nobb

I know this is an old thread...but Id like to bump it for more opinions on the condensation issue since winter is coming and I really want to get this working. I still havent found an issue to my problem...and I would hate to go the winter without the carpc.

I always thought that condensation was formed on a warm surface that is being cooled and not a cold surface being warmed (I think my prof said that in chem class last semester). That was also the impression that I was getting when I wiki'ed "condensation." Can someone verify or correct me if I am wrong? I am guessing this must be wrong because I was eating toast today and the hot toast created water droplets on my glass table when I let the slice of toast rest on the table. In fact, the area on the table near the toast was almost soaked in condensation...someone that I do not want to recreate inside my k301.

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turbocad6

I wouldn't worry about it, the lcd will be a bit sluggish till it warms up, but it works fine.. when it get's too cold is when your hardrive won't even spin up, even then, let it warm up a bit as the interior warms up, then it'll boot. there are extreme weather hardrives, but expensive & small, ok for mission critical apps, but a little warm up time is all that's needed really. the screen is no problem really.

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MY NEWEST INSTALL:modded infiniti fx with big screen - "If my typing sucks it's probably because I'm driving....................."

first windows carpc install........my liquid cooled LVDS screen :D

nobb

No, I realize the screen itself will be fine. Its just that the screen has a sensor that electronically prevents the screen from turning on until the temperature is higher than -10C. That is why I need to physically warm up the screen as I have no idea where the temp sensor is to maybe somehow hack it (the ideal solution).

nst6563

instead of a bunch of resistors, you could also use the resistive coil that's in those coffee cup warmers (you know, the ones made just for 1 cup of coffee that sell for just a couple $ ). The resistive coil inside most of those is thermally/electrically shielded with a fiberglass 'sleeve' so that it doesn't short out or melt the immediate surroundings (which in the case of the warmers is cheap plastic).

My guess is that the coil will heat up faster than a series of resistors as the coil was designed to do so. Even though most of those warmers are designed with AC in mind, feeding DC through the coil will still produce the heat (I had a small coil that got pretty hot running off a 9v battery).

mtnet2000

http://www.goldmine-elec-products.co....asp?dept=1196

turbocad6

can you get good pictures of the guts? modifying the screen sounds best.... I guess a 5 minute timer with a resistor array can work too, & if you play with it & balance it to not over do it, should be fine too, I'd much rather mod the sensing circuit, if you get good pictures of both sides or the board(s) I'm sure we can figure it out...

__________________
MY NEWEST INSTALL:modded infiniti fx with big screen - "If my typing sucks it's probably because I'm driving....................."

first windows carpc install........my liquid cooled LVDS screen :D

nobb

Yup...I made another post along time ago with pics of the circuit so that hopefully someone could figure out how to mod the sensing circuit (or atleast determine where it is). So far no luck and I think imageshack deleted them, so Ill repost the pics. These pictures are of the main circuit board. There is also probably some stuff inside the motorized screen itself..but I stripped the screw and cant get it off =(. Let me know if you guys want me to take pics in a different angle or something.

Higher res images located here (thanks for looking =)):

http://img390.imageshack.us/img390/867/img7797fe5.jpg

http://img390.imageshack.us/img390/3367/img7789vm5.jpg

Attached Images

  

Chris31

Not read the whole thread

Best to find that temp sensors

nobb

Good idea on the alu plate, but I dont really see how the resistor might get too hot in only one area. By the way, my current resistor arrangement is different from the picture as I have tried to place the resistors under more critical components and spread out more evenly. Also, the resistors are not in direct contact with the circuit board (there is a few cm gap) and I am relying on convection to evenly distribute the heat. So far, I am going to play it safe and not use any sort of timer mechanism. The heater just manually plugs in and out of the cigarette lighter and I just want to test to see if it will work.

Chris31

There are some thermally conductive epoxy that you might wanna use.

turbocad6

nothing looks like it on that board from what I see, but I'm no pro when it comes to electronics either, I think it's most likely gonna be in the screen housing anyway

I guess a heater could work... what about just a remote start & a delay circiut for powering the system, could be your own temp sensing turn on really

__________________
MY NEWEST INSTALL:modded infiniti fx with big screen - "If my typing sucks it's probably because I'm driving....................."

first windows carpc install........my liquid cooled LVDS screen :D

nst6563

here's an interesting find...
http://www.densitron.com/displays/lc...en_heater.aspx

Coach_Ng

I would seriously consider mounting those resistors to the outside of the back plate.

nobb

Its a single din screen....I wont be able to slide the screen in if the resistors are on the exterior.

BarryWoods

So there's no way to blow heated air over it from the car's heater?? The tape on the resistors is worrying me.

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