The Mobius & Heat Issues

I'm thinking that a small CPU cooling fan would do the trick and the best part is, I don't have to run it at full speed. I could add a resistor in series with the fan to keep the noise down.

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Source: http://en.wikipedia.org/wiki/Computer_cooling

Assume that I'll only allow a 36F (20C) rise in heat, the calculation would be: 1.76 x 1.5 Watts / 20C = 0.132 CFM of air flow. That comes to 0.99 gallons of air every minute or 3.7 liters of air every minute. That's about 2 oz of air per second or 62 ml of air per second. So not a lot of air need to move across the heatsink.

... Now if only SpyTec would stock the wide angle lens version ... :D
 
Given the low number of reported heat related failures, the fan is probably overkill! ;)
 
I keep bouncing back and forth between just putting on a larger heat sink as a precaution OR adding a small fan. The heatsink is the easy way, no extra power required, but the fan works the best.


Then again, maybe this will do: http://www.allelectronics.com/make-a-store/item/HS-180/HEAVY-DUTY-HEATSINK/1.html

:p

Bob Diaz

Perhaps you might consider taking a cue from the computer CPU overclocking community and install a liquid cooling system? :Do_O

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P.S. Longtime fan of All Electronics here. I love browsing their catalog to see what interesting new stuff shows up.
 
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RE: P.S. Longtime fan of AllElectronics here. I love browsing their catalog to see what interesting new stuff shows up.

Assuming that LA Traffic isn't bad, All Electronics is about a 1/2 hour drive from my house. However if it's really bad, it could be a 3 to 5 hour drive. :D
 
RE: P.S. Longtime fan of AllElectronics here. I love browsing their catalog to see what interesting new stuff shows up.

Assuming that LA Traffic isn't bad, All Electronics is about a 1/2 hour drive from my house. However if it's really bad, it could be a 3 to 5 hour drive. :D

I'll bet the retail store is a blast to visit. I'm sure I would walk out of there with an armload of stuff I didn't go in for. Alas, living on the East coast I've always been limited to their catalog and the web site.

For anyone who doesn't know what Bob and I are talking about, All Electronics is a place that specializes in surplus, odd lot and hard to find electronics components, parts, gadgets, cables, wire, LEDs, unusual offbeat items, etc. etc. etc.....all heavily discounted. Many Dashcam enthusiasts and DIYers would likely find items of interest to them or just enjoy perusing their website. You can also download a PDF of their regular printed catalog HERE. I read somewhere that being in LA, some of their biggest customers are special effects guys from the TV and film industry.
 
So, i using mobius few weeks now.
In estonia we have right now outside temperature +5 Celsius and there isnt any overheating problem with mobius. Heatsink goes pretty warm, but not so hot, that i cant hold finger on heatsink.

January/February maybe i can tell what happens, when outside have -25 or even lower temperature (depends on the winter) :p

Hopefully you understand my not so good english.
 
I just found this site (AWESOME!!), and thanks for letting me join y'all.
Mine came in yesterday and I noticed this issue immediately.. WoW!
Understand that I live in Florida on the northern border of the Everglades -- It gets hot... It gets humid. Given the fact that sending it off under warrantee for repair/replacement wouldn't be an option in the future, I popped the cover.
IMHO, No way is this camera setup for the mounting of an additional external heatsink, because of it's design. If there were a way to mechanically-bond a fin-type sink to the existing metal plates, I would go for it, but there simply isn't. The use of an epoxy cement or glue would surely interfere with the intended transfer function of those existing plates. If there were room for a hole to allow screw/bolt attachment of the fins to the plate (with the requisite heatsink compound), it would've been done while I had it apart to inspect. Unfortunately, there was no way.
The only real modification I can envision that could add any benefit, would be to apply a very thin layer of heatsink compound on both sides of that internal tin foil, which I DID do... Tho, I did find out why this was not done by the manufacturer. It was a real chore keeping the grease from spreading to areas it shouldn't (eew), but IMHO, it had to be done, period. I'm keeping in-mind that the whole purpose of a heatsink is to transfer heat away from heat-sensitive components. This heat must transfer and then be dissipated. If you cannot transfer the heat away by thermally-coupling the two surfaces, you're only insulating the sink plates, or blocking the cooling affect of the ambient air by putting an aluminum blanket over them. BTW, I agree. AllElectronics is one of my suppliers (retired and fixing CB radios in my garage for 'giggles'). Don't forget Mouser and DigiKey, tho -- both reliable, reasonably-priced and fast distributors (stateside, anyway).
EDIT: I forgot to add; there are some cheap,tiny, 5VDC fans that could be glued to the top over the plates (if you plan on using external 5VDC). They do make 12VDC fans this small also.
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here is a link
 
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Yes, a small 5Vdc fan would probably be the way to go. With say, a 2 amp USB power supply it would be fairly easy to power the camera and the fan from one cable. All Electronics sells a fan very similar to the one linked by Number Three but only 25 x 25 x 15mm and one third the price.
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You're better off using a 12V fan, assuming we are talking dashcam use.
No reason to make more waste heat turning 13.8 into 5v just to run the fan.
Plus there's a wider selection at 12VDC.
 
You're better off using a 12V fan, assuming we are talking dashcam use.
No reason to make more waste heat turning 13.8 into 5v just to run the fan.
Plus there's a wider selection at 12VDC.

Perhaps you are right. On the other hand, that would mean two cables going to the camera. I guess the point of suggesting the 5V fan is that the camera already runs on that voltage so you are already turning 13.8 into 5V and sending it to the unit.
12V 0r 5V, either way, it would be interesting to see what one of these tiny fans would do for the heat issues on the Mobius.
 
Maybe build a dual LM7805 regulator circuit? An LM7805 regulator IC would provide the required power for either the fan or the camera, but not both. At 1A available current, it falls short by the 230Ma the fan requires to run including 1amp specified for the camera. Mobius data specifies "1A when charging". We would also need to mount that heatsink intended to be glued to the heatsink of the camera onto the IC(s). Alternately, they could be mounted to any metal surface, for instance, the vehicle frame under the dash. :)
I tried to find a good sketch of such a "circuit", in the event others would like to do what I plan to do (make a regulated, protected power cable for the camera), but none Ive found after a short search include a fuse. Kind of important! The one below comes close.
I intend wire the 13.8VDC version fan (because I already have some) directly to the ignition... Of course, all you'd need for the 5VDC fan above is another 7805 regulator to run it... A dual IC regulator board maybe?
My first attempt at linking a pic -- hope it flies. The circuit illustrates a 7.5V input, but as much as 35VDC is acceptable with this circuit. The two 100Nf caps aren't critical, but the fuse they left-out is. Put a 1amp fast-blow inline with the load.

7805.gif
 
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@Isoprop
should of told 'em to add a thermometer and auto-shutdown failsafe if the camera gets too hot when you tested it.
that would made all of us a lot more comfortable, well worth the addition of +1$.
 
@Isoprop
should of told 'em to add a thermometer and auto-shutdown failsafe if the camera gets too hot when you tested it.
that would made all of us a lot more comfortable, well worth the addition of +1$.
If anywhere, this should be integrated in the DSP. However, I have never had any problems with heat issues and we tested the pre-release cameras without proper heatsinking and measured high temperatures. From the start we have known that heat can be an issue with any 1080p DSP. I even posted my feelings about this on the #26 RC thread long before the #26 was released because I knew that the Sunplus DSP (used in the #26) produces more heat than the Novatek. One user even told me that the #26 had no heat issues, even though it hadn't been released :confused:
I think too many people are afraid because the heatsink on the Mobius becomes very warm (hot), but that's the purpose of a heatsink! I know there have been one or two reports of the camera suffering from heat damage, but this is a tiny percentage of all all the cameras sold.
The developer also found that a weak external power supply can drastically increase the internal heat because the charger IC will constantly be charging/not charging the battery. These fast on/off cycles are poison to the battery and will destroy it in no time and could also lead of the premature death of the DSP. A stable 5V and a 1A supply current is essential when using external power.
Considering it's popularity, more people use the Mobius than any other similar, small camera so it can only be expected that more Mobius will suffer from heat issues than any other less popular model. However, there have been extremely few reports of the camera actually failing if used properly. Most reports are about people worrying ;)
As we know, the heat issue is more critical when the camera is used in hot environments. If we respect this fact and ensure the camera is used in an environment where the surrounding temperature doesn't exceed 47°C (118°F) there should be no problem. This figure is what the developer recommends for a safe environment.
 
I agree with you that it works as intended.
Just saying a failsafe mechanism would make us a lot more comfortable. Even if its just psychological.
 
If we respect this fact and ensure the camera is used in an environment where the surrounding temperature doesn't exceed 47°C (118°F) there should be no problem. This figure is what the developer recommends for a safe environment.

I assume that's the "ambient operating temperature"? Are there any figures for "storage temperature"?
 
I assume that's the "ambient operating temperature"? Are there any figures for "storage temperature"?
I try and avoid words where I think people who's native language isn't English don't understand, but yes, ambient is the correct word.
I have no figures for the storage temperature, but that's more of a problem for the battery. I doubt if there's anything really wrong if you store the camera at, say 40°C (104°F), but those temperatures are not at all good for storing the battery. Any storage temperatures above room temperature will lead to a high permanent capacity loss of the battery. For the battery, storage temperatures just over freezing point are ideal. Also remember that the battery must never be stored fully charged.
But this is becoming more of a battery storage problem than a Mobius storage problem.....
 
I doubt if there's anything really wrong if you store the camera at, say 40°C (104°F), but those temperatures are not at all good for storing the battery. Any storage temperatures above room temperature will lead to a high permanent capacity loss of the battery. For the battery, storage temperatures just over freezing point are ideal. Also remember that the battery must never be stored fully charged.
But this is becoming more of a battery storage problem than a Mobius storage problem.....

That's basically saying the Mobius isn't a suitable proposition for use in a vehicle - > an inside vehicle ambient temp of 40°C would be exceeded where I live during Winter. Summer is nearly here and it will be interesting... we get well over 40°C outside temps. Vehicle interior temps skyrocket in such conditions.

The Mobius in my wife's vehicle is mounted behind the rear view mirror and her car is always parked outside in the weather. Time will tell. ;)
 
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