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Breathing LED's Answered

I have seen this effect in halloween masks but I do not know haw to replicate this breathing effect. I made these videos to illustrate the effect
No idea on how to do it. A little help?

I'm sure it is fairly feasible but I am missing the instructable please see these 2 videos (1 minute each):


Here's what you want:

No microcontroller or 555 required.

At the time of this posting, unit is $3 AU.

ya i have been looking for the same thing for a model i was working on but i couldn't find one that just faded on  and off in one color


11 years ago

There are a bunch of circuits on the net based on a "standard" op-amp triangle-wave generator. Google for "Triangle wave generator led fader" Here's a representative circuit with what looks like some detailed tutorial info LED Throbber The dual op-amps used in these are cheap and pretty interchangable.

Other than that, I'd be inclined to go with a microcontroller-based solution like what everyone else is recommending, but there's significant overhead getting started. That "smart led" website is pretty neat.

The LEDs your refering to have the effect chip built into them. The RGB LED is especially sweet, that it rotates through every color of the rainbow in various patterns lasting three minutes.

Thank you for the Hint Las vegas, have you built anything like that? Man I'd really like to build that myself, where could I get that chip...

You can only buy the LED with the chip built-in. Probably the easiest way to get it is in one of those LED Pens that cost about $5. That's cheaper than buying the RGB LED alone.

I got a pen a while back from a career fair that glowed and faded in all six colors. You could search for those online and hack it.


using PWM and a microcontroller could do the job. Pulse Width Modulation switches the LED on and off very fast. The longer it is on, the brighter it seems to the human eye.
Search for PWM and ATtiny, for example.
Or have a look at: http://todbot.com/blog/2007/03/25/smart-led-prototypes/
Kind regards,

Thank you very much Alex!! Any idea on the price? I wanna buy the parts ASAP!!

Thanks man, I'll try to search for it. I wanted to make the instructable for people like me who want to just build it themselves, I'll keep searching

I agree with some of the responses. You should add a potentiometer to lower and raise the amount of voltage going to the LED.

This sounds good (I built a PWM many years ago, but that was for a train-set...) L

Looks like video editing to me. L

Yes, in fact I made the video because I have seen this effect in a halloween mask but I do not know haw to replicate this breathing effect. No idea on how to do it. A little help?

Sorry, I wasn't paying attention. Mechanical: Have a motor drive a crank connected to a potentiometer. Electronic: (don't know) L

2nd vid, Definitely. Used the Hue saturation rotation w/out masking off the bag and the LED in the second video. The first video looks okay to me.

Looks like an LED taped to tow button-cells.
Video also looks like a simple fade-out, fade-in effect, study it and the light distribution doesn't shift, only the overall brightness.