Mobius Thermal Tests

[BobDiaz]

I re-did the test with a few extra things. The room temperature was 21C (70F), the camera was recording at the low bit rate, and painter's tape was placed on the rear heatsink. Where rear is defined as the heatsink farthest from the lens. Past tests showed that at the 15 minute mark, the temperature seems to level off so all readings were taken after 15 minutes.

Using a temperature probe I measured:

Case = 38C (100F)
Front Heat-sink = 48C (118F)
Back Heat-sink = 46C (115F) Has blue painter's tape on it

The Thermal Camera measured the following:

Case = 43C (109F)
Front Heat-sink = 24C (75F)
Back Heat-sink = 43C (109F) Has blue painter's tape on it







The camera is cooling off and the next test is with a 12 volt cooling fan running at 5 volts. The reason for the lower voltage is that a cooling fan makes less noise if you don't run it full power.

 

[BobDiaz]

This test I added a small 40mm 12 volt fan running at 5.35 volts. Consider it a reduced noise setting for the fan with less airflow than at 12 volts.

Using a temperature probe I measured:

Case = 28C (82F)
Front Heat-sink = 35C (95F)
Back Heat-sink = 35C (95F) Has blue painter's tape on it

The Thermal Camera measured the following:

Case = 31C (88F)
Front Heat-sink = 21C (70F)
Back Heat-sink = 34C (93F) Has blue painter's tape on it

Even at low speed, the fan reduced the heat by 10C --> 13C (18F --> 23F).

The first photo shows the fan in position. After that photo, I had to remove the fan to take readings.

 

[BobDiaz]

If anyone is wondering which fan I used: http://www.allelectronics.com/make-a-store/item/CF-392/12VDC-40MM-COOLING-FAN/1.html

This fan at 12 volts moves 7 CFM (Cubic Feet [of air] per Minute) or 198 liters per minute. It's a reasonable amount of air for its size. The room temperature was 21C (70F) for all tests.

Using a temperature probe I measured:

Case = 29C (84F)
Front Heat-sink = 31C (88F)
Back Heat-sink = 31C (88F) Has blue painter's tape on it

The Thermal Camera measured the following:

Case = 26C (79F)
Front Heat-sink = 20C (68F)
Back Heat-sink = 29C (84F) Has blue painter's tape on it

If you compare to the low speed fan, the case appeared 1C higher with the high speed fan. The specifications for the meter rate the probe at +/- 1 degree C, so the reading isn't as weird as it sounds. It's also interesting to see that for a major increase in air speed, we saw only a minor decrease in temperature compared to the low speed fan. IF I decide to use a fan, the biggest gains come from no far to low speed fan. The increase in the air speed and noise only result in a smaller decrease in temperature. The decrease in temperature from low speed to high speed was 5C (9F).







With luck I'll be able to get the heatsink(s) to fit on the Mobius and I'll run those tests tomorrow or Saturday.

 

[murcod]

Nice work Bob.

(If only the Mobius could measure and log it's own internal microprocessor temperature!)

 

[BobDiaz]

murcod, Boy, would I love to know the inside temperature. Not impossible, but I would have to drill holes in the case to insert my probe into it. I may wait for a few months before I try that one.

The big test is the upcoming heatsink test. I really want to know how much of a difference that will make. In fact I have 2 different heatsinks to test with.

 

[BobDiaz]

I installed 2 TO-220 Heatsinks onto the Mobius:



Using a temperature probe I measured:

Case = 33C (91F)
Front Heat-sink = 39C (102F)
Back Heat-sink = 39C (102F) Has blue painter's tape on it

The Thermal Camera measured the following:

Case = 34C (93F)
Front Heat-sink = 34C (93F)
Back Heat-sink = 35C (95F) Has blue painter's tape on it







The TO-220 Heatsinks provided a 5C ---> 9C (9F ---> 16F) reduction in the amount of heat compared to not using heatsinks. The low speed fan did better: Even at low speed, the fan reduced the heat by 10C --> 13C (18F --> 23F).

Still the basic heatsinks did offer some reduction in the heat without the hassle of installing a small fan. Tomorrow I have a better heatsink that I'll try.

 

[BobDiaz]

I had planned to use the heatsink from All Electronics, but on closer inspection the metal bumps at each end meant a lot of careful grinding to remove them.



It was less work to go to the local electronics store and buy a better heatsink.



While it's somewhat large, it does a good job.



I measured the following after 15 minutes:

Case = 32C (90F)
Front Heat-sink = 35C (95F)
Back Heat-sink = 35C (95F) I was unable to put the blue painter's tape on this heatsink.

The Thermal Camera measured the following, it had trouble reading between the fins of the heatsink:
Case = 34C (93F)
Front Heat-sink = 31C (88F)
Back Heat-sink = 31C (88F) I was unable to put the blue painter's tape on this heatsink.







While the large heatsink didn't lower the case temperature as much as the fan, it did lower the heatsinks as much as the fan at low speed. This resulted in an 11C --> 13C (20F ---> 23F) drop in temperature by adding the heatsink. In every test the room was 21C (70F). The fan at maximum speed did the most cooling, but mounting it was difficult and the noise from the fan was recorded by the camera. The low speed fan has only a minor amount of noise recorded. IF keeping your Mobius cool is important to you, the large heatsink is the easiest modification to add to the camera.

 

[BobDiaz]

I had planned to use the heatsink from All Electronics, but on closer inspection the metal bumps at each end meant a lot of careful grinding to remove them.



It was less work to go to the local electronics store and buy a better heatsink.



While it's somewhat large, it does a good job.



I measured the following after 15 minutes:

Case = 32C (90F)
Front Heat-sink = 35C (95F)
Back Heat-sink = 35C (95F) I was unable to put the blue painter's tape on this heatsink.

The Thermal Camera measured the following, it had trouble reading between the fins of the heatsink:
Case = 34C (93F)
Front Heat-sink = 31C (88F)
Back Heat-sink = 31C (88F) I was unable to put the blue painter's tape on this heatsink.







While the large heatsink didn't lower the case temperature as much as the fan, it did lower the heatsinks as much as the fan at low speed. This resulted in an 11C --> 13C (20F ---> 23F) drop in temperature by adding the heatsink. In every test the room was 21C (70F). The fan at maximum speed did the most cooling, but mounting it was difficult and the noise from the fan was recorded by the camera. The low speed fan has only a minor amount of noise recorded. IF keeping your Mobius cool is important to you, the large heatsink is the easiest modification to add to the camera.

 

[fatpanda]

Bob, did you adhere this to the existing heatsinks or did you remove them completely?

 

[BobDiaz]

I put them on top of the existing heatsinks. In the case of the TO-220 heatsinks, I applied a thermal compound. In the case of the bigger heatsink, it came with a thermal compound/stick-on.

I won't be doing any major modification to the camera until after a few months. If by some unlucky chance the camera fails, it most likely to fail within the first few months. SpyTec has a 30 day return/exchange period, so I want to keep the camera in good shape if something does go wrong.

 

[niko]

I like what "we all" proposing here with extra heat-sink etc ( to resolve a overheating problem ), but additional heat-sink ruins idea of Mobius being small / discrete.
I think mobius has to start looking into other more size-friendly solution ( drilling holes into the case, or re-designing existing heat-sink etc. ), so size will stay same, otherwise there are other action cameras for dash-cam users out there who might compete with mobius if it will have big heat-sink.
But I understand @BobDiaz, - you just want to make an experiment and see how much changes will bring a bigger heat sink, - I appreciate those efforts !

 

[jokiin]

keep in mind this same processor is used in many other products without heat issues, I question the need for a heatsink at all

 

[Mtz]

As jokkin wrote in a previous post he said that the Innovv case is not hot. And I said on another post that my Innovv sample contains the chipset without anything over it which can transfer some heat to the case. If there is very hot inside the Innovv we should feel that hot when touching it. I know how hot can be a camera case because also I have the 808 #26 which is running the same processor and the heat transferred to the metallic case of the 808 #26 is making it hot as the Mobius heatsink.

I think that the Mobius developer added the heatsink there because he want to force the direction of heat to go in that area and not spread inside all case and damage the battery in time, because of heat.

Why just some dust entering in the Mobius can affect the functionality? Just think to old TVs with a lot of vent holes working more than 20 years without be opened. The Android TV sticks are full of holes and many many other examples.

enjoy,
Mtz

 

[niko]

Agree with @Mtz, - I dont think vent-holes and dust going inside will affect performance in bad way. Remember, if there are plenty of vent-holes, then dust goes in, but due to air free-flow, - dust goes out as well .
I have been following Korean dash-cam design progress and most of them going from fully sealed dashcam case into the case design with vent holes. I like latest Finevu CR-2000S where they even added vent holes around lens.
If look into all recent high-end Korean dash-cams, - they all have a lot of vent holes.
I know Mobius "blames" Innovv and Dimika of copying some details / ideas, but if Mobius could "copy" Innovv idea in producing full-metal shell / body, then I am sure overheating issue would be reduced or eliminated ( when also added vent holes ).

 

[BobDiaz]

I like what "we all" proposing here with extra heat-sink etc ( to resolve a overheating problem ), but additional heat-sink ruins idea of Mobius being small / discrete.
I think mobius has to start looking into other more size-friendly solution ( drilling holes into the case, or re-designing existing heat-sink etc. ), so size will stay same, otherwise there are other action cameras for dash-cam users out there who might compete with mobius if it will have big heat-sink.
But I understand @BobDiaz, - you just want to make an experiment and see how much changes will bring a bigger heat sink, - I appreciate those efforts !

The final heatsink I used adds 20mm (3/4 inch) to the height of the camera and I admit it looks a bit odd. The low profile heatsink from All Electronics would have added 11mm (under 1/2 an inch) to the height, but was to big a pain to modify. However there are many heatsinks of differing heights to chose from. The size issue is not a big deal for me, I can still fit it into my Smart Car. However, this is a personal choice as to what one likes and prefers.

The vent holes would allow for air flow and help keep the insides cooler. Some dust will land and stay on the electronics and this acts like a blanket for heat, but a closed case is far worse. It's also a mod that I'll do months down the road. Are all these mods needed, maybe it helps and maybe it makes no difference, but it can't hurt.

The all metal case is the best of all worlds, it allows for heat to escape, keeps the dust out, and if the metal is grounded, reduces any RF interference.

 

[niko]

The all metal case is the best of all worlds, it allows for heat to escape, keeps the dust out, and if the metal is grounded, reduces any RF interference.

In this direction should Mobius developers move in the future if they want to be competitive on non-RCGroup markets.

 

[murcod]

One of my Mobius has been going through thermal tests of it's own - of a different kind. It was 41 degrees Celcius here yesterday and today is forecast to reach 44 degrees (ie. 111 degrees Farenheit.)

The wife's car is always out in the sun at work and she commutes 40 minutes to/ from work. Three days a week her vehicle is also used for work traveling to different locations. I'll keep an eye on the Mobius in her car and check it's still functioning.

 

[GJHS]

keep in mind this same processor is used in many other products without heat issues, I question the need for a heatsink at all

That's the test I would like to see, the Mobius without the heatsinks. I'm all for vent holes; just not sure a beginner as myself can get the case off (especially on the heatsink side) having to remove the lens to even make the holes. If this is a simple process, please tell me.

 

[murcod]

One of my Mobius has been going through thermal tests of it's own - of a different kind. It was 41 degrees Celcius here yesterday and today is forecast to reach 44 degrees (ie. 111 degrees Farenheit.)

The wife's car is always out in the sun at work and she commutes 40 minutes to/ from work. Three days a week her vehicle is also used for work traveling to different locations. I'll keep an eye on the Mobius in her car and check it's still functioning.

Well the Mobius appears to have survived 3 days of 40 plus degree temps left in the vehicle and driven in the heat, however the car's starter battery died big time!

(While I haven't checked the footage, the Mobius red LED is still flashing away happily so I assume all is well. Point to note is I have added two small stick on heatsinks to the Mobius, which may help?)

 

[BobDiaz]

40+C (104+F) !!! Wow, you're really having a heatwave there.

My tests showed that in a room at 21C (70F), the TO-220 heatsinks were able to reduce the temperature by 5C (7F) on the case and 7C (13F) ---> 9C (16F) on the heatsinks. It will help cool the Mobius a bit.

Also, if it isn't too much trouble, could you please put some of the heat into a box and ship it to me? We're having some cold weather here and I'm freezing.