Step 6: Attach the LED

You will need to pull apart the legs of the LED a little, but trying to keep them roughly parallel.  They need to be about 5mm (1/4") apart, but this is not super critical.

Now push one leg underneath the cell (will go between the card and foam), and the other leg should go above the cell.

If you have done it correct, when you press down on the leg which is on top of the cell, the LED should glow purple.

If it doesn't glow at all, pull it out, rotate it 180 degrees (so the opposite leg is on the bottom), and put it back in.

If it glows all the time (without pushing), you will need to pull it out, spread the legs further apart, and put it back in again.
How does the lead of the LED not touch the battery when you attach the second ID card?
The foam is a little thicker than the battery - this, and the previous step (spreading the legs of the LED apart) mean that they don't both touch at the same time unless you squeeze the card.
Dear Ultra Violet Light Business card thanks for your help from your idea &amp; synchronized with a few other Canadians, a sauna guy &amp; his Dad, I came up with a heated Trumpeter Swan Nest, just really a giant version of your uv biz card with a 12Volt battery portable that comes with a flashlight from Amazon, your black foam but so thick it hides the whole battery &amp; casing, with a trip switch instead of a pressure point, &amp; let the Trumpeter Swans figure out how to switch it on &amp; off themselves at night, through the waterproof ink printed on white viny sandwich top...I will post the picture on the bottom of my How to make a Trumpeter swan nest Instructable now...give me a 5 to do please...<br>https://www.instructables.com/id/How-to-make-a-Trumpeter-Swan-Nest/
Shouldn't there be a current limiting resistor in the circuit?
Well spotted! Actually we are bending the rules here but it is quite justified for a couple of reasons:<br><br>1) Typical lithium cells of this size can't source enough current for long enough to kill the LEDs (usually quite a bit over 25mA)<br><br>2) Minimal current flows through an LED anyway until you overcome their 'forward voltage drop' which is usually a little over 3V for white, blue or UV LEDs. As this is less than the cell voltage (around 3V) then we get only a small amount of current (but then again, less light than we could otherwise)
<font color="red"><h1>WOW!</h1></font><br><br>How were you inspired to make this?<br><br><font color="blue"><h2>Good Job!</h2></font>
I think i will do this for our makerspace, except I am thinking of replacing one of the cards with an rfid card since our front door is rfid controlled. I think this would add some function at a small price increase.
Nice idea!
Nice momentary switch. I'd bend the tips of the legs on the LED, so that they anchor into the foam. Angled outwards to not short against each other, of course. What about adding some EL wire to the outer edge of the card? Is there a driver small enough to insert into the foam?
EL Wire would be cool
And finally, what about using double-sided foam tape? Could be layered if not thick enough.
awesome idea!
Spray adhesive - available in art shops - might be tidier (more professional?) than hot-melt or double-sided. Just make sure you get the kind that works for your materials, there are many to choose from and not all stick to everything (that's why there are many to choose from, doh!)
Good idea - you will find though that you don't see the tape or glue when assembled , particularly as the foam rectangle is slightly smaller than the cards on either side.
I was only advising to hire a professional GRAPHIC designer for that element as the benefits are well worth it. I apologise that I was not more clear in my wording.<br><br>Have a nice day all!
Lasertag cards? Nice! That would be an awesome giftcard to a lasertag business. The giftcard should have a small laser. I've seen some 3mW red laser modules on ebay that had the lens cast in place around the diode, so it's a really small package. No link, sorry.
I think your idea is great! It would be nice to have a unit that put out all of the band widths of light. Why didn't you use higher wattage LEDs? With the cost of the Chinese one, five and ten watt units at good priced I have a 1 watt UV unit and a one watt IR unit with a 5 watt white. It does a good job for not much more money.<br><br>Cheers!
Nice project! :D
Very cool idea !!<br>I thought about using some of the rectangular LED's so they are much thinner but they are only available in certain colors and not clear white or Ultraviolet .<br>Blue is the closest color to U.V. that I could find on this link.<br>Perhaps try Ebay<br><br><br>http://search.digikey.com/us/en/cat/optoelectronics/leds-75ma-discrete/524729?k=rectangular%20LED<br><br>What about incorporating one of those tiny modules that you can record a message onto like you find in greeting cards and such.<br>They have such a thin profile that it could work.<br>It would only cost you the card to get it .<br>We use the RFID cards at work for the secure area passkeys.<br>They are already about 1/8&quot; thick but I'm not sure there is much more room inside one to add anything else to it.<br><br>
I bow humbly to your simple elegance in design and execution.
Hi, I have looked at all your cards...... Pretty cool. How bout these ideas?<br>-incorporate an EL transformer for mini electric shock?<br>-LDR+tranny for auto light up card in dark?<br>-something involving lasers?<br>-a mini vibro motor from a mobile phone to make a card that won't stay still?<br><br>Keep up the good work<br><br>Jonny
An electric shock?? ...oooo.... an &quot;Anti-Business Card&quot; <br>You could print them with the names of your competitors.
LOL :) &quot;Anti-Business Card&quot; very amusing
Hey, you could make a card flashlight (Torch) that had a white or red LED on one side and an ultra-violet LED on the other- a two in one. <br> <br>Put the Morse Code on the blank back. <br> <br>Great item for a Scout troop.
What a great idea! Have just now done a version of this (see second picture on first step (introduction)). Have only done one side, but would be very easy to modify for the other LED. Are you a scout leader? I'm thinking of offering some pre-printed kits and this would make a great variation - what do you think? <a href="http://www.lightboxdesigns.com/contact.html" rel="nofollow">Let me know if you're interested.</a>
Very cool :)

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More by tomward:Ultraviolet Torch Ultraviolet Business Card Flashlight Flashlight Business Card 
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