How to make a fast blinking LED bike light

Step 7 The Electronic

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

Comments

[stexmetalac07]

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

[crashcup]

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

[creator22]

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]

It depends on the resistors and capacitors on the 555 timer. Check out http://www.doctronics.co.uk/555.htm or http://www.scribd.com/doc/38590997/Make-Intro-to-Breadboard-Electronics-551

[noapparentfunction]

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

[techmonster]

in the schematic did you mean to say 108 k ohm

[comodore]

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

[jmsaltzman]

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

[sridh]

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

[comodore]

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

[Srinu]

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]

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]

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]

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

[clark]

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

[comodore]

-_-

[Srinu]

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]

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

[gman2000watts]

I've heard that if you wire enough capacitors, the leds will dim when switched off. Not sure about dimming when switched on.

[comodore]

Well, I guess that would work...The capacitors charge and than take a bit longer to discarge witch in term makes the LEDs dim...

[Win7Maniac]

Definitely Arduino. It's cheap, and if you use it with a digital pot, it should work great.

[Win7Maniac]

You'd definitely want to use the Arduino with a digital potentiometer such as the AD5220. With this IC, you can send a pulse command to the IC, and it will change. In PBasic, used for Parallax microcontrollers, this command is the "pulseout" command. If you "pulseout 30", you set the pot to 30 "notches"; I think it has 250 both ways or something like that.

[comodore]

Agreed!

[boydtoamuse]

Won't all the LEDs pull too much current through the 555, burning it up eventually? I mean, little LEDs pull 20 milliamps and 555 timers are rated at 5-10 milliamps as a maximum rating. Have you found that your circuits burn out or anything?

[comodore]

No! I use it on my bike every time I ride at night... nothing burned up...

[lucas_br]

hello , I'm planing to use your Instructables as a base for another project how can I adapt it for a 12V power supply? (bike dynamo)

[comodore]

hi, first of all you don't need to use 12V. Limit the current coming from the dinamo whit an appropriate resistor so you get 9V coming out.Try useing a 150 ohm resistor and see how mutch it lowers the voltage.I think that would be the best solution. Good luck! Post some pics of your project when your done! If you have any more questions feel free to ask!!! :D

[DYLEGO]

About the 180 K Ohm resistors, is it okay if they are normal tan 4 band resistors? They are 180 K ohms, just not blue...

[comodore]

Yea, that doesn't mater...That is just the way of marking them... I will work fine!

[DYLEGO]

Is it okay if I use one 3vLED, 100Kohm resistors, and .22 uf cap? That should hive it 1 blink per second, right? I just want to know if I can use one.

[comodore]

I'm not shore that 3V LED will work, use a multimeter and mesure the voltage coming out... I think it is to low to power up 3V LEDs. Yea, 1M and 0.22uF should do, think.. I'm not that good at math, try assembling all that on a proto-board.... I'm interested in the results.. please keep me posted.... On the internet you have lots of 555 calculators....try using them to calculate the value of the capacitor and the resistor.... :D

[DYLEGO]

What if my capacitor is a polyester film(green boxy capacitor) and .1 uF? The closest electrolytic cap at Radio Shack was 2.2 uF and was non-polarized, so I got the polyester film ones. The guy said there should be no difference, but it still doesn't work.

[comodore]

Well, you need a non-polarized, it can be film or any other kind...But you do need a non-polarized capacitor.
0,22 uF, 16V
The voltage doesn't matter as long as it is twice or almost twice as big as the voltage you are putting to it. So in here you have a 9V battery so you cold put a 16V capacitor because it is very close to 2x9=18V, or if they don't have 16V try 62 or 100V....The voltage really doesn't matter....

[DYLEGO]

I'll have yo get one online then, RadioShack doesn't have .22uF... Also the polyester film one was nonpolarized.

[comodore]

You can make the same circuit but whit different values of resistors and capacitor... Look on the internet for a 555 Timer calculator and calculate your options... :)

[DYLEGO]

Three volts should be fine, 9v comes out, hits 300 ohm resistor, makes 3v. Should be good, don't know why I even asked if I knew the answer...

[comodore]

Yea, forgot about the resistor in my other comment, although i would pt a 6V instead... Read the comment i posted earlier....

[DYLEGO]

Which comment are you referring to?

[joao.torres]

use a transistor to amplify swich a secundary circuit

[comodore]

how, i tried but no effect! Can you make a schematic, where should i put the transistor circuit? Thank you!