Change Forum... Civil Aviation Travel, Polls & Prefs Tech/Ops Aviation Hobby Aviation Photography Photography Feedback Trip Reports Military Av & Space Non-Aviation Site Related LIVE Chat My Starred Topics | Profile | New Topic | Forum Index | Help | Search
 Need Help With V=IR (and TEC's On A Computer)
 Lehpron From United States of America, joined Jul 2001, 7028 posts, RR: 22Posted Fri Oct 13 2006 00:38:37 UTC (6 years 7 months 2 weeks 23 hours ago) and read 1901 times:

 I'm planning to use a TEC (thermo-electric cooler) in my computer and the math of these things are throwing me off. The simplest and most inexpensive approach I was thinking of was using a small 30watt TEC on the north-bridge of my motherboard using the stock heat sink. I did some analysis but I am confused as to how much heat is coming out. The TEC device I was planning on is by a company in New Jersy called Melcor, here's the link for the device. These are the important stats: Vmax=15.4 volts Imax=3.9 amps (max current draw at maximum voltage) Qmax=33.4 watts (at maximum current and voltage) Note: according to Melcor, Qmax is the maximum heat absorption, the cold side. Using the equation V=IR, Resistance of the device at Vmax/Imax is just under 4 ohms. Assuming that R is constant with temp, this TEC draws out a bit over 3 amps @ 12.38 volts from my PSU, which is 40 watts of electricity to run. I've set up an efficiency rating, that ratio of Q/(IV) should show how much Qmax is expected per total power used. For this device that efficiency is 0.55611 @ 25*C. If Melcor intends Qmax to be the coldside, that implies a 55.6% efficiency...is that realistic? That would mean that 44.4% of power going in comes out as heat. It is hard for me to accept that which is why I feel I may have made a mistake. As of my north-bridge, I'm not worried. The power levels are small and the stock aluminum heat-sink can easily pump out 22 watts of heat, if I think Qmax is the heat expelled to run the device. Ideas, anyone?
 The meaning of life is curiosity; we were put on this planet to explore opportunities.
 StrasserB From Singapore, joined Nov 2005, 1541 posts, RR: 8Reply 1, posted Fri Oct 13 2006 01:01:02 UTC (6 years 7 months 2 weeks 23 hours ago) and read 1893 times:

 To be honest, it might be that I didn't understand all of this technical stuff; but just one question: Are you sure, that the mentioned north-bridge is correctly located at 32°49'28.10" N 117°10'51.30" W?
 Still, even in the most arid desert is an airport somewhere ...
 Lehpron From United States of America, joined Jul 2001, 7028 posts, RR: 22Reply 2, posted Fri Oct 13 2006 01:22:45 UTC (6 years 7 months 2 weeks 23 hours ago) and read 1884 times:

 Forgot to mention, I want to figure out this so I could try something a bit more complex, like adding a 226-watt device to my videocard...which is a risk for now. For those who may not know, the north-bridge is usually located next to the main cpu on the computer desktop motherboard, it is the 'hub' of the motherboard. It properly allocates information from and to the major parts like the processor, memory, hard drive, etc. It gets hottest (for me) during 2D applications, like internet (right now it is about 51*C or 124-degrees F)
 The meaning of life is curiosity; we were put on this planet to explore opportunities.
 Ilikeyyc From United States of America, joined Dec 2003, 1373 posts, RR: 22Reply 3, posted Fri Oct 13 2006 01:55:24 UTC (6 years 7 months 2 weeks 22 hours ago) and read 1877 times:

 unless I am missing a brain cell or two: %eff= 100 x Q/VI Q= 33.4 V= 12.38 I = 3.2 (you estimated just over 3, so I used this number) 33.4/(12.38 x 3.2)= 33.4/39.616= .8431, or 84.31% efficient
 Fighting Absurdity with Absurdity!
 Lehpron From United States of America, joined Jul 2001, 7028 posts, RR: 22Reply 4, posted Fri Oct 13 2006 04:27:08 UTC (6 years 7 months 2 weeks 20 hours ago) and read 1863 times:

 Quoting Ilikeyyc (Reply 3):Q= 33.4 V= 12.38 I = 3.2 (you estimated just over 3, so I used this number) 33.4/(12.38 x 3.2)= 33.4/39.616= .8431, or 84.31% efficient

The Qmax of this device only occurs when the maximum voltage and maximum current is applied, since my voltage os lower and the coresponding current is lower, the Q value should be less than max, certainly cannot pass whatever comes. If the voltage was 6v the power requirements wou be 20watts, which the 33watts is greater than 100% efficiency. I still don't know if the values are either heating or cooling.

 The meaning of life is curiosity; we were put on this planet to explore opportunities.
 Top Of Page Change Forum... Civil Aviation Travel, Polls & Prefs Tech/Ops Aviation Hobby Aviation Photography Photography Feedback Trip Reports Military Av & Space Non-Aviation Site Related LIVE Chat Forum Index

This topic is archived and can not be replied to any more.

Printer friendly format

 Similar topics: More similar topics...
Need Help With New Computer Purchase! posted Mon May 22 2006 05:00:57 by AmericanF100
Australians: Need Help With Feelings On Anzac Day posted Wed Apr 20 2005 11:32:59 by QANTASforever
Work And Live In USA Need Help With Visa Info posted Tue Nov 16 2004 18:58:48 by Gr325
I Need Help With A Matrix Problem... posted Fri Oct 20 2006 18:00:22 by Iamcanadian
Need Help With A Name For My Business posted Thu Sep 28 2006 22:22:43 by B727
Need Help With Something... posted Thu Sep 28 2006 18:22:08 by Richardnhsv
Old Travel Channel Show, Need Help With Name posted Fri Sep 8 2006 05:12:19 by Lobster
I Need Help With A English/French Translation posted Mon Jun 12 2006 03:14:42 by 102IAHexpress
Need Help With Interactive Project posted Wed May 17 2006 21:16:17 by Checo77
Need Help With New Computer Purchase! posted Mon May 22 2006 05:00:57 by AmericanF100
Australians: Need Help With Feelings On Anzac Day posted Wed Apr 20 2005 11:32:59 by QANTASforever
Work And Live In USA Need Help With Visa Info posted Tue Nov 16 2004 18:58:48 by Gr325
Need Help With Marta (Atlanta) posted Fri Jul 16 2010 13:55:15 by Springbok747
Need Help With Directions In Brussels posted Thu Jun 17 2010 07:25:25 by AirTran737
Help With IPhone And BlackBerry IM Clients posted Tue Jun 1 2010 17:51:03 by Coal
I Need Help With A Gay Guy... posted Tue Jul 14 2009 17:56:45 by 7324ever
Need Help With Dialing A Number posted Fri May 29 2009 11:14:46 by Wardialer
Need Help With German Language posted Sun Mar 8 2009 16:09:37 by B727