I've searched but haven't found much of what is being done to help with thermal management.
Can't believe no replies yet. Let's get this heat party started.
Laser cooling:
https://en.wikipedia.org/wiki/Laser_cooling
All laser cooling techniques rely on the fact that when an object (usually an atom) absorbs and re-emits a
photon (a particle of light) its
momentum changes. The
temperature of an ensemble of particles is larger for larger
variance in the velocity distribution of the particles. Laser cooling techniques combine
atomic spectroscopy with the aforementioned mechanical effect of light to compress the velocity distribution of an ensemble of particles, thereby cooling the particles.
A massive spread of science has opened up in the past few years concerning shining a laser on a substance that makes it cooler. Nothing's free, this puts the heat in the laser and not the thing being lased.
Thermoelectric Active cooling:
https://en.wikipedia.org/wiki/Thermoelectric_cooling
Thermoelectric cooling uses the
Peltier effect to create a
heat flux between the junction of two different types of materials. A Peltier cooler, heater, or
thermoelectric heat pump is a solid-state active
heat pump which transfers heat from one side of the device to the other, with consumption of
electrical energy, depending on the direction of the current. Such an instrument is also called a Peltier device, Peltier heat pump, solid state refrigerator, or thermoelectric cooler (TEC). It can be used either for heating or for cooling,
[1] although in practice the main application is cooling. It can also be used as a temperature controller that either heats or cools.
[2]
Heat pipe cooling:
https://en.wikipedia.org/wiki/Heat_pipe
A
heat pipe is a heat-transfer device that combines the principles of both
thermal conductivity and
phase transition to efficiently manage the transfer of heat between two
solid interfaces.
At the hot interface of a heat pipe a
liquid in contact with a thermally conductive solid surface turns into a
vapor by absorbing heat from that surface. The vapor then travels along the heat pipe to the cold interface and condenses back into a liquid - releasing the
latent heat. The
liquid then returns to the hot interface through either
capillary action,
centrifugal force, or gravity, and the cycle repeats. Due to the very high heat transfer coefficients for
boiling and
condensation, heat pipes are highly effective thermal conductors. The effective thermal conductivity varies with heat pipe length, and can approach 100 kW/(m⋅K) for long heat pipes, in comparison with approximately 0.4 kW/(m⋅K) for
copper.
At the cutting edge, I would think active cooling would be on the horizon.
Heh. The tech is there, just seems like nobody is using it ATM, AFAIK. With these techniques, it'll move the heat but you still have to sink it somehow once it gets there.
I asked one well known modder and he told me active cooling and waterproofing don't mix yet.
People said that about liquid cooling a PC as well. All of the PC overclocking tricks apply, use 'em!
https://en.wikipedia.org/wiki/Computer_cooling#Piezoelectric_pump
A "dual piezo cooling jet", patented by GE, uses vibrations to pump air through the device. The initial device is three millimeters thick and consists of two
nickel discs that are connected on either side to a sliver of piezoelectric ceramics. An alternating current passed through the ceramic component causes it to expand and contract at up to 150 times per second so that the nickel discs act like a bellows. Contracted, the edges of the discs are pushed together and suck in hot air. Expanding brings the nickel discs together, expelling the air at high velocity.
The device has no bearings and does not require a motor. It is thinner and consumes less energy than typical fans. The jet can move the same amount of air as a cooling fan twice its size while consuming half as much electricity and at lower cost.
[6]
Oh, look at that. A fan with no real moving parts. How cool is that?
Are any manufacturers working on this?
Yeah! *YOU* if you're interested. Liquid cooling kits here:
http://www.amazon.com/s?ie=UTF8&page=1&rh=i:aps,k:pc liquid cooling kits
http://www.xs-pc.com/watercooling-kits/
http://www.xoxide.com/watcoolkit.html
Any other ways for managing heat?
Of course. You could just dunk it it a clear bucket of chilled baby oil and run it from there. We don't actually need a kit. CPFer Capolini did basically this trick with a snowbank one evening, bypassing a temperature sensor stepdown. The light did not step down.
Also, if you merely bonded a computer heat sink with fins to the head of the light, perhaps machining a flat spot and bonded the heat sink with something like Arctic Silver thermal epoxy, then this would accomplish two things:
1. Increase of thermal mass, extending possible runtime before stepdown.
2. Massive increase of surface area to dissapate that heat.
It wouldn't even have to be a big heat sink, this would massively help even without a fan and nothing's stopping you from adding one.
2 lions in series provides enough voltage to spin a computer 12v fan. They don't actually need a full 12v.
From my past of messing with computers, I discovered that a smooth heat sink is NOT what you want. The rougher the texture you can give the flashlight, you can almost double the surface area presented to the outside air. The more fins on the flashlight, the more surface area.
As a mechanic, I was amused to hear from a vehicle marque that polishing the engine voided the warranty as it cut the surface area for heat dissapation in half.
In short if you want better heat management, you don't necessarily have to get radical and crazy. A very rough textured flashlight is what you want, preferrably with a lot of cooling fins. A bead blast finish would be superior to the polished finish we typically see. The more knurling, the more surface area particularly when combined with bead blast. Also, the more thermal mass you add will extend the time before you should step it down.
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