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Larry Larry is offline
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First recorded activity by BoatBanter: Jul 2006
Posts: 5,275
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"Meindert Sprang" wrote in
:

450mA at 3.3V


450ma x 3.3V = 1.485w at 13V = .114A x 24 = 2.74AH which isn't much a
significant part of a small 330AH house battery, even smaller on the two
banks of beasts we drag around in the stern. 2.7AH a day isn't much of
an issue, is it? The stern running light uses 10-20 times that much
overnight.

PLEASE tell me you're getting the 3.3V from a highly efficient tiny
switching supply....not some 7800 series analog heat sink heater
regulator....please? 450ma x 13V off an analog regulator = 5.85w or
10.8AH/day....not so good....not a catastrophy, but not so good. My
friend Dan's Hatteras 56 got 12VDC to run the toys from the 32VDC train
engine power that ran the 8V92TA beasts-in-the-bilge. Most of the power
went up in smoke because they had 3 HUGE heatsinked analog regulators
wasting the 20 volt difference between the systems, heat created in
hundreds of watts. Of course, with power to burn on this oil burner, it
wasn't much of an issue, but seemed an awful waste as the main salon's
air conditioner had to pull this heat out of the cabin, wasting more
power from the two gensets. Me? I used to tell the pump boys at the
diesel dock to "fill 'er up and don't forgit ta wash the windshields"
(5). It wasn't my money, after all...(c;

We quibble about the tiniest things.....

When I used to work for the Federal government, we had a saying that went
something like:

"In any meeting, the amount of time spent on any line item was
proportional to the inverse square of its cost."

A $2 whazzit took hours to fight over. The $480,000 diggit took 10
minutes, mostly in motions to pass it. I never saw 'em buy something
over $1M, but that might have happened during one of my yawns and I
missed it.

If 2.74 AH/day is too much of a strain on the system, should we REALLY
sail it out of the harbor in the first place??



--
There's amazing intelligence in the Universe.
You can tell because none of them ever called Earth.