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By so1o
#185491
Hi Guys

I apologise in advance if this is the wrong section or has no relation to the forum but im depserate.

To cut a long story short, my projector fan is broken. Now i can get the fan but i need to know what kind of sensor output it has. I have contacted the manufacturer of my projector and also the fan manufacturer NMB but they could not help as it is quite old now.

Anyway the part numbers i have printed on the fan are as follows:
BM5125-04W-B49 - 12V - DC - 0.17A
DC BRUSHLESS FAN MOTOR
MINEBEA CO., LTD
T15
NFANSA013WJ00

I googled the part numbers and the fan is available but i have two choices.

The two part numbers that come up are as follows:

BM5125-04W-B49-L00
BM5125-04W-B49-L50

They are both identical except for the signal. The two signals are as follows:

TACHO Signal
A tacho output or “sensor output” as shown in the catalog indicates the speed
of the fan at different operating levels. Its purpose is to identify when the
fan drops below a certain RPM, and to identify a potential problem with airflow.
A tach output fan will always have at least 3 wire leads.

LOCKED Rotor Signal
A locked rotor is also a type of “sensor output”; that measures when the fan
has completely stopped or “locked”. It sends a signal, frequently called an
alarm signal, at either high or low voltage when the rotor locks. If the fan
starts spinning again, the alarm signal condition will go away. This is known
as a non-latching locked rotor signal, which is standard with NMB fans.

Which type do i need?

Image
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User avatar
By distro inferno
#185574
These images are too small to see clearly but it looks like the SEN line out of pin 3 goes to a bus- is it an I2C bus? The datasheets for the fans aren't too helpful in that regard, and I would need to see the rest of that schematic in your second image to figure it out.

Each fan is about $9, can you buy one of each and try them out?