LED question

Darth Homer · Post by **Darth Homer** » Wed Oct 18, 2006 10:00 pm

I have the Polar Lights 1/350 scale NX-01 and I want too light it, my plan is to battle damage it like in the Zindi episodes my question is there any way that you can make an LED flash with an irregular pattern? I want to make the red dome on the damaged warp engine flash like it is failing.

http://i4.photobucket.com/albums/y130/R ... ati-71.jpg

jwrjr · Post by **jwrjr** » Wed Oct 18, 2006 10:34 pm

Strictly speaking, no. Practically speaking, you can come close enough. See the damaged ship in the 'Starship Exeter' movie.

Sparky · Post by **Sparky** » Thu Oct 26, 2006 5:33 pm

You can build a pseudo random sequence generator. I haven't got my bread boarded version to look the way Iâ€™d hoped though. A computer program running on a micro controller might let you get it setup.

jwrjr · Post by **jwrjr** » Thu Oct 26, 2006 10:48 pm

If you do it using logic chips, the pattern length for an N bit pseudorandom number generator is 2N-1. Thus for an 8-bit circuit, you can get a 255 step pattern out of it. With a microcontroller, you can get as many steps as the program storage space will allow.

en'til Zog · Post by **en'til Zog** » Fri Oct 27, 2006 12:16 am

There's a farily simple way to get kinda random LED blinkage using a 4060 CMOS chip. The chip has a built in 'clock' or 'pulse soruce' or "thing that makes the chip GO" using two external parts (resistor and capacitor). The outputs of the chip just pulse ON and OFF, each output going half as fast as the next higher number. 12 of 'em. By connecting an LED to one SLOW output and one FAST output (and NOT to anything esle) you can get a multiple flash, pause, multiple flash... The 4060 provides all the power to the LED when it's wired this way.

To get a more random flash, you can combine outputs with a 4023 chip that makes a nice effect - I've used it for arc welding flashes, 'sparking' circuits, and fires.

Sadly, I don't have a place to stash these schematics (or wiring diagrams) on the web, but if you wish to eeeemail me I'll send em to you.

Pat Amaral · Post by **Pat Amaral** » Fri Oct 27, 2006 2:27 am

A few years ago, FSM had an article where a guy simulated a small fire by connecting a red LED to the ear bud leads on one of those little cheapie promotional radios. A don't remember which issue it was nor do I recal the particulars of how he engineered it but it sounds like it would be a really effective. . . um. . .effect.

Sparky · Post by **Sparky** » Fri Oct 27, 2006 1:10 pm

En'til Zog wrote:There's a farily simple way to get kinda random LED blinkage using a 4060 CMOS chip. The chip has a built in 'clock' or 'pulse soruce' or "thing that makes the chip GO" using two external parts (resistor and capacitor). The outputs of the chip just pulse ON and OFF, each output going half as fast as the next higher number. 12 of 'em. By connecting an LED to one SLOW output and one FAST output (and NOT to anything esle) you can get a multiple flash, pause, multiple flash... The 4060 provides all the power to the LED when it's wired this way.

To get a more random flash, you can combine outputs with a 4023 chip that makes a nice effect - I've used it for arc welding flashes, 'sparking' circuits, and fires.

Sadly, I don't have a place to stash these schematics (or wiring diagrams) on the web, but if you wish to eeeemail me I'll send em to you.

Please send to me, i'll post and keep a link the stickys. I have lots more space now so fire-away.