Slow on/off LEDs?

Sayanora · Post by **Sayanora** » Mon Mar 12, 2007 8:43 pm

Hi guys, sorry if this has been asked before but I searched for hours and haven't found my answer.

I'm working on lighting the PL 1/350 E and I'm going to have a switch somewhere that will switch between warp and impulse power. The effect I want to acheive is, when switching, I want the deflector dish light to slowly power on (1-2secs) while the impulse drive light slowly fades out and vice versa. Ive been able to make an LED fade out with a capacitor in parrallel but I can't make it slowly come on even with a higher value cap(3300uF) Any help or suggestions would be greatly appreciated guys!

jwrjr · Post by **jwrjr** » Mon Mar 12, 2007 10:38 pm

This is something that I've done before. It isn't particularly difficult using single-chip computers as I do. I even designed something to make the deflector fade from yellow to blue and back.

Sayanora · Post by **Sayanora** » Tue Mar 13, 2007 6:54 pm

Thats a great suggestion jwrjr but a little beyond me. I have no experience with programing something like that and at this stage in my progress on the refit I'm looking for something a little more simple. Any ideas?

I am intrigued by this though and would like to look into it for future projects. Do you have any links to referance material to get me started?

macfrank · Post by **macfrank** » Tue Mar 13, 2007 7:48 pm

There are plenty of simple fading circuits on the web. Bill Bowden has one called Fading red eyes

Here's basically the same circuit but with an animation of the results.

Frank

Sayanora · Post by **Sayanora** » Tue Mar 13, 2007 10:12 pm

Those are all really cool circuits and I think I have some good applications for them but its not quite what I'm looking for. I'm just looking to have one led slowly come on and then stay on, like a power up. I've figured out how to make one fade nicely but thats it.

jwrjr · Post by **jwrjr** » Tue Mar 13, 2007 10:35 pm

if you want me to build one for you, contact me via pm and we can discuss it.