"Dead" Battery Lamp

When batteries don't give enough juice to gadgets, you think that they are completely dead. But, all of them still have plenty of volts, and with a simple circuit you can unlock all of that power. This instructable makes an LED lamp which will suck all of the juice out of those batteries. If i had rechargeable batteries, such as sanyo's eneloop, I would never need to do this.

This is whats called a "joule thief" and it is an adaptation of those.

Step 1 Parts

You will need:
1 3904 transistor
Some 3 volt Super-bright LED's
1 1000 ohm Resistor
1 Ferrite Torroid
2 Different Colors Of Wire
1 AA Battery Holder
Shrink Wrap Tubing
8 in. of Heavy gauge wire
Altoids Tin
Cheap Wire
Tools:
Soldering Iron & Solder
Wire Strippers and Cutters

Comments

[HamenChips]

I wish I could something like this.

[starwing123]

Can this be used for commercial purposes?

 

[aliyevzaur1989]

What if i use NOT dead batteries? And please explain me how it works Thanks

[Jodex]

It would give too much volts for your LED and the LED might go broken.

[wizzywoo]

can someone please tell me the dimensions of the toroid as im trying to get one fom maplins?

[Jodex]

Well pretty much any size will work. About one-two centimeters is good. From a old computer motherboard you will get couple that works fine.

[raykholo]

can u give me an idea of the specs for the toroid when its made (meaning after the wiring...) i wanna build a smaller version of this so im just gonna get an already built one of these

[Derin]

10 windings of each wire

[raykholo]

sounds about right joule thief uses 8 thanks

[bobtrial]

Add the length of the wires IS "Take 2 same lengths of wire " Recommend "Take 2, 10(??} inch lengths of wire" Bob

[boullie]

That depends on the size of your toroid, just take enough to get 10 winds...

[mortaldoom780]

This is a good instructable. I see you saw the 'Joule Thief' HOW TO in MAKE Magazine. One thing to note is that you should include a schematic. All these written steps are good, but they can get a little confusing. I had to link to THIS site to build mine properly.

[imakethings]

will i get the ferrite toroid in a white bulb?

[Zem]

What size is the toroid?

[Superninjacamper941]

Where does the resistor go. thanks great ible

[zjharva]

one end to the middle transistor and the other to the non twisted toroid wire.

[Superninjacamper941]

Cool thanks i figured it out

[dyeniper]

whats the purpose of the toroid in the circuit???pls help

[yondaime]

can i use speaker magnet as a toroid?

[zjharva]

i don't think.

[Padlock]

Nice Project. Just a question though; would there be any difference if you used a small one, and did, say only a few wraps, then if you used a huge one and wound it very, very tight? Anyway, again, nice project. I used the design to light a green LED in my "mini" light saber. It's made out of a car cigarette adapter and a mini hot glue stick. I had only room for one AAA.

[Padlock]

Oh, in case you didn't figure it out, the first question is about the Ferrite Torroid. I forgot to mention that.

[zjharva]

There prob. wouldn't be any difference, as long as its the same basic idea.

[Juanarama]

what if I wanted a slow flash, like a lighthouse (I know a lighthouse does not flash but has that effect because of rotating source)

[rocketman221]

you can buy flashing leds or you could make a simple flasher circuit with a couple of transistors.

[strmrnnr]

You might use the cylon eye circuit for a light house. It could use more power than is available here. Just divide the lights up around the cardinal points and away you go.

[zjharva]

i don't know, you'd probably need a 555 timer circuit

[joinaqd]

how long can the thing stay on for?

[zjharva]

on a dead battery with half a charge, probably 2 days before it gets very dim.

[lolwut22]

I AM!

[zjharva]

but he is.....

[JellyWoo]

great ible! is the Heavy gauge wire required? also, where can you get a Ferrite Torroid? thanks.

[zjharva]

the heavy gauge wire is not required, its only for the neck. You can find toroids at radioshack, or on their website if you type in "toroid"

[looking4ideas]

can't you make a super charged Ferrite Torrid if you drilled a hole on a rare earth magnet ???

[Arx]

nope, doesn't work that way. I'm not certain, but I think you would just end up with a very biased core that would saturate constantly in one direction.

[looking4ideas]

OK a challenge for the people in Instructables. How can I make a super charged Ferrite Torrid ??

[static]

Define "super charged Ferrite Torrid" and what you expect out of one.

[looking4ideas]

OK ill give an example: make a electromagnet 5 times more powerful

[looking4ideas]

that's what i mean by super charged

[Arx]

Nah, you might be able to increase the field strength of the magnet slightly, depending how strong it was to begin with. But no, It's not magic.