Instructables
A couple of weeks ago, I had the idea to make an LED flashlight that would sit on top of a 9-volt battery clip, but would run on one of those 2 x AA holders with the 9V clip attachment. Well, I made it and documented the process and was very happy with the finished product. It can be used for finding your way in the dark, looking for that box of batteries you know you left in your closet, or better yet, (by adding a toggle switch) it can be used on your bike or scooter when riding home at night. The pictures of the light with a 9V battery are just for ease of recognition, I guess.
 
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Step 1: Stuff You'll Need

Picture of Stuff You'll Need
For some people, getting the materials for this light will be as easy as looking around your desk. For others, most all the parts can be easily obtained at RadioShack or somewhere similar. The things you'll need are:

- A 9-volt battery clip like the one shown
- A tactile switch*
- A non-diffused LED in the color of your choice
- A resistor to fit the requirements of your LED**
- A little holder for your LED***
- A battery****

- Soldering iron w/ solder
- Hot glue gun w/ glue

*You can salvage these out of tons of electronics. Listen for the buttons that make that characteristic 'click' sound when you press them
**Resistance equals Voltage divided by Amperage (R=v / i)
***Optional. If you want one, you can buy one, or you can make one, or you can get one out of disposable cameras as the holder for the neon lamp (that's what I did)
****A 9-volt works okay, but it may overpower your LED. You may want to try those 2 x AA holders with the 9-volt style clip on top from Radioshack that I talked about earlier.
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Kiteman5 years ago
Nice project. Good to chuck in the glove compartment.
Red is better because it doesn't effect "night blindness" nearly as much as blue, or green. Thats why they use red when submarines go into "combat mode" or whatever...
good point!
Alternatively, superbright white is good. At the price I guess these cost, why not build one of each? If you were using 9V then you could stack two or three LEDs in series to get the most out of your battery.
Radioactive_Legos (author)  PKM5 years ago
Good idea about multiple LEDs. I actually had a white one with me at the time, I just didn't want to use it and glue it in because they are so valuable. Thanks for the feedback!
Your LED holder also looks like it is east to change out diodes, so you could do that, or even get a multicolor LED and add a 3 position switch so you can control the colors by the flick of a switch... Cool project anyway!
john mosier3 months ago

sweet you should try to incase it so it doesn't get damaged

Schmidty161 year ago
Here an idea that i think u should use on this throw some surgru on it to protect the electical components
dark sponge5 years ago
I made a couple of these a long time ago. I used super bright white leds and didn't bother to include a switch. by the way, DON'T waste your money on 9v clips! Just dissasemble an old 9v battery and use the top of it as clip. You also get a nice metal case for other small projects and six AAAA batteries.
that is a great idea. i'd never thought of that.
the AAAA batteries are only in certain brands of 9v batteries I know Duracell has them. Other brands is hit and miss but at any rate you still get the 9v clip.
Energizer also. But I have a big pile of dead AAAA batteries that I might never use. I have only taken apart dead 9v batteries so the AAAA batteries I get are dead also =(
Most dollar store brands are layered acid cakes... But I'd go with Energizer or Rayovac because Duracell goes cheap with some batteries (Particularly 6v lantern batteries) Woohoo I replied to a prehistoric conversation!
Heh! Prehistoric conversation.
Due to the nature of the net, each set of comments is fresh for each reader down through history. And if we get to interject with a fresh post, the conversation has become time independent. Sort of like multitasking with long breaks between texting.

Nice comment about the brands with AAAA's inside of them, very usefull!
Bumping topics is fun!
(:
I have done the 9v clip thing before to great success. I needed a smaller clip for a altoids amp. Saving space with that clip was necessary to get a 9v battery, a half watt speaker, two potentiometers, a toggle switch, a headphone jack, a 1/4" male plug, an LM386 amp and circuit, a 2N2222 preamp, and a blue led into one altoids tin.
lol u call that messy u sould look at my desk now thats messy
(removed by author or community request)
I like your four LED version of the 9v flashlight.  What resistor did you use on it?  I am thinking of something similar and was curious.
serith4 years ago
 how many amps are in a 9v batt.?
or, even better, how many ohms does it take to reduce a 9v batt. to a 3v batt.?
good work
chuckr445 years ago
How long does it take to charge the caps? How do I know they are charged when I put my battery on the terminal?
i might make this but smailer with 2 wires in a heat shrink tube and then add to a project pox with a curcit behind the leds power and a nice toggle switch in the box so i can use a simple regulator and 9volt ac-dc power plug... who thinks that would be handy for many leds arround my soldering stationg so i can light up my solder from all angles for beta easer soldering???
hmmmm good job but can i use a switch instead of a button?
thats verry easy it only needs the power conecting with the led and resistor so u can easly do as with ease.
course u can. just replace the tactile with a toggle or whatever
ok thanks
Learndy5 years ago
You can even make the flash light smaller by using a smaller battery. There are some instructables on LED throwies showing how.

And if you use some Joule Thief circuitery you can use a regular AAA or AA battery. Or a supercap. Have a look at http://www.instructables.com/id/Flashlight_Without_Batteries_from_the_book_quot/ where you can find a schematic for that. Yes, I've tested it with two super bright white LEDs running on a single AA cell!
--
Airspace V - international hangar flying!
http://www.airspace-v.com/ggadgets for tools & toys
y not just make it a 9volt battery volt changer so when u change the batter amount of power gong through it...
Thaikarl5 years ago
strangely enough, just after reading this Instructable, i was at a dollar store and found this light. it has some weird gravity switch (the blue thing in the picture) that turns the light off when it's on it's side (tends to flicker alot tho) but it has all the ingredients in this instructable, except the switch... for 99 cents!
CIMG9820.jpgCIMG9824.jpgCIMG9821.jpg
Was the store called odd lot or something because i saw those and got a bunch lol great ible' cheers, mspark400
110100101105 years ago
2 things to make it simpler and cheaper 1 disassemble a dead 9 V battery for the clip and dont buy one 2 how to avoid the switch (making it less reliable - may light up unintentionally if placed in pocket etc) unfold the 'flower' on the clip (that goes to battery +) with pliers and hammer it to make it absolutely flat. now connect the LED without switch at all when you just put it on the battery there is tiny space between it and the + and it does not light. when you press it lights if it tends to light all the time insert a piece of plastic packaging foam in the battery + so it sticks out a bit and prevents accidental contact
i like the original idea with a tact switch more...
that will definitley light in your pocket, not a tact switch.
the piece of styrofoam prevents it from doing that
DrWeird1175 years ago
My switch won't close the circuit. : (
ledsales5 years ago
I love simple ideas like this, is one of the reasons I did them as a kit a few years back, if anyone's interested, see www.ledsales.com.au
billytwix5 years ago
sweet but this idea is already patented, and used by the us military http://www.9voltlight.com/

that dollar store one looks interesting/cheezy but its a dollar. i hope it lasts a while for the money...

cool use of the double-AA's. and i love the hand puppet!
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