Whether you’re fumbling for your keys in the dark or getting a late night snack, portable lighting is a handy thing to have. You may as well enjoy it with high novelty value by building an LED light into a mint tin. It’s reasonably simple, it’s cheap and offers the reward of a functional and visually pleasing gadget.
- 1x Mint Tin. Any tin of appropriate size with a lid will do. Mine measures 75mm x 40mm x 20mm.
- White 5mm LEDs. (DealExtreme) I recommend you use six, eight or ten LEDs for adequate strength. Must be a multiple of two however due to the way it’s wired up.
- 1/4 Watt 150 Ohm resistors. (Amazon) You need a resistor for every two LEDs in your light.
- 1x Switch. (Amazon) Can use many varieties of switch. I’ll be using a tact switch in this instance.
- 1x 9 volt battery (DealExtreme)
- 1x 9 volt battery clip (Amazon)
- Soldering Equipment including iron, solder, heat shrink tubing (electrical tape can substitute), wire cutters etc.
- A few tools including drill, bits, ruler, pencil and masking tape.
- Hot Glue Gun. Infinitely useful.
*Affiliate Links provided for suitable products on Amazon.com and DealExtreme.com
- Higher resolution versions of all tutorial images available in the build gallery at this link.
- Resistor values calculated based on a 3.2V diode forward voltage. This will be suitable for the majority of 5mm White LEDs however you may want to check the manufacturers specification.
- Use appropriate safety equipment.
Well there’s no use wasting delicious mints. Stash them elsewhere for future enjoyment.
Only the tin’s required where we’re going. I would recommend cleaning your work surface as your tin could get scratched and reduce the quality of the finish. Apply masking tape to the top of the tin and measure out where the LEDs will be mounted.
I’ve decided to go with eight LEDs. Once you’ve made your measurements, drill pilot holes with a small bit. Only apply light pressure when drilling to ensure minimal scratching or denting.
Drilling with a smaller bit and working your way up to 5mm using three or four bits will provide the cleanest finish. Going straight to a 5mm bit may produce some jagged or raised edges. Once drilled, you may also wish to smooth the edges with a file if necessary.
Remove the tape and use an LED to test that each hole has a good fit. You may need to widen some holes further with the drill.
Apply some tape on the side of the tin you want to place your switch. Measure and mark the switches location ensuring it will still allow the battery to fit in the tin and wont interfere with the lids closing once the LEDs have been added as it will add some bulk to the bottom of the tins lid.
Various switches can be used. If you have a dremel to cut the hole, you can install a slide switch (center). You can also install a toggle switch (left) or tact switch (right) using a drill easily. In this case I’m using a tact switch so I’ve drilled a pilot hole then out to the appropriate size to allow the tact switches shaft to protrude from the tin. If you’re using a different switch you may need to change to location or size of the hole to allow the battery to fit.
Time to start installing the LEDs. Each pair will be wired in series with a 150 Ohm resistor. Start installing the LEDs into each hole orientating the negative leg of each LED towards the perimeter of the lid and the positive legs to the center. The corner LEDs will have to be on a slight diagonal as all the negative wires will be connected later.
Bend the positive leg of each of the paired LEDs over to touch the positive wire of its partner, clip it to length and solder leaving the partners positive leg vertical.
Continue installing LEDs in the correct orientation and connecting the positive legs of each pair until they’re all installed and you have four protruding positive legs.
The negative wires will all be connected around the perimeter of the lid in a similar fashion to the positive legs. Bend the negative legs of each LED over to the next one, clip it to size and solder. Ensure you don’t connect any of the positive and negative legs together.
Continue this process working your way around the perimeter of the tin lid until you have two LEDs with unmodified negative legs remaining. Bend the second last LEDs leg so it connects the remainder of the LEDs negative connections and leave the last leg vertical so we have a single vertical negative leg.
We now have four vertical positive legs and a single negative connection. Clip the positive legs and one side of each resistor to around 5mm in length. Solder a resistor to each positive wire. Although it doesn’t really matter, it’s good practice to connect each resistor the same way.
You can now test each pair of LEDs. Connect your battery clip to the 9v battery. Temporarily connect the negative wire to the negative leg of the light, wrapping the wire around will do for testing purposes. Touch the positive wire against the long end of each resistor. If the pairs light up, you’re golden. The resistor is required to limit the current into your LEDs as they will receive too much if the battery was connected directly. Only connect the positive side of the battery to the resistor as you may burn out or reduce the life of your LEDs if you touch the positive directly to an LED pair.
Bend the resistors flat to connect towards the center of the lid. Bend one of the resistor leads vertical and clip the rest. Solder them together at the joining point. It should look something like the image above. Test the assembled light by connecting the battery.
Now we’ve confirmed it’s a working LED light, I’ll bring in my reliable old friend hot glue to secure the LEDs to the lid and insulate the connections. Apply hot glue around the wiring allowing enough clearance for the lid to close. If you apply too much, wait for it to dry and score the glue with a blade then peel off the excess with pliers.
Clip the negative and positive wires on the LED light to around 5mm in length. Solder the negative wire from the battery clip to the negative leg on the LED light. Solder the positive wire from the battery clip to a leg on your switch. Remember to use heat shrink tubing to insulate.
Cut a piece of wire a similar length to the battery clip wires. Solder one end of this wire to the other leg on the switch (If using a tact switch, solder to the leg diagonal from your previous connection to the switch like in the image above).
Solder the other end to the positive wire on the LED light. You can now connect the 9v battery and test the light by pressing the switch.
Install the switch by slotting it through the hole using a small pair of pliers and applying hot glue.
Connect the battery to the clip and slide it into the tin. Close the lid and you’re holding a mint tin LED light. Has a nice novelty appearance and will fulfill all your basic portable lighting needs. Here’s some other mint tin LED lights I’ve made using different switches and LED array sizes.
You can also try installing LEDs into other interesting and unusual housings.
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