Dimmable LED Dichoric Lamp

[ultinator]

Hi all,

I read that dichoric MR16 are being phased out due to heat reflection and are not advised to be used in recessed lighting.
[h=1][/h][h=1]I replaced some LV mr16 for dimmable cob gu10, and replaced the dimmers to suit. worked fine for a short time, then it stopped dimming, then stopped working........

there was 3 dimmers,

one with 2 x 5w dimmable cob on a 10-100w dimmer
one with 5 x 5w dimmable cob on a 10-100w dimmer
one with 8 x 5w dimmable cob on a 40-400w dimmer

The circuit with 8 x 5w remains functional....
So i was considering options and thought to buy better dimmable bulbs and saw these:[/h][h=1]Philips Master 240v 7w GU10 Dimmable LED Dichoric Lamp - Cool White

But my concern was with the dichoric reflector, but i could only find negative info regarding it, but that was all in reference to 12v 50w mr16, which obviously get hot enough to roast a marshmellow....

would the advisory to not put them in recessed fittings (downlights) still remain, or due the lower heat emissions of LED's would this be sweet as a nut?

cheers[/h][h=1][/h]

 

[SJD]

Just wondering, your post suggests you might be needing better dimmers rather than better lamps ... (if the dimmers have now failed) ?

 

[Richard Burns]

No LED lamps will be dichroic, but they will run much cooler than tungsten halogen.
To be dichroic they must have an IR transparent rear surface and all LEDs will have the control gear at the back.
There is no problem with fitting an LED lamp in a downlight, so long as it physically fits.

As SJD says make sure you are using dimmers that are suitable for LED lamps and lamps that are suitable for the dimmers.

 

[Guitarist]

It's amazing how often I find Dichroic in d/l's with the cable cooked above. I can't see an issue with any LED in place of a halogen in a d/l, as the heat output is minimal.
Not only is it important to get the correct dimmer, but also the correct trannie for LED lamps.

 

[ultinator]

[h=1]Varilight Trailing Edge Push Dimmer 3G 1/2W 3 x 300W/VA

This be the dimmer that done be used on the thing i done did, is that suitable in your professional opinions[/h]

 

[ultinator]

why do i need a trannie, the ones i fitted are cob gu10's so all the wizadry is on board surely

 

[Guitarist]

why do i need a trannie, the ones i fitted are cob gu10's so all the wizadry is on board surely

My bad, misread...

 

[ultinator]

sorry for being blunt, i am thankful for all relative posts. It just seems there is some inherent problems with dimming led effectively at the moment.
I considered using LED mr16 but heard that its better to use mains....no im starting to wonder, maybe a couple dummy dimmers will suffice haha

 

[Richard Burns]

Varilight Trailing Edge Push Dimmer 3G 1/2W 3 x 300W/VA

This be the dimmer that done be used on the thing i done did, is that suitable in your professional opinions

Should be a good dimmer, V-pro are better than LEDlite in my opinion.

 

[ultinator]

well it worked and looked great, i like the way they kinda dim up when turned on, then noticed the one with 25w load cut out intermittently, so had a fiddle. seemed ok again. then showed a tenant of the clients and poof, no dimming. impeccable timing. so back tomorrow to change the dimmmmmer. (originally had 2 x 1 gang varilight dimmers and put onto a triple front plate with a 40-400w dimmer)

hopefully it will be sorted with a ready made 3 gang

 

[ben2012]

I've been told by my local wholesaler that the lamp manufacturer should recommend a specific dimmer, bare in mind that due to the low wattage of LED lamps the loading might not be large enough for the dimmer to function correctly. If you've only got 2x 5w lamps on one dimmer the dimmer might not be rated low enough for it to operate correctly.

 

[SPARTYKUS]

Its a different kettle of fish, dimming a LED.....

I remember fiddling with the little red, green and yellow ones you could get from the electronics shop in the late 70's /80's, I used to string all the batteries in the house together to see how bright I could get them...which was quite bright

 

[Guitarist]

As already said, match the dimmer with the LED based on manufacturers recommendations.

 

[Pat Tester]

mains leds are not a purely resistive load, two lights may be well below the dimmers rated minimum load. You might try a dummy load resister in circuit to assist the dimmer.

 

[ultinator]

just thought id feed back, yes my concern was that the 2x5w bulbs may be too close the the 10w minimum rating and so they have been replaced with 6w which seems hunky dory.
The circuit with 5x5w turned out to have a faulty lamp. which had tripped the breaker after i left, maybe the bulb was damaged in store or something...replaced that and got a 3 gang dimmer and all is good in the hood.
excellent results now.