Pulsing led

B

Bitman

New Member

• Aug 29, 2005

• #1

Hi!

I would like to build a circuit what is pulsing one or more led.
How it is possible? What should i use? ICs, condenzators or transistors?
So i need some helpful message to do it...

Nothing extras just a little circuit


Thanks in advance!!!

 

zachtheterrible

Active Member

• Aug 29, 2005

• #2

This'll work.

 

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B

Bitman

New Member

• Sep 12, 2005

• #3

Thx, but i want to pulse it, so decrease and increase its brightness.
Like the pulsing neon under the cars in NFS: Underground...

ThX in advance!

 

S

stevez

Active Member

• Sep 12, 2005

• #4

There used to be an IC that did this nicely and provided a little more visibility by means of a short duration but higher than normal supply voltage. I googled on LM3909 and found some info on it. One site described a discrete component replacement.

 

jrz126

Active Member

• Sep 12, 2005

• #5

so you want the LEDs to fade on and off?

 

zachtheterrible

Active Member

• Sep 12, 2005

• #6

It would take some experimentation to get the right values and what not, but try putting a resistor and capacitor from pin 3 to ground in that order. The idea being that the when pin 3 goes high, the capacitor sucks current, not letting all of it go through the LED. When pin 3 goes low, the capacitor drains through the LED.

I'd start out with a resistance of 1k and 100uf, but that is a total guess, if anyone wants to do the math be my guest, im too lazy :lol:

 

B

Bitman

New Member

• Sep 13, 2005

• #7

jrz126 said:

so you want the LEDs to fade on and off?

Click to expand...

Yes, exactly!

Okay, thanks for the help! But somebody can calculate it? (just about)

Any help appreciated!

ThX!!!

 

B

Bitman

New Member

• Sep 13, 2005

• #8

Hi all!

I can found a lot, with the keywords "fading led circuit" in google..

I think I'll do it soon:
**broken link removed**

ThX again for every help! This forum is very useful!!!!