[Closed] long shot - faffing with LED replacements bulbs, drivers and dimmers

bump!

Most LED drivers require trailing edge dimming, which your triac dimmer switch can't do. Varilight do a decent range of cheap digital dimmers.

Are you absolutely sure your new drivers are dimmable? Should say on them which type of dimming to use.

You covered it in your post.

You've got a dimmer designed to vary the current. LED's are very susceptible to current fluctuation, again as you've mentioned (constant current drivers), so the fact is that when you add the two things together you've got a recipe for problems, especially when you have such low loads. (i.e. a 1 watt variation on a load of 50W is 2%, on 7W its 14.28%, so not surprisingly it has a different impact)

The development of LED lighting has been rapid. Until recently it was to provide a light source similar in output to Halogen that didn't make you look like you were on a mortuary slab. Right now its for a dimmable solution. I import a range of high quality LED downlights purported to be dimmable, we choose not to advertise that as a feature. Experience shows that even in ideal conditions all sorts of anomolies occur as you describe. We have hunted high and low for a suitable dimmer, and to date have not found one that works in all conditions.

Personally I wouldn't go anywhere near an LED replacement lamp, unless they are a top brand, as the power supply issues are just too likely to cause you problems. My inbox is full of offers of these things from every two bit factory in the Far East, and I guarantee one thing, and that is that 99% will be utter crap.

Thanks folks

I think what I need is

1. dimmable high quality LED lamps
Got Philips dimmable 7W bulbs - tick

2. Dimmable LED drivers (with stated leading/trailing edge control)
Not found these yet (the ones I have do not state they are dimmable - bought them on a guess and can return these) -the search goes on!

3. a digital dimmer switch (240V) for the wall, leading/trailing edge to match the drivers.
Will search for this when drivers located.

Any advance on this as a plan? any recommendations for item 2 (dimmable drivers)?

Thanks
TM

Sorry for the hijack:

My cooker hood has 2x25W halogen G4s. I'm tempted to buy LED G4s and install a driver transformer inside the hood itself.

Am I insane?

twiglet - Philips do a range of dimmable LED drivers but as Berm Bandit says none of them are perfect.

The Philips ones will dim a load from 0 to 50W and work fairly well, but have a high capacitance leading to potential issues with soft start dimmers. They flicker slightly at the very lowest setting, but I'd say they dim properly from 5% output and higher.

Molgrips,

Yes, you don't need the driver. Suspect the current bulbs are mains voltage so just replace with mains voltage led bulbs. Works great in my cooker hood.

Berm Bandit

wish I'd seen you post earlier as I've just ordered 6 replacement G9s

Are these going to suck?

http://www.energybulbs.co.uk/kosnic+4w+g9+led+capsule+-+warm+white/1813415572

I have 14 days to return them

Do you sell retail?

Kosnic are pretty good, though that particular bulb seems a bit overpriced.

Yes, you don't need the driver.

Hmm.. the bulbs I saw said that you needed a steady enough power supply otherwise they'd die.

What brand did you get? Got a link perhaps?

twiglet, those Aurora 35-105W are transformers not drivers. They are dimmable with a standard dimmer.

I also assume the LED's you have are MR16 retro fit LED's?

You have two weak links, one is the transformer, they're consumable and prone to fluctuation and interference.
And secondly the ceramic lampholders can break up and cause flickering. Quite often it's the lampholder that's gone, and the user thinks it's either the lamp or transformer.

I never like to recommend retro fit LED's on LV systems, and dimming is double trouble. LED's really don't like it.
What I do is remove the transformer. Then replace the LV lampholders with 240V GU10 lampholders.
If they still want dimming, I fit dimmable LED's and retro fit a trimmable dimming module into their existing dimmer.

I don't really like dimming, instead I prefer switched banks of varying outputs.

I think the key issue in this thread is MR16, i.e. low voltage as opposed to GU10 mains voltage. The GU10 stuff is much more stable for the reason oldgit has stated. Basically the lamp has a driver built in, so all those issues are covered straight off. I'd still steer well clear of dimming personally, but thats a personal call.

So thats the answer to the questions about G4's and G9's in my opinion. Regarding selling to the public, its a case of the worn out turks head ........ we're a distibutor to the trade, and its a problem for me to do that, but all the advice above, which is pretty much on the money all the way through the thread should see you right.

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(A Frayed Knot 8) )

What brand did you get? Got a link perhaps?

Lidl own brand ones in the cooker hood so nothing special.

@twilight_monster, it’s not uncommon for hobbyists to find themselves in a situation where we can have a lamp in kitchen which takes 600W. Now 600W is actually a lot of power to be spent on a lamp. I think 7W Philips LEDs would be the accurate fit for your issue. I bought them recently and I’m really happy with their power saving as well as the colour which is not too bright that it irritates your eyes and not too dull that it looks yellow. The brightness of these lights is just about the right quantity.