Intro: The Ultimate 1 $ Emergency Light
In India There are many villages where there is no light , children can't study at nights.and this is not just in India,
Every developing country have the same issues.There are many available products for solving the problem ,but the light output vs price is not that economical for a poor man. In India it would be much better to buy under 100 but i decided to do it under 1$ 60.
Features of this lamp:
- Lithium ion Powered
- Long lasting -once charge can last more than 4 hours(tested max and still running on that charge)
- Outputs like a 20w ccfl
For making this lamp you will need
- Lithium ion battery (i used camera battery)i bought at 40 INR
- SMD led i bought 10 for 20 INR
- Switch for 1 INR
- and a case for 5 INR
Total 66INR equals to 1.00 $
Step 1: Preparing the LEDs
SMD led don't have led so they can't be attached to pref board .but i like to differ in it instead of using legs i rather solder to led directly on the perf board in this , In this way we actually made and array of led , this led are made such that all the 10 are connected in parallel but in 5 each row.
Why using 5 in each row ?
Simply because i wanted the light to be compact and the source to be strong ,if you won't you can use other arrangement . you can tell me how you would do.
What are the led
I actually i don't know what are the leds i brought them from a local shop .they were cheap :)
Step 2: Connecting the Battery and Switch
Choosing the battery
I wanted to use lithium ion as they are light can be easily used in portable projects.
I could have used the 18650 battery but those were too big so i changed it to camera battery, as they were fitting perfectly inside the box i had chosen.
they are smaller than the bl-5c and also they are 1600 mah
decent power for a light
Choosing the switch
I firstly use a small mini switch but later my mind shifted to this switch it looks better and since its only about on and off,
SPDT are great for the work
The connection is given in the figure
- connect positive to switch end
- connect other switch end to led anode
- connect led cathode to battery ground
- take two more wires and connect that with ground and positive of the battery,this will be connected to rechargeable block(In my case it connects which is two female header ) that connects to a external rechargeable module.
Step 3: Preparing the Case
Any Electronic circuit are incomplete without a chassis ,or enclosure.
I need to put everything inside a enclosure so i used this tiny box for the purpose .i need some drilling specially for the switch . also for the header for the recharge module .
I used a Dremel drill bit and then a sand bit to make the hole in the figure.
Then it was time for putting everything inside the box .
I used a glue gun to put everything in its place firmly also to insulate everything.
Step 4: Painting the Case
I used a transparent case will make light come out from ever corner so it needs to be painted .
So i need to mask it .
I did not had any masking tape so used simple black tape for the work.i used an xacto knife to cut the side of the tape to match the surface of the box.
Then i used my spray paint to paint the box.
Spraying using a spray can
- Shake the can well
- Spray on the object and keep the spray constant
- apply the paint on every surface
- Give atleast 30 min to dry depending on temperature of sorrunding
- Repeat the step for 3 times
- you will end with a sexy matte finished surface(i also painted the switch black)
Step 5: Peeling Off the Mask and Using It
After the paint has dried its time to peel the mask off
The mask can also pull some paint from the surrounding as the paint is a continuous layer.you need to use the knife to make sure the the masks does n't take the paint of.
i made the mistake , but thanks it could be reverse .
Peel Slowly and gently and nothing shall go wrong but if it goes , use a brush and apply paint where the paint goes out
So last we end with the 1 $ pocket emergency light
i have been using this last week it helps me a lot i just had to charge once and still it is working fine :)
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