Electronic fireflies

Jan 10, 2013 2 Replies

My wife bought some of these and they are actually pretty cool but expensive for what they are.



The operation is there are 6 LEDs on long leads from a small plastic box and 3vdc coming in



Each light comes on and dims out like it was on a capacitor for about



3-5 seconds.

The cycle time is pretty slow, maybe 15- 20 seconds each and somewhat random.



What's in the box? I am thinking the simplest relaxation oscillators possible firing a shot every now and then but how do they get the delay off? There is not much room for capacitors.


These days, a small microcontroller can do that job cheaper than the parts count of a discrete component solution.

A pseudo-random pattern and PWM modulation of the LED brightness is simple to do in software.

Bicycle rear tail light arrays as an example.

And those little "color organ" random light thingys for kids at the dollar store.

I still remember the 'speaker cabinet' style things with fluorescent lighting diffuser panels as a 'front screen' and 4 colored light inside. All wired to an analog audio amp which it lights when the music was above a certain threshold.

You want amazing on your hdtv?

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