LED House Lamps

[SteveB]

My lamp supplier - Bulbtronics, is warning me that 1-2 years from now I may start having problems getting 40w A19 lamps, of which I use approx. 450 in my assorted house lighting.

My GM has indicated we should research an LED equivalent, as our lamp changes run about $1000 3-4 times per year, plus the cost of lamps.

To that end I am researching if anyone has used any sort of LED in a dimming application in an audience chamber.

Bulbtronics recommended we test run the Lighting Science Group A19 60w equivalent - Lighting Science

I just ordered 10, but any thoughts or experiences appreciated.

 

[derekleffew]

I have absolutely nothing to contribute; I'm only posting so SteveB can see this thread. This message will likely be deleted once he has acknowledged seeing it.

EDIT: I DID think of something pertinent!
Steve, wasn't there a post/discussion on the SML within the past few days discussing a medium screw-base LED A-lamp, maybe a 100W? I'll try to look for it.

EDIT2: Found it/them.

Take a look at these guys too: http://www.switchlightbulbs.com/ From
everything I've read about them so far, they may be worth waiting
another 6 months or so for before shelling out the $$

Discussing another bulb available at HomeDepot:

I have 5 of them throughout my family room, and they do the best job =
I've seen yet in replicating the color temperature and non-flickerness =
of a incandescent.

As long as you have a globe or shade on the light, you really can't tell =
the difference. They come on instantly, to full brightness. They dim =
down significantly (20% or so), but not quite all the way.

Bottom line, I love the things. I see them as a normal light, and have =
to remind myself they're not incandescent. I calculated that with the 4 =
I use most often, I'll save around $80 a year over incandescents, so =
it's a year or two payback.

If the look of them is too weird for an exposed bulb, they also make =
ones with frosted covers that use the same tech at lower wattages, like =
this: =
http://www.homedepot.com/h_d1/N-5yc...3&langId=-1&keyword=philips led&storeId=10051

Basically, I won't buy another CFL again.

Obviously the smooth dimming all the way to zero (highly desirable, if not imperative, in a houselight bulb) is the sticking point.

EDIT3: Anyone know how Dave Cunningham is progressing with making incandescent lamps more efficient? (See this thread: http://www.controlbooth.com/forums/...ghams-new-project-make-better-light-bulb.html .)
You'd probably still have the, relatively, short life issue, however.

 

[Esoteric]

I have absolutely nothing to contribute; I'm only posting so SteveB can see this thread. This message will likely be deleted once he has acknowledged seeing it.

EDIT: I DID think of something pertinent!
Steve, wasn't there a post/discussion on the SML within the past few days discussing a medium screw-base LED A-lamp, maybe a 100W? I'll try to look for it.

EDIT2: Found it/them.


Discussing another bulb available at HomeDepot:


Obviously the smooth dimming all the way to zero (highly desirable, if not imperative, in a houselight bulb) is the sticking point.

EDIT3: Anyone know how Dave Cunningham is progressing with making incandescent lamps more efficient? (See this thread: http://www.controlbooth.com/forums/...ghams-new-project-make-better-light-bulb.html .)
You'd probably still have the, relatively, short life issue, however.

There is currently no fully dimmable LED replacement lamp. The best will dim from 100% to 20% before just clicking off.

 

[bdkdesigns]

We have Dimmable LED's made by (I think) Omega, which appears to be a Phillips product, as our house lights. We got them last Fall and Alabama Shakespeare Festival was interested in them as well due to an energy grant they got. They brought in someone to do a demo of them and they were able to dim them individually all the way down to 0% but were told when wired together, they would snap off at 10% because of the DMX control card. Supposedly they will be able to dim down again to 0% when they figure out how the card works. They gave a hopeful timetable of 2-3 years. While great news for me that they might someday dim, it didn't work for them and they just bought a lot of them for hallway, lobby, and bathroom lights.

I must say, I came in mid-renovation so I never had to worry about changing the houselights but the rig that was set up was certainly sketchy at best. The LED's are much brighter than what was there previously and I never have to change them out....so I personally can live with them snapping off at 10% for at best 2 more years. I'm much more annoyed with the decision to install a Smart Fade at the Stage Managers station that only talks to the first universe (our FOH are on Smart Bars on the second universe) instead of putting that money towards a remote.

 

[JD]

One trick may be to supplement the house lighting with a few parnells or other incandescents. 30 minutes before the show, bring them up, and the at showtime, dim the LEDs first, letting them snap off, then do your graceful dim with the incandescents. Your panic system will still bring on the LEDs and the parnells would only be used for 30 minutes before showtime.

 

[SteveB]

A thanks for the replies.

The application is to replace existing 40w (34w) A19's, of which our
orchestra section alone has about 400 lamps, in 5 rows (think Radio
City Music Hall type curved ceiling), with the existing fixtures being
recessed coves of strips with medium screw based sockets. The cove
design has the lamps hidden from audience view, excepting the front 5
rows or so. The coves are designed with curved aluminum reflectors,
so in theory, the lamp can shine into the reflector and then light the
white ceiling. There is then a lot of recessed fixtures with 150w
Halogena lamps that provide the lighting at floor level (as well as
the reflected ceiling light).

The dimmers are ETC Sensor 6kw's (3) feeding an existing branch
circuit panel (the A, B and C buss-bars), with 15amp branch circuit
breakers. I have been in touch with ETC tech services about the use
of these dimmers with LED's.

The plan is to buy 10 lamps ($25 ea.) and install into a test jig to
test the dimming curve. One comment from ETC was keeping as little as
one 40-60 watt incandescent lamp on the circuit (dimmer) can help the
curve and response.(ye olde phantom of the load trick).

Then we can install into the coves to test coverage. Then we can deal
with either tricking the existing dimmers into liking the LED's,
moving upwards to changing to a 20a dimmer (the load would be approx.
1700 watts per dimmer), as well as adjusting the dimmer response and
curve in the CEM+ software.

The lamps I linked to are supposed to dim to 5%, which may be adequate
for our use with the caveat that the recessed cove provides some
forgiveness in terms of how ugly the lamp looks or spreads.

To that end we are testing 60w lamp equivalents (13.5 w actual) so as
to possibly lamp alternating sockets, which essentially halves the
initial purchase.

We currently do about 3-4 lamp changes per year (not every lamp every
time),paying $.55 per bulb, with about $1000 in crew costs per change,
so in theory, the payback comes in 3 - 4 years or so. We do not pay
the electric bill, so not cost savings there.

 

[Esoteric]

You still have to install dimming for the PARnels which kind of defeats the purpose of LED house lighting.

You could just use purpose built LED fixtures.

I would believe a smooth dimming curve to 5% when I see it.

That being said, if it can get to 5% that is certainly a step in the right direction. On the other hand, even the "blink" on from 0% to 1% that you get with 99.9% of LED fixtures is often too much for house lights for my theater clients.

Unless you are doing 2-3 second house light fades the "blink" from 5%-0% will be VERY noticeable.

Mike

 

[dj41354]

There is currently no fully dimmable LED replacement lamp. The best will dim from 100% to 20% before just clicking off.

We have Dimmable LED's made by (I think) Omega, which appears to be a Phillips product, as our house lights. We got them last Fall and Alabama Shakespeare Festival was interested in them as well due to an energy grant they got. They brought in someone to do a demo of them and they were able to dim them individually all the way down to 0% but were told when wired together, they would snap off at 10% because of the DMX control card. Supposedly they will be able to dim down again to 0% when they figure out how the card works.

I'm gonna go out on a limb here and suggest that the "dimming hardware" being used may be a significant part of this problem. There are quite a few different "dimming methods" that have very different schematics/circuits/components. I suspect the typical incandescent load works fine with most (if not all) but LEDs load a dimmer really differently... So where you may have not had to worry about your dimming circuitry in the past, with the LED units, it becomes important. Here's a link that talks about some of the issues: Dimming LED Lights | Polar-Ray.com Mostly this talks about the "leading edge" & "trailing edge" dimming methods, which are intended for either magnetic/inductive loads (regular transformers) versus capacitive loads (electronic transformers). Here's a more in depth discussion: Light Dimmers

Other dimming methods worth mentioning: "sine wave dimming" TheSilence of the Lamps: The New Wave in Dimming This was discussed in an eariler Controlbooth thread http://www.controlbooth.com/forums/lighting-electrics/17719-sine-wave-dimming.html I suspect this method is not suitable for most LED units, but there may be some that would work well with it. It chops the halves of the AC waveform into a bunch of slices, and adds/subtracts slices as it brightens/dims the lamp. My guess is that lamps using high voltage LEDs like the LUXEON H LUXEON H High Voltage LEDs | Philips Lumileds Lighting Company coupled with fast rectifiers would work.

Then there's the variac.. I'd be willing to bet that a lot of the cheaper LED units (again.. lamps with LEDs connected directly to the mains using rectifiers) would dim really well on a variac.

There are others too.. I read somewhere that the Lutron dimmers use their own custom technology http://www.ledsmagazine.com/press/27034 (still looking for some better info on this...) And I know a guy who used to work at CK that told me that faced with this problem, CK did their own custom dimming circuitry for use with some of their LED fixtures.

 

[JD]

Here's the thing; DMX LED fixtures achieve dimming by pulse width modulation and therefore can achieve a nice low end slope. The Power supply is always on. This is NOT how the screw in LEDs work. On those units, the incoming AC power is rectified and the resulting DC is applied to a chain of one or more high output LEDs. As the supply voltage drops (or, "chops" from a dimmer) a point is reached where the supply can no longer sustain output above the LED forward drop voltage and the lamp winks off. (Even on a variac.) Operation off a conventional "chopper" style dimmer gets a bit flakey as the loading on the dimmer drops below the minimum system load at lower settings as the "Lamps" drop into "open-circuit" mode. This is why ghost loading helps.

Other LED lamps use a free-running switch mode supply (as compared to the regulated type we are all familiar with.) Again, when the line voltage is too low to sustain oscillation the lamp will wink off.

 

[dj41354]

I guess what I'm trying to say is, it's the combination of the specific "screw in LED" lamp you're using, and the dimmer you're using, that's going to determine how successful your result is. I've built LED lights that are simply a string of low voltage LED's powered with a low voltage transformer and a bridge rectifier. This kind of LED light will dim with garden variety dimmers, but some dimmers work MUCH better than others (all tested with the same light). A variac dims this kind of light perfectly.. nice and smooth all the way down to zero (there is no "wink off" point where it was at like 5%, and then just shuts off). It could be that if someone is unhappy with the dimming on their screw in LED lamp, they should look at what they are using for a dimmer, and see if something is available that might dim their specific lamp a little better.

 

[Esoteric]

I guess what I'm trying to say is, it's the combination of the specific "screw in LED" lamp you're using, and the dimmer you're using, that's going to determine how successful your result is. I've built LED lights that are simply a string of low voltage LED's powered with a low voltage transformer and a bridge rectifier. This kind of LED light will dim with garden variety dimmers, but some dimmers work MUCH better than others (all tested with the same light). A variac dims this kind of light perfectly.. nice and smooth all the way down to zero (there is no "wink off" point where it was at like 5%, and then just shuts off). It could be that if someone is unhappy with the dimming on their screw in LED lamp, they should look at what they are using for a dimmer, and see if something is available that might dim their specific lamp a little better.

Perhaps. But remodeling the dimming system defeats the purpose of using screw in lamps in a remodel (keeping the cost down). Otherwise we would use purpose built units. But I would be interested to see a demo of a screw in LED lamp and dimmer that dims smoothly to 0. I might be able to do a lot of work in new installs with that setup.

 

[MircleWorker]

I have been testing a Sylvania (E327386)LED Lamp/bulb for about a year now. they dim out as well as the other lights.
Our lighting system uses Colortran iSeries Dimmers. only problem is that the light dosen't shine twards the base of lamp so I get a dark spot in middle on the sconce. these are 3200K so much whiter than the normal 40Wbulbs

 

[Footer]

They are trying to shove these down my throat right now. National Grid is giving the state a deal where each bulb is 8 bucks. They have already done about two-thirds of the plaza. I have 3 different test bulbs in place now. All of my house lighting is off of two 12k dimmers. So far the ones we have we are really not that happy with. We also don't have any type of smart controller on our houselights that we can adjust the curve. I want LED's in all my work lights, halllways, etc before I get them in the house. Right now our hard line is don't change the lamps in the dressing rooms or in the house.

 

[porkchop]

If the projected price I found of $20-25 for the Switch LEDs is accurate and they play nice with your dimmers they sound like a really good way to go. Haven't ever thought about how an LED lamp would work in a reflector made for an incandescent lamp before.... Would certainly have to buy test lamps before committing to a change over, but could certainly be worth the time and money.