Montana Actual
New Member
yea, it's been way hotter where I live, and global warming is a myth. "science"
yea, it's been way hotter where I live, and global warming is a myth. "science"
I've often wondered if dashcams need to be stuck to the windscreen. If they could be mounted further back then they wouldn't be subject to direct sunlight and the subsequent heat issues.
Difficult one to implement though.
You mean heatsinks don't exist? And if one wants a smaller heatsink then a fan is the solution to increase the flow of the medium.I think the technology to proper cool 3 channels just isn't available. Meaning 3 channel setups run too hot, and in warmer weather, face the challenges of overheating.
E.g. Viofo MT1The only working solution at present is to mount cameras on windshield but have these cameras field to a main unit tucked under the glove box or out of direct sunlight. Something no one has designed yet.
Would reduce the problems. Which I still haven't encountered (despite measured 75°C). I'm still interested in your measurements via something more accurate than meat thermometer (then in your car could be even higher temperature than 70°C).Getting the main unit (holding the sd card and handling processing) out of the sun would eliminate the problems I've described.
You mean heatsinks don't exist? And if one wants a smaller heatsink then a fan is the solution to increase the flow of the medium.
And if even the ambient temperature is too high for the silicon, then the only solution is to use "a better one". But since A139 in 25°C ambient runs at about 60°C, then in 65°C ambient (means the Viofo's advertised maximum) it must be super hot and there is "a room" for improvements on the heatsink side.
E.g. Viofo MT1
Would reduce the problems. Which I still haven't encountered (despite measured 75°C). I'm still interested in your measurements via something more accurate than meat thermometer (then in your car could be even higher temperature than 70°C).
Actually the fact I still haven't seen the issue is a pity because basically I have the perfect setup for the testing of the proposed idea of not exposing it to Sun. In my case the front unit should fail and the rear should be still working.
There are heatsinks which are able to cool down even hundreds/thousands of watts of TDP... And since there is such big difference between ambient and chip temperature in A139, the heatsink could have been bigger...Heatsinks and thermal paste exist, but are inadequate to disperse the heat sufficiently to properly cool a 3 channel setup. I'm unaware of a camera that uses a fan. Not sure how viable a fanned heatsink option would be in a dash camera. As computers rely on fanned or water cooled setups. But a practical setup in a dash cam seems difficult.
Oh so you finally acknowledged the Viofo's 65°C, ok then.From my tests with a meat thermometer, the car is getting 65-70C. Thus, hitting the Viofo's advertised Thermal Max.
Well, that's well expected since h264/h265 needs a "proper end" of the file... So in case of segmentation into smaller files the last gets corrupted, in case of one big file the whole file gets corrupted. That's why it's advantage to have dashcam footage divided into smaller files (to eventually corrupt only the last ones).Now if you turn off loop recording and let the camera record to one huge file, I've found my SD card becomes totally corrupted until formatted. Happened Twice. A problem that I never experienced with loop record set to 5 minutes.
That's why it's an example. But "it's not that hard" to add a third de/serializer combo into A139 to make the front sensor remote as well. The point is, there is such solution...Not a 3 channel setup and it's a two channel motorcycle camera not designed for cars.
I thought your A139 were shutting down at around 70+°C. At least I remember questioning myself why you are dissatisfied with a camera not able to withstand 70+°C ambient despite the manufacturer claimed from the beginning it's for 65°C max...Well considering my measurements have shown two different cameras overheating at the same thermal max, I'm pretty sure my tests are accurate. Seems Viofo's 65-70C is pretty spot on about when the camera shuts itself down. Seeing my car reached those temperatures, and the camera turned itself off, I'm not sure what more you want?
Well, these I said several post before, so yeah... But still, 70°C ambient in a white car is the same temperature as 70°C in a black car.2. I have a dark colored car (Volvo S60). Yes the windows are tinted, but that only slightly prolongs the cabin heating up.
3. Remember, if you drive a white or light color car, it reflects sunlight. On a dark colored car, it absorbs heat.
In my testing, dark tinted windows absorbed more heat, and the temperature next to the glass where the dashcam is was hotter, the temperature of the seats was lower as less sunlight reached them, but that doesn't help the dashcam.2. I have a dark colored car (Volvo S60). Yes the windows are tinted, but that only slightly prolongs the cabin heating up.
I think probably it is mainly that the van is taller. The hot air collects in the top few inches of cabin space, in a car that is where the camera sits, in a van the camera is down in the cooler air.1. @SawMaster uses a fan. A van has a greater surface area and interior space to heat up. Meaning it won't get as hot as a Sedan (my car is a Volvo S60).
If you have to park in direct sunlight, park facing north, problem solved.4. I have parked my car in DIRECT sunlight for my tests. Again, dark color car heating up.
But you need to define what "hot air" and "hot heatsink" mean... As long as there is an energy difference, you will always be able to blow hot air over hotter heatsink and get better results than let it to difusion. In case of A139 we are talking about around ΔT=40°C, where if size is the limiting factor, you can use fan as the workaround.As for the fan, fans work well when they blow cool air over a hot heatsink, they don't work well when they blow warm air over a warm heatsink, which is what would happen in a dashcam, also fan life would not be great working in 65 degree plus air, they are all designed for 20 degree air, so they would add an unreliability problem. And as always, fans consume power, and that generates heat, and when they are not making much difference because the incoming air is already hot, adding heat from the fan makes them even less effective!
Dashboard reflections tend to become worse as you move the lens away from the windscreen. Plus, the windscreen is a nice stable thing to mount a camera on.I've often wondered if dashcams need to be stuck to the windscreen. If they could be mounted further back then they wouldn't be subject to direct sunlight and the subsequent heat issues.
I don't think it is that much, if it operates up to 65 then 65 + 40 would be 105, which is too much for reasonable reliability, even supercapacitors die quickly at that temperature.In case of A139 we are talking about around ΔT=40°C,
Remember the camera only uses about 4 watts of power when using 3 channels, so adding a 1 watt fan is a significant power increase.I wouldn't consider a small fan which runs on its lower RPM as somewhat a large source of heat and therefore to be ineffective.
Also, any rain/dirt/scratches show up far more easily once they are not completely out of focus.Dashboard reflections tend to become worse as you move the lens away from the windscreen. Plus, the windscreen is a nice stable thing to mount a camera on.
Not to mention windscreen heater wires!Also, any rain/dirt/scratches show up far more easily once they are not completely out of focus.
The SG9663DR, like the MT1 and others, show that dual remote cameras are technically viable. Going to triple remote is not such a big step given the hardware in the A139 is capable of processing three video streams, but as @jokiin has already pointed out it may not be commercially viable given the products already in the marketplace.The only working solution at present is to mount cameras on windshield but have these cameras field to a main unit tucked under the glove box or out of direct sunlight. Something no one has designed yet.
Getting the main unit (holding the sd card and handling processing) out of the sun would eliminate the problems I've described.
Not sure it can receive three remote video streams, and even if it can, the local (front) stream uses a different communication method which allows higher resolutions than FHD, these days dashcams need higher than FHD resolution on the front. So you need a higher specification processor and remote transceivers including power transmission, and the extra remote camera, all of which makes them uncompetitive as general consumer cameras.Going to triple remote is not such a big step given the hardware in the A139 is capable of processing three video streams,