- Joined
- Sep 28, 2007
- Messages
- 1,520
- Points
- 0
Just to make myself clear on this the 3 wires on PC fans are + - and one for the speed sensor right?
LPF Donation via Stripe | LPF Donation - Other Methods
Links below open in new window
ArcticMyst Security by Avery
3 Wire PC Fans
- Thread starter lamborgini8
- Start date
- Joined
- Jul 27, 2007
- Messages
- 3,642
- Points
- 63
lamborgini8 said:
yep the third wire is RPM monitoring, some fans have a fourth lead for PWM input
Niko said:
That was addressed in this thread
the third pin is for information (RPM Speed, etc.), if there is a fourth one is for PWM control
[/quote]i know i meant when i shop for fans on newegg and dx i look for a dc 2 wire fan, but only see the 3 wire ones, because i assumed they were "brushless" 3 wire ones that needed a special controller.
now i'm going to buy some to play with
the area i put my ps3 in gets toasty, i was gonna help it out with some fans
- Joined
- Oct 1, 2007
- Messages
- 466
- Points
- 0
i think some brushless 3 wire fans use 3-phase ac voltage from variable fequency drives, just like large industral 3-phase motors. the only difference it that they use 5 or 12 volts ac instead of 208, 230, 460 volts ac.
erdabyz
0
- Joined
- Jun 30, 2008
- Messages
- 286
- Points
- 0
yeah, indeed most of them have 3phase motors, but they have integrated circuitery to drive the motor from 12VDC, so there's no need for external 3 phase input because the fan generates it itself. That's why you can't easily change rotation direction changing polarity.
The third wire is for communication, some kind of serial port communication
The third wire is for communication, some kind of serial port communication
- Joined
- Jan 20, 2008
- Messages
- 1,724
- Points
- 0
Today I replaced a noisy fan in a computer power supply, I used a 3-wire case fan but the power supply's fan only used 2 wires. Since the case fan's connectors went black, red, yellow (-, +, rpm), and the header went black, red (-, +), I just plugged it in with the yellow wire not connected to anything. Works fine, I do this on a regular basis.
As long as you make sure the positive and negative are connected correctly, the extra wire is optional.
As long as you make sure the positive and negative are connected correctly, the extra wire is optional.
- Joined
- Sep 28, 2007
- Messages
- 1,520
- Points
- 0
Whoops, forgot about this thread.
Its going to be used in my scanner build hence the fans I am looking at are 40mm. I just wanted to confirm the wires because the fan will be wired to the scanners PSU, last thing I want is to wire up the wrong ones.
The fan will be run at 15V instead of 12V, im sure it will be fine but I don't think there are any 15V fans about.
Its going to be used in my scanner build hence the fans I am looking at are 40mm. I just wanted to confirm the wires because the fan will be wired to the scanners PSU, last thing I want is to wire up the wrong ones.
The fan will be run at 15V instead of 12V, im sure it will be fine but I don't think there are any 15V fans about.
