Easy LED Color Changing "Candle"





Introduction: Easy LED Color Changing "Candle"

About: Science Geek! Been to Space Camp 3 times and want to go again!!

This is a simple color changing light that is great for kids and adults. Looks beautiful in a dimly lit room, great for the holidays, and makes a pretty cool night light.

Step 1: Materials

Glue Gun - We are using a low temperature glue gun. It hurts when the glue touches your skin but it does not burn your skin

3V Battery

Film Canister - With inside closing lid (Fuji style)


Two Magnets - One must have a hole in it and not be bigger then the battery. The other magnet must be small enough to fit into the lid of the film canister

All these parts can be bought off of e-bay. We will be selling kits at Cat's Science Club if interested.

Step 2: Make the "Candle"

Take your LED and bend the longer (positive) leg at a 90 degree angle.

Insert the short (negative) leg through the hole of the magnet.

Bend the short leg up and around the magnet as shown.

Add the battery negative (-) side facing the magnet and LED.

Bend the longer leg around the outside of battery as shown.

We like to bend the positive leg around so that it is not touching the battery. There is a bit of a spring in the wire. In this way, when we set the "candle" on to the base the pull of the magnets forces the leg to touch the battery, causing the light to go on.

Hot glue around the bulb of the LED.

Move battery around to adjust as needed.

Step 3: Make the Base

Take the second magnet and check its polarity. We do not want the magnets to repel each other when we try to connect them.

Take the second magnet and glue it into the lid of the film canister. If the polarity is correct it will pull the "candle" into place. Do NOT put "candle" on to base yet. Test polarity before gluing.

Add glue around the top of the magnet that is in the lid. Do NOT over do it. A nice thin layer that stays inside of the lid works best.

Let all glue dry.

Step 4: Altogether

Now it is time to put it altogether.

Once the glue is totally dry, put the LED, magnet, battery ("candle") onto the film canister lid, magnet (base).

Adjust as needed to get light to turn on.

Put film canister over the light and snap into place.

Simple, easy, and very cool looking.

Step 5: Alternatives / Suggestions

Instead of the bead of glue on top of the magnet in the lid, add a washer to the lid. It provides for a better connection with battery, a flatter surface to set the "candle" onto, and it looks nicer. BUT it is not necessary.

The light can be turned off pretty easily just by sliding it out a tiny bit to stop the wires from completing a circuit (touching the battery on both the positive and negative).

Flip the battery around to turn off the light or for storing.

Light does not turn on? Try sliding the battery around to adjust where it is touching the legs of the LED. Is the positive leg toughing the positive side of the battery? Is the battery upside down?



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    Hi there sorry to bother you but i wanted to ask if i wanted to make an led that turns on when you light it with fire how can i make that and what will i require please

    4 replies

    No bother at all. Light it up with fire? Perhaps that statement did not translate. What are you trying to do?

    Hi there what i meant to say was i would like to make a candle and add a led to it but would like the led to switch on when the candle is put on and switch off when the candle its put out

    On ours we simply take the battery out. There are tea lights that are sold that have an on off switch that we replaced the LED with a color changing LED. Then we put the film canister over the tea light.

    When we tried putting in a regular on off switch on our design, we did not like the looks of it.

    Hi thanks for that but that is my issue i dont want it to have a switch i want it to light up with fibre optic and normal wick

    The battery life varies. We have had them last just over a week when on constantly. They will last much longer if you only have them on when you are using them.

    I think it would be a good idea to specify a colour changing RGB LED because some people may think you are talking about a 4-pin RGB (which are more common). Also, great instructable!

    Here is a short vid of me lighting up a slow change RGB with nothing more than a 3V button cell....


    but why does it change color? is the voltage changing? or is it because the self induced magnetic field (due to the current flow) interacting with the voltage?

    2 replies

    The led has a chip built into it that controls the color change.... You have to do nothing but be sure the polarity and voltage is correct... All the rest is automatic... Just be sure you get a SLOW CHANGE led... A fast change one will drive you crazy like police car flashing lights...

    i think you have to use a color changing led

    Have you tried it yet? Pretty easy. We have had fourth graders build them :-) and they had very little trouble.

    I saw on cat's science club's Facebook page the video of these. Very very cool!!!!

    1 reply

    This is incredibly clever and the old canisters I had lying around are about to get turned into cute stocking stuffers! Thanks so much for the idea.

    1 reply

    Made 52 of these in a few hours or less. I was playing with my phone too. ;-)

    How did yours turn out?

    Very cool. I love the changing colors.