4pin fans connected to a 3pin fan controller header.

[Dylan_46]

ok so i have 4pin fans in my system and was thinking about getting a case bay fan controller to easily change the speed of my fans ect... but i can only find fan controllers with 3pin fan headers and obviously i want to connect my 4pin fans to this controller. i know the 4th pin on the fan is for the pwm function but will i still be able to control my fans speed from the controller.

in short if i connect my 4pin fans to a 3pin fan controller will i still have the ability to change the fan speeds... thanks in advance.

 

[clutchc]

PWM=Pulse Width Modulation
3-pin fans are controlled by varying the voltage, 4-pin (PWM) fans are controlled by varying the length of time the DC voltage is applied to the motor. (The pulses)
The 3-pin controller will vary the speed of the 4-pin fans just as if they were 3-pin fans. But as the voltage varies, so will the brilliance of any LED lighting the fans might have.

 

[Toxikaraidur]

PWM=Pulse Width Modulation
3-pin fans are controlled by varying the voltage, 4-pin (PWM) fans are controlled by varying the length of time the DC voltage is applied to the motor. (The pulses)
The 3-pin controller will vary the speed of the 4-pin fans just as if they were 3-pin fans. But as the voltage varies, so will the brilliance of any LED lighting the fans might have.

To me, LED fans are not nearly as much of a concern so much as the fan actually doing its job. So in general, the more fans I want to run through a fan controller the more *amps* I will need per channel, yes? I shy away from the '100w of power per channel!!!' ones due to expense and general insanity, but at 12 volts and 3 amps per channel, I'd have good headroom and some marginal expand-ability per channel.

I have been searching high and low for a 4-pin bay fan controller and no such luck without it being an octopus with a clip for mounting inside the case or even a set-down-on-desk fan hub. So any old 3 pin controller that can match the 12v 3 amp per channel should do me well, yes?

 

[Paperdoc]

Yes.

As clutchc indicated, the design of 4-pin fans includes this backwards compatibility feature: when connected to a 3-pin header (uses only Voltage Control Mode), a 4-pin fan WILL be powered AND speed controlled by the header. Technically this method of control is not quite as good a PWM Mode, but only for a few relatively unimportant features.

Because of this design, third-party fan controller makers see no reason at all to market different units for 4-pin fans. Doing so would only raise their costs of both types of units, so anyone who does that will become un-competitive in the market. So you are right - there appear to be NO third-party fan controller add-ons that are designed only for 4-pin fans.

 

[Toxikaraidur]

Yes.

As clutchc indicated, the design of 4-pin fans includes this backwards compatibility feature: when connected to a 3-pin header (uses only Voltage Control Mode), a 4-pin fan WILL be powered AND speed controlled by the header. Technically this method of control is not quite as good a PWM Mode, but only for a few relatively unimportant features.

Because of this design, third-party fan controller makers see no reason at all to market different units for 4-pin fans. Doing so would only raise their costs of both types of units, so anyone who does that will become un-competitive in the market. So you are right - there appear to be NO third-party fan controller add-ons that are designed only for 4-pin fans.

Thank you for your time on that solution. It is a shame that all my PWM fans will be controlled 3-pin style, as I put a lot of extra work in locating the best PWM fans for my build. That being said, performance-wise there are no comparable 3-pin fans I would consider.