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Step 3Heat it!
Clean the processor, check for dust or other stuff that could prevent the thermal paste apllication or smell bad when heated.
Cut the USB cable to expose the wires, isolate green and white. These are USB data, we only need the power, which comes from red and black.
Solder the two resistors in series, then solder the black and red from the USB cable. No polarity issue here, so don't worry about who goes where, as long as you respect the design and keep the wires distant enough to avoid a short circuit.
The chopstick was used to spread the thermal paste under the processor. You could also use some thermal adhesive, heard about it but never seen these. I did some soldering between the processor and resistors terminals to hold them together with a small piece cut from them (a poorman's solution for lack of thermal adhesive).
Cut the USB cable to expose the wires, isolate green and white. These are USB data, we only need the power, which comes from red and black.
Solder the two resistors in series, then solder the black and red from the USB cable. No polarity issue here, so don't worry about who goes where, as long as you respect the design and keep the wires distant enough to avoid a short circuit.
The chopstick was used to spread the thermal paste under the processor. You could also use some thermal adhesive, heard about it but never seen these. I did some soldering between the processor and resistors terminals to hold them together with a small piece cut from them (a poorman's solution for lack of thermal adhesive).
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Where'd you get the yellow and black wires? And is the solder in the last step (To connect the metal to the processor) nesscesary, or can you take a little bit of electrical tape to connect it? ALSO, what kind of a volt of a AC/DC charger would I need to make this for the wall? The lowest I can think of right now is 12, and that seems a little high...
But if anything I asked right now doesn't make very much sense, just wait until tomorrow when I can see straight instead of having to put my face right up to the keyboard.
The maximum current out of an uninitialized USB port is 100mA, not 500mA.
This 100mA have to be enough for a USB device to establish communication with the USB host and request up to 500mA. Which might (or might not) be granted by the host.
Fortunately for all the USB gadgets around, most (if not all) USB hosts (read: PCs, laptops, hubs) ignore that part of the specifications and just deliver 500mA (or even more - good for those hard drives ;-) ).
So, without any USB-logic on the heater, it most probably will work, but only 500mW are guaranteed.
The tip with the powered USB hub is very advisable, just be aware, that your gadget might kill your precious notebook when it's connected directly even when it worked with the hub.
Otherwise: nice idea to use a Pentium as hotplate.
http://www.usb.org/developers/docs/usb_20_040908.zip
But beware, it is the official hardcore stuff...
If you dare to download it, see file usb_20.pdf.
In chapter "7.3.2 Bus Timing/Electrical Characteristics" it says that an "Unconfigured Function" (that is any current consumer that has not negotiated all the protocol details with the host - e.g your two resistors beneath a Pentium) are allowed to get 100mA max. On the other hand, it is not prohibited that a host supplies more than 100mA.
For endolith's (and other's) suggestion to combine 2 or more ports the same restrictions apply. 100mA guaranteed per port, maybe more...
About your concerns, see chapter "7.2.1.2.1 Over-current Protection". According to the spec, the absolute maximum is 5A (that would mean 25W and a hot coffee!) or whatever the driver can handle and the driver has to be over-current protected.
Only problem here: Those PTC and other protection devices are (relatively) expensive components - and hey, why shouldn't the producer make a few cents into his pockets? 99.9% of the customers will never need the over current protection... except you, of course (There is hardly anything in the world that some man cannot make a little bit worse and a little bit cheaper...John Ruskin)
So I would strongly advise to use a powered hub to protect your PC or at least use a USB port that is not on your main board, but on a separate PCI card (not helpful for you laptop users out there).
Or, why violate an USB port at all? It's a data port. If you want energy, use one of this wall warts (errr. power supplies). They are cheap, come with a lot or voltages and some can deliver a lot of current. For the heater thing, it even doesn't matter if it is AC or DC. Just use a reasonably low voltage ;-)
Yep, the older EPROMS came in ceramic packages - they felt as expensive as they were. Especially the ones that could be erased with UV light and had a window where you could look at the die.
I still didn't read the whole document (I'll do it), but I found a curious point on Maxim's website when searching for Li-Ion charging controllers (MAX1551 looks cool). The section is called What Your Mom Didn't Tell You About USB. It brings a bit more confusion to our minds, maybe, but I am glad with this subject, I believe we all are learning more and more about the USB standard.
As I've seen on a post somewhere here @ intructables: 'One can be very sure when he knows everything or nothing' , something like that.