This fan is a high-quality 48V brushless DC fan made by Comair Rotron. These fans are NEW in box, but come from surplus stock with a manufacture date of September 1995. They are tested and working. Current models with similar specifications retail for about USD $50; I am selling these below half price.

Red lead is positive (+) power, Black lead is ground (-), and Blue lead is tachometer sense. Connector is a plastic shroud containing 3 standard male header pins on 0.1" spacing.

These fans are reasonably quiet and move quite a bit of air for their size. The RPM and airflow can be controlled by supplying a variable voltage up to a nominal 48V. Minimum operating voltage seems to be around 16V. (I have tested this myself)

Note: I checked the tachometer output on my oscilloscope, and it does not look like a logic-level signal. It appears to be a weak (<0.5V) pulse that probably comes from one of the driver transistors in the motor. Using the tachometer would probably require ac-coupling the signal (through a dc-blocking capacitor), high-pass filtering, and amplification. If you don't plan to use the tachometer output, just leave it disconnected. :)

Specifications

• Variable speed: 16V - 56V DC operating voltage range
• 0.11A, 5.3W at full power
• 3000 RPM, 100 CFM airflow, 50 dBA acoustic (estimated)
• Die-cast all-metal zinc housing
• Composite blades with noise-reducing serrated edge
• Ball bearings
• Integrated tachometer
• Protected against reverse polarity
• Protected against overcurrent by resettable PTC fuse (polyfuse)
• Automatic periodic soft-start from locked rotor condition
• Designed for 80,000+ hr continuous duty at 40º C.
• Weight: 1 lb 4 oz (570g) (approximate)

As far as I can tell, the original datasheet for this model is not available. The linked datasheet is for a similar, current fan from Comair Rotron with slightly different specifications, for reference.

Be sure to check out our other awesome Creltek products on Tindie!

Note: As these items are from old stock, the following disclaimer applies:

THESE ITEMS ARE SOLD "AS IS", WITHOUT WARRANTY OF FITNESS FOR A PARTICULAR PURPOSE OR WARRANTY OF MERCHANTABILITY, EITHER EXPRESS OR IMPLIED. BUYER ASSUMES ALL RISK AND LIABILITY AND EXPRESSLY INDEMNIFIES AND HOLDS HARMLESS THE SELLER FOR ANY AND ALL RISKS AND LIABILITIES THAT MAY ARISE FROM THE USE, APPLICATION, OR RESALE OF THESE ITEMS. THESE ITEMS MAY CONTAIN LEAD AND MAY NOT BE COMPLIANT WITH CURRENT RoHS AND/OR ELECTRONIC SAFETY CERTIFICATIONS.