Flip Lantern

This is a very simple lantern that looks both charming and intriguing. No buttons, no cables, no wall warts; just a jar. An ordinary upturned jar just begging to be flipped the correct way up, and when it is, the whole room is lit with its mysterious cool glow, just like magic! These lanterns make excellent night lights and can be carried through dark halls as they have no wires! I have made a few now and they are really cool, flipping just one over is enough to light up the whole room!

The lantern is very easy to make with just a few parts and tools. You will need to do a bit of soldering but only a small amount and the circuit is very simple. You will also need a method of gluing; superglue will work but I prefer the hot glue gun.

These lanterns use a 1 Watt LED; these little guys are super powerful! So take my advice when I say that it is not a good idea to look directly at an undiffused LED while on. The jars are frosted which diffuses the light but being excited to use these high power LEDs, the first thing I did was to get one lit up while looking directly at it and I was seeing spots for about 10 minutes after. SO PLEASE BE CAREFUL!!

With that said, materials and tools are listed in the next step :)

You will need:

• AAA Battery pack that holds 2 AAA batteries. Actually any combination or size of battery would work so long as the total voltage is 3V and they fit in the jar.
• 1 Watt LED - As mentioned before, these are super powerful and as such are often sold mounted to an aluminum heat sink. However, be aware that not all 1 Watt LED are sold this way! be sure they are pre-mounted on a heat sink. You can use any colour you like, I got 5 for £4.50 on ebay.
• Tilt switch - They are essentially small tubes that contain a metal ball, when the ball is at one end of the tube the circuit is broken, but when the ball rolls to the other end it becomes part of the circuit and closes it. Again, ebay, 5 for £2.50.
• A length of wire - about 2 inches should do it, but better to be over than under.
• Elastic Ribbon - Only a small piece, just a little longer than the diameter of the jar's lid.
• Glass Frosting Spray - I used Rust-Oleum frosted glass spray, gives a nice finish.
• Glass Jar - I used a Kilner brand jar for two reasons. Firstly, the lid is actually in two parts as shown in the photo, making it easy to work with. Secondly, they are being sold cheap a a local store :) But you can use any jar.

Tools:

A hot glue gun is what I used to do all the gluing but superglue would probably work too. You will also need a soldering iron and some solder. If you are new to soldering you can find many guides through your favorite search engine.

This first thing I did was to frost the glass. I used an old card tube to hold the jar while I sprayed the outside. It is best to take it slow for an even coat; too much in one place will cause a drip to form which doesn't look so nice. Also, even though you'll want to do this in a well ventilated area, be aware of the wind when spraying outside. If the wind is too strong it will just carry the spray away before it hits the glass, forcing you to move it closer and increasing the likelihood of a drip forming.

Once a nice coat has been achieved, you can place the jar somewhere to dry, I put the tube into a glass highball which held it nicely. It will take at least over night to dry but I recommend leaving it for 24 hours. While it is drying you can be working on the circuitry.

As you can see from the photo, the circuit is super simple. Simply connect the negative (black) wire from the battery pack to the negative pad on the LED (it is labeled with a little "-" symbol) and connect the positive (red) wire to either of the legs of the tilt switch. Then use your extra bit of wire (blue) to connect the other leg of the tilt switch to the positive pad on the LED (again, marked with a "+" symbol).

The tilt switch is non-polar. This meant that it does not matter which leg is positive and which is negative. However, the LED IS polar! this means the negative must connect to negative and positive must connect to positive. The LED has 4 pads; 2 positive and 2 negative. it doesn't matter which pair are used as long as the black wire goes to the negative pad and the red/blue goes to the positive.

Anyone with experience using LEDs might have noticed a lack of resistor usage. Normally I would never dream of running an LED directly from a battery. However, these 1 Watt LEDs are way more powerful than your standard LED and will draw about 350mA at their peak performance which requires 3.3 - 3.5V to do so. By under-driving them at 3V they draw about 200mA and are still pretty bright.

Now that you have your circuit made, you may test it (being careful not to look directly at the LED). This will also help you to get to grips with the tilt switch and understand which way up it must go when we fix it in place in the next step.

Now that you have your circuit made and working, you will now need to fix the tilt switch in place. If you haven't already found out by playing with your circuit, the LED will be ON when the legs of the tilt switch are pointing DOWN and will be OFF when they are pointing UP.

You will need to glue the tilt switch to the battery pack so that it is in the OFF position as you are working on the inside of the lid. The legs should be pointing up as shown in the photo.

The elastic ribbon will be used to make a little battery pack holder that secures the electronics to the jar lid while still making it possible to slide the battery pack out to change the batteries. The photo shows a strip of elastic ribbon holding a battery pack in place, this is to give you an idea of what we're doing with the ribbon but I later found out that it is of benefit to thread the ribbon through the circuit loop before gluing it down as shown in the third photo. Doing this will make the wires easier to tidy away.

Once you have glued the elastic ribbon in place the last thing that need to be done is to glue the LED to the ribbon. Excess wires can be tidied away under the ribbon and the whole lot can be slid out to change the batteries. It should be noted that the blue wire in my photo is about 1 inch long and is actually a but of a stretch to remove the battery pack, this is why I recommend a 2 inch length even though it does not look necessary, it does in fact help a lot.

Finally, just put the lid on the jar and enjoy your new flip lantern :D

If you have any issues or problems just leave a comment or send me a message and I will be happy to help.