device that will randomly flash a set of 7 lights

[T J R]

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

 

[David L. Jones]

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

What about one of these LED christmas tree things:
http://www.grantronics.com.au/projects.html
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

 

[T J R]

What about one of these LED christmas tree things:
http://www.grantronics.com.au/projects.html
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

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

 

[David L. Jones]

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

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

 

[Robb]

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

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.

 

[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

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

 

[T J R]

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.

Sound like a plan!

Ill have a closer look at that.

Thanks!