Do 2 wire case fans have sensors?
Posted: Fri Dec 12, 2014 6:20 pm
Just curious if the case fans with a black and a red wire (2 wires total) will have a speed sensor.
Thanks!
Thanks!
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Do 2 wire case fans have sensors?
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Posted: Fri Dec 12, 2014 6:27 pm
Your motherboard should adjust the speed according to your temps.
Posted: Fri Dec 12, 2014 6:36 pm
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.
Posted: Fri Dec 12, 2014 9:49 pm
I do not believe so. The 2 pins should be power only.
Posted: Sat Dec 13, 2014 11:11 am
Yeah come to think of it, they would need to be 3 pin(wire).
Posted: Sat Dec 13, 2014 7:34 pm
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
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
Posted: Fri Jan 09, 2015 10:21 pm
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....