Hey all,
I'm building an ISO A1 sized lightbox for university. The illuminated surface measures 650mm x 900mm. It is made of wood, with a thick perspex top (the surface for tracing), and stainless steel grates on all 4 sides for heat ventilation. Traditionally, these are illuminated by using 2 or more fluorescent tubes. The trouble with this is that they have to be plugged into a socket, get very hot, and wreck your eyes after about 40 mins. Not much help if you're going to be tracing architectural plans for about 6 hours straight! they also usually end up quite bulky, as the perspex has to be about 200mm away from the lamps or else it melts.
Basically, i was thinking of making one using LEDs. They're easy enough to diffuse, and if i used white or blue ones, they'd probably be bright enough to trace through (its one blank a1 sheet on top of another). I suggested the idea to a friend, and he estimated 100 LEDs, but he doesn't actually realise how bright they can be! I estimate a number closer to 15-20. (21 would give 3 rows of 7, which i think if diffused properly, should be ok)
So my big problem at the moment is trying to figure out a power source. Ideally, i'd like to use a 9v battery, or several 9v batteries, and totally avoid using a plug. The studio tends to lack in free sockets when it comes to projects and everyone's got their laptops plugged in!
Can anyone help me come up with a good power source and give me an idea of what kind of resistors i'd need. The perfect setup i'd like to have is an on/off switch and a dimmer.
Thanks all,
tm
I'm building an ISO A1 sized lightbox for university. The illuminated surface measures 650mm x 900mm. It is made of wood, with a thick perspex top (the surface for tracing), and stainless steel grates on all 4 sides for heat ventilation. Traditionally, these are illuminated by using 2 or more fluorescent tubes. The trouble with this is that they have to be plugged into a socket, get very hot, and wreck your eyes after about 40 mins. Not much help if you're going to be tracing architectural plans for about 6 hours straight! they also usually end up quite bulky, as the perspex has to be about 200mm away from the lamps or else it melts.
Basically, i was thinking of making one using LEDs. They're easy enough to diffuse, and if i used white or blue ones, they'd probably be bright enough to trace through (its one blank a1 sheet on top of another). I suggested the idea to a friend, and he estimated 100 LEDs, but he doesn't actually realise how bright they can be! I estimate a number closer to 15-20. (21 would give 3 rows of 7, which i think if diffused properly, should be ok)
So my big problem at the moment is trying to figure out a power source. Ideally, i'd like to use a 9v battery, or several 9v batteries, and totally avoid using a plug. The studio tends to lack in free sockets when it comes to projects and everyone's got their laptops plugged in!
Can anyone help me come up with a good power source and give me an idea of what kind of resistors i'd need. The perfect setup i'd like to have is an on/off switch and a dimmer.
Thanks all,
tm