LED Dimmer

[jactac]

I've recently installed 3 LED down lights fed from a 1 gang switch, but find that even though the LED's can be switched between 3 different light modes ( cool, warm, daylight) via an onboard switch in each LED unit, they are still a bit too bright.
The LED's are dimmable, so my question is, do I need a dimmer switch that is compatible with LED's or will a standard dimmer be ok ?


Thanks for any advice.

PS, The LED units are NOT low voltage.

[big-all]

yes you need both an led compatable dimmer and dimmer compatable leds

[Someone-Else]

It really depends on the LED lamps, some will work with a "normal dimmer" some will not.
There is also the "Minimum wattage" to consider. If you have not yet purchased a dimmer, look for one that says "Trailing edge" and make sure its minimum load is lower than the load of your LED lamps.

[yartin]

I bought LED BG dimmer from Wilko and worked with my China-import-ebay LEDs, I think they work on all.

[ericmark]

Unless the LED lamps are marked

Not-for-dimmer-switch.jpg (21.72 KiB) Viewed 2361 times

then they should work, seems daft but lamp manufacturers have to state if can't be dimmed not if can be dimmed, there is a Best Practice Guide 9 on use of LED lights, but in real terms it does not say how a dimming switch must work.

So there are three basic methods to dim a bulb, resistors, transformers, and wave form chopping, the latter is cheapest and most common, however if the bulb can be dimmed using the other two methods, it is dimable as so don't need to tell people it is non dimming.

Clipping the wave form well even just using a solid state switch, can cause the bulb to flicker, also most electronic switches which do not need a neutral need bulbs over 5 watt, and from bitter experience even 5 x 2.2 watt will not work, each bulb needs to be 5 watt. Bulbs have a little leakage so that the inductance and capacitive linking in the cable will not cause them to flash when switched off. However when the switch allows current to flow as well to work the electronics then often bulbs will flash.

The

Not-for-dimmer-switch.jpg (21.72 KiB) Viewed 2361 times

will be on the packaging and likely that has long since gone in the bin, I think it is unlikely a colour changing bulb will work with an external dimming switch.

[yartin]

I should also have said, the led must be dimmable. Not all leds are.

[Scotty001]

Jactac if you have the box the leds came in or the info/instructions packed Inn the box (that piece of paper) that's folded over so many times, has writing that can only been seen using the hubble telescope in 25 different languages, and is ignored by 99.9% of men (until we realise that yes we do need it, I'm stuck now) either will say if they are dimmable and what dimmer you need for them.

If you have done as most and binned the lot a Google search for that led, go to the manufacturers website and you should be able to get a spec sheet, datasheet and install sheet in pdf which will tell you if you can use a dimmer and which dimmmer you neetld to use.

[Someone-Else]

But he already said

The LED's are dimmable

............and IF the instructions say about a dimmer it will say use a "trailing edge" dimmer

[yartin]

Then buy from screwfix, has leading and trailing option.

https://www.screwfix.com/p/lap-1-gang-2 ... hite/273cc

[Someone-Else]

Nice find.

[jactac]

Thanks for your replies.
The box says dimmable.
but nothing about what type of dimmer !!
They are 5.5W each and I want to dim 3 of them.
There is an icon on the box like this but WITHOUT the X going through it

Not-for-dimmer-switch.jpg (21.16 KiB) Viewed 2330 times

[jactac]

Then buy from screwfix, has leading and trailing option.

<span class="skimlinks-unlinked">https://www.screwfix.com/p/lap-1-gang-2 ... 73cc</span>

I've looked on Screwfix for this but cant find it in polished chrome that matches existing switches that will be within the same location

[jactac]

But he already said

The LED's are dimmable

............and IF the instructions say about a dimmer it will say use a "trailing edge" dimmer

Why "trailing edge" and not "leading edge" ?
Screwfix have loads of "leading edge" in Polished chrome, Sod's Law Eh !

[Someone-Else]

Why "trailing edge" and not "leading edge" ?

Trailing edge dimmers work very well with LED lights, leading edge dimmers don't work too well with LED lights, they can (and do) create more hum and electrical noise, they are also not "smooth" when you use one to dim an LED light

Just saying: Technically you can't dim an LED, but you can pulse it very fast so the eye thinks it is being dimmed, also unlike old incandescent lamps, LED lamps don't change colour, where as as you dimmed the old style lamp it changed colour from being white to a orange / yellow colour, which was much nicer.

[jactac]

Theres an electrical store here called TLC, I think they may have trailing edge dimmers ?