I'm looking for a very very simple circuit to make a single LED flicker... it doesn't need to be random, and the WHOLE circuit, including battery and LED needs to fit into a cylinder 5/8" tall and just below a half inch diameter. (16mm tall by 12mm diameter in metric) the LED can stick out slightly, or the battery can stick out slightly, but not much, as these are going to be jewlery, and have to be a specific size.. If you know something that will work, please let me know! thank you.
Well, I don't have any specifics, but I'm thinking you could use a surface mount 555 chip, a small button cell battery (like they use in watches, but larger since you have 1/2" to work with), and other necessary surface mount components, I think you need a resistor and one cap for a basic 555 circuit to flash an LED? With some creative soldering techniques you wouldn't even need a circuit board. Then you could maybe hold it together with a glob of glue (epoxy, Goop/E6000, etc). Actually, that may be overkill. Given that amount of space you could probably use normal sized components and maybe even a small perfboard or PCB for mounting the 555 chip. Of course if you want a challenge, you could go for surface mount components and get it even SMALLER.
dunno if this is waht your after but maplin do an led that already flashes when power is applied. go to www.maplin.co.uk and seach for "flashing led" and it will come back with a list. that way all you would need is a battery and possibly a resistor and your done.
I once read you can make a led, or anything low-current flicker randomly with a TL light starter... though that's way too big
Rapid (and probably US suppliers) do a couple of transistor-size 3-pin chips to make attached LEDs flash on/off, for a flicker it's more complicated as you need a random effect. My bookmarked link is now dead, but try the Internet Archive copy here.
A 555 with some resistors a capicitors should fit in there. And 2 lithium button batteries (same as on the motherboard), would do the trick. Or just buy an flashing led, and hook it up too one of those lithium batteries and voila. Offcourse you could use an uC programmed to flicker the led semi random but I think that wuold be overkill
says it doesnt need to be random...( i had to reread it a couple of times to make sure i understood) if you want a simple almost trouble free get flashign LED's. no other components to add possible problems!
It's the indefinite pronoun 'you', not specifically Lyrric If one does want a true random flickering effect, this circuit claims to give one.
