Flicker circuit

[cgarwood]

I would like to build a couple "flicker boxes" for some lights we'll be using in a haunt this year. Ideally something a bit customizable, with a pot that controls the flicker rate (which should still be semi-random) and intensity.

I've seen tutorials where people use fluorescent starters to do this but that doesn't even look remotely safe. I'd like something I could ideally run about 250 watts or 4 60 watt bulbs off of.

I don't know much about designing the actual circuit, but if someone could tell me what all I need and how to wire it up or provide a schematic I can build it.

Also... could someone point me to some good guides on Vixen and trigger inputs? Got a room that needs to have a lightning sequence triggered when the actor pushes a button, and a few rooms that need to trigger sequences when a motion sensor is tripped. I've never used trigger inputs before, and haven't been able to locate a good tutorial on them.

Thanks!

[n1ist]

I'd look into writing some custom firmware for one of the regular boards (renSS, dmx4ssr, etc) as it already has all the hardware you need, and can easily be triggered or controlled by Vixen.
/mike

[chilloutdocdoc]

There's a couple of ways that you "could" do this... Each depending on the level of complexity and cost I can for see you wanting to pursued.

Custom firmware for an existing board could be written probably quite easily.
If you're going to go to the trouble of having to write new firmware AND design a board. Something that was made to plug into a SSR could be useful, and then the SSR could be re-used.

Either way it shouldn't be all that hard to do, the firmware would just randomly trigger the OPTO on... If you want a random flicker it's probably easiest to do this with a small PIC. You could get away with a 555 timer circuit to trigger the opto, It wouldn't have to be sync'd up to AC current as it's just flickering. I may have to stop at ratshack after work and pick up a 555 timer to try that out and see what it looks like for an interesting effect.

my $.02 YMMV

[cgarwood]

I would prefer to keep it all standalone if possible. Decent idea with customer firmware, but I wouldn't even know where to begin writing firmware and don't have a pic programmer.

Thinking more about it all I need it like 4 "channels" flickering, which could run a variety of lights across the haunt off the 4 channels. Probably want to run it to separate relays though as to not overload a single flicker channel.

Already got plans for my Ren-24s and 595 controller and at least 1 show PC, so if I could build and run these standalone that would be ideal.

[budude]

Someone here or on ACL had come up with a strobe very similar to the ACL strobe using cheapo PIC10F200 PICs but left the input pin open into the ADC to use as a random number generator - it seemed to work pretty well and might provide a very random appearance using a mixture of white, red, amber LEDs. The ACL strobe could run three 20mA LEDs (in series) so this might look pretty good with this mix.

[DennyMo]

Scroll down a little from this link to the section on "Flickering LEDs", maybe it'll help?
http://forum.allaboutcircuits.com/blog.php?bt=812

[mlkren]

Scroll down a little from this link to the section on "Flickering LEDs", maybe it'll help?
http://forum.allaboutcircuits.com/blog.php?bt=812
Very cool Website, lots of good info.

[DennyMo]

Found another idea that might work:
http://www.kpsec.freeuk.com/projects/xmastree.htm
Use red, yellow, and orange LEDs, play with the speed until you find a combo that looks like fire.

[dmcole]

I don't know much about designing the actual circuit, but if someone could tell me what all I need and how to wire it up or provide a schematic I can build it.


Sorry if this is a bit of an elderly reply ... you can read ad naseum about my flickering light saga at http://www.45mm.com/lighting/flickering.html

\dmc

[lalder]

this works really well
http://4.bp.blogspot.com/_4iBagGBk5pY/TJAJ5qajqBI/AAAAAAAAAH4/wGvgVOpslUA/s1600/AdjustDistance.jpg

[lildave]

If you want the good stuff lookup simflame. thats what we use.

[mlkren]

simflame (http://www.simflame.com/) does look cool, but a little expensive for my taste. I wonder how you could reproduce the device. :)

[lildave]

The photocell works pretty good. Led candles are great for low power. jaycar sells a kit for a mr16. Maybe a led candle or pic with a transister.