I know this has been discussed before, but that was a while back. Any updates?

Client bought an existing house, has a bunch of CFL and wants to go LED.

The last house I did would not dim down very far before going off. Client was OK with it, but it was not like incandescent where you could create some really cool scenes for night music jamming with just a glow through out the house.

Before I suggest a RA2 system, I wanted to see if anyone has any suggestions.

Tks, RR

LED lighting is still a bit of a crap shoot. I recently tried a SmartRay LED bulb and was very impressed. I use Crestron lighting and it was by far the best bulb for dimming I've used.

http://www.smartray.ca/

Ra2 you say?

[Link: lutron.com]

I am not looking for paper dude, I am looking for real world experience. I tried out a bunch of crap that Lutron said was good, only to find out that it was no better that bulbs I could get at HD.

these look nice, but how far would they dim down. I have seen most that dim about 50% down and then they go off. I am looking for ones that truly dim to about 5-10% of wide open.

I have had great luck with Cree bulbs with URC Vivido dimmers in my own house.  I think I bought them at Home Depot.  The dimmer can go all the way down and they don't shut completely off.

Thanks Duct,

I think I will have to get me a RA2 dimmer and start some testing again.

[Link: lutron.com]

Yeah because the engineers at Lutron have NO idea what they're talking about when they test LED lamps with all their devices and give you comprehensive reports on them.

Buy the cheapest Crees you can find at Home Depot, set your low trim on your dimmer so they don't pulse when they're supposed to be off.

About what percentage do the LEDs seem to be at when the dimmer is all the way down?

The entire problem is that they cannot be made to behave the way incandescents do. Instead, the best I've seen with simple parts is dimming down to about 30%; full off only by removing power totally; then when you restore power you have to raise the control output until they suddenly pop on at about 50% or more.

I've seen just one killer system, but we had to start from scratch with the wiring and even the conduit runs. Crestron controlled a DMX lighting controller. Its 0 - 10V output fed a Lutron magnetic circuit dimmer; the Lutron outputted an AC voltage that dimmed all the way to zero; each such circuit had a 120V - 12V power transformer, a full-wave bridge rectifier, and a large filter capacitor. And even this had visible dimming steps near zero, despite there being 1024 distinct ouput levels. And who's going to install an 8x8x8 NEMA box near each light circuit?

Edit: I just realized I forgot to say that the bulbs we used were 12 volt LEDs, in the range of ten watts each. If I remember correctly, about 400 watts illuminated a room about 60 feet by 40 feet. It was bright enough for a theater, not quite bright enough to comfortable read in.

The problem with those Cree LEDs is that as they dim down to 15%-20% BUT they never change color. They get dimmer but their color temperature is the same whereas incandescents get cooler as the get dimmer.

I use these Phillips [Link: homedepot.com] where they have a 2-stage LED in there. At low levels they are a cool color temp and at high levels they move to about a 3000 kelvin.

They are the closest to incandescents as I've seen for coloring but they dimming is a little herky jerky.

The point of dimming is the end point, not the dimmer travel anyway.

This is info that I was looking for thanks. The first link just gave bulbs and watts.
I was trying to get real world installers views, not engineers, as they are like trying to get info out of the light bulb itself :>)

I don't really care about how cool it looks on the way down, just being able to dim it low for cool affects. I agree Lowhz, changing color is important to get the look as they go lower.

I just have the in wall Crestron standard dimmers and the light will turn on at 5% (4.3% to be exact) and dim down to it. Best dimming LED I've ever used.

I'm not trying to be mean, but we usually speak of incandescent lamps as getting "warmer" when dimmed because of the color shift toward red. (Lower filament temperature) I'm guessing that this is because we associate "warm" with the orange sun and "cold" with bluer wintry days. I've had some people object to LED lamps because they don't (usually) change color when dimmed. In my opinion this is a learned response, but it still needs to be taken into consideration.

Successful dimming depends on synergy between lamp, dimmer, and wiring. It's really hard to provide smooth dimming with a two terminal solid state dimmer in series with the bulb. If the dimmer has leads for power, neutral, and the lamp, it has the best chance of smooth dimming. However, this is still not a guarantee when attempting to dim LED or CFL, because these are electronic devices that may not perform well at low levels. Dimming fluorescent lamps is difficult because the bulbs cannot not fire at low voltage and one must keep the cathode warm.

EDIT: I didn't see buzz's reply when I wrote this. As always, he's on point and accurate.


Before very recently we have only had dimming incandescents, so we have simply gotten into the habit of seeing the color change. Nobody said "let's invent a type of bulb that goes yellowish before going out." That's just the way it worked and we accepted it.

The system I described above used cool white 12V LEDs and the client loves it. There is no color change at any level and it has never been an issue with anyone.


A cool color temp is 5000 - 6000-ish K, 3000 is a lower K but we call it "warm white." But yeah, I see the idea.


I think it's the controller, not the LED, but that's what you get when you try to power control circuitry off of a voltage that is declining to zero.


True, but when the dimmer travel always exhibits jumps in level at the same place, rather than a smooth transition, people could complain about that.

We are technologists.* Doing BOTH well is possible and important.

The point of stopping at a stop sign is to stop, but if the driver gradually slows, then at ten MPH they STAND on the brake, people could complain about that.



*[Link: remotecentral.com]