Shadow-box?

[Uruk-Hai]

Hello Figureteers!

I promised myself to do a shadow-box. The work is going forward, but I have some questions regarding the electricity that I hope some of you could help me out with.

Im opting for a 12 Volt system to be plugged into the wall using a transformer or a charger.

The source could be a charger or a transformer?

The difference if Im not mistaken is that the charger is DC while the transformer is AC?

Bulbs runs longer time if the source is AC? How much is the difference in running time?

Is a fan needed to prevent damage from the lamps warming up the box?

I have a hard time finding a fan that runs on 12 Volt AC. Any tips?

The voltage in the wallsocket here in Sweden is 220-230 Volts. Suppose Ill bring this shadow-box to be, to Boston? If Im not mistaken the voltage in the US is 110 Volts and therefore a new transformator/charger would be needed? Where to get me one? Radio Shack?

Views, ideas and warnings are most apreciated.

Cheers

 

[homellop]

Hi Janne.
You'll be working with DC current on both systems,The only difference will be the transformer takes current from the main AC socket and transforms it into DC current.The batteries give you directly DC current.
I think every transformer can work with both current voltage,220(Europe) or 110(US,Japan).Ask in a Electronics shop to be sure.
How many lamp bulbs are you going to use?How many Watts each?What's the size of the shadow box?.These questions are important when you're planning the ventilation.But working with 12v bulbs doing some ventilation holes to allow the convection of air should be enough.
Hope it helps
jaume

 

[Brent Fordham]

The wall type plug-in transformers often, but not always, work on both 220V-50Hz and 120V-60Hz. Most of the power supplies I have for cameras and chargers work with both, but I have found some that only work for 120V. You just have to check on the transformer label or ask the store to be sure, and then get a plug adapter so that it will fit physically into the North American wall receptacle. HTH and good luck.

 

[Uruk-Hai]

Thanks for your inputs and advice, Jaume and Brent!

The scene is 11 cm broad, 11 cm deep and 9 cm in heigt. Its a closed room with stairs on the right going out of view(open end/no wall) and a large window on the right(there will be a backdrop outside the window). My idea is to have the main light source from the window since its daytime and some fills from the stairs. Perhaps some spots on the figures depending on how the other lights works out.

I have not establish the lights I will be using in this setting yet. At the moment Im building the scene and posing the figures. Ill get back once I made some progress.

I think I have dwell a little bit further into the ventilation question as well as Im not certain about vent-holes being enough.

The transformer voltage in the US vice Sweden. However, ELFA, the firm a bought the stuff from were very helpful indeed to a layman as myself so I hope that will be solved in a near future.

Cheers

 

[Uruk-Hai]

Forgot to add:

Ive read Shepherds Paines book as well as Ray Andersson, but I havent found much on ventilation, barely mentioned.

Cheers

 

[John Long]

Low voltage bulbs probably won't create enough heat to require any real ventilation. The front of your shadow box will be open and will likely provide all the ventilation required.

Transformers are actually rated by ratios. 10:1 etc. Assuming a 10:1 ratio 120v in will render 12v out. 220v in will render 22v out.

 

[Jim Hockett]

Another possible option? I built a boxed diorama of the Warriors firefighters raising the flag at ground zero. My light source was an LED lantern that I dismantled and re-wired. It will run for several days continuously on a set of batteries, and for occasional display they will easily last more than a year. The light is pretty white, which worked well for the dust-filtered effect I wanted, but that could be easily adjusted with colored acetate in front of the light. Not sure if it would work for your application, but I was very happy with the resuls, and plan to try another one one of these days.

Jim

 

[btavis]

I use cold cathode tubes which give off virtually no heat and least for years. There are several sites devoted to model lighting not just for shadow boxes but special effects. VoodooFX is one place where I get lighting supplies. The owner is very helpful on lighting projects.

 

[Uruk-Hai]

Thanks again for more answers fellow Figureteers.

I tested a Halogen 12v bulb that Ive bought. It had a tremdeous light but got hot in an instant. I actually recieved a light burn when I touched it for removal after no more than 12 seconds.

Some follow up questions though.

Jim.
These coloured acetats youre mentioning? Where can I find me a good selections of those? Shepherd Paine writes about coloured filters for theather light effects?

Bob.
I assume that you use the 4" cathodes. What voltage are they and do they run in AC or DC(which put together would form the name of one of my favourite rockgroups )? In addition, do you recomend and special colours for special settings?

Cheers

 

[homellop]

For the filters,you can take a look here: http://www.leefilters.com/
cheers
jaume

 

[Jim Hockett]

You can obtain the filters through a theater or photography supply house. Alternatively, you can purchase inexpensive report covers or dividers wherever school supplies are sold, cut them up and use them for filters.
Jim

 

[Uruk-Hai]

Thanks fellows.

So the filters are almost the same as the ones used in photography.

Cheers

 

[btavis]

If you are using the filters close to a lamp then they have to be theatrical gels as they are heat resistant. Transparent cellophane cannot take heat.Roscolux is one of the leading makers of theatrical gels.

 

[Bluesking]

Why not rig it to run off your mobile phone charger?

 

[Don]

Could you use fibre optics as a light source. Any number of small lights could be run off a 6 9 or 12 volt battery. The light source could be under your stairs consisting of one bulb, torch or flashlight bulb, can provide a lot of light via the optics and the bulb provides very little heat. Battery could be attached at back of box.
This would save you worrying about draging a charger across to the US and you could get a battery anywhere and with fibre optics the battery would last a while.
Hope this helps.
Don

 

[Uruk-Hai]

Thanks once again for your input.

The cell-phone charger is running DC which shortens the lifetime of the lamps, or so Ive been told. Im gonna further investigate in how much however.

Ive also bought some fibre-optics that Im evaluating and experimenting on. They come amazingly cheap.

Thanks for the warning, Bob.

 

[megroot]

Maybe another solution.

In my short carriere as a electrician maybe i can help a littlebit.
All trafo's you buy on the world are for 220 - 110 if they are CEE norm.
You can swith from 220 - 110 mostly with a little swith.
So that problem is dissolved.
For the lightbulb it doesn't matter if you used DC or AC. So if you buy a trafo that goes to 12V you can buy a automotive light. (carlight). If you buy the citylight you don't have a large fitting.
Every lightsource that is ready for 12 - 24 V will do.
If you use LED light than you have to equalize from AC to DC. LED's let the power go just in one direction. Because AC is from - to + from a zero line, you have to make it equal.
You can take for LED light a powersource from a PC. They go from 220/110 V AC to 5 -6 V DC.
The heat may no trouble. The power of a lightbulb with this is to light. If you use great carlights it maybe become a problem.
But if you have the powersource from a PC you can buy also a PC fan. It is used for cooling the processor.

Hope this is usefull for you.

Marc