EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: sequoia on December 30, 2021, 09:06:13 am
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Original fan on my Rigol DG1022Z was always annoyingly loud, then it developed annoying 'whine' so it was time break the warranty void sticker...
Original fan is: Delta EFB0512LA (DC12V 0.08A)
Fan size is 50x50x10mm (but there is plenty of space to use thicker than 10mm replacement fan).
I noticed DG1022Z seems to supply about 10.4V to the fan (at 24C ambient temperature), so fan is not run at full speed normally.
Also, unit doesn't appear to monitor fan current, since disconnecting the fan doesn't seem to have (immediate) effect how unit functions, and there
is no warning about fan failure displayed...
I replaced my old noisy fan with a Sunon KDE1205PHV3 (DC12V 0.5W) fan, probably not the best choice, but it was only 50mm fan I had laying around...
Sunon fan seems much more efficient since its rated 10.2 vs 7.5 CFM for Delta (and 0.12 vs 0.068 Inch-H2O).
I measured current draw at 12V: 38mA (Sunon) vs. 68mA (Delta)
As the Sunon fan had tachometer output, I measured fan speed at 3990rpm at 12V and 3510rpm at 10.4V.
Since I wanted unit to be bit more quiet than with stock fan, I added 100ohm (2W) resistor in series.
With resistor I measured fan speed 3000rpm at 12V and 2550rpm at 10.4V, still bit high, but cant really
get this fan running much slower by reducing voltage as with 150ohm resistor fan didn't anymore start at 10.4V input....
Since I had the chassis open I decided to also remove the 'useless' fan grille on the chassis, as it doesn't seem to do anything but impede airflow,
it was really easy to cut out with a 'nibbler' tool that is meant for cutting square holes in sheet metal...
So far I'm happy with the result, unit is much more quiet now. Fan is still audible if you listen carefully, so if going for 'silent' solution then fan in 1500-2000rpm range might be better bet....