[time-nuts] HP5370 power supply measurements
Dr. David Kirkby (Kirkby Microwave Ltd)
drkirkby at kirkbymicrowave.co.uk
Fri Jul 15 09:17:31 EDT 2016
On 13 Jul 2016 08:31, "Charles Steinmetz" <csteinmetz at yandex.com> wrote:
> An external fan blowing on the heatsink keeps my 5370s nice and cool, for
about $10 each.
So more noise.
> *if the counters were operated 24/7/365*. I sometimes take data for a
few months straight, but very, very far from 24/7/365 on average. So for
me, break-even would be more like 50 years.
I don't suppose Poul's main motivation is to reduce his electric bill.
> Speaking of fan noise -- you can't really get away with replacing the
internal fan with one that moves less air, so it is hard to find a
replacement that generates significantly less noise. If you find one,
please share the make and model -- all 5370 owners would love to know.
> Best regards,
Surely one of the main advantages of the SMPS route is the higher
efficiently means less cooling air is required. That means less noise.
I often here of people replacing fans with quiter ones, but I suspect that
all they really do is reduce the airflow. I believe that most of the noise
one hears is the movement of the air. From what I have read, sleve bearing
fans make a bit less noise than ball bearings fans. However, although the
MTBF of both types is similar at 20 degree C, the MTBF of sleve bearing
fans decreases quite a bit with only a modest increase in temperature.
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