I remember seeing 7912ADs and HBs in final test and Cal. They would use
them lead that had holes drilled in it for all the adjustments and test
points. today at wouldn't be hard to use a piece of luck Sanders just a
sheet of scrap aluminum. But what the 7912 you do want to make sure there's
air moving across everything
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On Wed, Jul 4, 2018, 10:44 AM Adrian <Adrian@...> wrote:
Hi Craig,
That's not an odd question at all, it's one that I should have asked
myself before thinking about blown racks!
The fan pulls air in (quite a lot of it), through the PSU module which
then exhausts through a wide horizontal slot low down on the module
front face. From there it effectively blows between a gap under the
'widthways' cardframe carrying the PSU interface and MPU cards and
thence into the 'open' end of the 'longways' cardframe carrying the
other seven cards among which, perhaps significantly, is the video
processor and scan control card. The chassis vents at the top, front
half of each side panel so the airflow is along the cardframe
backplanes, up between the cards and across the top front then out the
sides.
So by running with no top panel I may well have short circuited the flow
by allowing most of the flow to escape to atmosphere from the top of the
first frame and prevented any effective cooling of the second?
I will replace the panel, test and report - I was contemplating doing a
temperature test under controlled conditions but turns out this beast is
too long for my environmental chamber!
Adrian
On 7/4/2018 5:26 PM, Craig Sawyers wrote:
Here's what may seem an odd question - does the rear fan pull air in, or
push it out?
Craig
My 7912AD runs happily with no extra cooling, I think the interior
layout is designed to pull air
past the
major boards
