Opposites Attract: a Magnetic LED Valentine Heart





Introduction: Opposites Attract: a Magnetic LED Valentine Heart

This Instructable will take you through the steps on making a magnetic LED valentine by which one can convey their feelings through a thought-felt message and glowing red LEDs. ;) Send your loved one one half, get a puzzled look, and the unite the two to form the one Valentine to RULE THEM ALL!

Please rate this if you like it! Thanks!

Step 1: Gather Materials and Cut Out Your Heart (from Cardboard)

What you need for this project:

~Four (4) red LEDs, any size/shape
~Four (4) small magnets
~Cardboard to cut the heart from
~A 9-volt battery & clip
~One (1) 330-ohm quarter watt, 5% tolerance resistor
~A soldering iron

Start out first by cutting out your two heart halves from the cardboard or other material you obtained. I just cut once by duct taping the two halves together and sketching a heart on one side.

Step 2: Add Your Message!

Pour out your heartfelt message onto the heart through your own handwriting or via a printout. I ended up doing the latter because my handwriting is so-so. .

My message read "You Complete Me", pun very much intended. I grabbed some rubber cement and glued that sucker right onto the cardboard.

I positioned the LEDs four on each side to solder in a series circuit connected by the magnets later on.

Step 3: Wire It!

I first tried a simple circuit out with the magnets to make sure it works. I then proceeded to wire up the existing LEDs mounted in the heart to the magnet combos. I decided I would be wiring a 9-volt battery out through a 330-ohm, quarter watt, 5% tolerance resistor to power the LEDs. When I saw that it worked, I then hot glued the magnets, LEDs, and the battery clip into place.

If anybody who knows more about electronics and could teach me how to better use battery power or use a better circuit, let me know via a comment or on my orangeboard. Thanks!

Step 4: Clean-Up -- Make It Fancy

I finished up the design, got rid of those pesky stray hot glue wires, and added some red ribbon for the full Valentine's day effect. It was complete. The beast had been created. Enjoy!



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    21 Discussions

    well i made one myself changed it a lil bit added a pager motor so when it contacts it vibrates and its double layered to hide batteries and stuff


    I have used this instructable to make a gift for my wife, very original, thank you! Only I have used wood instead of cardboard. As PMCharlemagne_920 said, using aluminum foil to cover the magnets did the trick, although it was a bit tough to solder the wires to the magnets. Thanks again for a great idea!

    2 replies

    That's great! Did she like it? Also, did the 120 ohm resistor work?

    I had a different setup because the leds I got were 3 volts, so I did not need a resistor at all :) And yeah, she liked it... who wouldn't?

    1st of all cool post & how did you solder the magnets without demagnetizing them 2ndly you could parallel the LEDs & reach the exact voltage with button cells making it less cumbersome ;) but also killing life span :(

    1 reply

    Thanks, and as for the soldering of the magnets, I'm not exactly sure why it didn't demagnetize, but there seemed like there was a coating on them, which could be the answer. Also, there would be less heat needed to add the solder for the small magnet, so that may be the reason. Either way, it worked. If anybody could clear this mystery even further, it would be appreciated.

    Thats pretty cool... I like the use of the magnets as part of the circuit :)

    1 reply

    Awesome idea! I'm going to go a bit more crazy with the decorations and stuff, but fortunately I have until Friday before we exchange gifts :)

    Just a heads up for others who are interested, if you can't get the magnets like the kind he has there (my Radio Shack only had ceramic ones that have no continuity in a circuit), you can wrap them in aluminum foil to create the connection. I did a quick test without any wires (just touching one 150 ohm resistor leg to the + side of the battery, the other trapped between 2 foil-covered magnets, the + leg of the LED touching the magnets, and the - leg touching the - battery), and it worked fine.

    I plan to have 2 circuits (and a 9v on each half to power them) on my heart though. The first is with bright red LEDs (3000 mci) set up like your's on the outter edge.
    My second circuit is tied into the idea to have interchangeable messages on the heart. I'll have "So Happy Together" instead of "You Complete Me" and they'll be held on via magnets. I'll have other magnetized messages that can be substituted in too (Happy Valentine's Day, Be My Valentine, etc.). When all 3 message spots have a magnet holding a word in place, 6 other LEDs will light up (dimmer ones from the Radio Shack assorted bulk pack). There may be an easier way to have continuity depend on the messages, but my plan is to have 2 magnets on the underside of the heart close to each other but not touching. The message will have a longer magnet on it, connecting the 2 under-magnets. Sorta like this:

    [====] <-- Message with magnet on the bottom
    - ----- ---- <--poster board or cardboard or whatever I make the heart out of
    [==] [==] <-- Magnets underneath the card

    It'll take some work to keep the 2 under-magnets from snapping together long enough for the hot glue to hold them in place, and to make sure that a connection is made when the message is put into place, but I think it's doable.

    Anyways...again, thanks for this idea! Excellent Instructable for this week!

    1 reply

    Cool, I'm glad I gave you a good gift idea! That sounds pretty sweet, I'd love to see it when you finish. Post some pics here when you do, if you don't mind. Thanks!


    11 years ago

    A nice decorative touch might be to spray the card with a fixing glue and covering it with a gold/silver glitter. Then using wood PVA (one it had dried) write out your message, and cover with a different type of glitter. No good if you can't write like me, but will give it a nicer finish. Girls love glittery things, much in the way that males are attracted to blue LEDs

    1 reply

    "..much in the way that males are attracted to blue LEDs" Haha you got that right! I'll have to make an improved version sometime with that. Thanks!

    Wouldn't a 120 OHM resistor be sufficient for this setup?