Thin flexible low-heat light source

[richard]

Hello

 

Doe anyone know of a thin, flexible, low-heat light source, a friend is currently trying to make a kind of wallpaper which is decorated with light, so preferably needs something that can just be glued on to the paper. It woul hopefully be low voltage and very thing?

 

I have seen that the RSC use some funny kind of rope to lay across the front of their stages during techs, it then glows when light is applied, but I have no idea where they get it from and I haven't seen it anywhere before.

 

Another option, I would have though, could be fibre optics, but I am not sure of the best way to implement that!

 

Cheers

 

Richard

[colinmonk]

You could use side emitting fibre optics running up the wall from a fibre source, could then have a colour change wheel in the source, not sure how efficient they would be though....

[Brian]

What sort of lengths does he need? One option would be electroluminescent materials. Farnell sell 'wire' in a variety of lengths and colours as well as sheet material.

 

EDIT

 

just spotted the 'low'voltage' bit, EL needs a few hudred volts to run (at very low currents) but you use a small inverter so your main power is around 12 volts.

[Tom Baldwin]

Electroluminescent sheets (for example, Farnell p/n 393-4664) fit the bill for thin, flexible cool running light sources, but using them on the same scale as wallpaper would cost a *lot* of money (1 off A3 sheet is £63.79). There's not a massive range of colours available, and the brightness isn't great:

Brightness: Typically 70-100Cd/m2 when driven at 115V, 400-600Hz

They run via an inverter which delivers the low current, high(ish) voltage AC to drive them.

 

Is your friend really trying to wallpaper a room with an emissive material? :D

 

Depending on the constraints of the project, would UV be an option? Paint UV active paint on the areas which are required to glow, and illuminate with the appropriate source (UV tube, or Lee 181, depending on how contrary you're feeling ;) ) - if so, take a look at:

Wildfire FX

or

Glow Shop

 

Finally, one other possibility - how about the insanely reflective material used to make the white stripes on high visibility clothing?

 

Keep us posted on this one, sounds interesting!

 

Cheers,

 

Tom

 

EDIT: Why does Brian always type faster than me?

[richard]

That wire sounds interesting, doesn't need to be too LV, but needs to be safe - so high voltage may not be good??

[MattH]

Hi Guys,

 

Could be wrong but EL generally works on a high frequency rather than voltage. You could therefore run it from mains or low voltage as long as the frequency is around 400Hz (hence the invertor battery pack).

 

It's this high frequency that'll give you a nasty nip from a 4v battery pack (similar I suppose to electric cattle fences)

 

Matt

[egw]

Hi,

 

Could you not use a phosphorescent material in the same way as those little glowing stars you used to be able to get from the Gadget shop - these people sell the things I mean:

 

Glowing stars

 

When I was younger a friend of mine had wallpaper with miniture stars embedded in it which glowed in the dark, is this the sort of thing you have in mind? If so then these glow in the dark paints may present an alternative (or they might be able to help):

 

The Glow company - paints

 

By the way, whilst I don't know much about EL stuff an electric fence generally uses at least 2000v. However, power is only supplied to the fence in pulses lasting a few microseconds so the shock is painful but not dangerous.

 

cheers,

 

Ed

[gareth]

I seem to be recommending Howard Eaton Lighting a lot these days! Perhaps I should speak to him about a commission!

 

Howard's stand at PLASA a couple (perhaps 3?) years ago was showing some rather neat low-profile electroluminescent strip, in a variety of colours, that was a few mm wide and flexible enough to be bent around some pretty tight contours. More than that I can't recall, I'm afraid, because I was paying too much attention to the "Hell" beer that Sue was handing out ... :)

[Brian]

Just found some info I was looking for yesterday...

 

I once had some pricing from an outfit in Leicester called E.L. Technology on EL films. A look on the web shows their web-site not working so they may have gone bust but...

 

they used to be able to supply film in up to 1m x 2m pieces which they could screen print onto (lots of beer pump signs now use the technology). A single piece of unprinted film A0 sized (that's 16 sheets of A4) was £375.

 

The nominal voltage to drive the stuff was 115 volts at 400Hz.

[Guest lightnix]

On the electroluminescent front, you could always try "el-wire" (or "el fibre). It will probably work out cheaper than EL sheets, comes in 10 different colours (although the "white" is very green), four different diameters and can be driven by a variety of cheap battery or mains powered inverters. I'm thinking of using some 5mm on the stall this summer. You could make star shapes out of old wire clothes hangers and fix it to them.

 

I got some el wire as test materials last year from Coolight in the US, although there are other suppliers. Don't forget to add shipping, VAT and duty to any US$ prices you see.

 

It is the frequency at which EL material is driven, which determines how brightly it glows. The brighter you run it, the shorter its "working life", which is defined by the manufacturers as being the time it takes for the output to decrease from full strength (when new) to one third of that level. If you run EL material at 400Hz, the working life will probably be a few thousand hours; if you ramp it up to 8kHz, you could be looking at just a few hundred.

 

The real pain with el wire, though, is that it is as fiddly as f :) ck to solder up, involving stripping two layers of insulation, without breaking the two, hair-thin outer wires which wrap around the electroluminescent core and then messing around with little bits of adhesive-lined black heatshrink.

 

However, if you have the time and patience, you could get a really good result.