DC Fans Speed Control

DC fan speed can be controlled in order to optimize cooling, reduce noise and decrease system power draw. There are various methods of controlling fan speed.
(Please place the mouse cursor over each item to show a diagram)

2-speed Control

Temperature Detecting Variable

PWM Control

2-speed DC Fan Motor

Characteristics:

Customized two speed fans are available from Minebea. The high and low speed may be specified by the customer. The low end operating speed is fixed in order to reduce noise and lower power consumption.

External connection of 2-speed DC fan motor (Example)

Control by relay contact	Control by transistor

Switch-over of fan speed S.W. OFF : LOW SPEED , ,ON : HI SPEED

Correct Signal Connection:

Correct signal connection is important to prevent damage to the internal fan IC. Connection should be designed as shown below:

In case of signal output

In case of RPM control signal