August 4, 2021

Make your own floating light bulb jar lantern

Jar Lantern Main Image

This floating lightbulb lantern is not only beautiful, but perfect for use during emergency situations as well!

Jar Lantern

Do we still need to state the obvious? This DIY jar lantern is made from a CFL lightbulb and a jar that’s just big enough to contain the bulb. It’s easy to store, very handy. And because this lighting is enclosed in a jar, you can definitely use it even when it’s raining. 🙂

But what we like most about this DIY lantern is that, unlike standard emergency lights, you don’t need to charge it for hours before you can use it. (Not to mention that some emergency lights lose power if left unused for a long time, which will require you to recharge it. Good if you remember!) As long as you have an ammunition of AA batteries, you’ll survive with this DIY jar lantern.

It’s beautiful floating light effect makes it a nice side table or night lamp. You can also make it a travel essential to bring for camping trips or trekking.

Why not make one for each member of the family? 🙂

Materials:

  • Jar with Lid
  • CFL Bulb
  • Disposable Camera
  • AA Battery Holder
  • Switch
  • Magnet Wire

Tools:

  • Soldering Iron
  • Screwdrivers of different sizes
  • Diagonal Cutting Plier
  • Razor Blade

Steps:

Jar Lantern

Open the disposable camera: Open up the disposable camera case. Be mindful not to touch the large capacitor which could potentially give you a nice jolt.

Jar Lantern

Cut away capacitor and flash: Discharge the capacitor by bridging the leads with a long screwdriver that you don’t care much for. Be careful not to be touching the metal part of the screwdriver while doing this. Once discharged, cut it from the board so that it will not recharge.

Jar Lantern

Also, cut the flash tube away from the circuit board.

Jar Lantern

Hack a CFL: Use a pair of diagonal cutting pliers to make a hole in the plastic body of a CFL bulb.

Jar Lantern

Next, use this hole to insert a screwdriver and gently pry the the base apart from the glass tube.

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Finally, unwind the CFL tube’s wires from the posts on the circuit board.

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Bridge the switch: Remove the push tab atop the flash charge switch. Solder the switch’s terminals together.

Continued Page 2…

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Prep the CFL Bulb: Scrape the coating off the wires coming out of the CFL bulb using a razor blade.

Jar Lantern

Twist the wires together and tin them with solder.

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Remove extra parts: Remove any parts the stick out from the board such as battery terminals.

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However, remember to make note of which terminals on the underside of the board they are connected to for future reference.

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I also removed the wire connecting the top of the trigger transformer to the flash tube for the heck of it.

Jar Lantern

Trim the circuit board: Trim away any corners that have unnecessary electronic traces (or no traces at all).

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Prep the magnet wire: Strip away 1/2″ of plastic coating from both ends of two 3″ pieces of magnet wire using a razor blade.

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Hack a camera flash: Now is time to connect the wires to the board that will power the light.

Solder the first magnet wire to one of the terminals connected to the ground plane.

Jar Lantern

Solder the other wire to the terminal of the inverting transformer that the diode is connected to.

Note: If you are confused, a more hands on way of figuring this out is to use aligator clip jumper cables to connect the battery to the board. The board should now be live, so be careful of high voltages!

Using another cable, connect one of the bulbs leads to ground. Finally, connect a fourth cable to the other battery lead. Briefly touch this wire to various spots on the board until the bulb lights up. Once its lit, you have found the proper connection.

Jar Lantern

Connect to a switch: Trim the battery holder’s red wire in half. Solder the trimmed pieces to the center terminal of the switch and the red wire still connected to the battery holder to the switch’s outer terminal.

Continued Page 3…

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Drill the lid: Drill a 3/16″ hole near the outer part of the lid for mounting the switch.

Jar Lantern

Mount the switch: Pass the switch up through the underside of the lid and lock it in place with its mounting nut.

Jar Lantern

Connect power to the camera flash: Solder the red wire from the switch to the spot on the camera flash circuit board where the positive terminal of the battery was connected.

Jar Lantern

Solder the black wire to ground.

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Hot glue: It’s the perfect adhesive for connecting the circuit board and battery holder to the inside of the lid.

Center them inside the lid and then glue them in place as flush to the lid as possible.

Use a generous amount of glue, but be mindful of not getting any on the lid’s inner edge, or it will no longer twist shut.

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Connect the bulb: Solder one of the magnet wires to each of the CFL bulb’s leads.

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Insert the battery into the battery holder.

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Twist the lid onto the jar.

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If the lantern is not already on, power it up by flicking the switch.

Jar Lantern

Go forth and make good use of your new lantern.

Thanks to  for this great project!

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