i think.

I agree rating on that incandescent is silly... dont know why they spec 130v.  Its just he only "60 watt" bulb I had lying around - the only thing I still use them in are shop lights and the garage door openers.


----------



## woodgeek (Dec 23, 2012)

I got three of the L-prize guys for my dining room...a place I want good color, lumens and deep dimability.  I also got the special dimmer made for LED's. Very nice.  Amazon had them marked down on Black Friday.

I put the previous gen Phillips in my outdoor light last year.  So far so good.   Instant on in the cold is good, as is the eff running 8 hours/night on a timer.

When you get very close to the L-prize guys...you can hear them buzzing a little.  Not noticeable in normal use.


----------



## woodgeek (Dec 23, 2012)

jharkin said:


> The power quality around here is not great... I rarely see anything over 120v. Its not my house wiring as we have a new 200A service and Ive redone most of the circuits in the house... While I was doing the test my wife was baking Christmas cookies so the voltage would bounce up and down as the oven element cycled i think.
> 
> I agree rating on that incandescent is silly... dont know why they spec 130v. Its just he only "60 watt" bulb I had lying around - the only thing I still use them in are shop lights and the garage door openers.


 
When I had 200A put in, the utility refused to upgrade the aerial line (which they own). Seemed kinda small gauge to me. True or not, my electrician said the utility 'liked' the aerial lines to be undersized in case of fault (i.e a hard short in the house). I know the snow on the line melts, (esp when I pull 20 kW).


----------



## jharkin (Dec 23, 2012)

woodgeek said:


> When I had 200A put in, the utility refused to upgrade the aerial line (which they own). Seemed kinda small gauge to me. True or not, my electrician said the utility 'liked' the aerial lines to be undersized in case of fault (i.e a hard short in the house). I know the snow on the line melts, (esp when I pull 20 kW).


 
Same thing happened with us.  The aerial lines look small compared to the line down from the weatherhead which is something like 4/0 Al.  Ive heard some electricians say they are allowed to undersize the areal lines because they get more cooling in free air.  Not sure what to believe, but its annoying nonetheless.


----------



## jharkin (Dec 23, 2012)

Another anecdotal note - I put the 3rd bulb as mentioned in the bath, in a NuTone ceiling fanlight fixture.  Previously I had a 23watt  (100w equiv) CFL in there to brighten up the room.  Switching to the LED is just as bright if not brighter.

But begreen is right - these are not cost effective even at high NE elec rates.  Its more of a comfort / experimental thing right now.


----------



## velvetfoot (Dec 23, 2012)

Are these the Phillips that are yellow when off?


----------



## jharkin (Dec 23, 2012)

They are, but I think the previous generation Philips led also were.


----------



## woodgeek (Dec 24, 2012)

velvetfoot said:


> Are these the Phillips that are yellow when off?


 
The old generation have the yellow phosphors and a 'silver' tone body...the L-prize have v similar yellow phosphors, white bodies, and are 20-30% higher lumens/Watt and much better color.  The L-prize are sensibly indistinguishable from IC bulbs on color render, and almost 2X as eff as CFL, and fully dimmable (at least with a designed dimmer).


----------



## woodgeek (Dec 24, 2012)

If you want more info, there is a teardown here:

http://www.molalla.net/members/leeper/L prize bulb.htm

Looks like they get good color by mixing different color LEDs, and high Lumens/watt by driven more LEDs at lower than max rated power.


----------



## seige101 (Dec 24, 2012)

Been buying these http://www.homedepot.com/h_d1/N-5yc1v/R-202668646/h_d2/ProductDisplay?catalogId=10053&langId=-1&keyword=led light bulb&storeId=10051

locally they are 19.95 a piece

I would say they put out the light equivalent of a traditional 75 watt incandescent. Every time i make a trip to the depot i buy one. Replaced 7 bulbs in the house in the last 7 months. Also upgraded the recessed lighting to these http://www.homedepot.com/h_d1/N-5yc1v/R-202240934/h_d2/ProductDisplay?catalogId=10053&langId=-1&keyword=led retrofit&storeId=10051 locally they are 24.95

Love the led bulbs, instant 100% brightness and dimmable unlike the CFL 'dimmable' lamps that have like 2 dimmer settings, kinda on and full brightness.

As an added bonus when i replaced the outside light with an LED bulb virtually no bugs are attracted to it.

For the 2 island pennant lights i used these http://www.homedepot.com/h_d1/N-5yc1v/R-202188260/h_d2/ProductDisplay?catalogId=10053&langId=-1&keyword=led light bulb&storeId=10051 They are now on from dusk until around 10 or so pm


----------



## raybonz (Dec 24, 2012)

jharkin said:


> Same thing happened with us. The aerial lines look small compared to the line down from the weatherhead which is something like 4/0 Al. Ive heard some electricians say they are allowed to undersize the areal lines because they get more cooling in free air. Not sure what to believe, but its annoying nonetheless.


http://www.sfasoft.com/look/32 yes the ampacity is much higher in free air.. You probably have XHHW cable but you need to know to determine the ampacity. As for serious voltage fluctuations there may be a bad or overheated high resistance connection at the street. This happened here years ago and after re-torquing my meter socket which was tight the power company found an overheated insulug connector which is essentially a butt splice crimp connector. My voltage problem was much worse than yours though as I would see my voltage drop to 70-80 volts when it got really bad with any heavier load on! Could be you're seeing the start of a bigger problem so keep an eye on it..

Ray


----------



## raybonz (Dec 24, 2012)

jharkin said:


> The power quality around here is not great... I rarely see anything over 120v. Its not my house wiring as we have a new 200A service and Ive redone most of the circuits in the house... While I was doing the test my wife was baking Christmas cookies so the voltage would bounce up and down as the oven element cycled i think.
> 
> I agree rating on that incandescent is silly... dont know why they spec 130v. Its just he only "60 watt" bulb I had lying around - the only thing I still use them in are shop lights and the garage door openers.


Quote from another source:

"The thicker filament in a 130 volt bulb, when operated on typical 110-120 line voltage, provides less resistance to the electrical current flowing through the filament. As a result, the bulb burns cooler, uses less energy (watts), and lasts longer; however, as a trade-off, the bulb is also slightly dimmer and has a lower (more yellow) color temperature."

Ray


----------



## raybonz (Dec 24, 2012)

My concern with the LED lamps are the power supply that feeds the LED's more than the LED's themselves. LED's operate on low voltage DC power created by a built-in power supply. I deal with high quality regulated DC power supplies in my work and they will fail in approximately 10 years and I don't expect the power supply in a $10.00 lamp to last as long as a high quality power supply.I guess we will have to wait to see if the new LED lamps withstand the test of time..

Ray


----------



## jebatty (Dec 25, 2012)

I'm satisfied with my first foray into LED lighting. EarthLED had a closeout on 40w equivalent LED's at $5.00/each. Light is very white, which is OK for 3 wall sconces + 4 track lights, with a traditional dimmer, that provide ambiance off a fireplace wall. They are not bright enough for task lighting or for reading, but work OK as now being used. My "problem" is that my CFL's are lasting too long -- must have lucked out and got some good ones -- some of our CFL's now have been in place for 15 years, and they are well used can lights which are "on" a lot in our kitchen.

Is there any new technology after LED's?


----------



## raybonz (Dec 25, 2012)

jebatty said:


> I'm satisfied with my first foray into LED lighting. EarthLED had a closeout on 40w equivalent LED's at $5.00/each. Light is very white, which is OK for 3 wall sconces + 4 track lights, with a traditional dimmer, that provide ambiance off a fireplace wall. They are not bright enough for task lighting or for reading, but work OK as now being used. My "problem" is that my CFL's are lasting too long -- must have lucked out and got some good ones -- some of our CFL's now have been in place for 15 years, and they are well used can lights which are "on" a lot in our kitchen.
> 
> Is there any new technology after LED's?


Fluorescent lamps last much longer if not cycled on and off frequently.

Ray


----------



## woodgeek (Dec 25, 2012)

jebatty said:


> I'm satisfied with my first foray into LED lighting. EarthLED had a closeout on 40w equivalent LED's at $5.00/each. Light is very white, which is OK for 3 wall sconces + 4 track lights, with a traditional dimmer, that provide ambiance off a fireplace wall. They are not bright enough for task lighting or for reading, but work OK as now being used. My "problem" is that my CFL's are lasting too long -- must have lucked out and got some good ones -- some of our CFL's now have been in place for 15 years, and they are well used can lights which are "on" a lot in our kitchen.
> 
> Is there any new technology after LED's?


 
I think LEDs have a lot of evolution ahead of them. Any breakthroughs will likely be different solid state devices (i.e. lasers or different materials) which will have the same form factor to the end user. Think microprocessor chips...revolutionary changes in engineering, right under our noses, but invisible to us.

These L-prize guys are crossing the benchmark of 100 lumens/watt, for the first time in something that looks like an edison bulb with good color. But there is plenty of room for improvement. Physical limits are around 500-600 lumens/watt. There are plenty of solid-state devices in the lab now that run 200-250 lum/W.


----------



## jharkin (Dec 25, 2012)

http://en.wikipedia.org/wiki/Luminous_efficacy#Lighting_efficiency

I don't know how good the reference is but it puts the limit for LED at 300 LM/w


Funny thing about microprocessors.... That is an area that is already approaching physical limits, there is not much smaller they can go on the transistor size and we are at that stage where each addition step down in gate size comes at a big cost in power efficiency. Hence you see most of the advancements now are from parallelization - everything is dual, quad, six core or more and video cards are implementing hundreds of processors.


----------



## begreen (Dec 25, 2012)

jebatty, that is our problem too. I stocked up on compact fluorescents for our recessed cans, mostly in the kitchen. It doesn't get direct sunlight so the wife has them going 12 hrs a day in the winter. I date the bulbs and we are getting 2-3 yrs out of them which means we are set for the next 4 yrs or so. Maybe by then LEDs will come down. I saw the light output of the Cree 6 and really liked it, but it will have to be a lot less expensive for me to go for it.


----------



## woodgeek (Dec 28, 2012)

jharkin said:


> http://en.wikipedia.org/wiki/Luminous_efficacy#Lighting_efficiency
> I don't know how good the reference is but it puts the limit for LED at 300 LM/w


 
Agreed. Still, a 3X improvement from here (300lum/W) gets a 60W IC equivalent, now in a 9.5W L-prize, down to a 3.2W (future) LED bulb.  Imagine the light of a 60W IC bulb coming from something that uses less than the (4W) nightlights I grew up with!



jharkin said:


> Funny thing about microprocessors.... That is an area that is already approaching physical limits, there is not much smaller they can go on the transistor size and we are at that stage where each addition step down in gate size comes at a big cost in power efficiency. Hence you see most of the advancements now are from parallelization - everything is dual, quad, six core or more and video cards are implementing hundreds of processors.


 
I don't consider parallelization evidence for physical limits....just shows another way of engineering the desired 'ends'.
Most people don't know/care their CPUs are multicore. End users see the performance/price just keeps going up.


----------



## jharkin (Dec 28, 2012)

woodgeek said:


> I don't consider parallelization evidence for physical limits....just shows another way of engineering the desired 'ends'.
> Most people don't know/care their CPUs are multicore. End users see the performance/price just keeps going up.


 
Maybe its not solely due, but definitely a devolpment that has come as it gets difficult to manage ever larger and faster chips.

http://en.wikipedia.org/wiki/Moore's_law#Ultimate_limits_of_the_law
http://en.wikipedia.org/wiki/Moore's_law#Parallelism_and_Moore.27s_law

We are pretty close to atomic scale with the current 22nm process in the newest chips. Not much smaller they can go, placing limits on how much faster single Chips can go. The compute power per watt efficiency today is horrible compared to 10 years ago, hence the need for massive heatsinks on modern systems. Parralel CPUs is one way around this limit, but we are still catching up with software that can really take advantage of massive parralelization... For home users at least.

Eventually the way forward will be in quantum or optical computing, but that is a while off.


----------



## Laszlo (Jan 19, 2013)

jharkin said:


> When the price comes under $10 I will seriously think about starting to swap them out around the house. The only question at this point is will something even better come along before these hit break even?


 
You're in luck! Massachusetts and Rhode Island utility customers can now buy up to twelve L-Prize bulbs for $10 each instead of $25. And according to my calculations, when replacing 60-watt incandescents, these will have a payback period of 1100 hours use given the cost of $0.1437 per kWh (the avg MA residential rate in Oct 2012). If you have any lights on 12 hours/day then that's a return-on-investment of only 3 months! I've made a Google Docs spreadsheet comparing various types of A19 bulbs and their TCO over 30,000 hours. You can save a personal copy, then put in your own values to update the graphs to reflect your own electric rates and bulb prices.


----------



## jharkin (Jan 19, 2013)

In luck? Now i m kicking myself I didn't wait a couple months.


----------



## Laszlo (Jan 19, 2013)

Count yourself lucky that you didn't have to stomach a $50 price-point to try them out. No utility discounts in my neck of the nation, so that's what I paid. But I agree with you that they're very nice lights and intend to get more myself. I'm very jealous of your opportunity to get them at such a low price.


----------



## raybonz (Jan 19, 2013)

Laszlo said:


> Count yourself lucky that you didn't have to stomach a $50 price-point to try them out. No utility discounts in my neck of the nation, so that's what I paid. But I agree with you that they're very nice lights and intend to get more myself. I'm very jealous of your opportunity to get them at such a low price.


Lazlo where are you located? Welcome to the forum! I will try these lamps if I happen to see them! I suggest you update your info and create a signature that will appear in all your posts..

Ray


----------



## Laszlo (Jan 19, 2013)

Thanks! I'm from the PA, and I was _just_ looking for how to edit that! Fancy features you have in this forum, but still haven't found the page...


----------



## raybonz (Jan 19, 2013)

Laszlo said:


> Thanks! I'm from the PA, and I was _just_ looking for how to edit that! Fancy features you have in this forum, but still haven't found the page...


At the top of the screen hover your mouse over your name..

Ray


----------



## raybonz (Jan 19, 2013)

Tons of PA people here BTW..

Ray


----------



## jharkin (Jan 19, 2013)

Ray you can order from the EFI link as a MA resident. That's where I got mine at 25 last month.


----------



## raybonz (Jan 19, 2013)

jharkin said:


> Ray you can order from the EFI link as a MA resident. That's where I got mine at 25 last month.


EFI? Where is this JH?

Ray


----------



## jharkin (Jan 19, 2013)

Laszlo posted the link.


----------



## raybonz (Jan 19, 2013)

jharkin said:


> Laszlo posted the link.


Yes thanks I just found that.. Will buy 3 for free shipping.. Worth a try..

Ray


----------



## Laszlo (Feb 6, 2013)

raybonz said:


> Yes thanks I just found that.. Will buy 3 for free shipping.. Worth a try..


How do you like them? I just received ten bulbs I bought through a friend in MA and I'm shocked at the difference they make. Big boost to brightness over my old 14-Watt CFLs. Much more "productive looking" in my office, and dazzling in the bathroom, with no warm-up time.


----------



## jharkin (Feb 6, 2013)

I think they put out the light of a 23w cfl.


----------



## raybonz (Feb 6, 2013)

Laszlo said:


> How do you like them? I just received ten bulbs I bought through a friend in MA and I'm shocked at the difference they make. Big boost to brightness over my old 14-Watt CFLs. Much more "productive looking" in my office, and dazzling in the bathroom, with no warm-up time.


Tried to order them and got some weird error message  Wrote the power company and got no reply..

Ray


----------



## jharkin (Jun 12, 2013)

And just like that ... the L-Prize lamp is gone!

Seems that they where too expensive to produce here in the US and make a profit even at the $50 retail (I paid $25) so they where discontinued.


All is not lost as Philips introduced a new A19 bulb to replace the older offerings. Looking at the specs its not as good as the L-Prize but is a bit better than the old EnduraLED and is priced a lot better ($25 retail, $10 with utility rebates). Most interesting is that the new one looks a lot more like a traditional bulb

Philips A19 dimmable 11w LED








Edit to add... Here is how the bulbs compare:


----------



## begreen (Jun 13, 2013)

Looks like a good compromise. My wife hated the look of the older Philips.


----------



## woodgeek (Jun 13, 2013)

My 3 L-prize bulbs are now 'collectibles'.


----------



## jharkin (Jun 13, 2013)

I just now noticed the new Cree A19/60w replacement bulb is out as well for like $13 at Home Depot.  The 'new' Phillips is closer to 25 but I can get them for $12 from NStar.  Might be interesting to pick up one of each and compare.

Looks like the Phillips will be very slightly brighter, but the Cree has an efficiency edge and is American made.  Best I can tell they have identical CRI spec.


----------



## jharkin (Jun 13, 2013)

woodgeek said:


> My 3 L-prize bulbs are now 'collectibles'.


 
Mine as well


----------



## begreen (Jun 13, 2013)

Cree has become a leader in this field. Are you sure they are made in the US? I know they do R&D here and part of the mfg process, but I thought they bought a factory or two in China several years back for the LED pkg assembly.


----------



## Laszlo (Jun 16, 2013)

begreen said:


> Looks like a good compromise.


 
I disagree. Not been too impressed with the light from this replacement (appearance of the bulb itself is not a concern for me). I'm likely in the minority for caring about differences in CRI above 80, but it's a definite downgrade in light quality from the fixture holding this new bulb. It's a shame if the L-Prize is truly gone, because no manufacturer is likely to take on the extra effort and expense to provide 90+ CRI during the run-up to higher lumens/Watt. Rather than compromise efficiency by covering all colors, they'll aim for too much blue--which LEDs emit most efficiently, or green (which results in higher lumens for a given brightness, as human eyes are more sensitive to greenish light).


----------

