Tiny 9V Clip Flashlight!

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Introduction: Tiny 9V Clip Flashlight!

About: A Bay Area native interested in electronics, mechanics, and robotics, and automobiles. Formerly the electronics captain of Team 100 in the FIRST Robotics Competition, I now study Mechanical Engineering at U...

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.

Step 1: 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.

Step 2: Gluing and Soldering

You can glue first then solder, of solder as you go. I prefer the second method.

1. Glue down your switch as shown. If your switch has 4 tabs, you can probably break off the ones on one side.
2. Glue down the resistor, bend the wires and solder one of the leads to the switch.
3. If you have an LED holder, go ahead and glue it down. If you don't, then glue your LED where the holder would be.
4. Put the LED in the holder and solder a lead the the resistor, making note of the polarity
5. Clip the wires from the 9-volt clip to length and solder one to the switch and one directly to the LED

Great! You're done building it. Now let's test it...

Step 3: Testing

Press the switch. If all is well, the LED will light up. If not, make sure the polarity is correct throughout and that your battery still has a charge in it. After things are fixed, try it again. It should light up brightly. Some modifications that could be made to optimize this little light for biking are changing the switch from a momentary tactile to a toggle or slide. You could also swap out the LED for a flashing one to become more noticeable. Make sure to comment!

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    59 Discussions

    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...

    4 replies

    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.

    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!

    Here an idea that i think u should use on this throw some surgru on it to protect the electical components

    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!

    lol u call that messy u sould look at my desk now thats messy

    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.

     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.?

    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.

    4 replies

    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.

    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 =(

    How long does it take to charge the caps? How do I know they are charged when I put my battery on the terminal?