how? --> making a flashing led

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hey guys, i'm curious if you might have different methods of creating a flashing led. Like you see in cars.

My plan is to make a flashing led. One that i can easily set a delay with. Then i would like to attach a capacitor to it and make it fade in and out, instead of turning on and off. Unless you guys know a method without using a cap?

Thanks :)
PedroPO said:
If you want a very very very simple flashing led, you buy a Pink Floyd Pulse CD (vinyl doesn't have it) and U get one for free:D

haha i thought about doing something like that. :)
But then i found something similar lying around my place.
basically it's a chip covered in a black coating. then theres a tiny resistor, and a diode, and 2 transistors. I wanted to modify it to change the flash time and also add a cap to make it fade in and out..... but... I have no idea how it works. :( damn!

Though I am looking for the simplest circuit available... hehe

Thanks for the information coming in, i'm looking into it. :)

keep emm coming if anyone has more ideas :)
AudioFreak said:
ok well you can buy flashing led's but they wont fade in and out ... you could use a 2 transistor oscillator with the cap and led ... that circuit would achieve all of your objectives and is probably the simplest available for the task.

hmm... i hate to sound like an electronics newbie... :)
which i unfortunatly am...

a 2 transistor oscillator, what would be the part number for that, or how would i know what piece i'm looking for? I know oscillators from ..... uhm... fm radios, they have oscillators which turn to tune frequencies ( if i remember correctly ). Would you have a sample circuit handy? It does sound like a simple circuit.

Thanks :)
SteveG said:
a 555 timer makes a very simple oscillator. You can download the datasheet at, and it has example circuits and explains how the chip works. I don't see why you couldn't put a cap in series with it to ramp up/down.

hmmm that's one area i'm not good at... chips... i would love to use a 555 timer since it's made for this... perfect for my project...
i will take a look at the 555 info on

thanks :)
Account Disabled
Joined 2002
The 555 is about as simple as it gets, and they will directly drive an LED... 1 chip, a few small caps, a couple resistors, and there you go! Seriously, it's extrememly simply to build on a piece of perf. board. If you want any help, let me know.
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