BFGoodrich PS-823 - 5. Functional Description; 6. Specifications

BFGoodrich Avionics Systems,
Inc.
Component
Maintenance Manual
P/N 501-1075-()
5. Functional Description
Model
PS-823
Emergency
Power
Supply
consists
of an adjustable
oscillator
that
drives four
power
transistors
in an H-bridge
configuration. The
current
flow between
them
passes
through a
transformer that develops a square
wave
signal.
Part
of the
output
is
stepped-down
and rectified to
provide
charging current to
internal batteries. A
timing circuit
maintains
added
shifted-phase
voltage for
starting
3-phase
gyro motors. The inverter
within Model
PS-823
will
not
operate
if both
the
aircraft
and internal
battery voltage are
below
20.0Vdc. Normal input voltage to
the inverter
is
between
22.0 to
32.0Vde;
from the
aircraft
DC
bus
or
the
Model
PS-823
internal batteries.
The
PS-823E,
F, G
and
H
models
have
some internal
rewiring and
removal
of
the
5 Amp
fuse and
fuseholder
to
accommodate
revision of
the
manual
emergency
bypass
circuits
to
comply with FAA
requirements.
6.
Specifications
Weight:
PS-823A/C/E/G,
7.6
pounds*
PS-823B/D/F/H,
11.2
pounds*
*(Add
0.4
pounds for /T units)
Dimensions
(Including
handle)
(Inches)
2.4W x
7.62H x
14.llL
(cm)
6.2W x
19.4 x
36L
Rack Size: 1/4 ATR
Short. Rack
No.
404-.25-S-1/DPXB-0
Input:
28.0Vde nominal (4.6
Amperes
per 100VA output). Normal operating
range
22.0-
32.0Vde
Output: 115.0Vac
+7%,
-10%
for
maximum load of
100Va.
26.0Vac
+7%,
-10%
for maximum
load of
20Va
4.6Vac
+7%,
-10%
for
maximum
load of 10Va
Additional
5% tolerance,
26 and
32Vde inputs
24Vde
minimum
with
fully charged
batteries and inverter
operating
Frequency:
400 ±8Hz
for
20.0-32.0Vde
input
Waveshape:
Square wave
Efficiency
75% at full rated load
Temperature:
-30
to
+55
degrees
C
(Batteg
only)
-55
to
+71
degrees C
(Inverter)
Humidity: 0 to
95%
Batteg
Charger: Automatic as long as
inverter
operates
35mA
from
aircraft 28.0Vde
145mA from
inverter
RFI: Intemal
suppression on output
and 28.0Vde
line.
Meets Cat. A of
TSO-C73
and
Cat.
A/Z of
DO-138.
msmljtp202DescriptOpsdiskl59
24-20-03
Page 2
Revision
A June
30,
1999