Step 4: Preparing the hot plate

Picture of Preparing the hot plate
locate the ground pins in your CPU and that can be done by reviewing the CPU data sheet or simply by the devastating trial and error.

Cut the USB wire and pass it through the hole you made previously in the base.

Strip the USB cable and locate the black and red weirs (black wire = ground, Red wire = +5V). You can cut out the white and green data weirs for more space.

Now connect the black wire to the ground pins and the red wire to voltage pins.

The best way to attach the weirs to the pins of the CPU is to cut the wires without striping them and then slide the pins inside.

Finally, you have to attach the CPU to the grill by Epoxy


TRAXXX5 years ago
work good at 10v 1A :D hehehehe it s hot
0.o How did you get 10v 1a from a standard USB port?
I think he means he hooked it to a different power supply. That would blow that processor pretty quick, i'd think.

i have run mine from 30V 2A for about 20 min and it worked fine!

maybe with 2 usb ports
TK1756721 year ago

For those wanting the datasheet: sometimes it is better to search the pin-out of the socket it came from (mine was a socket 7) since (i believe) all CPU's going in socket 7 will have the same pin-out.

pclever12 years ago
I just tried this myself and the cpu got up to 96F and was able to melt chocolate. However the cpu clearly states that it runs at 1.525V. I tried it again latter and it want working (I checked the connections). Do you think I fried the cpu?

I used a phone charger for this that runs at 500ma (also 5V).
umerji10002 years ago
could someone please help me find the voltage and ground pins on my cpu.
here is the dash sheet: http://download.intel.com/design/celeron/datashts/30235305.pdf
Nice tut!

I found the datasheet for a CPU that I'm looking at on eBay. It states "For clean on-chip power distribution, the Celeron processor on 0.13 micron process has 85 VCC (power) and 181 VSS (ground) input", does that mean I can solder the power wire to any one of these 85 VCC pins, and the ground wire to any one of the 181 VSS pins? Or will mine have a specific one that needs wiring to? Or maybe I'm not undeerstanding the statement correctly?

Also, when done would I be able to plug this into something such as an iPhone charger, I believe they are 5v?
emilsegna5 years ago
Do anyone have pinout for Pentium 4 socket 775
bhuot emilsegna3 years ago
Check on the CPU itself, the model number and have it correspond to the page on that URL:
nakayanGD4 years ago
how to locate ground pins and voltage pins in Intel pentium 133
deamonlord4 years ago
PLEASE can someone tell me which are the ground and voltage pins on a pentium 1 processor? I found a datasheet through google but it went over my head. If someone understands that techie language, please help me!
RAMZI_PC4 years ago
can i use an old CPU, like 368 one or 486
threepwood5 years ago
Hello! I Have an old amd duron 800 cpu, and I want to make that, but I have a little problem...: can´t find the voltage and ground pins. I´ve searched the datasheet, but all i could was lots of names and numbers... it would be very nice if anyone could help me! :) Thanks! (and sorry for mi english) ;)
rosenred5 years ago
Excellent 'ible! If I may, I have a remark. The fact that I am somewhat clumsy, would certainly guarantee liquid spilled on the hot plate. So,  a way to protect the under side of the cpu, would be crucial in my case.

How about a piece of pcb (from an old hard drive or mb) cut in the size of the box, with a square hole in the middle for the cpu? It could be sealed with epoxy or even hot glue since the pcb of the cpu does not get that hot ;)
Andy-K5 years ago
Would it damage the CPU if I tried to solder the + and - leads from the USB cable to the CPU. I think this would make a more reliable connection, but I'm not sure if the heat would damage anything in the CPU. Any advice would be greatly appreciated.
all semiconductors have a "thermal budget" temp and time at temp are the critical factors. In the step of the manufacturing process I oversee wafers are routinely subjected to +1000c for up to 6 hours(silicon melts at ~1200c) to diffuse dopents and passivate the surface charges. the die size inside the chip package is very small, connected to the pins by gold(melts @ 1064c) wires.

Soldering even a good chip should cause no damage, though running it as a heater will eat up its thermal budget faster and will make it useless for anything else eventually.
GreenD5 years ago
 I'm wanting to make a variable hot plate - these cost 300+$ commercially.

I know by heating this above>200C you may desolder the board. But would a variable resistor be enough to change the temperature here?
articice5 years ago
Nice idea, but you should have used all the pins and various voltages (to heat the entire thing, not just parts of it) and installed a current/temperature controller, possibly coupled with an active USB device - to get more current and to control the temp via a usb2serial interface or whatever.
and, a wooden box may not pass some firefighting regulations or so LOL
emilsegna5 years ago
What cpu are u using? P4 socket 478?
pravardhan5 years ago

CPU's work with low voltage. Older ones (upto Pentium 3) requires about 2volts. But, the newer ones (Core2's) require just about 1.7volts or even less.

And, there are special IC's that will provide with the proper voltage from the +12V supply...!

Shiftlock5 years ago
How hot does this get?  I can't imagine it gets very hot, considering CPUs draw 40+ watts, and the maximum current from a USB port is 500mW (1/2 watt).
Marsh Shiftlock5 years ago
 Actually a USB port delivers 500 MilliAMPS, not mW. 500 milliamps at 5 volts is 2½ Watts. That's all a USB port can deliver. The CPU could however attempt to draw more than that. There's probably a current limiter built in to the port to prevent any damage though.
good idea, but why not just use a Peltier? you could could make a hot and cold plate. Thats how i made cooling/heated cup holders for my vw.
 Hey, this is a great Instructable, but I keep wondering, How did you attach the CPU to the grill?