Re: [amsat-bb] super capacitors

[Robert McGwier <rwmcgwier@xxxxxxxxxxx>]

Joe and others:

It sounds like you guys need to join the Eagle power team!

Lou McFadin is leading the power effort.  He and his team have proposed 
a highly redundant collection of clusters.

I have already done the calculations for the team that show that a 2700F 
supercapacitor (about what you can buy now) has about the same capacity 
as an ordinary D cell.   We are also have the same kind of lithium 
batteries that are on the Mars rovers and are working so beautifully 
(same manufacturer).    Lou's team is designing a very careful charging 
system for the Li-Ion cells.  If treated properly, the rovers show they 
will live a long life.

In the currently planned orbit,   we will short eclipses and the cells 
will not be discharged a lot.   We will also not have really bad 
seasons.  Our solar panel plans are to have adequate power for our 
transponders at all sun angles and enough to run "paying experiments"  
between 1/3 and 1/2 of the year.

As engineers with new technologies at our disposal,  we are now able to 
mitigate some of the things which have bitten us before.

Bob
N4HY


Joe Leikhim wrote:
> What about constructing a highly redundant power system of clusters of 
> low voltage batteries and solar cells. Each solar cell would be paired 
> with one NICAD cell and this pairing would include its own low voltage 
> boost regulator (charge pump). There could be dozens of these feeding 
> a higher voltage bus. The failure of a battery, solar cell or boost 
> regulator would not load down the high voltage bus. There would only 
> be a degraded source of current. There would be no requirement for 
> potentially unreliable A/B back up switching as all cells would be on 
> line at a time.  K4SAT
>
>


-- 
AMSAT VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats,
NJQRP/AMQRP, QRP ARCI, QCWA, FRC. ARRL SDR Wrk Grp Chairman
"An expert is a man who has made all the mistakes which can be
made in a very narrow field."  Niels Bohr
----
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