Introduction: How to Make a Fast Blinking LED Bike Light

Picture of How to Make a Fast Blinking LED Bike Light

In this Instructable I will show you how to make a simple fast blinking LED light that you can attach to your bike or any where you want. It blinks more than 3 times in a second.
It is cheaper to make one than to buy one.
You can make it whit your favorite LED color,red,green,blue,yellow,RBG...
This was my first electronic project, so I recommend it to all beginners in the interesting field of electronics.
This bike light is easy to make,looks cool and most importantly, effective!

Step 1: Components

Picture of Components

For your fast blinking LED you will need:

1. LM 555 timer chip

2. 180 K ohm resistor

3. 330 Ohm resistor

4. 0,22 uF, 16V or 100V capacitor

5. 9V battery snap

6. 9V battery

7. LED (go to step 2 so I can help you choose which one)

8. Circuit board

9. Plastic housing for electronic circuits



Step 2: Choosing the LED

Picture of Choosing the LED

There are lots of LEDs out there. 10mm,8mm,5mm,2mm,red,blue,green,yellow,UV.......

For this project I suggest 10mm LEDs, which color is up to you.

Here you can buy LEDs

Step 3: Tools

Picture of Tools

You are going to need some tools to do this project:

1. Soldering Iron

2. Solder

3. Vacuum for desoldering (just in case)

4. Wire cutter

5. Wire insulation stripper

6. Scalpel

7. Sand paper

8. Screwdriver

9. Telephone wire

10. Something to make a hole in the plastic housing (a drill)

Step 4: Makeing the Circuit Board Fit

Picture of Makeing the Circuit Board Fit

Cut the circuit board so it can fit inside your plastic box. Use the wire cutters or a scalpel.


Step 5: Cut the Plastic Box

Picture of Cut the Plastic Box

Peel of some of the plastic on the side (the longer side) of the plastic box. Use the scalpel and the sand paper. The opening should be 1mm wide, just for the wire from the LEDs.

Step 6: Make a Hole

Picture of Make a Hole

Make a hole on the side of the box. The hole is for the switch. Use a drill or anything that can make a hole.

Step 7: The Electronic

Picture of The Electronic

OK. First I will give you the schematic, electronic plan, and in step 8 i will explain it.

Step 8: Connecting It All Together

Picture of Connecting It All Together

Solder the 9 V battery connector where the battery is shown, with the negative (black) wire to pin 1 and the positive (red) wire to pin 8. We'll refer to these points later as "Ground" and "+9 V" (photo 1 and 2)

Pin 8 is connected to pin 7 through a 180 kilo-ohm resistor, and pin 7 is connected to pin 6 through a second a 180 kilo-ohm resistor. (photo 3 and 4)

Use a telephone wire to connect pin 2 to pin 6. (photo 5)

The 0.22 uF capacitor connects pin 6 to pin 1. (photo 6)

Pins 4 and 5 should be left unwired.

Pin 3 is our "clock" output

Solder the LEDs to the board and connect them together. Example: If you have 6 LEDs the positive (+) pin of LED 1is connected to LED 6 through the positive pins of LEDs 2,3,4 and 5 to the 6th LED (photo 7)

Take the output from the 555 (pin 3) and connect it to the positive side of the LED, through a 330 ohm resistor, and then to the ground (-).

Step 9: Attach the Switch

Picture of Attach the Switch

OK. You are all most done. Now attach the switch. Cut the wire from the battery snap, peel of 1mm of the wire on both sides and connect it to the switch.

Step 10: Put It All Togother

Picture of Put It All Togother

Push the switch through the hole in the plastic box, attach the board to the box and close it.



It is finished. Go ahead and attach it to your bike or what ever. Hope you enjoy my Instructable. Go easy on me, this is my first. Please leave a comment.


hamolton (author)2010-04-13

 I'm thinking of making, like, making arrows on the back of a jacket for turning signals when biking. How would I figure out the resistor values for the 5mm leds on ebay I would buy?

shaddaz (author)hamolton2010-07-09

To start with dont touch Ebay LED's they are very poor and not worth bothering with for safety lights go to a good retailer and pay around $1 per LED much better brighter and last longer MUCH longer if you want resistor values google there is a page out there with a formula to calculate this just can not remember where it is sorry

DakLak (author)shaddaz2016-12-08

E-Bay/Amazon resellers usually buy the cheapest LEDs from China.

I live in VietNam and the cheapest (ungraded) LEDs are sold by the kilogram, as are the lowest quality graded LEDs.

The best quality are graded and sold by the 'each' price. Bright Red 3mm LEDs are going for 10 for USD$00.01 (1 cent) today.

steve000 (author)shaddaz2011-06-02

WTF! i buy all my LEDS from ebay. most retailers also get LEDS from same or similar manufacturers as ebay sellers.

and seriously $1 per led... i buy 20 at that price.. if 18 of them die ive still saved money!

steve000 (author)steve0002011-06-02

BTW.. Ive never had any die unless i was doing something stupid with them e.g. 5v into a 3.6v led

Ive used quite literally 1000's over the years

I started when ebay led's were 70c each

ajones40 (author)steve0002011-12-12

u pay $1 for LEDs?!?!? WOW! to me, even $0.50 is OUTRAGEOUS! i searched the internet top to bottom to find the cheapest LEDs. finally, i found this website had: LEDs, Resistors, Prototyping Boards. Capacitors, and WAY more. the AMAZING thing about this website is that LEDs are anywhere from $0.02 to $0.06. Although the items you order are coming from Bangkok, the shipping is EXTREMELY fast and cheap.

I just wanted to let you guys know, that way you can buy more for less.

comodore (author)hamolton2010-04-18

Depend on what circuit you use?
If you are using my circuits, the resistor values are the same...
I think you have an Instructables just for the project that you mentioned.

DakLak (author)2016-12-08

I made this and fitted it to my motorcycle helmet so even crazy Vinasun taxi drivers can see someone is in front of them!

ketan11293 (author)2016-08-14

How can i turn it into a 5v supply circuit ? i wish to use it on a usb power bank.

jarvis4664 (author)2016-05-26


YashS4 (author)2015-03-14

can we slowdown the time of the blinking of L.E.Ds.

I made it but its too fast !!

RichavitP (author)YashS42016-05-10

please explain to me how you made it!! please I'm begging you!

Onamarora (author)2016-03-16

Can I connect 4v rechargeable battery

SmitP2 (author)2015-10-10


sparsh.mahajan.90 (author)2014-08-09

i wanted to ask that why 5mm res and blue LEDs don’t glow simultaneously when connected together but glow perfectly when connected individually. i need an awnser fast please..

Ok so the reason the 5mm res and the blue LEDs wont glow simultaneously, I've had the same issue. its the voltage the two different LEDs need aren't the same. I don't get why but that's just how they are made. So i got this box of LEDs and so all the LEDs worked fine except for the yellow and the red LEDs. Later on I figured out the yellow and red LEDs work on 2.2 volts. the others LEDs were on 3 volts. So the two LEDs work on separate voltages so it "Trips" the timer and doesn't blink at the right time. Hope that helps! Sorry its been a Year XD

p mishra (author)2015-03-26

plz can i use a 0.47 uf capasitor? ???

sajidbutt007 (author)2012-12-09

its realy good

chetancc (author)2012-11-24

Can you please upload video so that we can see how it looks while blinking?

Ihackedyouraccount (author)2012-06-12

Could I use Texas instrument tlc555ip timer chip instead?

chandansarkar92 (author)2012-05-19

Can i use 12v. battery? 

YASH02 (author)2012-04-18

Where do have used 330 Ohm resistor???

ismael01 (author)2012-04-02

what modifications would i make if i wanted it to run off a 3 volt battery?

sputhran (author)2011-11-25

last sentence i didnt understand ,and thent to the ground but which one t o the ground???????????? and the negative led side to attach where

stexmetalac07 (author)2011-07-04

E brate koliko bi max dioda mogao da povezem na 9v na istoj shemi?

ploomus (author)2011-03-27

Looks very nice

crashcup (author)2010-09-20

Which components affect the rate of blinking? Could this be made to blink maybe 5-6 times per second?

creator22 (author)crashcup2010-10-29

if you use a .47uf cap(which is what i used) yuor led(s) will blink faster than 22uf cap BUT be careful not to use to low a cap that it will looke like a normal light cuz it blinks so fast also any lower then a 4uf cap the led will get dimer

miked123 (author)crashcup2010-10-02

It depends on the resistors and capacitors on the 555 timer. Check out or

Jr Hacking kid (author)2010-08-23

Hmm IS there a way I can Connect two of these together And use one switch? Cause I like the way it looks And IM planning to MAke A Turning Signal MInd if u can help me out?

Yes there is, and if you would like i can upload a video onto Youtube showing you how this would work. And if you want i will send u the Schematic for it.

noapparentfunction (author)2010-08-15

Where does the 330-ohm resistor go in this circuit?

techmonster (author)2009-06-30

in the schematic did you mean to say 108 k ohm

comodore (author)techmonster2009-07-14

No, why? In the components step you can see it sais 180 k ohms...

jmsaltzman (author)comodore2010-06-06

Looks like just "180 ohms" in the schematic, though you do indicate that it's 180K (not 180) elsewhere.

sridh (author)2010-05-15

Can any one tell me how to draw these circuit   any specific Software .

comodore (author)sridh2010-06-03

Ah, you have a ton of them....
Probably the best is Eagle! :)
Good Luck!

Kosre (author)2010-05-15

I agree with peterlonz. Not to burst your bubble, but just saying a 10 mm LED doesn't really cut it. What's the forward voltage and most importantly when dealing with resistors, the current? These variables are highly dependent on which resistors to use.

Apart from that, awesome tutorial, keep up the good work!

comodore (author)Kosre2010-06-03

Thanks Kosre!

I do agree that I left out some important facts, but I can garantee that any LED that you pick, apart from those special, uber, ultra, bright, godlike LEDs, will work!   :)

peterlonz (author)2010-03-24

You say you will help in the choice of LED but you suggest only that 10mm size is used.
You don't say why, or indicate the preferred forward voltage, or the best mcd rating.
Also I note that waterclear & diffuse are two types with significant price differences, does it matter?
Good instructable, thanks.
Peter O

shailendra1988 (author)2010-01-15

sir your project is great
i m thinking to make a big project after this in that project im thinking to glow my name first and when led showing my name get off at same time my surname appear like in adds on malls, multiplex etc.. i want a electronic name plate in front of my house which will  be a attraction to people.
so i want to ask some question
1. how shoud i glow large no of leds about 100 leds, 9 v supply is sufficient in simple words my question is how to calculate amount of power required to glow large number of leds

2. how should i know or how u know  the value of resister and capacitors

3. connetion diagram so that i connect leds for my name and for my surname seperately

4. 555 timer work in this ciruit or should we have to use different ic

sir i want to build my basic so that i can make different different  circuit for diffferent purpose 
i think u make a reply as soon as posible

comodore (author)shailendra19882010-01-17

I am glad you like my project!
I am younger than you so you don't have to call me sir!  :D
You have an ambisiuos project and you will probably need someone who knows how to solder and some basics with electronic....
Well lets start with the simplest question:

2. Resistors have colored ring on them (4 or 5) and that's how you determen their resistance... You can find these kinds of calculator on the net. Just google resistor calculator.... As a mater of fact, here is one:
And for the capacitors, usually their value is written on them.
4. I think that the 555 time wont work for this.... Google the 555 timer and read up on it....the time between blink, the on/off time is determened buy the resistors and capacitor....Maybe the easiest way would be to use a Microcontroller like and Arduino! You could maybe use 556 IC whitch is like 2 555 ICs in one! But I am not really sure.... As for your question, could you make something like this with a 555 timer, I would say NO.
3.As I sad I don't know any diagram, schematic, or as you say connection diagram that will do what you want....
1.  Well, depends on how you wire them, parallel or in series.... In this Instructables I wired mine in parallel.... There is not much to it but there is difference! I suggest that you look at this instructables  ( )  I hope it helps you!

Feel free to ask me if you have any more questions!  


Srinu (author)2009-02-10

Hi, I have a doubt. Am working on something for which i don't need blinking lights but need lights that gradually become dimmer and then brighter. Can someone tell me what to do?

jbw825 (author)Srinu2009-12-31

You would need to use an inductor and a 555 timer to do this. You would need to make the frequency of the timer slow enough so it would dim and grow brighter at the proper rate.

comodore (author)jbw8252010-01-12

If you ask me the easiest way is to use a microcontroler to make your LEDs dim and brighten....
I am not familiar whit any schematic that does that but I am sure that you can find one on the net!

comodore (author)Srinu2009-02-10

Hmm, I am not shore how to do that, but you can do that by hand with a potenciometer... :P

clark (author)comodore2009-02-12

potentiometer* ...sorry, it just bugs me when things aren't spelled right haha

comodore (author)clark2009-02-13


Srinu (author)comodore2009-02-13

hey thanks for answering the query but what i want is the led to automatically glow brighter and dimmer after switching it on. any suggestions?

comodore (author)Srinu2009-02-13

Arduino! If you know the basic of programing you can easily make this...There are lots of great Arduino tutorials on the net!

About This Instructable




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