Simulating CPU electricity changes

Discussion in 'The Projects Forum' started by JoelG90, May 17, 2010.

  1. JoelG90

    Thread Starter New Member

    May 17, 2010

    I'm in my second term of physics and needed to come up with a physical experiment and write a report about it.

    Last term I wrote a paper on what was more limiting to CPU performance/advancement and came to the conclusion that physical size was the limiting factor and not heat. This term I want to work with the heat aspect.

    I want my project to explain what effect each of the different components of electricity have on heat output for a CPU/GPU. I talked to my instructor and he suggested using a 555 chip, but wasn't able to get much more from him.

    I want to measure the different components of electricity and what it does to a processor's heat output. Like changes in voltage, current, amps, etc and which makes the chip output the most heat and why.

    I'm planning on using multisim to get my circuit laid out then physically construct it. Problem is, I don't know what components or where to start. I'm aiming for a controllable power source (amps, voltage, etc) so I can test the effects on something that emits heat when electricity goes through it. Preferably something that might resemble a CPU (semiconductor part?)

    Any help would be greatly appreciated
  2. retched

    AAC Fanatic!

    Dec 5, 2009
    Well, youve come to the right place:

    Scroll down in the above link and start with intro to the 555.

    You will see many uses for the 555 chip and the components that make it work.

    Here is a datasheet for a NE555. It has the temperature information you will need to see the correlation between current and heat.:
  3. Markd77

    Senior Member

    Sep 7, 2009
    How about using a PIC12F675 from Microchip. It can operate on 2-5.5V and there is a clock input which you can control from DC to 20MHz with an external function generator.
    Unfortunately you would have to program it because the default oscillator is RC mode (although you could vary the frequency with RC mode but it would also be voltage dependant.)
    Unprogrammed, this microcontroller will still step through its blank instructions and would have similar power and heat values to one running a real program.
    It isn't really realistic to control current to a CPU as it normally takes as much current as it needs and no more.
    It isn't going to get very warm so you would need very sensitive temperature monitoring.
  4. JoelG90

    Thread Starter New Member

    May 17, 2010
    Overclocking brought this topic up for me. I dropped my CPU's voltage by .012 and it dropped 10 degrees Celsius and was stable, such a small change in voltage having such a large effect on the heat output really made me curious.

    Thanks for the replies!

  5. JoelG90

    Thread Starter New Member

    May 17, 2010
    Hello again,

    I'm trying to get a monostable 555 to actually do a timed pulse and for the life of me I cannot get it to. I've tied so many schematics and different user defined and multisim 555s and still no luck.

    What am I missing?

    I haven't even gotten to the actual controlling it and running the electricity through something to measure the heat. Classmate and I are utterly stumped.