Connect with us

3-wire CPU cooling fan

Discussion in 'Electronic Design' started by mc, Jun 18, 2006.

Scroll to continue with content
  1. mc

    mc Guest

    What is the function of the 3 wires of an Intel CPU cooling fan?

    Power, ground, and RPM sense?

    Is the power wire PWM modulated?
  2. Luhan

    Luhan Guest

    No, it just runs on 12 volts DC.

  3. Reg Edwards

    Reg Edwards Guest

    So if it runs from 12 volts DC, where does the 3rd wire come from?
  4. Nico Coesel

    Nico Coesel Guest

    Yes. Yellow is usually RPM sense.
    Power wire may be voltage regulated or PWM modulated.
  5. Luhan

    Luhan Guest

    Come from? It comes from the fan, its usually the yellow one and the
    ones I tested are open collector to ground. Comprendo?

  6. mc

    mc Guest


    But the speed of my fan definitely varies with CPU temperature. Surely the
    power is PWM modulated or *something*.
  7. mc

    mc Guest

    Ah! Thanks.
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day