device that will randomly flash a set of 7 lights

Hi!

I need a device that will randomly flash a set of 7 lights (the bulbs can be

3.5 or 12 volt). I would like the on/off timing of the flashes to be random (anywhere between up to say, 10 seconds) and for the number of lights lit during the 'on' cycle to also be random. I really have no clue where to start with this - would I have to build something or can I buy something that will do the job for me?

I would be very grateful for your advice!

Thanks all,

Tim

Reply to
T J R
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What about one of these LED christmas tree things:

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I think Jaycar or DSE et.al do a kit for it. It uses a microcontroller to get the "random" sparkle effect.

There is random and there is random, what "kind" of random visual effect are you really after?

Dave :)

Reply to
David L. Jones

in article snipped-for-privacy@v33g2000cwv.googlegroups.com, David L. Jones at snipped-for-privacy@gmail.com wrote on 4/1/07 03:51:

Hi Dave,

Thanks for the reply.

I suppose I'm looking for the 'illusion' of randomness .. I have a set of 7 lamps in a metal control panel. Rather than have them all blink at the same time like a car's turn signal I would like to behave (for example) like: lamps 1, 4 and 7, lit for 5 seconds then lamps 3 and 6, lit for 2 seconds then lamps 2, 3, 5 and 7, lit for 8 seconds then lamp 4, lit for 6 seconds and so on

By random I really mean that I don't mind the order in which the lights light, or how long they stay lit.. Just that the lamps on the control panel appear to be running some random cycle... like something you would see in an old sci-fi film :)

Tim

Reply to
T J R

Hi Tim In that case you want randomness over a limited bandwidth. i.e. you probably don't want very fast flickers like 0.1sec ON and 0.1sec interval. As it would probably look like your panel is malfunctioning.

If I was doing it I'd probably want a pre-programmed sequence, so it looks like it's actually doing something useful rather than just being random. In which case a microcontroller or pre-programmed EPROM is the way to go. If you didn't mind the size and power consumption then an old DOS PC could be used with the parallel port controlling the LEDs.

The most impressive display of a "fake" panel I've ever seen was at the Kennedy space centre in Orlando. The entire moon-shot control room was recreated (with all original equipment), and if you believe the signage, all of the lights and displays on the all the control panels lit up in their original correct sequences as per a mission. Fantastic stuff.

Dave :)

Reply to
David L. Jones

You may want to try as Dave suggested the xmas tree approach. Yrs ago I made one with 4 or so standard LEDs in different colours in series with a flashing LED (Green from memory) and a limiting resistor. There were 3 or 4 of these strings in parallel. The flashing leds ran at slightly different rates - the result looked quite "random". It stll works years later off the same crap box plug pack.

Reply to
Robb

in article snipped-for-privacy@42g2000cwt.googlegroups.com, David L. Jones at snipped-for-privacy@gmail.com wrote on 4/1/07 21:32:

Thanks Dave!

I sounds a bit involved to be honest. The whole panel is no bigger than a small shoebox (though interestingly it is part of a missile launch system). I suppose I'm just hoping to butcher some existing equipment, a kids toy perhaps..

Tim

Reply to
T J R

in article 459e3921$0$20020$ snipped-for-privacy@per-qv1-newsreader-01.iinet.net.au, Robb at snipped-for-privacy@spammo.com wrote on 5/1/07 11:40:

Sound like a plan!

Ill have a closer look at that.

Thanks!

Reply to
T J R

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