heat sink added into 0803

[Rayman.Chan]

heat sink added into 0803 for lower IC temperature (more stable);
and the housing material was changed for better heat resistance.
the updated version will be mass released soon.

 

[mr_milo]

Interesting! Looks like an easy enough add-on for current owner willing to open their units.

 

[Dashmellow]

That heat sink appears to be a standard LED emitter star of the kind often used in flashlights. This seems like a clever way to use one as a heat sink solution that fits the circuit board and housing. The star and some thermal cement would cost very little but could be a big improvement in camera performance.

 

[soddo]

Yea its a torch heat sink

If you can fit this it would be better:

Its copper and mostly used on pc memory, cost is about $3-4 for a pack of 8

 

[Dashmellow]

If you can fit this it would be better:
Its copper and mostly used on pc memory, cost is about $3-4 for a pack of 8

I don't believe these would fit inside the housing which is likely why a flat solution was used.

 

[jokiin]

considering there's another PCB which plugs into this one it would never fit, lucky to even get the one they're using in there

 

[Nigel]

The star and some thermal cement would cost very little but could be a big improvement in camera performance.

It's not going to make the image any better, that's presumably the processor rather than the sensor chip. The only thing it may do is improve reliability in hot conditions, but only if you are having reliability problems which most people aren't.

That heat sink doesn't remove any heat from the camera, just moves it from the processor into the rest of the camera more efficiently. The most heat sensitive part of the camera is probably the battery and this heat sink will not help at all with that. If you actually want the camera to be cooler then you need to add cooling to the case and/or give the case a sun shield so that it's not being heated from above. Putting those copper heat sinks pictured above on the outside of the case would help, preferably on the bottom so that they are never heated by the sun.

 

[Dashmellow]

I wasn't suggesting that the image quality would improve. I was referring to Rayman.Chan's statement that the camera would be more stable.

 

[jokiin]

Has stability due to heat related issues been reported as a problem? Seems to be just minor firmware bugs still for the most part

 

[Nigel]

Has stability due to heat related issues been reported as a problem? Seems to be just minor firmware bugs still for the most part

I have heard of a couple melting their cases, but I assume that those were battery failures. A lot of people have reported them getting hot, but they feel hot at the normal case temperature of 45 degrees C which doesn't appear to be an issue. In a camera with such a small case, the case will get hot since the heat has to come out and a small case will concentrate the heat, doesn't mean that the internal components get any hotter than they would with a big case.

Must be a reason for adding the heat sink though...

 

[rtrski]

Great...I just bought one about 3 days ago and expect delivery end of the week...bet I beat the clock on the change...sigh. (Sorry jokiin...still want a Guardtrak too but want something in the meantime).

It's not going to make the image any better, that's presumably the processor rather than the sensor chip. The only thing it may do is improve reliability in hot conditions, but only if you are having reliability problems which most people aren't.

That heat sink doesn't remove any heat from the camera, just moves it from the processor into the rest of the camera more efficiently. The most heat sensitive part of the camera is probably the battery and this heat sink will not help at all with that. If you actually want the camera to be cooler then you need to add cooling to the case and/or give the case a sun shield so that it's not being heated from above. Putting those copper heat sinks pictured above on the outside of the case would help, preferably on the bottom so that they are never heated by the sun.

Most of what Nigel said sounds pretty good. Some of the restarts I've been reading about could be heat-related resets, although the reports of intermittent connections to the base seems a more likely culprit, so I plan on shimming immediately upon receipt. So reliability might be helped by a sink...but not by much. Hypothetically speaking, depending on the internal microcode the processor might clock itself based on temps as well which could influence recording quality I suppose - kinda doubt it for inexpensive electronics like this though.

The bigger reliability impact of a passive heatsink on the outside of a processor is that it slightly slows the temp gradient after turn-on...the processor will still hit the same max temp where it matters on the die itself...but over a slightly longer time constant thus slightly relieving thermal stress.

Heatsinks 'on the case' won't do anything but remove heat from the case by spreading it out a tad, thus dropping case temp a little bit, but not much else. Without a very low thermal resistivity path to anything that matters like the processor, battery, voltage regulation components, etc....the internal hot spots will likely be the same exact peak temp...even a finned heatsink doesn't matter if there's not actually any ambient airflow for the fins to interact with. Everything is thermal resistivity and boundary condition dependent. I do EE design but work (microwave and RF...I'm useless at digital stuff) with a lot of ME's for cooling simulations, and it took me a long time to realize that passive heat sinking, especially in a non-flow environment, does not decrease peak temps (say, at an actual transistor junction inside a chip) over 'continuous use' timescales, it only really sinks or spreads heat on very short duty cycle timescales thus slowing the rise to that same peak temp as stated before. And of course nothing passive drops you below ambient (my new 0803 will be broiling in Texas sun, since I didn't plan on removing it each day...I park in a guarded lot during work hours and with the windows cracked my car interior easily hits 130 deg F or more ...will be curious to see if I get any afternoon recordings or if I need to consider dismounting and putting somewhere cooler during the day).

I do worry about batteries under that condition. The whole purpose of the dashcam is to help me in case of an accident, not to cause an insurance claim because it went 'poof' and burned up my mirror housing next to it.

Anyone working on a dashcam with a small thermoelectric chiller unit? Electricity is basically 'free' when the car is running...of course you wouldn't want it on during parking mode. :-D

 

[Nigel]

the processor will still hit the same max temp where it matters on the die itself...but over a slightly longer time constant thus slightly relieving thermal stress...

I'm not convinced about that, the heatsink should spread out the hotspot caused by the chip so that the centre of the hotspot stays a few degrees cooler even though there is the same amount of heat coming out. The case itself seems to be made of plastic that is thermally conductive which is why it feels hot at only 45 degrees C so there is a decent temperature gradient even without active fans..

Anyone working on a dashcam with a small thermoelectric chiller unit? Electricity is basically 'free' when the car is running...of course you wouldn't want it on during parking mode. :-D

Those thermoelectric chillers generate a lot of extra heat!

If you really intend to leave it on during the day, which I'm sure jokiin will tell you not to, then the most effective things to do are to fit the camera with a sunshade so that the sun can not shine directly on it from above (your car may already have a sunstrip on the glass) and to ventilate the car so that the ambient temperature doesn't build up too much - solar powered extractor fan? Both those are probably capable of decreasing the temperature by 20 degrees.

 

[Dashmellow]

Has stability due to heat related issues been reported as a problem? Seems to be just minor firmware bugs still for the most part

Good point. I think drawing off heat is a good thing to do just in general.

 

[jokiin]

Agree, not sure it's their biggest issue right now though

 

[Dashmellow]

Those thermoelectric chillers generate a lot of extra heat!

Peltier Effect tiles are heat pumps that transfer heat, they don't generate heat. In a beverage cooler a thermoelectric chiller will generate heat just the way a refrigerator compressor does but if used as dedicated heat sinks you have a different scenario. The are commonly used for cooling or heating as well as thermoelectric generators depending on how they are configured. So, if you apply electricity to them you can get a heating or cooling effect but you can also use heat to generate electricity too. Thermoelectric tiles are sometimes used to replace standard heat sinks for cooling microprocessors because they actively cool the module while heat sinks only provide passive cooling. I have wondered about the possibility of using these Peltier tiles in dash cams and was thinking of posting about it so it's interesting to see it come up in conversation. They are very cheap to produce and available in small sizes. It seems like it wouldn't be too hard to design a dash cam using a very small thermoelectric chip along with a housing the would allow for the heat to escape to the outside.

See Wikipedia for further info:

Thermoelectric effect

Thermoelectric cooling

 

[Nigel]

Peltier Effect tiles are heat pumps that transfer heat, they don't generate heat.,,

If you have a processor that gives out 10W of heat, then you need a Peltier cooler that consumes 20W of electricity to keep the processor cool, the total heat output is then 30W - very rough figures. In a drinks cooler you are only removing whatever heat is leaking back in so with good insulation you don't need much power but for a processor it's a different story.

 

[rtrski]

I'm not convinced about that, the heatsink should spread out the hotspot caused by the chip so that the centre of the hotspot stays a few degrees cooler even though there is the same amount of heat coming out. The case itself seems to be made of plastic that is thermally conductive which is why it feels hot at only 45 degrees C so there is a decent temperature gradient even without active fans..

Trust me on this one - I've sat with the ME's doing the thermal simulations. At constant use sort of scenarios (time on the order of hours, not minutes), heat sinking or even spreading, with no forced heat extraction (convective cooling by air moving over the sink, negligible in small housings w/ no fans) does almost nothing for peak temperatures on-die (by which I mean single transistor-junction type temps, not the BGA package surface). It only affects the time slope to when the constant maximum temperature point is reached. The critical factors are the base temp (in this case, ambient temp of the case) and thermal resistivity bottlenecks from the die all the way out.

But all this is beside the point if the thermal issue wasn't the driver for the resets...all it will accomplish is a little better chip lifetime due to reduced thermal stress gradients (statistically).

Those thermoelectric chillers generate a lot of extra heat!

...In a drinks cooler you are only removing whatever heat is leaking back in so with good insulation you don't need much power but for a processor it's a different story.

Well, they're not 100% efficient, so yes, it will take more than "10W" to remove "10W" worth of heat, but the point is positioning. A small Peltier tile cemented with good thermal paste to the top of a chip package can 'cool' the BGA surface to even below ambient temps (e.g. below the 'base' temp environment), which would permit lower junction temps. All that comes in exchange for more heat on the hot side of the thermoelectric gradient, and more demand on the source(thus a bit more heat in voltage regulator chips, etc). All active cooling systems - thermoelectric, fans on heat sink/spreaders, forced liquid cooling, etc. - are net-heat inefficient (the TE effect, pumps, fans motors, all need power). But they selectively decrease temps, locally, in exchange for more heat generated overall. If chip temps are part of what is influencing video processing speed, that might be a valid trade. Plus you could 'cool' the chip down from a super high non-functional ambient (sitting in a closed car) quicker than your A/C will reach the bits that matter thru the case.

There are even thermoelectric based wine coolers now vs. compressor units...said to be preferred because they don't vibrate the wine sediments up ;-) . So yes, TE is for actual refrigeration, not just 'slowing down heat moving into the system' as you described.

Do people here mostly remove their cams from their mounts during the day, those of you who are in hot climates? I thought that was mostly for theft prevention. Admittedly, I wouldn't leave my cellphone in my hot car and expect it to work w/out cooling off (although the car stereo, nav video system, backup camera, etc. all do just fine) so I may have to rethink because of the battery and the right-on-the-windshield exposure. I don't expect it to work in the hot car with the engine off (already read that the G-shock feature of the 0803 should be assumed to not work before I committed to buy, and I don't have a constant-power harness planned).

 

[Nigel]

Do people here mostly remove their cams from their mounts during the day, those of you who are in hot climates? I thought that was mostly for theft prevention. Admittedly, I wouldn't leave my cellphone in my hot car and expect it to work w/out cooling off (although the car stereo, nav video system, backup camera, etc. all do just fine) so I may have to rethink because of the battery and the right-on-the-windshield exposure. I don't expect it to work in the hot car with the engine off (already read that the G-shock feature of the 0803 should be assumed to not work before I committed to buy, and I don't have a constant-power harness planned).

I've been leaving it mounted, just switched off when the car is parked up. I've not seen decent evidence to say what it can cope with but turned off I wouldn't expect any issues. The backup camera etc. either don't sit in full sun or have the bodywork as a heatsink and in any case have considerably less processing power. It's only generating around 6W of heat though so solar radiation is probably capable of adding significantly more heat than the processor is, it's just the small size which means that it is not easy to get rid of that heat into dry air.

 

[rtrski]

Thanks, leaving it mounted when not in use is what I was hoping to do. I will do my best to mount as much of the 'body' behind the dotted part of the windshield as possible, to reduce the insolation heating.

 

[taile]

omg! I just got mine and it's burning HOT while driving under the sun!

Wish I waited a little~!!!