Talk:Thermal management of electronic devices and systems
From Wikipedia, the free encyclopedia
 |
Please help improve this article or section by expanding it. Further information might be found on the talk page or at requests for expansion. This article has been tagged since January 2007. |
 |
This article was nominated for deletion on 3/27/2006. The result of the discussion was keep. |
I disagree with deleting this article. Where else will you put stuff on heatsinking and fan cooling of electronic equpt etc. If you can come up with an alternative page title, I'm willing to listen . Otherwise, please leave this page alone.--Light current 01:19, 23 March 2006 (UTC)
Contents |
[edit] REmoved from page, pending rewriting and severe editing
I really do think this stuff doesn't belong here. Where it does belong is a matter of opinion. 8-(--Light current 02:51, 7 January 2007 (UTC)
[edit] Size vs. heat
What one has to remember about heat is that electronics only get hot because they are never perfect conductors nor perfect insulators {though we can make nearer-perfect insulators than we can conductors}. A perfect conductor will never get hot, no matter how much current you put through it, because the voltage drop across it will be nil and power = voltage * current. Nor will a perfect insulator, because this time, the current through it will be nil.
CMOS is based around two transistors, a P-channel FET which goes conductive when the gate is driven low, and an N-channel FET which goes conductive when the gate is driven high. The P-FET is trying to pull the output high and the N-FET is trying to pull it low. Both the gates are joined together, and this is the input. This is a simple NOT gate.
For a NAND gate, where any input 0 will drive the output to a 1, we have several P-FETs in parallel trying to drive the output high, and so many N-FETs in series trying to drive the output low. Each P-FET gate joined to an N-FET gate is one input. When they are all high, all the N-FETs turn on allowing the output to go low; when any one is low, the chain of N-FETs is broken, one or more P-FETs turn on, and the output goes high. For a NOR gate, where any input 1 will drive the output to a 0, we put the Ns in parallel and the Ps in series. You can make AND gates from NAND+NOT, OR gates from NOR+NOT, and any other combination you like. In fact you really don't need both NAND and NOR, because you can make either one out of the other; but it turns out they're equally as easy to make as each other in CMOS {not like many other technologies}.
In an ideal world this would never dissipate any power, since the input cannot be high and low at the same time so only one of the transistors will ever be on. In practice what happens is that the gates act like capacitors which take a finite time to charge and discharge. They do not switch instantaneously from conductive to non-conductive. So one stops conducting while the other is starting to conduct, and for a brief instant while the inputs are changing state both transistors are conducting a little. It's not a dead short circuit of course, otherwise something would give way ..... hopefully a fuse.
Now every time something changes state, you get a little pulse of heat. Which is why fast processors need cooling. Additionally, to make sure that the logic gate output has changed state before the next clock pulse, you need to make the gate capacitances charge up quickly -- which means using a higher voltage than you could get away with at lower speeds. But 2x more volts means 2x more amps means 4x more watts.
Smaller transistors should have less gate capacitance, and so be capable of switching more quickly.
[edit] "Heat sink" to "Thermal management of electronic devices and systems" merge discussion
Against — perhaps Electronics needs weeding and an article named "Thermal management of electronic devices and systems" makes sense (maybe), but merging Heat sink here is "biting off your nose to spite your face"! See also: WP:NOSE. The heat sink article is about the objects: heat sinks; the same way we have the article Arrow and the article Hunting. A closer match is this article and Computer cooling, but that is not a merge suggestion on my part, just a note-worth observation. --Charles Gaudette 09:29, 7 January 2007 (UTC)
Against — This article is about a specific heat management component called a Heatsink, but it is not as general as you suppose. The article about heatsinks does not deserve to be merged with a topic as general as this, because: 1.People that are new to computing technologies and hardware will have a difficult time distinguishing the relevant material from the irrelevant material 2.The students will have to spend less time looking up what they need. This also ties the heatsink page, to the other pages that cover other components in the computer hardware range. --12:46, 13 January 2007 (GMT)
Against — You might also consider that one definition of a 'heat sink' is simply a generic term for a thermodynamic cooling device. Typically it refers to a solid-to-fluid type of heat exchanger, where the term fluid means either liquid or gas. So by this definition the term 'heat sink' can apply to many things from a CPU cooler to an engine radiator. Also in a thermodynamic system, such as a heat engine, the heat sink is complementary to the heat source. Oddly enough I see no article for heat source, perhaps because it's more appropriate for the dictonary instead of the encyclopedia. Mikiemike 09:47, 6 February 2007 (UTC)
Against — The term heat sink is widely used in science as a term for a simple hot to cold heat exchanger. Much of the current content of heat sink may, however, be more appropriate in thermal management of electronic devices and systems to remove the massive bias from the heat sink article. - Zephyris Talk 22:24, 22 February 2007 (UTC)
[edit] Heatsink#Use in electronics
Given the response here I have moved the merge template to the "Use in electronics" section, please discuss! - Zephyris Talk 16:00, 6 March 2007 (UTC)
