I was thinking of a computer mod I wanted to do, but I'm not sure if it's a
good idea (like I'll let THAT stop me). What i'm wanting to do is cut out one
side of my case and put a lava lamp in a window. I figure I could probably
use a fluorescent light or mabye a yellow neon light to illuninate the window.
I am having trouble coming up with a way to heat the substances though. My
inital thought was a spare power supply connected to some sort of coil. I was
also considering something like a heat pump, but I don't know if they come
small enough. I am also concerned about the heat effecting the hardware. Does
anyone have any advice they would like to share? Thanks in advance.

16 responses total.

The heat is definitely going to be difficult, since that's basically how the
lava lamp works.

I've seen non-lamp things that use a mixture of oils to do various neat
things, either rocked back and forth for waves or else you have to turn it
upside down.  I wonder if something like that could be put behind the window
and rotated?

The lava lamps are heated with the light bulb that illuminates them.
Incandescent light bulbs put out quite a bit of heat.

Yeah, I had already ruled out the incandescent bulbs, that's the reason I was
trying to conider different heating mechanisms. I figured that a fluorescent
or yellow neon may still be able to provide decent lighting.

Why did you rule  out an incandescent bulb?

I just assuming that the heat produced from an incandescent bulb would have
negative effects on the computer (that's why I hadn't mentioned the use of
them in the first post). 

You won't get a lava lamp to work without a heat input. That's what drives
the circulation. 

What I was assuming was that I might have been able to find an alternate
heating source that was more efficent than a light bulb, because I know they
radiate a lot of heat. I was thinking something more along these lines:

http://www.mod-tronic.com/Minco_Miniature_Heating_Elements.html
and
http://www.herbach.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=HAR&Pro
duc
t_Code=TM92HVC2178&Category_Code=HVC

Do you think something like this would work too?

If you're really set on using a real lava lamp... The bulb is 40 watts, and
perhaps you could reduce the radiation of heat with some insulation around
the metal base.  You want to dim the lamp slightly to compensate...

But as far as heat dissipation goes, I've seen reference to how many watts
various CPUs dissipate, so that's a clue about how much heat you've already
got inside the case.

Re resp:7: How efficient do you want?  90% of the power that goes into
an incandescent light bulb is heat!  Only 10% comes out as light.

And much of that light will be absorbed in the system - as heat. Consider
a light bulb as just a heating element, with a little light as a
byproduct.  You need some light to see the "lava" circulating, anyway. The
only drawback, perhaps, is that it won't be possible to fix the (light
bulb) heater to the bottom of the vessel. However it could be put into a
partially insulated chamber below the vessel with all the heat thereby
directed into the vessel. You would have to watch out for overheating,
though. Even a 7 watt lamp will get pretty hot if enclosed. It might be
useful to cement "cooling fins", such as used on ICs, to the bottom of the
vessel, to facilitate heat transfer to the vessel. 

But the glass itself will be hot, since part of the function of the heat is
to melt the wax blob.  Plus the top has to be cooler than the bottom for the
movement to happen.

The heat melts the goo...but then causes it to expand more than does the
surrounding fluid, which leads to the circulation. But yes, the bottom of
the glass vessel must be heated. 

Obviously, you want to use the CPU to heat the lava lamp.

You'll probably need to find lower temperature wax if you actually want
to *use* the computer too.

Lower temperature (if by that you mean its melting point) wax is not the
only problem. Another problem is the difference of coefficients of thermal
expansion of the wax and the surrounding fluid. This would have to be
greater in order to operate at a lower temperature difference. I suspect
they have already devoted considerable effort in finding such a fluid
pair, along with the substances having all the other necessary properties. 

But, good luck, if you search for a better fluid pair. 

I'm sure there are all sorts of fascinating questions dealing with
thermal viscosity, conductivity, chemical stability, etc.  Typical
engineering perspective, in short.  But you're completely missing the
marketing angle.  This is a cool liquid cooling aparatus with visible
user feedback for correct and safe operation, for which you will be
willing to spend many hundreds of $'s.  All that materials research on
$20 lava lamps is completely wasted.  The real question is, how do you
get the CPU to emit interesting and pretty colors, and still work?

Thanks for everyone's input. I'll let you all know how it turns out  (if all
goes well). It just so happens that cpu came out with a special modding guide
the month that happens to have a picture of a computer with a lava lamp in
it.  There's some other cool prjects there as well. The url is:
http://www.lucentrigs.com/Narcosis.htm

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