# LED Beginner Project: Part 2

This project was my next step in my exploration of the world of LEDs. Here, I will show how to wire LEDs in parallel in order to make a simple bike light. Wiring LEDs in parallel is useful in that you can run multiple LEDs off of a single, low-voltage source.

## Step 1: Materials and such.

I've always been looking for a reason to use an Altoids tin as a project box, and this project seemed to be it.

- Altoids tin
- 2 AAA battery holder from Radioshack.
- three way toggle switch that I scavenged. I used a three-way switch becuase I plan on eventually adding a circuit that will make the light have a blinking mode. If you don't care to add this extra complexity to the light, just buy a simple SPST on-off switch.
- three white, 3V LEDs given to me by a friend.

In my previous Instructable, I explained how LEDs need to have resistors wired in series with them to keep them from blowing out. In this case, I didn't need resistors, because the supply voltage was exactly 3V and the requirement was 3V. If you are using LEDs with a lower voltage requirement, you will need to add in a resistor to keep them from burning up.
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ekgeml.6 months ago

Will either of these on/off switches work?

Toggle switch single pole throw on off 125vac @5 amp

or

a push button switch momentary 1 amp 250vac

I'm looking for some VERY inexpensive ones and these are about a buck each at Jameco. If they won't, what amps/vac should I be looking for? Thanks!

7 days ago

The first one will, the second one powers off once you let it lose. If you would like to use the last one you'd need a flipflop.

fastfilmsinc5 years ago
if you had a 6V power source and 6-1V  would you need resistors is you did it in the parallel way?
3 years ago
I think I understand what you mean. You have 6 LEDs that require 1V each and you have a 6V power supply. This is perfect for wiring in series. I did this with a 9V battery and 3 3V LEDs in my Bike Light instructable.
Charthage6 years ago
You might want to add some rubber inserts on it so you don't short out your LEDs.
4 years ago
Good point and very true about adding the rubber. I did a thin strip of black electrical tape around the inside lining of the tin.
Salsa7665 years ago
Incredible tutorials, I can't figure out how to make a flashing LED circuit b/c all the other instuctions aren't as thorough as yours. So if you could make an instructable on how to make those LEDs flash, that would be awesome. :)
lifesavin6 years ago
I am totally new to all this stuff. Could you add say a 4 AA battery box and add more LED's and use this as a flash light or as a lantern for camping or such?
5 years ago
THIS IS EXACTLY WHAT I AM LOOKING FOR...CAN YOU CONNECT 4 LED LIGHTS TO A BOX AND HAVE A SEPARATE SWITCH FOR EACH LIGHT ON A SEPARATE BOX(LIKE A REMOTE CONTROL THAT IS ATTACHED TO A LONG WIRE-ABOUT 2-3 FEET AWAY)???  LOOKING FOR THIS FOR MY CLASSES-I AM A TEACHER...THANKS!!!
5 years ago
you could probably do it if you did the leds in the parallel way...
jonsbuks5 years ago
Excellent hands-on follow up to your first tutorial. My Bunker Hill wireless alert signals an intruder by issuing a doorbell sound...as-well-as... three LEDs blinking together. I plan to cut the speaker wires to make the unit function in a silent mode with only the LEDs activated, but presently the LEDs blink once, when the intruder breaks the transmitter’s beam. Is there a way to keep the LEDs lit until I hit a reset switch?
legendofmatt5 years ago
Thanks for the Instructable. I used a 100 ohm resistor, a 9V battery, and a Momentary push button switch. a little different but I like yours better. here are some photos :D
Wonderful Instructable. Thanks! This really showed me how to work with LEDs. But I used a 2.4 volt LEDs with a 150-ohm resistor along with a 9V battery. I also didn't clip the LED. .
abbtech6 years ago
Nice job! As Jeasterlingtech mentioned I would suggest using some current limiting resistors. The Altoids tin seems to be so popular for these cool small enclosures and looks great in this project. :)

If you are looking for some LEDs with some cheap shipping rates (starts at \$3.00) please have a look at our store http://alan-parekh.vstore.ca/index.php/cPath/4

If you are wanting to run an LED from a single AA battery here is an idea.
youarealwaysfree8 years ago
Thanks for the instructable - this was my first electronic thing out of components. I went for the "cadillac" version and bought a small prototype case. It turned out more of a flashlight than bikelight:
Willd (author)  youarealwaysfree8 years ago
Dude, that looks awesome. I need to find a place to get cheap switches like that, theres not end to how useful they are!
6 years ago
buy in bulk online for cheaper prices
8 years ago
Thanks! That one is a Philmore on/on switch (only wired half of it) i picked up at Fry's for about a buck . Seems kinda expensive, though? i bet you could find it cheaper elsewhere/online.
7 years ago
RadioShack has a good selection of switches, most are relatively cheap as well.
7 years ago
BULL THATS SO BULL THERE LIKE 5 BUCKS FOR THE CHEAPEST ONE!
7 years ago
No, the ones at my store average at around \$1-\$2, are you thinking of other components?
7 years ago
no...look online at radioshack type in SPDT flip switches and you will see
7 years ago
Online prices tend to be more expensive.
7 years ago
not if it says "our exclusive" which means they always have it in the store at that price
7 years ago
Look dude, they're no more than \$2 at my local Radioshack, please stop arguing with me. I know that, I buy them often. I promise I'm not trying to mislead you or anyone else here. If they're different where you live so be it, prices vary.
7 years ago
arguing is what comments are for! and i will check that out the next time i go there i usually look um up online at radioshack and then buy them in the store...so yeah....i will check that out my friend
7 years ago
I FOUND FOR 50 YKr OR LESS ps.YKr is our currency which is like the us cent.According to today's equal rates that should make 63 cents
7 years ago
O.o we were kinda done with the argument a while ago...
TrickedOutPc7 years ago
I am new to leds can the legs of the leds be touching the tin or would it short it out. I noticed now it looks like your ends are sticking up off the tin. I am using 3.5v leds and a 2.5 would I need a resistor and if so which one. I am doing 2 3.5v and 2 2.5v leds. thanks for your help.
rmcnaugh7 years ago
great tutorial. I made mine from a small car tin, so the battery holder is on the outside. I also used one red led and 2 ultraviolets. It's my 2nd led project. one thing, no matter how i wire the leads to the switch, the center led (this case the red one) blinks in1.5-2sec intervals as if there is a timer chip, in the switch. Is this the case? I like it, but I want to be able to control the blinking function. overall I'm kind of happy with it. In the dark, it reminds me of the "spinner" from blade runner. also I made another led project with altoids box with a green, high powered red and RIF led. do you have any tutorials for RIF leds. rmcnaugh
Rae-senpai7 years ago
Thank you for posting this! I've been looking for a simple LED project to start with, and I chose this! I also had to mess with the switch a bit before I figured it out, but otherwise your instructions were clear. Thanks again :)
tonton1017 years ago
A very comprehensive tutorial for beginners! That's a plus! Anyways, How long will it stay on? a week?
7 years ago
100000 hours total if battery drain ignored but i dont know with drain in calculation
lacrosse2man7 years ago
where do u get leds
Shifrin7 years ago
Hey, Nice Instructable! I'm planning on making one, I'll post up the results!
MaxL9 years ago
I went to Radioshack and I couldn't find any LEDs with a voltage of 1.0. In fact, I couldn't find any with less than 1.7. Where do I get LEDs with such a low voltage requirement? Is there a place I can get detailed information about LEDs?
7 years ago
a couple of types will serve you well. white, green, blue and UV require 3.4 vdc for the published brightness. red,orange,yellow, and amber have a forward voltage of 1.2 vdc. most circuits require a current limiting resistor to keep them out of thermal runaway. 4.5vdc (3 aa cells) and a 47 ohm resistor should be about right for one w,b,g,or UV LED. 470 works fr 12vdc. 3vdc and a R,O,Y,A led will work also w 47 ohms and one led. 680 for 12 vdc. a string of 3 white and a 100 ohm resistor will work on 12vdc. you get the idea.
7 years ago
major mistake R,O,Y,A have 2.1 forward voltage . pleasee correct above. sorry
8 years ago
Hey MaxL you actually need 3V LEDs as the materials says. These LEDs are in parallel so each has to have a 3V voltage drop over it to consume the 3V's being supplied by the AAA batteries.
azebra57 years ago
I've never really built anything on my own, just put together some kits with kids. I'm ready to go back to one of the kits which won't work and who knows maybe I'll be lucky and find the fault in it. LEDs fascinate me and hubby has shown me how they can be put together to make lights. A SAD light is required yesterday. It got me started with LEDs and your instructables are feeding my continuing need to know. Thank you so much.
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