nobb

Well, I have a K301, and I am a bit dissapointed that my $400 screen does not operate in the cold (has a protection circuit). I have been trying to locate the sensor which senses the temperature, but so far, no luck.

I randomly stumbed across a page where the guy built a "dew heater" for his telescope using some resistors, and that gave me a thought. Why not use a bunch of resistors to make a heater for my LCD. So thats what I did. Here are some pics:




I took some resistors from some old broken circuit boards and stuck them onto the bottom plate of my K301 (of course taking into account how to wire them properly). This system of resistors will dissipate 25 watts of power at 14 volts. I am hoping this will work for the winter time, but I am not sure. What do you guys think? Is 25 watts enough? Keep in mind that this system relies mostly on convection to heat up the entire unit. I tried to fit a fan with a system of ducts, but that was just too difficult.

Does anyone know how hot a resistor may get? I am using some standard resistors, ceramic, and wire wound (these get hot). I am just hoping my tape wont melt. I also have some silicone (used for windows, doors, moldings...), do you think I should use that to glue on my resistors instead of tape?

Advice or comments are welcome.

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helllordkb

i would defidently use the glue. i think tape is a bad idea. depending on the resistor they can get very hot.

2JZGTE

why didnt you just direct the heater in your car past the LCD screen?

pate60

xuruiheng

this is the first I come here

nobb

What do you mean direct the heater to my car screen, could you clarify? Relying on the car's heating system alone is not enough to heat up the LCD because it takes a very long time for the heat to be transfered from the cabin to the screen (takes an hour when the temperature is -30C).

dyne

I think you need to build some sort of circuit that will turn the entire contraption off when it gets warm enough (or just after a set amount of time). I can't imagine pumping heat into the LCD for hours at a time would be good for it.

I would also mount the resistors with thermal tape

sebberry

I think using a peltier cooler backwards would be a much cleaner, safer installation of a heater...

I can't remember, but if you can simply reverse the polarity on it instead of flipping the cooler, you could create something that cools the screen in the summer too.

Just a thought.

nobb

Oh I am manually operating this heater (with a cigarette plug) for the winter. I'd like to see how this goes before doing something automated.

GiODi

Does this ever cause you monitor to overheat and shutdown?

nobb

No, because winter hasnt come yet, so I havent tested it. Also, its manually operated for now, so its not like its going to be running all the time.

NightHawkFG

yeah resistors get hot i ahve burn my fingers on them many time chargeing capcitor with them. just cant remeber to size they they were. but certain one get really ******* hot.

rsd212

Look for high-temp epoxy or "thermal glue". I've done some recent work on heaters and you quickly realize most tapes and househole adhesives dont hold up after a couple temperature cycles.

Thermal glue is an alternative to silicone chip paste. Instead of just being a runny paste its sets hard. Used in putting heatsinks on regulators in power supplies or sometimes for power transistors.

__________________
MII-12000 / Ampie / Lilliput 7" / BU-355 / PicoPSU / uSDC
Currently: Enjoying the setup, but always contemplating my next move...

turbocad6

hey man, don't know if you thought of this, but do you know what happens to a can of soda when you take it out of the fridge & leave it on the table in the summertime? condensation....

anytime you rapidly warm a cold object it will cause condensation to form, now I'm not saying what your doing won't work, but this is definatley something to at least be aware of & look for in your testing... if anything you may want to slow down the heat-up time to lessen the buildup of condensation, hate to see you fry it...

__________________
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

Yea I dont know about the condensation issue yet. I got this idea when I saw the rugged LCD's that autonode sells:
http://autonode.com/displays.html
Some of them have a heater option. Does anyone know how those are designed?

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