Downlighters

[Cj24]

Hi can someone clear up the difference between 12v and 230v downlighters for me obv I knw the main difference and all about the transformers but what would make u choose one over the other, I assuming one is more energy efficent but surely everyone wud choose this option or is it the less energy efficent is brighter too

 

[miner69er]

The biggest difference is.... If the transformer goes wrong, can it be accessed in the ceiling? Probably not. so i always use 230v downlights. also there is less fire risk as there is no transformer to set on fire somewhere in the ceiling where you won't smell it smouldering. Mrs miggins can't fit a totally incorrect bulb to a 230v light as most will accept both 20w and 50w bulbs. you wouldn't beleive how many times i have found melted connectors to the transformer because a 50w bulb was fitted and the sticker on the face of the light clearly states 20w MAX.
Hope thats helpfull to you

 

[Mark.W]

Another difference is that the 12V lights are a lot "whiter" than the 230V ones.

 

[Dazza1976]

Both are said to have their advantages. In terms of energy used there isnt much in it apparantly, The 12 V ones are said to use just as much energy if used with 50w bulbs.

The 12 V ones give a better light output, but I havent noticed a major difference. They are more expensive to install though because obviously you need to buy a transformer for each light, which is also another thing that can go wrong with them, but the lamp life is a lot better than the 230v ones.

The 230v ones are cheaper and quicker to install, but the lamp life seems to be far less than the 12v ones.

I will probably only use 230V (GU10) from now on, as I had a nightmare with my last job, with a loud buzzing noise at the mcb, which was apparantley due to the transformers being incompatible with the dimmer switch. Although the lamp life is less, there is far less that can go wrong with them otherwise.

 

[nick123]

IIRC, mains downlight lamps tend to (maybe always) have aluminium reflectors that reflect heat out the front of the lamp, whereas the 12V ones are often dichroic and reflect heat through the back of the lamp, though you can get 12V's with aluminium reflectors at typically higher cost. Another factor in lamps is whether they are constant colour or not, i.e. whether the colour changes over time, which can be an important consideration on an install. There are constant colour dichroics, but I can't recall whether lamps with aluminium reflectors are available as constant colour (or if they inherently are).

 

[ezzzekiel]

and usually customer provides 20 downlights and one transformer

 

[alarm man]

240v led ones are great for energy,but the light output is so poor..anyone found a decent led one yet?

 

[nick123]

The recent team up with Bridgelux (makers of LED's producing up to 4500Lm) and Molex to produce the Helieon modules is exciting (see youtube for some recent vids), and there are manufacturers using Xicato modules and others; when you've an LED pulling 2 amps or more per fixture at around 12V forward voltage, there are issues to deal with though. Heat management is the biggie, needing substantial heat sinking or even active heat sinks (i.e. heat sinks with a fan on them). Farnell will be stocking the Helieon modules, which don't include a heat sink so need to be mounted on a suitable base. There are also some reasonable modules using the latest Cree LED's with 50mm diameter lens arrays for 3 or 4 LEDs so that they can fit standard down light fittings. Heatsinking needing to be incorporated somewhere also gives some interesting designs to luminaires. So we're definitely getting there.

 

[nick123]

Here's one vid for the Helieon Module. [ame="http://www.youtube.com/watch?v=NKEOKvJKdpE"]Helieon module[/ame] Output stated as comparable to 75 to 100W light bulb (incandescent probably rather than halogen). Just bought a couple of modest 800Lm Bridgelux LED's to test, but haven't got the 1A constant current supply that they need yet

 

[alarm man]

good light output..but that case isnt going to look good on the ceiling..

 

[cjp1]

I really like the halolite mains voltage 11w enery saving downlights.
Good quality fittings and the halolite bulbs last for ages unlike the cheap GU10 cfl bulbs which I find keep blowing.
I think it was about £25 for the bulb and fitting last time I brought some from electricfix .

 

[Joe.Smith]

Hi, I don't think there is much difference between 12V and 230V lights or downlights, other than the obvious. Which one to install... I would decide it based on the system already applied or if the ceiling and the house you are going to use it at is highly flammable, would rather go for the 12V. Brightness or performance depends on the wattage, regardless of the voltage.
This Bridgelux looks pretty cool to me. Though I rather prefer any type of Cree as they have longer lifespan.

 

[Doomed]

Imho if your using them for display as yet 12v dichroics are still the best, especially on glassware.
I did see some nice LED lamps from halers lighting on display at edmundsons the other week. I'm looking for an opportunity to try them out.

 

[nickblake]

yes maybe not but you wont need a switch just shut the case

 

[nick123]

This Bridgelux looks pretty cool to me. Though I rather prefer any type of Cree as they have longer lifespan.

Not sure about the lifespan; Bridgelux quote 50,000 hours for at least 70% of initial lumens, which is good enough for me The drivers are far more likely to fail in that time. Cree have some great devices too, but cost 2 to 3 times as much for a similar output. There are some more useful lenses from Ledil for Cree and others, with standard 50 and 35mm sizes, whereas their reflectors for bridgelux are 45mm and some upcoming 70mm ones; I'm thinking, why not have added a 2.5mm rim just to bring up to a standard size.

Anyway, I fired up a modest 800lm BL warm white last night, after having a heck of a time soldering to the pads because the aluminium PCB was so effective at conducting the heat away. My solder paste seemed to have gone off so I couldn't reflow in the toaster oven, and soldering only worked once I wound the iron right up to 450C. I knew it would be bright, but I still wasn't prepared for the output, which was nothing short of huge. 3000K from the warm white is very nice, worked well with some coloured gels, and on its own there was ample light flooding the room I was in to work by. I've got it on now aimed away from me towards a wall because the old ceiling lights are dim in comparison. The medium and wide reflectors also work very well, giving an even distribution and no artifacts or colouration around the edges that you tend to get with halogen. Mounted on a large enough metal base, perhaps at a lower current (because an 800 might be too bright!) and with no reflector and spaced quite far apart, they could make very nice under cupboard kitchen lighting. Lumens per watt will presumably increase still further, but devices like the BL or a unit with several of the latest Crees definitely already beat other light sources once they're in usable packages.