[MPlayer-dev-eng] Opportunity for list members (w/ attach)

[Jeff Gladnick]

Jan Knutar wrote:
> On Wednesday 22 September 2004 00:53, Jeff Gladnick wrote:
> 
> 
>>Well lets say the system is already on, but power is completely cut to 
>>the LCD.  Basically I want a box that can be popped in and out as 
>>quickly as possible.  We had some other ideas, laser from wall to wall, 
>>pressure sensor, etc.  However, the camera is already built into the 
>>system and I figure that would be cheaper in the long run.  I am still 
>>open to other ideas.
> 
> 
> That depends entirely on the power usage, of which I can't really be of
> assistance :/
> 
> 
>>Unfortunately the gondola door opens every time it reaches the station, 
>>whether people get in or not, so thats out.  I hadn't considered 
>>extremely bright relfections from mountains.  I am hoping that black on 
>>white contrast will be enough that it can be seen even in extremely 
>>direct sunlight.
> 
> 
> Well, in general in my experiene, with, let's say, less than professional quality
> webcams, the background scenery consisting of, erm, sky, and uh, clouds,
> will completely outshine any local details such as interior black vs white paint.
> Atleast that is what I would think, based on lighting conditions in finnish lapland
> ski resorts, with cheapo webcam.
> Of course, a laptop and said camera in gondola would be easy and elementary
> experiment to determine the charchteristics of the camera and its drivers. :)
> Does the particular camera have Linux drivers even?
> Best case of course you'll always be able to tell teh X shape(s) from non-X,
> problem solved. Worst case, it wont work at all.
> 

Yes, i will have to give it a show.  the motion website has a list of 
linux compatible webcams.  I am going to buy one of them.  ~ 50 bucks.

> 
>>Li-ion has the best size to power ration, especially compared to 
>>lead-acid.  Also, how many cycles can you get out of lead acid?  Does 
>>anyone know?  They are also extremely heavy and may have some tramway 
>>board issues about added weight.
> 
> 
> Hm, yes. I freely assumed you could add a hundred K or so of weight to the gondole.
> The best quote I could get on lead-acid was "a few hundred" cycles.
> Elfa has batteries which supposedly reaches 1200 cycles according to DIN standard.
> Another battery reaches 300 cycles @ DIN & 600 Cycles @ IEC...  The latter battery
> goes for about $400 @ 85Ah, 33 kilograms (12V). Subfreezing temperatures which
> you will undoubtedly be dealing with, might affect this though, perhaps Li-Ion even
> more so.
> Anyway, if weight if the primary concern, by all means go for higher capacity Li-Ion,
> it has superior power/weight performance and at a guess, also tolerates deep decharge
> and cyclic use much better.

As for the weight thing, the laws and standards vary depending of 
manufacturer and in the US, state.  For example, one of our products 3 
years ago added ~ 20 pounds per 2 person lift chair.  The tramway 
committee did not like it at all, and "suggested" we work to reduce the 
weight lest it not be approved in its current state.  Since Gondolas are 
built to carry a LOT more weight, perhaps this would be less of an 
issue.  I will have to check into it.

Also with Li-ion, the batteries could be enclosed inside of the computer 
box, and the heatsink could be used to help keep them (and everything 
else) warm.  I suppose some experiments are in order for this.