AEE03A48-7 Astec Power, AEE03A48-7 Datasheet - Page 23

• Manufacturer Part Number: AEE03A48-7
• Manufacturer: Astec Power

TEL:
FAX:
USA
1-760-930-4600
1-760-930-0698
Parallel Power Distribution
Figure 15 shows a typical parallel power distri-
bution design. Such designs, sometimes called
daisy chains, can be used for very low output
currents, but are not normally recommended.
The voltage across loads far from the source
can vary greatly depending on the IR drops
along the leads and changes in the loads clos-
er to the source. Dynamic load conditions
increase the potential problems.
Radial Power Distribution
Radial power distribution is the preferred
method of providing power to the load. Figure
16. shows how individual loads are connected
directly to the power source. This arrangement
requires additional power leads, but it avoids
the voltage variation problems associated with
the parallel power distribution technique.
Mixed Distribution
In the real world a combination of parallel and
radial power distribution is often used. Dynamic
and high current loads are connected using a
radial design, while static and low current loads
can be connected in parallel. This combined
approach minimizes the drawbacks of a parallel
Parallel Power Distribution
Radial Power Distribution
Mixed Distribution
Fig.15 Parallel Power Distribution
Fig.16 Radial Power Distribution
A A
A A
1 1
1 1
+Vout
E E
E E
-Vout
8 8
8 8
+Vout
E E
E E
-Vout
V V
V V
R
d d
R
d d
L L
G
L L
L
= Lead Resistance
= Ground Lead Resistance
c c
c c
I 1 + I 2 + I 3
R
R
o o
o o
L1
G1
w w
w w
t t
t t
R
R
Load 1
R
R
o o
G1
G
o o
L
L1
= Lead Resistance
= Ground Lead Resistance
Load 1
P P
P P
Europe
44-(0)1384-842-211
44-(0)1384-843-355
3 3
3 3
o o
o o
6 6
6 6
w w
R
R
w w
V V
V V
L2
G2
I 2 + I 3
e e
e e
d d
d d
Load 2
R
R
L2
G2
r r
r r
c c
c c
Load 2
H H
H H
& &
& &
i i
i i
g g
g g
R
R
L3
G3
3 3
3 3
h h
I 3
h h
6 6
6 6
Load 3
V V
V V
E E
E E
R
R
Load 3
L3
G3
d d
d d
f f
f f
f f
f f
c c
c c
i i
i i
c c
c c
t t
t t
i i
i i
o o
o o
e e
e e
n n
n n
Asia
852-2437-9662
852-2402-4426
7 7
7 7
c c
c c
5 5
5 5
y y
y y
V V
V V
d d
S S
d d
S S
design when a purely radial design is not feasi-
ble.
Redundant Operation
A common requirement in high reliability sys-
tems is to provide redundant power supplies.
The easiest way to do this is to place two con-
verters in parallel, providing fault tolerance but
not load sharing. Oring diodes should be used
to ensure that failure of one converter will not
cause failure of the second. Figure 18 shows
such an arrangement. Upon application of
power, one of the converters will provide a
slightly higher output voltage and will support
the full load demand. The second converter will
see a zero load condition and will “idle”. If the
first converter should fail, the second converter
will support the full load. When designing
redundant converter circuits, Shottky diodes
should be used to minimize the forward voltage
drop. The voltage drop across the Shottky
diodes must also be considered when deter-
mining load voltage requirements.
Redundant Operation
c c
c c
e e
e e
r r
r r
I I
I I
i i
i i
n n
n n
e e
e e
p p
p p
s s
s s
u u
u u
D D
Fig.17 Mixed Power Distribution
D D
+Vout
t t
t t
-Vout
+V
+V
, ,
-V
, ,
-V
C C
Fig.18 Redundant Operation
C C
www.astec.com
1 1
1 1
out
out
out
out
-
-
D D
5 5
D D
5 5
C C
C C
W W
R
R
W W
R
R
G1
G
L
L1
= Lead Resistance
= Ground Lead Resistance
C C
a a
Load 1
C C
a a
t t
t t
o o
o o
t t
t t
n n
n n
O O
O O
v v
v v
R
R
u u
u u
e e
e e
L2
G2
t t
r r
t t
r r
Load 2
p p
p p
t t
t t
e e
e e
u u
u u
r r
r r
t t
t t
s s
s s
R
R
L3
Load 3
Load
G3
R
R
L4
Load 4
G4
-23-