[time-nuts] DC-DC converter
hmurray at megapathdsl.net
Sat Sep 26 19:03:35 UTC 2009
> If you want cheap, use 6 12V to 9V DC-DC converters from old thin
> ethernet cards with the outputs in series! This will give 54V. You
> also get the isolation transformers and 10MHz filters see G4HUP's page
I don't see how that will work. They can't provide enough power.
The paper above says the little bricks put out 9V at 200 mA, 1.8W. 6 of them
will total 11W.
My copy of the Z3801A manual says "< 25 Watts (nominal)". I'm a bit
surprised HP didn't mention the startup requirements.
Google found a graph at the bottom of:
It shows a measured 0.85A at 47V during startup. That's 40W. It drops to
35W in a few minutes, then gradually ramps down to 32W over a half hour and
drops to 20W after an hour. (The text on the graph is tiny. I might have
I don't know what the startup power looks like at the sub-second level.
That extra 15 W probably explains most of the startup troubles that have been
reported. I'm using a way-overkill 48V regulated supply and I haven't
noticed any troubles.
These are my opinions, not necessarily my employer's. I hate spam.
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