|
Re: Cold Electricity?
I got a few things to say...
As an overclocking advocate and avid cooling freak, I need to put in my two cents about peltiers.
One: They are not very controllable. Adjusting the voltage or current does NOT adjust the heat difference. You must remeber, the peltier is always working to keep those two sides at an exact temp away from each other. (I heard 20 degrees C, but I guess 40 isn't unthinkable) By adjusting the voltage or current to a peltier, you start preventing the unit from keeping those sides at different temps. Simply put, you cannot adjust the amount between the hot side and the cold side, but you can adjust its ability to keep the hot side and cold side different. A slight difference, but important nonetheless.
Two: Battery life. These things drain current like no other. I have had one pull 15 amps out of a battery, and that was a small, low powered one. If you were to keep that up constantly, you may blow one of your fuses on the robot or maybe even run the battery down. Keep in mind that even though some motors drain at 40 amps, that's typically not a continuous measure. It spikes at 40 amps. A peltier stays at a high number all the time.
Three: This may sound like a mundane problem, but one thing a peltier causes a lot of is CONDENSATION, the bane of electronics. CPU coolers typically use copious amounts of thermal paste or neoprene to block off airflow, but nothing is for sure. When you turn it on, stuff freezes on it. When it's off, it melts back into water and frys what you are trying to cool. Bad.
Four: Stud Man Dan is absoultely correct in his post. A peltier is not so much a cooler as a, as many overclocking sites refer to it as, a heat pump, so it may be farther away from the component being cooled, but you still have the heat to deal with. People often do water or phase-change cooling on peltiers to get the drop in temp, but it often is hard and complex. Not the kind of thing you want on a robust machine that is going to get pummeled by two robots that are about 130 lbs each. (three, if your teammate is really mean!)
That's my 2 cents. Peltiers are cool, but rather complex. Try putting a heat sink on your component. Even better, connect a block of aluminum to your component and the other end to the chassis. Don't use peltiers.
Sparks
|