Posted on 2006-07-11
This may not be the correct forum for this question, but hopefully, if I can't get a specific answer, maybe I can get some pointers on where/how to look for this info.
Here's what I've currently got: 1 manual switch box with 70 switched circuits. I use this to fire cues in personal fireworks displays. While this definately works, I'd like to build a timing circuit that allows me to preset times for specific cues to fire.
I have the following timeline: Cue1-0:00, Cue2-0:53, Cue3-1:06, Cue4-1:23, etc. The best I can figure with my limited knowledge is to use something like a CMOS4206 (or 2 or 3) and have those clocked from a 555 timer. Then, I could use a sequence of AND gates to logically figure out when my Cue-times happen and trigger a relay to pass the charge along. Unfortunately, this is very cludgy and would be hideous to redo the logic each time the Cue-times change, especially with a set of 70 cues.
So, what I'm looking for is either what chip(s) might be able to perform this function for me (maybe a programmable chip with a certain number of output triggers)? Or a site with a simple project that encompasses this that I could use as a template. They do sell professional items that will do this, but as I'm only a hobbyist, I can't justify shelling out a few grand for one of these boxes.
Thanks for any input!