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How to make multiple leds flicker at different time Answered

I want to make a picture to hang on my daughters wall, but i want to add multiple leds onto the sky so as they twinkle like stars etc. How would i go about doing this ?? Thankyou.

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technoplastique

10 years ago

You can get a strand of LED christmas lights at Target for about $10 that are already set to flicker if you want to go the easy way!

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Goodharttechnoplastique

Reply 10 years ago

That would probably be the easiest, then he could simply put them in a fairly random pattern.

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tech-king

10 years ago

i have a circuit at home that varies the flash rate depending on wich capacitor value is used (higer=longer delay). ill post it when i get home.

actually, i think led cristmas lights is a better idea because there is no power supply problems.

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Patrik

10 years ago

I believe I have seen blinking LEDs, i.e. LEDs with a little blinking circuit built-in - could those be useful? Another shortcut would be to multiplex the LEDs - connect 16 LEDs into 4 rows and 4 columns, by wiring all the anodes for each row together and all the cathodes for each column, then activate only one "row" and one "column" at a time. The downside is that only one LED will be lit at a time, but that might be acceptable. The upside is that now you only need one controller with an 8-bit output to control 16 LEDs. Make three of these to control 48 LED's, of which only 3 LEDs will be on at a time. (Alternatively, use a 7x7 setup to control 49 LEDs with only 14 outputs, but I'm guessing that three independently flashing batches of 16 LEDs will look better.)

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NachoMahma

10 years ago

. Each LED doesn't have to have it's own timer. You can flash 2-3 LEDs at the same time and still get a nice effect. If the on times overlap, it might not even be noticeable.

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Goodhartguyfrom7up

Reply 10 years ago

Looks like he might need as many as 45 555 timers *sign* or aobut 11 quads.

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Goodhart

10 years ago

First a little friendly advice: posting an email addy on a publicly accessible forum as this will give you lots of new email, most of which you will not want to open. It is not a good idea. Each LED could be connected to it's own timing clock (that would be kind of messy if one was using a 555 for instance, maybe using a quad-timer IC for each four). OR one might be able to use a countdown IC and hook the "sequences" up in a pseudo-random fashion.