LED dimming, from very low to maximum.

Hello,

I have one light feature which uses incandescent lighting and it dims up and down from very low to maximum (over 4s). Looks nice. I can't do the same with my LED lights though. They seem to turn on at a low-ish level and then ramp up to maximum.

I know there has been a lot of discussion generally about LED dimming in older threads, so is this something that has been now solved?

Cheers,

P_R.

 

Hi,
I should elaborate a little with the above post.

If you are building a new house, chances are you won't have incandescent lights. Since these are now limited to 25w maximum, they have been relegated to use in feature lights. Same goes for halogens. I would suggest that most new houses have LEDs and their default lights, with maybe some fluorescent lights for garages, roof space/attic. In this new house you will probably want to dim some of these. I've read (please correct me!) that LEDs by their nature can be dimmed from very low to their maximum. I'm talking here purely about chips/diodes that make the light.
In practice this isn't the case. Why is that? Is it because houses have 240v cabling for lights which is not ideal for LEDs to dim well? Or is it the dimmers we use have been designed for an incandescent world?
Wiring for houses includes 240V mains, Ethernet, garden low voltage cable (think solenoids for sprinklers), low voltage speaker cable and maybe others. If LEDs need different cabling to achieve excellent dimming, then why isn't this done for new builds? Electricians are used to having multiple types of cabling as it is.

If there is combination of LEDs and c-bus modules that can produce excellent LED dimming similar to what incandescent lights can, then can someone point me in the right direction please?

If not, why are there no such products or combination of products?

Cheers,

P_R.

 

So many things here!

You have nailed it on the head here, the world of phase dimming is almost the last thing you want when using high frequency, low current and voltage electronics. Personally, just due to current physics phase dimming will not be able to dim LED the way we all want.

Yes, but it does involve a learning curve. Having a seperate control protocol is the way to go, DALI or DMX with things like the ELDO drivers. However you then need to match your drivers to the LED fittings you are using. That is where it can get tricky and is a whole other discussion. However I would be looking for DALI or DMX controllable light fittings which come with the driver as well. They will be on the pricey side, but remember you only need one or two gateways on the c-bus side to do all your lights as compared to needing lots of dimmer channels at $200+ each.

 

Hello Jboer,
Thank you for the compass. I also have long extendable ladders to climb that curve

But can I ask, if phase dimming (I don't know what that is) is not the best diet for LEDs, then will we see a new 5508DimLED c-bus unit at some stage which is made for this purpose? One that is friendly to LEDs, their drivers and can be wired up in place of existing incandescent type dimmers?

I am happy to tinker with DALI or DMX and for where I want it, the theatre room/man cave, I can take my time and investigate. But if you are building a house and select c-bus, adding DALI or DMX seems like an unnecessary hoop to jump through to get the equivalent incandescent dimming.

Thank you for the info, I'll be reading up on all those.

Cheers,

P_R

 

I inquired about a proper cbus led dimmer a year ago or so and was told that there were no plans as there are existing suitable solutions. Dali and DMX are fine for new builds but almost impossible to retrofit to existing installations. Someone needs to come out with an open standard for wifi dimmable led light fittings. And definitely one that doesn't require the cloud to work.

 

Thank you Ashley,
My new build (completed just under 2yrs ago) was specced from the start to have c-bus and nearly all lighting is LED and most were to be dimmable. Not knowing enough about the details of what dimmable LEDs would be like at the time, I accepted what my integrator had planned. But had I been given a choice I might have opted for one of the solutions mentioned above, at least for a few rooms.
Maybe most people, when given a choice to have good enough dimming vs excellent dimming (but +$$$) would probably opt for good enough. Hence no justification for a 5508DIMLED

If there is any push to make one of these devices, +1 vote from me. And I'll order two 8ch versions

If Clipsal simply dropped the current dimmer and replaced it with a proper c-bus LED dimmer, who would miss it? We'd all opt for the new one.

P_R

 

Part of the issue is that is it extremely (read almost impossible) hard to make a universal LED 'Dimmer'. If you have a look at the electrical groups everyone has just as much issues with standard light dimmers as we do with automation ones. Even the 'LED' dimmers have issues, I have about 5 different ones in my house to play with them on all sorts of LED loads and if some of them are wonderful at dimming LED they then have issues with ripple and ect.

The issue is that controlling LED isn't always simple, and making one that works with the cheap fittings is even harder. Array size and configuration, driver builds, the characteristic of each batch of LED can make big differences and when basically all you can do is cut the 240V phase in some way you are very limited.

Some of the guys like Brightgreen have spent thousands of hours in R&D to try and work these things out in their drivers, but they can still have problems. There is only so much you can do when you are getting a little blip of power every 20ms and sometimes that blip isnt even a nice clean blip depending on the dimmer. That is on the driver side.

Then if you are trying to make a dimmer, you can try and make it so that the low end is actually high and a clean cut. But then depending on the driver this actually makes the cut off worse rather than better..

 

Hello.
Thank you jboer for pointing me in the eldoLED direction. I looked on their website and found the product I needed. Then I found the contact details of the distributor and they put me in touch with the Australian retailer. Next I went to a local lighting retailer and they found me a LED light without driver which I could pair up with the eldoLED. I then I ordered two SOLOdrive 1061/A drivers from the eldoLED retailer. These units can dim from 0.1% to 100% smoothly (logarithm or linear), have DALI and 0-10V inputs and are rated at 100W. Cost is $225 each. So far, all looked promising.

They arrived a few days ago and I was very disappointed. Have a look at the pictures to see what I mean.

The box in the background is what they came in. Both are dirty as though handled by greasy hands.

The lid across the top appears to have been opened.


So I asked about this and was assured by the retailer that they were new and never used. He also told me that all the other ones they had were also like this. They did offer a refund. Maybe they are new or maybe that's what they received from their supplier. But would anyone accept these as being new? Is this typical of drivers or such products?

I tried to contact the distributor to advise them of the state of the products and to ask if someone else can sell me these in Australia, but I am yet to receive a response. I contacted eldoLED directly, they too have yet to respond (nearly a week now). Last roll of the dice I thought to contact the parent company of eldoLED and tell them my story. I've only just done this, so maybe I will get a response.

If they don't respond then I won't be pursuing this further, as it is I feel like a crack pot for going this far. My two drivers look so poor that unless I can see what I am buying, I won't be getting any more eldoLEDs. The irony is that the product seems to promise everything I was looking for, and I'm sure this is not what they look like coming out of the factory.

P_R

 

That is unfortunate, it looks like to me that they had a box that was dropped at some point and just shoved back in and sold. The problem is that it could have happened any point along the chain. We just get ours from most electrical wholesalers and so far they have been without issue. I personally would take the refund and go to a local electrical wholesaler and ask for them.

 

Or a coal pit...

 

Hello jboer and Ashleigh,

Happy to PM each with questions about suppliers, but (and this is sounding very dumb as I write it), I can't figure out where to find your PM. Do I simply start a one on one conversation?

P_R