Pulsing led - Electronic Circuits Projects Diagrams Free

Bitman · 29th August 2005, 04:13 PM

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 · 29th August 2005, 04:53 PM

This'll work.

Bitman · 12th September 2005, 04:19 PM

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!

stevez · 12th September 2005, 04:36 PM

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 · 12th September 2005, 05:38 PM

so you want the LEDs to fade on and off?

zachtheterrible · 13th September 2005, 02:20 AM

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:

Bitman · 13th September 2005, 06:41 PM

Quote:

Originally Posted by jrz126

so you want the LEDs to fade on and off?

Yes, exactly!

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

Any help appreciated!

ThX!!!

Bitman · 13th September 2005, 06:53 PM

Hi all!

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

I think I'll do it soon:
http://ourworld.compuserve.com/homep...5.htm#eyes.gif

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

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29th August 2005, 04:13 PM	(permalink)
Bitman	Pulsing led 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!!!

12th September 2005, 04:19 PM	(permalink)
Bitman	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!

12th September 2005, 04:36 PM	(permalink)
stevez	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. __________________ stevez

12th September 2005, 05:38 PM	(permalink)
jrz126	so you want the LEDs to fade on and off? __________________ Jeff To the optimist, the glass is half full. To the pessimist, the glass is half empty. To the engineer, the glass is twice as big as it needs to be.

13th September 2005, 02:20 AM	(permalink)
zachtheterrible	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: __________________ I'm no electronics god, i just talk too much.

13th September 2005, 06:53 PM	(permalink)
Bitman	Hi all! I can found a lot, with the keywords "fading led circuit" in google.. I think I'll do it soon: http://ourworld.compuserve.com/homep...5.htm#eyes.gif ThX again for every help! This forum is very useful!!!!