Hello DJA727@aol.
"I have a 7 amp hour battery as my #2 battery in the second electrical system"
How many amps does the 914 fuel pump draw when under pressure @ 12 volts, and
also
lesser voltage?
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I am thinking I may want to have ability to plumb into various parts of
electrical
system with some Model Aeroplane batteries for redundency and starting aid..
The new fangled Nickel Metal Hydride cells are pretty amazing. If I made up a
Zapped
12 cell pack of lets say 2600mAs, unloaded voltage would be 14.4 volts. This
would
weigh in at under 2 pounds. For one thing could use it as a boost to start motor
if
uncooperative lets say when hot, these things for limited time can push over a
hundred
amps. In addition could plumb into a fuel pump for back up, or plumb into radio
or
other for backup. I love Anderson Power Pole connector. McMaster sells em under
modular connectors. Very nice thing. You do not want to leave plumbed into
electrical
for too long with alternator running. Batteries can be fast charged with a Delta
Peak
charger, such as an astro 110D or 112D. Of course I would gut one of the
chargers
and
make a nice compact battery/charger combo that you could charge from the
aircraft
electrical system. I am quite comfortable with needs and caring necessary. Could
easily either carry 2 packs or use larger cells. or add another cell to get a
real
quick cranking for hot motor.
Oh yea, if i find a problem with hot starts, I will not hesitate to implant a
few
oz
motor somewhere under the cowl, that could be run from this NiMh pack. Could go
prop,
folding prop or ducted fan. really need to play with aeroplane to see best
approach.
Could easily sew up an inflatable embilical that pumps ambient air where it
needs
to
be to keep things cool. Heck for cheap could use a speed 400 motor and gunther
prop
with 5 or 6 Rat Shack NiMh cells for not much money and not much weight. Could
set a
predetermined timer, or put on a low voltage cut off. Whole thing could be made
under
a pound and the size of 2 fists for easy storage
If Mitsibushi MU-2s can play with old technology NiCads with good sucess, no
reason
NiMhs can't find good sucess in Europa.
See:
http://flydma.com/batteries/index.html
Look down to HR-SC 2600. This is one amazing cell. It outperforms the RC-2400SCR
(NiCad) that is a great cell.Click on See Performance Chart. Pretty amazing that
a
cell a bit over 2 oz can hold up so well at 40 amps. I don't think these cells
mind 4
or 5 seconds at 60 to 80 amps and end up giving you great service life. F5B
types
probably pull over a hundred amps for 5 second bursts.
Downsides:
They ain't cheap.
You need a hundred dollar plus charger.
Can't charge them when they are hot from use.
If you short them, they can catch fire and belch smoke/explode.
Using Power Pole connectors, you can have ability to plumb easily in flight to
run
fuel pump. you can nest the Power Poles together, look at the male/female slots
on the
sides. You can parallel them. You can key them so you can't short or reverse
polarity.
I don't know exact what type of connnectors i will use when removing wings/cowl
for
strobes/lights, but will give a hard thought about not using these.
http://www.andersonpower.com/products/pp/pp.html
again McMaster sells em under modular connectors.
Ron Parigoris
BTW
Check out silent AE-1
http://www.alisport.com/pag_ing/silent_ae.htm
These guys are out there and doing it. That said they are using a brush motor
and
NiCads. They are not using the latest greatest is 3 phase brushless motors with
super
duper Samarium Cobalt magnets (or other exotic stuff). The latest greatest does
not
even having sensors, they use the down third leg to figure out where things are
at!
they use a speed controller that pulse width modulates and is at a pretty high
frequency that gives very good partial throttle efficency. New Generation NiMhs
could
provide much more better electron flow, with either lesser weight for same
output,
or
for same weight, either greater duration or more power. Brushless motor again
for
same
weight more power or smae power at lesser watts to do it. neat thing about
brushless
is you can run them at a greater RPM compared to brushless, no brushes to hop
and
give
priblems. So run a gazillion RPM and use a redrive to turn a nice large prop to
gain
efficency there.
Hmmm. Maby IC needs to be switched to Electric power when glider wings fitted.
Hmmm
maby the glider wings need solar panels on top of wing to charge when soaring so
landings/extended glide later can be made with full charge. Hmmm some batteries
can go
in glider wings. If batteries take one more leap from the latest greatest NiMhs,
this
may not be so far fetched. Have a WW2 Guru down at end hanger. He loves DC3s.
said
they are so well thought out for maintaince. all the right fittings and
attachments.
Said entire motor out in a half hour with 2 guys1 And not much longer for
install!!
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