The Ultimate 1 $ Emergency Light

by geekrex

32K23581

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
  • Rechargeable
  • 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

  1. Lithium ion battery (i used camera battery)i bought at 40 INR
  2. SMD led i bought 10 for 20 INR
  3. Switch for 1 INR
  4. 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 .

I had a matte black paint spray so i decided to use it for painting, but i need to make sure the upper side from which Light will come out be transparent.
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

  1. Shake the can well
  2. Spray on the object and keep the spray constant
  3. apply the paint on every surface
  4. Give atleast 30 min to dry depending on temperature of sorrunding
  5. Repeat the step for 3 times
  6. 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

CAREFUL

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 :)

Don't forget to follow me for upcoming projects
and like my facebook page Makewithrex

84 Comments

snavewinter 8 years ago

You can avoid the use of the TP4056 module if you are using a CellPhone Battery, this already come with a little module similar to TP4056, if you disassemble a CellPhone Battery, you will get the horizontal circuit that make the same functions that the TP4056, BUT if you Litium Battery don't have that module already installed, you will need an TP4056 module, please check this tutorial to understand my point.

https://www.instructables.com/id/DIY-carbon-heated-...

Anyway it's a good idea and if you can recycle all the components from another source, you can make this project more cheap.

Good Luck.

snavewinter 8 years ago

Batteries usualy have 3 contacts (modern can have 4 or 5) but you can find "-" and "+" mark on your battery.

My
battery has overcharge ic board inside so I can connect it directly to
any USB. If you will use unknoun 3.7v battery you should use a charge
board like this one:

http://www.ebay.com/itm/Li-ion-Lithium-Battery-Boa...

geekrex 8 years ago

Thanks a lot for the suggestion the question is in my case the battery has two - one plus , so can i charge it directly with 5v usb ?

will it be safe ?

snavewinter 8 years ago

I suggest that you first learn the configuration of the model of your current battery and if it count with a inner regulator, will be safe to connect directly to any USB 1W, but if you are not sure that you have that regulator, it's better to use a external one.

snavewinter 8 years ago

I suggest that you first learn the configuration of the model of your current battery and if it count with a inner regulator, will be safe to connect directly to any USB 1W, but if you are not sure that you have that regulator, it's better to use a external one.

snavewinter 8 years ago

I suggest that you first learn the configuration of the model of your current battery and if it count with a inner regulator, will be safe to connect directly to any USB 1W, but if you are not sure that you have that regulator, it's better to use a external one.

snavewinter 8 years ago

And also, you can recharge your flash directly connecting it to any 5V USB source easy and fast.

BurgersBytes 8 years ago

10 LED's in parallel would divide the current 10 ways. I found some similar looking SMD LED's with the ratings pictured below. 300 ma each X 10 = 3,000 mah so it would last 1/2 hour on a 1600 mah battery. Also the LED is only rated to 3.3 volts

geekrex 8 years ago

My one 0.03 $ each

geekrex 8 years ago

Sorry but this led are 5630 my ones are 5025 with 50 ma each that equals 500ma theoretically so i should get 3 hours but the it is lasting more than 4 hours but lumes drecrease

tushar3353 8 years ago

good ...but these components are expensive in here
that switch is 10 inr
battery 150inr
.
.

geekrex 8 years ago

where do you live bro, i brought all the things from local market also i buy alot so i get cheap

vina1991 8 years ago

40 Rs for 1600 mAh battery????

how 10 LEDs work on 3.7 v battery????

i can't believe it

gdriver 8 years ago

Hi

You are worried that 10 LEDs should need 10 x (3 to 5V). Worry not - these LEDs are in parallel so only need 3V to 5V.

What you should be worrying about is the lack of any kind of proper current limiting - this innocent may have got away with it - the current will be set by whatever resistance is in the battery/wiring and whatever volts these LEDs happen to operate at. This is a BAD circuit.

pmshah 8 years ago

Just add LM 317 in TO92 transistor package as current limiter and you should be OK.

maurov10 8 years ago

With a regulator You Will have too much drop voltage, in order to limit current try to put a lillte resistance or a filament lamp in series.series.

gdriver 8 years ago

TI datasheet says the min. recommended volts drop is 3V, and it doesn't come in T092. Apart from that...

pmshah 8 years ago

I myself have in the transistor package. Of course I got these from Singapore. The 3 volt recommended drop is for using it as a voltage regulator and in TO-220 or TO 3 package not for current limiter configuration. There is also another voltage regulator from Panasonic in TO 92 package which can go down to 1.2 V. You will have to search for it.

RicksterInstructables 8 years ago

That would double his price! LOL.

But seriously, as others have pointed out, LEDs don't tend to share well with others. Just setting up a fixed current of ten times one LED and feeding it to ten in parallel could quickly lead to a really neat cascading failure.

It goes like this. One LED is selfish and pulls a little more than his share. He starts to overheat and this makes him draw more (an unfortunate side of LEDs). This makes him overheat more... And then he dies in a bright flash.

Now there are only nine LEDs left to consume your current. One may be a hog...

As this cycle repeats, you can see how it speeds up.

Pretty soon you're down to two LEDs getting that ten LEDs worth of current, then one, then none.

Blink.........blink.........blink......blink.....blink....blink...blink...blink..blink.blink

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