If you want to build it and test it out (if you beat me to it), please post of a better version of the schematic you're using. If it doesn't work exactly like the original, then there is NOTHING stopping you from posting the schematics up and ACTUALLY making the thing open. I know it doesn't work exactly like the original, and as far as I'm concerned, that's a good thing. There is a thread on a Polish electronics forum where someone (ostry_18) has made a demo (with schematic) that works pretty much the same: I'm not really sure what's going on there at the output end, and I haven't gotten around to building anything yet to try it out. I do know that it's 'heart' is an LM324 quad-op amp. I'd quickly change that 'open source' part around real fast. At least the tables USED to be DIY, but now they sell them pre-built? If I had the money to get one of their sections. these LED sections (and most of their products) are neither. Be warned that you should not look directly at superbright LEDs for more than a moment, as you can permanently damage your eyesight.That's been my beef with EMS for a while now. You may wish to use both white and blue LEDs, but have separate intensity controls so that you can vary the color anywhere between all white and all blue.īefore you invest in dozens of LEDs, I suggest you just obtain one or two of various colors that are of the superbright variety. For something like that, you would need a PWM drive in addition to the current regulation.Īlso, you may not be happy with all blue LEDs. However, that leaves you with no practical means of lowering the intensity of the LEDs should they prove too bright. For the most simple current regulation that would give a stable current, an LM317 or LM317L per string would work. Power supply: it's not really necessary that the power supply itself be regulated, if you use current regulation in each string, like Bill was saying. Figure out how far away LEDs with that kind of viewing angle would have to be from your plexiglas diffuser in order to ensure a reasonably even illumination and diffusion. Since you are familiar with architectural drafting, you must have at least a fleeting acquaintance with mechanical drawing.

You need more like a 80° to 110° viewing angle. You would not have room enough inside the box to get far away enough from the diffuser to spread the beam. You would wind up with 40 moderately bright dots on your plexiglas diffuser. The viewing angle of the LED's you're considering is 4°. With this one, i was just wondering how hard it would be to put a simple on/off switch in to the circuit?Īll these things in mind, could someone possibly give me an idea of what way to go about the circuit, like for resistors, series/parallel etc? i just do not know where to start. SO the new problem is, do i chance Blue LED's? They probably would be bright enough that we could still see the pencil through it, right? To quote: '446 to 477 nm wavelength light is supposed to be the most effective for treating seasonal affective disorder (second to natural sunshine, of course).' which is blue. HOWEVER, i also came across an interesting article which explained how blue led's are better for your mood than any other light. They'll be approx 50-75mm (2-3 inches) away from the plexiglass. Fixing them to the surface is no problem at all. The main problem here, is deciding how many LED's ill need. Firstly, the LED's themselves will be diffused, but also, the plexiglass they'll be illuminating will be diffused too. They're actually going to be sort of dual-diffused. Ok, so the dimension of the illuminated surface is 600 x 900 mm (or approx 64 x 35 inches). My questions for this is, 1) How can i tell which wire is + and which is - (One of the wires has a white stripe on it by the way) and 2) will 3v be enough to power the leds? The other problem with this is that it's only a 3v charger. (is there some way to tell which one is which?) It's an old Minidisc charger. The wire itself coming out of the plug is split in 2, so i'm guessing thats a + and - wire.

I did some research, and i've decided to use a normal DC adaptor. I've a few questions, so maybe someone could help me out: I know a limited amount, but not enough to make this circuit. So i figured one out of LED's would be a)less painful on the eyes b)lighter, skinnier, and generally more mobile, and c) less roasting.īasically, im not too knowlegable about circuits. However, when you're tracing drawings for 5 hours over them, you roast and become very dehydrated. Traditionally, these are made using fluorescent lights. Finally getting going on this, now that i've found out that i've passed all my exams.īasically, I'm making a Light Table (Or Light Box) using LED's.

Led lighttable