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) Temperature Detecting Variable
2-speed DC Fan Motor 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 Temperature detecting variable speed DC fan The
RPM is automatically controlled and synchronized with
temperature variation by installing a thermistor. Connection
diagram (Example) Speed variation is enabled by varying the
control voltage (0 to 6V) between the Signal wire and ground.
PWM Control DC fan In PWM speed control, a fixed frequency
square wave is applied to the speed con