Kiriakos Project (July 2013) : 92mm High Power DC fan (Test bed).

[Kiriakos GR]

I have this special motor fan (regarding design) in storage for some time.
After finding the proper box which will host the fan on it, the all project took about an hour of work so to make it.

This is actually a nice test bed, with practical and educational benefits.

The educational is the inspection of the pulses which are coming from the RPM signal cable, and how the pulse rate change in different RPM settings.

This specific fan model is capable for automatic RPM control due thermal probe which I have removed and replace with a potentiometer.

Also the specific fan is a small monster regarding CMF and power consumption.
It can be used as DC load which will discharge any NiMH battery pack.
You can even test in long term any small PSU in the range of 100 to 700mA for over all stability.
And also it can be used as mobile fan system on the bench, so to cool down any heat sing, or even it helps as personal cooling device in the summer time.

The specific fan is know as DELL PC fan but is actually an NMB 3612KL-04W-B66.

•  Model: NMB 3612KL-04W-B66
•  DC12V 0.68A
•  Input Power: 1.25W
•  Speed: 1400~3800 RPM Thermal Control with Heat Sensor
•  Air Flow: 25~69.91 CFM
•  Noise Level: 17~43.5 dBA
•  10-Inch / 3-Wire / Dell 3-Pin Connector.
 
What I did is some extra testing of how it responds to several voltages.
The fan needs a minimum of 6V so to start spinning.

6V / 10mA
7V / 20mA
8V / 300mA
9V/ 350mA
10V/ 400mA
11V / 450mA
12V / 500mA
13V/ 550mA
14V/ 616mA
15V / 670mA

One last improvement that my DC fan test-bed needs is to add some weight on the bottom of the plastic box, other than that it is perfect.
And naturally one fan guard for the open side of it, this fan is not a toy. 

[Kiriakos GR]

Close up of the test bed.