STP-2000-2115 Signal Transformer Inc., STP-2000-2115 Datasheet - Page 62

• Manufacturer Part Number: STP-2000-2115
• Description: Power Transformers & High Frequency Magnetics Your One Source For All Your Magnetics Needs!
• Manufacturer: Signal Transformer Inc.

How to Specify Power Transformer & Filter Parameters
3.
4.
How to specify power transformer
& filter ratings
rectifier using a capacitive filter and is the most common
selection for moderate power, regulated DC supplies.
The following assumptions can safely be made:
the transformer secondary voltage:
V NOM
V LOWLINE
the ratio of the nominal AC line voltage to the required low line conditions.
supply requiring an output of 5V DC at 2A DC to operate
down to an input voltage of 95V RMS.
How to specify power transformer
& filter ratings
rectifier using a capacitive filter and is the most common
selection for moderate power, regulated DC supplies.
The following assumptions can safely be made:
the transformer secondary voltage:
V NOM
V LOWLINE
the ratio of the nominal AC line voltage to the required low line conditions.
supply requiring an output of 5V DC at 2A DC to operate
down to an input voltage of 95V RMS.
www.signaltransformer.com
Full-Wave Bridge
Uses full secondary winding continuously with no requirement for center-tap. This bridge requires 4 diodes. As can
be seen above, the choice between FWCT and bridge configurations is a tradeoff. The bridge rectifier has the best
transformer utilization but requires the use of 4 diodes. The extra diodes result in twice the diode voltage drop of a
FWCT circuit so that the FWCT is usually preferable in low voltage supplies.
The remaining choice is that of a rectifier circuit configuration. The most common single phase circuits are:
Dual Complementary Configuration (full wave center tap with 4 diodes)
The dual complementary rectifier circuit is the combination of two FWCT circuits and offers a very efficient way of
obtaining two identical outputs of reversed polarity sharing a common ground. It is also termed a “center-tapped
bridge rectifier.”
The diagram below represents a full wave center-tapped Rectifier using a capacitive filter. This represents the most
common choice for moderate power, regulated DC supplies.
The following assumptions can safely be made:
1. VREG is approximately 3 volts DC or greater
2. VRECT is about 1.25 volts DC.
3. VRIPPLE is about 10% VDC peak.
The following formula may be used to determine transformer secondary voltage:
The diagram below represents a full-wave center-tapped
The following formula may be used for determining
A sample illustration of the above will be shown for a
V OUT = 5V
V REG = 3V
V RECT = 1.25V
V RIPPLE = 0.5 (1V p-p)
The diagram below represents a full-wave center-tapped
The following formula may be used for determining
A sample illustration of the above will be shown for a
V OUT = 5V
V REG = 3V
V RECT = 1.25V
V RIPPLE = 0.5 (1V p-p)
V AC = 9.75 x 115 x 1 = 9.27 V AC
Full-Wave Bridge
Full Wave Center Tap
0.9
is
is
95
M2
rectifier circuit” is the
combination of two FWCT
circuits and is a very efficient
way of obtaining two identical
outputs of reversed polarity
sharing a common ground.
It is also called a “center-
tapped bridge rectifier.”
How to specify power trans
& filter ratings
rectifier using a capacitive filter and is the most common
selection for moderate power, regulated DC supplies.
The following assumptions can safely be made:
the transformer secondary voltage:
V NOM
V LOWLINE
the ratio of the nominal AC line voltage to the required low line conditions.
supply requiring an output of 5V DC at 2A DC to operate
down to an input voltage of 95V RMS.
rectifier circuit” is the
combination of two FWCT
circuits and is a very efficient
way of obtaining two identical
outputs of reversed polarity
sharing a common ground.
It is also called a “center-
tapped bridge rectifier.”
The “dual complementary
The diagram below represents a full-wave center-tapped
The following formula may be used for determining
A sample illustration of the above will be shown for a
V OUT = 5V
V REG = 3V
V RECT = 1.25V
V RIPPLE = 0.5 (1V p-p)
V AC = 9.75 x 115 x 1 = 9.27 V AC
Therefore, the transformer secondary voltage can be
The “dual complementary
Dual Complementary Rectifier
1. V REG is approx-
2. V RECT is about
3. V RIPPLE is
1. V REG is approx-
2. V RECT is about
3. V RIPPLE is
imately 3 volts DC
or greater.
1.25 volts DC.
about 10% VDC
peak.
imately 3 volts DC
or greater.
1.25 volts DC.
about 10% VDC
peak.
0.9
is
7
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[e-mail] • [e-mail]
95
M2
©2008 Signal Transformer — Specification subject to change without notice. 07.08
rectifier circuit” is the
combination of two FWCT
circuits and is a very efficient
way of obtaining two identical
outputs of reversed polarity
sharing a common ground.
It is also called a “center-
tapped bridge rectifier.”
The “dual complementary
DC supply) the transformer RMS curre
for FWCT
for bridge
Dual Complementary Supply
a dual complementary supply for ± 15
V OUT = ±15
V REG = 3
V RIPPLE = 0.75 (1.5 V p-p)
V AC =
(15 + 3 + 1.25 + 0.75) x 115 x 1 = 19V
1 AC = 1.8 x 100 mA = 180 mA RMS
RMS. Possible Signal parts would be S
PC-40-250. A precautionary calculation
That is, the increase in voltage at the fi
regulator) caused by a high line conditi
highest line voltage to be 130 V AC the
output (compared to low line) would ris
In the 5V supply, for instance, the follow
*Even though we have dropped choke input filters from th
DC supply) the transformer RMS cur
for FWCT
for bridge
Dual Complementary Supply
a dual complementary supply for ± 1
V OUT = ±15
V REG = 3
V RIPPLE = 0.75 (1.5 V p-p)
V AC =
(15 + 3 + 1.25 + 0.75) x 115 x 1 = 19V
1 AC = 1.8 x 100 mA = 180 mA RMS
RMS. Possible Signal parts would be
PC-40-250. A precautionary calculatio
That is, the increase in voltage at the
regulator) caused by a high line condi
highest line voltage to be 130 V AC th
output (compared to low line) would ri
In the 5V supply, for instance, the follo
V AC = 130 x 9.27 = 12.7V
they are included for reference.
1. V REG is approx-
2. V RECT is about
3. V RIPPLE is
*Even though we have dropped choke input filters from
For instance, in our particular exam
The total transformer specification
One more common example will be
The transformer secondary rating is
500 Bayview Avenue, Inwood, NY 11096
they are included for reference.
For instance, in our particular exa
The total transformer specification
One more common example will b
The transformer secondary rating i
imately 3 volts DC
or greater.
1.25 volts DC.
about 10% VDC
peak.
Full-Wave
Center-Tap
Full-Wave
Center-Tap
Full-Wave
Bridge
Full-Wave
Bridge
95
0.9
Full-Wave
Rectifier
Center-Tap
Full-Wave
Center-Tap
Full-Wave
Bridge
Full-Wave
Bridge
0.9
Circuit
bridge
FWCT
Rectifier
Type
Circuit
bridge
FWCT
Type
VRECT = 1.25
VRECT = 1.25
Choke Input
Capacitor
Input
Choke Input
Capacitor
Input
Filter Type*
Choke Input
Capacitor
Input
Choke Input
Capacitor
Input
Filter Type*
18.5 CT @ 2.4A
RMS = 43.2 VA
RMS = 36 VA
18.5 CT @ 2.4A
10.5 @ 3.6A
RMS = 43.2 VA
Secondary
1.2 x 2 = 2.4 A
1.8 x 2 = 3.6 A
RMS = 36 VA
10.5 @ 3.6A
Secondary
1.2 x 2 = 2.4 A
1.8 x 2 = 3.6 A
Rating
Rating
95 M2
95 M2
0.7 x DC Cur
1.2 x DC Cur
DC Current
1.8 x DC Cur
0.7 x DC Cu
1.2 x DC Cu
DC Current
1.8 x DC Cu
DC sup
for FW
for brid
Dual C
a dual
V OUT
V REG
V RIPP
V AC =
(15 + 3
1 AC =
RMS. P
PC-40-
That is
regulat
highes
output
In the 5
V AC =
In the d
Secondar
*Even th
Second
they are
Requir
For
The
One
The
Requ
Poss
ST-7
Ra
Pos
241
ST
R
2
7