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5
The
sizing
of
static
port(s)
requires
that
you
first
calculate
the
volume
of
the
electronics
bay
as
follows:
Volume
=
Bay
Radius
(inches)
x
Bay
Radius
(inches)
x
Bay
Length
(inches)
x
3.14
Next,
use
the
appropriate
single
port
formula
to
calculate
the
size
of
a
single
port:
For
volumes
<
100
Single
Port
Diameter
(inches)
=
Volume
/
400
OR
For
volumes
>=
100
Single
Port
Diameter
=
2
x
SQRT
(Volume
/
6397.71)
If
you
plan
to
use
multiple
ports
(recommended),
determine
how
many
ports
to
use
(a
minimum
of
3
is
recommended),
then
calculate
the
size
of
each
port
using
these
multi
‐
port
formulas:
Single
Port
Area
=
(Single
Vent
Diameter
/
2)
x
(Single
Vent
Diameter
/
2)
x
3.14
Multi
Port
Diameter
=
2
x
SQRT
((Single
Vent
Area
/
#
of
holes)
/
3.14)
Power
and
Wiring
Considerations
The
RRC3
is
designed
to
be
operated
with
a
standard
9
‐
volt
alkaline
battery.
Standard
9V
alkalines
are
an
optimal
choice,
providing
an
inexpensive
and
widely
available
battery
type
with
secure
snap
connectors.
Always
purchase
and
use
premium
alkaline
batteries.
Other
battery
types
can
be
used,
including
NiCd,
NiMH,
LiPo,
or
other
battery
chemistries.
Your
battery
choice
must
source
and
maintain
an
absolute
minimum
of
3.5
volts,
and
also
be
limited
to
a
maximum
of
10
volts.
It
should
be
noted
that
9V
alkaline
batteries
can
source
a
maximum
discharge
current
of
about
3
amps
into
a
short.
The
Drogue,
Main,
and
Aux
outputs
of
the
RRC3
are
rated
for
3A
service.
When
using
other
batteries
chemistries
that
can
source
higher
discharge
currents,
users
should
ensure
the
output
connections
to
the
Drogue,
Main,
and
Aux
are
not
shorted,
and
the
connected
electronic
match
loads
do
not
exceed
3A
to
avoid
damaging
the
unit.
The
brownout
capacitor
is
optimized
to
prevent
an
over
‐
current
brownout
condition
when
operating
the
RRC3
with
a
9
volt
battery.
Lower
battery
voltages
reduce
the
total
brownout
time
capability
of
the
capacitor.
If
you
do
choose
to
use
a
lower
voltage
battery
than
9V,
ensure
your
battery
has
adequate
voltage/power
reserve
to
prevent
a
brownout
condition
during
flight
due
to
a
voltage
dip,
and
that
you
pay
extra
attention
to
the
loads
required
by
your
e
‐
matches.
Nominal
power
consumption
for
the
RRC3
is
approximately
6ma.
When
beeping
or
flashing
however,
power
consumption
can
jump
up
to
≈
35ma.
During
Pre
‐
launch
on
the
pad,
and
Post
Flight
after
recovery,
the
altimeter
will
beep
and
flash
the
LED.
During
flight
operations,
the
LED
will
illuminate
when
the
velocity
discriminator
lockout
conditions
are
active.
IMPORTANT:
Always
use
a
battery
system
of
10
Volts
or
less
to
avoid
damaging
the
RRC3
.
IMPORTANT:
Always
load
‐
test
your
battery
prior
to
flight
to
ensure
adequate
power
reserve
for
reliable
operation
and
ignition
of
the
ejection
charges.
Inadequate
sizing
of
an
external
battery
system
or
high
‐
current
demands
on
the
battery
system
during
event
initiation
may
lead
to
power
and
processor
brown
‐
out
conditions,
resulting
in
recovery
failure.