Mooney M20K - Page 101

MOONEY
AIRCRAFT
CORPORATION
M20K
SERVICE
AND
MAINTENANCE
MANUAL
U6.
Comparator
U7
monitors
the
output
of
a
Hall
Effect
functions
in
a
similar
manner
to
the
Left
AnematorRow
current
sensor
which
measures
the
left
altemator
VolWOver
Volts
circuit
with
the
single
exception
that
output
current.
The
signal
from
the
Hall
Effect
sensor
is
this
circuit
does
not
detect
low
aircraft
bus
voltage.
compared
with
a
predetermined
bias
set
by
adjusting
When
low
current
is
detected
the
annunciator
channel
R59.
It
should
be
noted
that
the
divider
ofR74,
R59,
flashes,
and when
overvoltage
tn’pped
is
detected
the
and
R75
actually
consists
of
R74,
R59
in
pai~ailel
with
annunciator
channel
illuminates
steady.
Comparator
U8
R83
(see
f=igure
7),
and
R75.
The
points
labeled
monitors
the
output
of
a
Hall
Effect
current
sensor
ALTBIASH
and
ALTBIASL
are
common
to
both
left
and
which
measures
the
right
anemator
output
current.
The
right
aitemator
sense
circuits.
As
LAINPUT
is
reduced
signal
from
the
Hall
Effect
sensor
is
compared
with
a
in
value
below
the
voltage
set
by
R59
the
comparator
predetermined
bias
set
by
adjusting
R83.
h
should
U7
goes
high
and
again
drives
012
into
conduction
again
be
noted
that
the
divider
of
R74,
R59,
and
R75
through
the
bias
network
R70,
CR23,
and
CR28,
thus
(see
Fig
6)
actually
consists
of
R74,
R59
in
parallel
with
illuminating
DS10,
but
the
signal
FLASH
will
remove
R83,
and R75.
The
points
labeled
ALTBIASH
and
this
drive
signal
as
the
flasher
cycles,
thus
flashing
ALTBIASL
are
common
to
both
left
and
right
altemator
DS10.
A
*28
VDC
signal
applied
to
LOVERRIDE
also
sense
circuits.
As
RAINPUT
is
reduced
in
value
below
drives
Q12
into
conduction
regardless
of
the
states
of
the
voltage
set
by
R83
the
comparator
Us
goes
high
either
comparator
U6
or
U7.
Similarly
TEST+
will
dn’ve
and
drives
013
into
conduction
through
the
bias
Q12 into
conduction
regardless
of
the
states
of
either
network
R82,
and
CR33,
thus
illuminating
DS11,
but
comparator
U6
or
U7.
The
channel
Left
A~tematorRow
the
signal
FLASH
will
remove
this
dn~ve
signal
as
the
Volts/Over
Volt
does
not
dim.
The
van’able
resistor
R59
flasher
cycles
thus
Rashing
DS11.
A
+28
VDC
signal
Is
accessible
through
the
front
of the
annunciator
on
IAl
applied
to
ROVERRIDE
also
drives
Q13
into
Part
Number
9500326001,
while
an
equivale?t
variable
conduction
regardless
of
the
state
of
comparator
U8.
resistor
mounted
e>demal
to
the
annunciator
Is
required
Similarly
TEST+
will
drive
013
into
conduction
forthe
9500326000
annunciator.
regardless
of the
state
of
comparator
U8.
The
channel
Right
Aitemator/Over
Volt does
not
dim.
The
van’able
8.0
RIGHT
ALTERNATOWOVER
VOLT
resistor
R83
is
accessible
through
the
front
of
the
The
Right
Alternator/Over
Volts
circuits
are
shown
in
annunciator
on
IAl
Part
Number
9500326001,
while
an
I=igure
7.
This
channel
is
designed
to
accept
two
equivalent
variable
resistor
mounted
e>demal
to
the
signals,
the
analog
signal
RAINPUT
from a
current
annunciator
is
required
for
the
9500326000
sensor,
and
the
+28
VDC
signal
ROVERRIDE
from
the
annunciator.
overvoltage
tn’pped
output
on
the
n’ght
alternator
regulator.
This
circuit
is
an
exact
duplicate
of
and
2VDC
R77
4.
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RU3i(jK8VDC
DS11
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INCUOS
CR
U8
INcYe5
4
L3
CL3
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l/o-(1C3382
RBi
R88
)6-
OK
INPUT
CR 31
1BUO~MISSS
1HCe8S
OVERRIDE
TEST+
FIGURE
7
~tTERNRTOR/OUER
VOLT
24-39-06
22
OLDWILLWAYNE