Results 1 to 7 of 7

Thread: Do 2 wire case fans have sensors?

  1. #1
    Advanced Member westy's Avatar
    Join Date
    Dec 2000
    Location
    New Market, MN. USA
    Posts
    874

    Do 2 wire case fans have sensors?

    Just curious if the case fans with a black and a red wire (2 wires total) will have a speed sensor.

    Thanks!
    "We do not inherit the Earth from our parents, we borrow it from our children."

    Asus P5Q-E LGA 775 / Intel Core 2 Duo E8500 Wolfdale / Artic Cooling Freezer 7 Pro / NVIDIA GTX650 Ti Boost / Corsair Dominator 8GB DDR2 1066 (PC2 8500) / Corsair CMPSU-650TX / Asus 20X DRW-2014L1T / Klipsch 4.1 / Creative Sound Blaster Z / Crucial MX100 CT512MX100SSD1 2.5" 512GB SATA III MLC Internal Solid State Drive / Too many hard drives to mention.....

  2. #2
    R.I.P. Nov 2015 RaisinCain's Avatar
    Join Date
    Jun 2009
    Posts
    1,951
    Your motherboard should adjust the speed according to your temps.

  3. #3
    Advanced Member westy's Avatar
    Join Date
    Dec 2000
    Location
    New Market, MN. USA
    Posts
    874
    What I'm wondering is if the connections on my motherboard will "read" the (2 wire) fan speed if connection to the headers on the mobo.
    Last edited by westy; 12-12-14 at 05:53 PM.
    "We do not inherit the Earth from our parents, we borrow it from our children."

    Asus P5Q-E LGA 775 / Intel Core 2 Duo E8500 Wolfdale / Artic Cooling Freezer 7 Pro / NVIDIA GTX650 Ti Boost / Corsair Dominator 8GB DDR2 1066 (PC2 8500) / Corsair CMPSU-650TX / Asus 20X DRW-2014L1T / Klipsch 4.1 / Creative Sound Blaster Z / Crucial MX100 CT512MX100SSD1 2.5" 512GB SATA III MLC Internal Solid State Drive / Too many hard drives to mention.....

  4. #4
    Senior Member Easto's Avatar
    Join Date
    Dec 2000
    Location
    So. California
    Posts
    5,009
    I do not believe so. The 2 pins should be power only.

  5. #5
    R.I.P. Nov 2015 RaisinCain's Avatar
    Join Date
    Jun 2009
    Posts
    1,951
    Yeah come to think of it, they would need to be 3 pin(wire).

  6. #6
    Administrator Philip's Avatar
    Join Date
    May 1999
    Location
    Jacksonville, Florida, United States
    Posts
    10,476
    Blog Entries
    6
    Two wires are power only, the motherboard can't read their state as already mentioned above. Most likely it will not change/control their speed.

    However, even with two wires the speed of a fan can be reduced by varying voltage to it.

    Fans run on 12v, however, they will start with as little as 5-7 volts at a slow speed, and varying voltage up to 12 will speed them up. This is often used with inline fan speed regulators (they just put a resistor/potentiometer to reduce the 12v and vary speed). There are others that simply use the different pins from a simple 4-pin power connector (yellow-red-black-black)... Yellow is 12v, Red is 5v, black is ground:
    Ground+5v gives you very slow speed
    5v+12v (7v difference) gives you medium speed
    Ground+12v for full speed.
    All three of those speeds can be achieved with a simple 4-pin power connector.

    In addition, the fan itself can have temperature sensor and speed control on it, that is regardless/independent of a third pin (remote control).

    I hope this helps some

  7. #7
    Advanced Member westy's Avatar
    Join Date
    Dec 2000
    Location
    New Market, MN. USA
    Posts
    874
    I was just wondering if I hooked them up to the fan leads on my mobo if they'd show the RPM of the fan. Right now, I have them connected to a PS cable. Guess not....
    "We do not inherit the Earth from our parents, we borrow it from our children."

    Asus P5Q-E LGA 775 / Intel Core 2 Duo E8500 Wolfdale / Artic Cooling Freezer 7 Pro / NVIDIA GTX650 Ti Boost / Corsair Dominator 8GB DDR2 1066 (PC2 8500) / Corsair CMPSU-650TX / Asus 20X DRW-2014L1T / Klipsch 4.1 / Creative Sound Blaster Z / Crucial MX100 CT512MX100SSD1 2.5" 512GB SATA III MLC Internal Solid State Drive / Too many hard drives to mention.....

Similar Threads

  1. Case wire color question
    By purecomedy in forum Hardware & Overclocking
    Replies: 10
    Last Post: 04-26-04, 04:20 PM
  2. Case fans
    By aagiants in forum Hardware & Overclocking
    Replies: 17
    Last Post: 10-28-02, 12:22 AM
  3. Case Fans
    By BaLa in forum Hardware & Overclocking
    Replies: 7
    Last Post: 10-10-02, 07:27 AM
  4. Case and CPU fans help
    By LuiKhang in forum Hardware & Overclocking
    Replies: 8
    Last Post: 05-26-02, 03:27 PM
  5. Case fans ?'s
    By aagiants in forum Hardware & Overclocking
    Replies: 4
    Last Post: 02-13-02, 01:52 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •