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Tom B.

CMB16D - Not Fading LED MR16 Floods

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I also agree, the dc board is not broken.

Like i said in my earlier post, the MR16 dims as expected, just not like an incandescant, which is also expected.

I also ran tests on the MR16 so I could adjust my programming. I have not rcvd my ordered from Paul yet, but I tested some Phillips LED strings that I bought during previous years and they dim just fine with the AC board.

Off the subject, the standalone feature on the DC board is great. I set up some MR16's Friday night in front of the house and played aound. Very nice, cant wait till showtime

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I don't want people to to think I meant there was some thing wrong with the board or any thing else. I was asking about a firmware update as a fix not that the board need to be fixed. I have the 20 ohm resistor that came with the lights and I will use them. sorry for any confusion this may of caused



Dale

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Not a problem Dale, I would love to have the firmware update too! (hint hint)

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Dale wrote:

I don't want people to to think I meant there was some thing wrong with the board or any thing else. I was asking about a firmware update as a fix not that the board need to be fixed. I have the 20 ohm resistor that came with the lights and I will use them. sorry for any confusion this may of caused



Dale


Hi Dale,

Went back and read what I wrote and see what you mean! It comes across a little different than I meant it to. I am also looking forward to getting the wrinkles out of the enhancement.

Dan

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Thanks Dan

I didnt want anyone thinking I was saying it was broke or any thing I know a lot of new users read these forums :P

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LightORamaDan wrote:


We have not finished the major enhancement required to the CMB16D so that it can dim the MR16 bulbs. This is not a fix to the CMB16D as it was not broken:). The CMB16D does dim bulbs designed to be dimmed uisng PWM however the MR16s that you are talking about are not really designed to be dimmed in that fashion. "Normal" LEDs and incandescent bulbs will dim fine with the CMB16D. We have something that almost works (it dims the MR16s you are talking about very nicely), but it has some bugs in it that we have not yet worked out.

Dan



Has this issue ever been resolved? Any updates on a firmware fix?

I have a huge project that I am working on the next 2 weeks that involves 160 LED mr16 bulbs and 48 channels of DC controlled LOR.

I have ordered about 5 different kinds of LED MR16s and different assortments of LED strips and they all behave exactly the same. The only dim to around 90% or so and then just turn off when. I have to put a 22 ohm resistor on each one to get it to dim but it still only goes down to around 10% and then just turns off.

I even bought a $35 LED MR16 bulb that is advertised as "Dimmable" and I still get the same result. Here is a link to the bulb I am talking about.

http://www.environmentallights.com/products/12671/MR16_GU5-3_4w_12V_LED_Flood_10o_Warm_White

Many of these bulbs though work if I hook them up to a variable power supply and change the voltage from 0v to 12v and them dim fine. I have never seen any kind of DC based LED light work with the LOR DC Boards.

The LOR team a year ago annouced on this thread that they did get a firmware version working that would dim LEDs better but I have not seen any improvements including the DC boards that just arrived from LOR today via UPS.

Looks like I am going to be spending a few days soldering 160 resistors inline with all the LED bulbs I have to use.


Sigh....

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Most DC LED dimmers use pulse width modulation to alter the percentage of on time on the lamps, to reduce perceived brightness. The issue is that many of the LED floods are designed for AC landscape transformers, and contain a rectifier and capacitor to smooth out the AC into a nice DC supply for the lamps. When this is fed a pulse width modulated supply, all that happens is that the capacitor now pulls a higher current during the on phase to recharge itself.

Adding the resistor in series limits the charge rate to the capacitor, so that varying the percentage on time results in the capacitor charging to different voltages, giving different brightnesses to some extent.

The early reports that WireKat's lamps worked fine with a different brand DC card turned out to actually be that the first order of his lamps worked fine with either brand of card, but that the second order worked correctly with neither brand.

While there may be improvements to be made to the general response curve in the firmware, it most likely will not do a lot for the lamps with capacitive filtering in them, short of maybe having a really skewed response curve that pulls the on time way down, but causes the mosfet to current limit the charge rate, and puts more stress on both the mosefet, and the capacitor...

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Thanks for the info KLB.

The bulb I listed in the thread above is advertised as working with 12v AC or DC so it must have a rectifier and capacitor like you talked about.

Does anybody know of any colored & Warm White MR16s that work correctly with the LOR DC Board? Because I can't find any and I need to order all these bulbs very soon.

I am guessing there is no way to have any LOR Equipment do 12v AC is there?

-Richard

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You can feed the right half of a standard LOR AC controller with 120VAC, and the left half with 12VAC, as long as the 12VAC lamp is listed as dimmable. I would not try it with ones that are not specifically listed as dimmable, as sometimes AC dimming of items with capacitors can be even worse than DC.

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I just bought a bunch of super flux pirahna led's, resistors and some blank pcb's that are designed to make MR 16 flood lights that fit perfectly into my MR 16 holders. They are designed to be used with PWM. I hope to have time to put them together before I start my show. Due to my job and work schedule, it will be the first week in Dec before my show starts. If I dont get a chance to use them for this years show, I will definitely post some results later.
Richard

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richardh wrote:

LightORamaDan wrote:

We have not finished the major enhancement required to the CMB16D so that it can dim the MR16 bulbs. This is not a fix to the CMB16D as it was not broken:). The CMB16D does dim bulbs designed to be dimmed uisng PWM however the MR16s that you are talking about are not really designed to be dimmed in that fashion. "Normal" LEDs and incandescent bulbs will dim fine with the CMB16D. We have something that almost works (it dims the MR16s you are talking about very nicely), but it has some bugs in it that we have not yet worked out.

Dan



Has this issue ever been resolved? Any updates on a firmware fix?

I have a huge project that I am working on the next 2 weeks that involves 160 LED mr16 bulbs and 48 channels of DC controlled LOR.

I have ordered about 5 different kinds of LED MR16s and different assortments of LED strips and they all behave exactly the same. The only dim to around 90% or so and then just turn off when. I have to put a 22 ohm resistor on each one to get it to dim but it still only goes down to around 10% and then just turns off.

I even bought a $35 LED MR16 bulb that is advertised as "Dimmable" and I still get the same result. Here is a link to the bulb I am talking about.

http://www.environmentallights.com/products/12671/MR16_GU5-3_4w_12V_LED_Flood_10o_Warm_White

Many of these bulbs though work if I hook them up to a variable power supply and change the voltage from 0v to 12v and them dim fine. I have never seen any kind of DC based LED light work with the LOR DC Boards.

The LOR team a year ago annouced on this thread that they did get a firmware version working that would dim LEDs better but I have not seen any improvements including the DC boards that just arrived from LOR today via UPS.

Looks like I am going to be spending a few days soldering 160 resistors inline with all the LED bulbs I have to use.


Sigh....



I do not expect that there will be a change in the CTB16D this year. It is a bit too late to make changes.

Dan

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