The Mobius & Heat Issues

I now have the Mobius and a Thermal Camera; here's a first look at the heat images:





By the way, the 105F spot in the center market is 40.6C. I do find the images odd in the fact that the heat sinks are cooler than the case. This makes me wonder if the heat sink is making contact with the chip. The room temperature is 67F, 19.4C.

As soon as some other things arrive, I'll be testing the camera under four different conditions and filming the results:
(1) Just the camera with nothing extra.
(2) Camera with a 40mm 12V fan running at 5 V.
(3) Camera with a 40mm 12V fan running at 12V.
(4) Camera with extra external heat sinks added.
 
(if you're keen) I'd be very interested to see the heat images with no heatsinks, every other camera that uses this same chipset does it without a heatsink, there's been some hints that the thermal contact isn't great and I can't help thinking if that's the case then perhaps the heatsinks are more of a hindrance than a help
 
The test without heatsinks will have to wait for a while. IF there's a problem, I want to be able to return the camera for an exchange without having someone at SpyTec complaining that I took the thing apart. So wait a few months on that one...
 
The test without heatsinks will have to wait for a while. IF there's a problem, I want to be able to return the camera for an exchange without having someone at SpyTec complaining that I took the thing apart. So wait a few months on that one...
understood :)
 
I now have the Mobius and a Thermal Camera; here's a first look at the heat images:





By the way, the 105F spot in the center market is 40.6C. I do find the images odd in the fact that the heat sinks are cooler than the case. This makes me wonder if the heat sink is making contact with the chip. The room temperature is 67F, 19.4C.

As soon as some other things arrive, I'll be testing the camera under four different conditions and filming the results:
(1) Just the camera with nothing extra.
(2) Camera with a 40mm 12V fan running at 5 V.
(3) Camera with a 40mm 12V fan running at 12V.
(4) Camera with extra external heat sinks added.
Nice work Bob. :)

I was just wondering how long had the Mobius been left running and at what settings when those thermal images were taken? I know the heat sinks on mine get significantly hotter than the surrounding case (ie. burn your fingers hot!)

I don't know much about thermal cameras- but I assume it can also read higher than the indicated 105 F (or is that just the temperature at the indicated mark and not the maximum the camera read?)
 
I found that after 15 minutes that the temperature didn't rise very much above that point. The photos were taken after 1 hour of operation. The camera was recording 1920x1080@30P and the bit rate was the middle rate of 15 Mbps. Today if I can find the time, I want to test low data rate vs. high data rate. In about 1 hour the camera cools down to room temperature.

The little center mark is where the temperature reading is coming from. This allows me to do a spot reading on the camera. the 105F (40.6C) reading is on the hottest part on the camera I could find. The closest focus is 1 meter (the camera has a 10mm lens) and I'm moving in a bit closer than 1 meter, so the image is a bit fuzzy. The resolution of the thermal image is 160 x 120 pixels placed on a 360 x 212 image. Details on the camera are found here:

http://progressthermal.com/products/kestrel_mk2/

Because the room temperature at the time of the photo was 67F (19.4C), the camera didn't get as hot as your camera did. Also be aware that metal has a much better heat transfer than plastic. While the metal may feel hotter than plastic, it's transferring heat faster to your finger.

I assume the reason that the heat sinks appear cooler than the plastic is because the metal is doing a better job of releasing the heat to the air than the plastic. I have this camera for 1 month, so more tests and images are coming....
 
Thanks for the extra info and link Bob.

I was looking at the specs page on that link and noticed this:
Temperature Accuracy +/- 10% (based on .95 emissivity)

That might be where the temperature readings are coming unstuck. Shiny metal is very hard to get an accurate IR thermal reading from - I tried it recently with an IR thermometer gun. Here's one chart I found with the emissivity readings for various metals: http://www.omega.com/literature/transactions/volume1/emissivitya.html

What is emissivity?
Emissivity is the ability of an object to emit or absorb energy. Perfect emitters have an emissivity of 1,
emitting 100% of incident energy. An object with an emissivity of 0.8 will absorb 80% and reflect 20% of
the incident energy. Emissivity may vary with temperature and spectral response (wavelength). Infrared
thermometers will have difficulty taking accurate temperature measurements of shiny metal surfaces
unless they can adjust for emissivity.
from http://www.eutechinst.com/tips/tm/01.pdf

So, it's possible the heat sink is in fact hotter, but the IR camera doesn't pick it up as it's not "tuned" to the emissivity of the polished metal surface. You could try sticking some tape over the metal heatsink (probably insulation or masking tape would be best?) and that will change the emissivity and should give a more accurate reading.

Have a read of this (I just found it) - it shows an example of an aluminium bottle filled with hot water seen through an IR camera. http://www.idealheatseeker.com/asse...-and-Radiometric-Temperature-Measurements.pdf That's exactly what I've been trying to explain! You need to put tape over the heat sinks for an accurate temperature reading. ;)

Have fun experimenting! :)
 
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Hey, I'm no expert on using thermal cameras (I've never even seen one!)

I learnt the hard way about the effects of different material's emissivity when attempting to monitor the IR temperature of some LED lights. My temp gun has adjustable emissivity and it made a huge difference to the readings, but I still had errors on curved surfaces. Sticking tape over the metal is the easiest way to prevent errors- it's even mentioned in the manual for my gun.

Give that a try - I'd be interested to see your results.
 
Hello,

I bought Mobius cam, and yes Heat was worring me. So what I did:
ni44x21.jpg

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I put small aluminium heat sink.

Results:
Without Heat sing Temp: 47°C
With Heat Sink Temp: 44°C
With Heat sink, and little airflow to window: 36°C (airflow in my case was Opel Astra H blowing to front window, at level 2(max is 7))

Now I'm facing another issue: By accident I connected -GND and +VCC to wrong wires.
Now my PC can't see Device, but it works. Any suggestions on this issue?

I can do settings, though file. as I know.
 
Nice - you've cut a hole through the case and directly attached the heatsink. :)

PS: I hope the heatsink sticks better than mine did (to the case/ stock heatsink) they fell off after about 12mths. I haven't bothered replacing them as the cameras seem to handle the heat okay.
 
The problem with the Mobius' heat dissipation is that the camera was designed to be used with the heat sinks facing up (as you know, heat rises) but dashcam usage requires the camera to be upside down, significantly decreasing the efficiency of the heat sinks and causing heat to be trapped inside the casing,

This is so old. People were saying this about Mobius 3 years ago. Mobius has proven so reliable & durable over the past 3 years, it's self-evident that the heat dissipation myth is exactly that.

Owners worldwide have proven time & again that Mobius can endure any climate even while mounted upside down. No modifications necessary, though the capacitor kit is always a good idea.
 
This is so old. People were saying this about Mobius 3 years ago. Mobius has proven so reliable & durable over the past 3 years, it's self-evident that the heat dissipation myth is exactly that.

Owners worldwide have proven time & again that Mobius can endure any climate even while mounted upside down. No modifications necessary, though the capacitor kit is always a good idea.
A myth is what I would also call it ;)
The heatsink on the Mobius 2 (M2) is built into the bottom of the camera. I'm sure the developer wouldn't have chosen this option had there been problems with the original Mobius being mounted upside-down as a dashcam.
 
Nice - you've cut a hole through the case and directly attached the heatsink. :)

PS: I hope the heatsink sticks better than mine did (to the case/ stock heatsink) they fell off after about 12mths. I haven't bothered replacing them as the cameras seem to handle the heat okay.

If you look closely in two corners, heatsing is behind plastic. So it holds the heatsink very strong.
Edc2gIX.png
 
I’ve got x2 mobius v1 c3 cameras and have taken out the standard battery’s for super capacitor battery’s. I’ve noticed when recording the outside of the heat sink plates seem to pick up a lot of heat not hot but hot enough...I’d this normal? Assuming these get a lot hotter than the smaller standard battery’s? Being inside the plastic housing etc I assume it generates heat to the top of the heat sink plates?
 
Yes it's normal- it means the heat sink is working. In the summer mine gets so hot that it will burn even my calloused fingertips, yet the cam doesn't seem to mind at all :cool:

I can't say if the caps run hotter than the battery, only that you are very unlikely to have heat-related issues with Mobius in the UK, especially with caps (y)

Phil
 
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