I've been searching for a very small fan.
at least small enough to fit in a battery tube (max ~25mm ) but ideally, fits is a driver recess (~17mm)
25mm
15mm
http://www.mcmelectronics.com/product/83-11830
Unfortunately, shipping on that tiny one is more than the product costs!
Anybody know of other sources or products?
thanks
I'd like to hear about your ideas for using a little fan. Sounds interesting.
I hope high-pitched whining noises don't bother you. Small fans are notoriously annoying.
would this work
nice find! i'm going to email them and ask....looks like that auction is for the larger one?
well, the zoomie that i just checkered the adjustment ring on is a handy little light, but since the pill moves up and down it has basically no heatsinking to the body and so is only driven <1A on high
the fan I linked could fit between the pill and driver - of course venting the body for air movement would be an issue...but it actually already has two holes w/ a rubber thingy in them for a charging port...
i'm building a light in a pistol grip host w/ two fans - one 60mm blowing on a vga cooler and a 40mm in the tail to get air into the body. I've got a lot left to do it will be at least a couple months before its done, since I've now got everything BUT the emitters.
The fans have thermistors and I robbed the thermistors from matching fans and wired them in parallel to make the fan power up at lower temp. When connected to 3x18650 at room temperature they're silent, but hold the thermistors between your fingers and they're audible - short out the thermistors and they're downright loud - BUT (if I can get the drivers wired properly), the lumens OTF will make anybody forget all about the noise 
Obviously the light will be unusable in the rain - those fans create a lot of suction.
It will be for blinding intruders, and solicitors, and checking the yard for skunks before letting the dogs out...
But the TINY fans...we'll have to see what I come up with. I mostly just want to do one as an experiment...to see if it is worthwhile.
| FYI |
Dear ezcreationpb,
Is the auction for one of the larger of the two fans shown? Do you also sell the smaller fan?
Not to discourage you but are you sure you want to shorten the runtime by using a fan? Also you should make some intake and outtake ports for the air to circulate in order to maximize (and that way make it usefull) air circulation. Waterproofing is out of the question either way not to mention cleaning the fan now and then. Messy. Perhaps a differnt host multicell would make a better option but still you must plan it to be not moisture or water drop friendly at all. One way would be to use a waterproof fan (expensive one) and isolate the cooling system so it can be cleaned under water tap if needed and this preserve even waterproofness.
If you're going that way (i would like you to explore active cooling) use it on a triple XM-L light where active cooling is probably a good idea and power requirements are rather huge so a fan current draw would be almost meaningless. A quad 2S2P 18650 just screams to do it. Output voltage is 6-8,4V and many 12V fans would work in that range pretty easily and with substantially less noise while generating not much less airflow. Be sure the heatsinking is worthy of a fan with not so dense fins or you might end with an annoying whistle. The most annyoing part is there are virtualyl no quad 18650 hosts in the budget price range... a pity.
This sounds interesting - I'd love to hear of progress on this. The tiny fan ones could be tricky like you say - but they need zillions of rpm to shift enough air to inconvenience a mosquito. And may sound like one. I don't think they'd work all that well (or perhaps at all) undervolted. But I'd love to hear of any results on this.
yeah, the waterproof thing is an issue.
the 15mm fan i linked is water resistant (i looked up the manufacturer's page.
you could pot your circuits...
but really, i'm not too worried about it. I have a lot of lights, so if the weather looks bad I'll use a different one :)
the current draw is very small really, if you don't mind at least some trade off for brightness...
same w/ noise
A peltier plate under the emitter with a small finned heatsink on the hot side and one of those fans making sure the sink gets air flow. Would work great on something with a big battery pack.
yeah, not sure the tiny fan is worth it, probably not, but I'll have to prove it to myself...
the ones in the build i've already started move a lot of air, they're both quality case fans - 28cfm and 10 cfm - although in the host i'm using they don't have the ability to reach any where near that spec... power consumption at full tilt is .5A at 12V
yeah, I agree, or in a light that is 12V for connecting to vehicle :-)
probably try a peltier if this build works out - there is literally NO more room in this host w/ the parts I've picked (yeah, I know they're thin....still...no more room)
Several years ago I was going to do a (at the time) Monster light with active cooling. Never did it because of cost, but there's plenty of ideas and fans out there for low draw and high spped fans.
that's pretty close to what I'm doing - x9 emitters
probably end up w/ a >$200 pile of junk 
but i've been planning for a long time, so if i don't just finish it I will be bugged by the idea forever
im not the seller of the tiny fan that i posted on post#2 might have to email him and ask...sorry
I asked him - https://budgetlightforum.com/t/-/6580#comment-125048
When I have some time to waste I'll scour the web for a better price on the 15mm one I linked in OP
Instead of tiny fans you could use tiny pumps to water cool the light. Make the cooling fins into cooling coils. Then it could be waterproof!
that's actually a great idea
don't some heatsink/cooling systems move the coolant w/ convection...no extra power required?
some old school lanterns use convection to feed air to the flame - i've thought about cooling a camping lantern that way...
Active cooling was used on the Wavien light, which also used their patened "light recycling" collar and aspheric lens.
It was sold through Frontgate.com for a short time for around $400, IIRC.
Those tiny fans look like they have great potential. I look forward to seeing your results.
Heatpipe cooling is likely to what you're referring. The pipes are usually copper, with a coolant inside, under vacuum.
The vacuum allows the fluid to boil with a small Delta T, and at room temp. This allows for heat transfer from one end of the pipe to the other. Imagine being able to send the heat of the LED from the star to the tailcap, very efficiently.
If you've ever seen the "drinking bird" toy, or the "love tester" toy, they operate on a similar principle.
i have a couple heatpipe type processor heatsinks here (scavenged). weird thing is, the pipes and contact plate are copper but the fins are stainless steel
if that tiny fan can let me use 1.4A in this light, instead of 1A, I would consider it a huge success