Ceramic Bearing Extraction Fan - 120mm 12V
DescriptionThis 12 Volt, ceramic bearing fan uses a quiet DC brushless motor (46dBA) and will move 87.02 cubic feet per minute (CFM).
The fan comes with the usual red & black connection cables and a white cable (pulse sensor).
You don't have to connect that white wire when using the fan in normal low-voltage applications.
A lot of small low-voltage DC fans are used to cool PCs or other electronic equipment and appliances. An extra useful side effect of a DC fan is that the fan speed can often be varied by simply changing the applied voltage (unlike small 240V ac fans of the same size). Most just have 2 wires, red and black, but others have an extra one.
The third wire carries a square-wave signal, generated by the fan internally, and the frequency of the pulses is proportional to the speed of rotation. In required applications, this signal can be employed by an intelligent controller or electronic circuit as a "feedback" or confirmation signal that the fan is in fact rotating, and that it's going at the desired speed.
Power consumption and background noise of say a PC or workstation can be reduced with a slower fan speed. But the most valuable aspect of utilising this feature is that a stalled fan could be detected by the pulses disappearing all together. The equipment can be shut down automatically if designed to do so. A well designed controller could even detect a sluggish or poorly performing fan (due to dirt, an obstruction, a shorted-winding or bearing grease getting dry) and flash a fault message or code etc.
Dimensions: 120mm x 120mm x 25mm
Weight: 0.2 Kilograms
Warranty: 6 mths