•
•
•
•
Encapsulated PC Transformers 1VA - 160VA
Power Transformers 1VA - 7.5kVA
Encapsulated Styles 1VA - 500VA
Special Mounting Configurations
magnetics
nt
In Standard Configurations and to Customer Specifications
nuvotem
Toroidal Transformers for Universal Application
SECTION 1
TALEMA PROFILE
The TALEMA International Group of
companies began in 1975 with the
formation of Talema Elektronik
GmbH in Munich, Germany. Five
years later, in 1980 Nuvotem Teo
started manufacturing in Ireland.
In 1988 Talema began production
in India and expanded into the
Czech Republic with the formation
of TALEMA spol s.r.o. in 1992.
Today the TALEMA International
Group, with three manufacturing
facilities and over 1000 employees
in Europe and the Far East, is a
world leader in the manufacture of
toroidal transformers and related
magnetic components. The vast
majority of the output, around 85%,
is of custom built products although
a comprehensive range of standard
devices is also available.
Application
TALEMA Toroidal Transformers meet
modern day requirements for a small
size, low magnetic interference field
transformer. Featuring a nearly ideal
physical construction, the design
engineer can expect excellent
performance. Small size and weight
(approximately 50% of conventional
transformers), extremely low noise and
low magnetic interference field make the
toroidal transformer ideal for compact
power supplies. Modern production
techniques make it possible to produce
toroidal transformers at practically the
same prices as conventional
transformers making them ideal for a
wide range of applications including:
• professional audio equipment
• computers and peripherals
• video monitors
• motor controls
• compact power supplies
• medical equipment
• instrumentation
• office machines
• industrial control equipment
• low voltage lighting
Volume and weight
The toroidal core has the optimal shape
for producing a transformer with the
minimum of material. Because the
quality of the core is such a vital
consideration for sensitive applications,
TALEMA has invested heavily to provide
extensive core manufacturing, annealing
and testing facilities.
All windings are symmetrically spread
over the entire core which makes the wire
length very short. A higher flux density
is possible as the magnetic flux is in the
same direction as the rolling direction of
the grain orientated core allowing
significant savings of volume and weight
. A higher current density can flow
through the wire as the whole surface of
the toroidal core allows efficient cooling
of the copper windings.
The iron losses of the toroidal core are
very small, typically 1.1W/kg at 1.7
Tesla and 50Hz, giving very small
magnetizing current, which contributes
to the excellent temperature rating of the
toroidal transformer.
Transformer hum
Because there are no air gaps, there are
no loose sheets which can vibrate. In
addition, the high quality of the grain
orientated silicone alloyed electric steel
makes the magnetostriction very low,
thus allowing the disturbing hum found
in most common types of transformers
to be almost completely eliminated.
Mounting details
For sizes up to 1000VA, a low cost
assembly can be made with a center-
ing washer and a center screw or bolt.
Transformers in the range of 15VA
through 500VA can also be potted in
standard Polyamid housings. All
transformers can also be center potted
- either with a center hole or with a
threaded insert.
Production program
Standard Distribution:
Open wound, Standard and Mini; Encap-
sulated; Print & DIN Rail Transformers -
230V primary, with ENEC KEMA-KEUR
marking (see page 8);
Customer standards:
Open wound, Encapsulated, Print, DIN
Rail, a wide range of secondary volt-
ages and mounting styles (see page 6);
Specials:
per customer specification (see page 5)
• Power: 1.6VA - 7.5kVA per phase
• Special sizes; extremely flat or small
diameter, i.e., up to 250VA with
96mm O.D. for European P.C. formats
• Electrostatic copper shielding
• Operating frequencies up to 20kHz
• Assembled 3 phase sets
• Magnetic shielding
• Potting in special housings for sizes
up to 1.2kVA
• Secondary voltages available up to
1kV
Note: All products manufactured by
the Talema Group are RoHS com-
pliant.
THE TALEMA GROUP • Toroidal Transformers for Universal Application
2
Safety
All TALEMA Stock Transformers from
15VA to 1kVA are delivered with ENEC
KEMA marking according to EN61558
(VDE 0570, EN61558) protection class
II, tested with 4500V
AC
between primary
and secondary windings. Special types
can be made as safety transformers
according to EN61558. This European
Standard replaces the generally known
VDE Standard 0570. Additionally. upon
request we supply toroidals according
to conventional standards, including UL,
CSA and others, for office equipment,
data processing, entertainment
electronics and medical instrumention.
Efficiency
The toroidal shape gives a significantly
higher efficiency compared to
conventional transformers of the same
size. The advantage is either an
increased output power with the same
size or a lower weight and smaller size
at the same output power.
I
nternationally Recognized
Quality Systems and Approvals
Factory / Process Approvals
ISO-9001 approved quality systems
ensure all internal processes run
smoothly and efficiently, from incoming
purchase orders through Resource
Planning, Scheduling and Production, to
the delivery of the finished products.
• NT Magnetics s.r.o., ISO-9001:2000,
Cert. No. 1210024333
• Talema Electronic (India) Pvt. Ltd.;
ISO-9001:2000, Cert. 9910001047
TS 16949:2002, 1211127793/01TMS
ISO-14001:2004, 1210427793TMS
Product Approvals
TALEMA-NUVOTEM has numerous
approvals covering a wide variety of
international standards, including both
standard and custom designed parts. By
working closely with equipment
designers and international test houses,
the TALEMA Groups’ engineering teams
can assist in ensuring swift and smooth
approval of equipment using its
transformers and inductors.
Family Recognitions
The TALEMA Group have invested
considerable time and effort to obtain
“Family Approvals” enabling automatic
recognition of custom transformers
without having to send each new design
to a certified test facility for approval,
saving the customer both time and
money.
UL Approvals
• UL506,
General Application
Transformers - Family approval to
3000VA for classes A & B
UL File No. E215495
• UL544,
Transformers for Medical and
Dental Equipment - Family approval
to 3000VA for classes A & B
UL File No. E218027
•
Insulation Systems with Temperature
Classes B, B1 & F, applicable to
transformers for both UL506 , UL544
and UL60601- UL File No. 217412
• UL1950,
Information Technology
Equipment, including Electrical
Business Equipment - 70000K
series PCB transformers
UL File No. E218027, Vol. 2
• UL6500,
Audio/Video and Musical
apparatus - 70000K series PCB
transformers - UL File No. E218027,
Vol. 2
• UL60601-1,
Medical Equipment -
Family approval to 3000VA for
classes A & B - (UL File No. E251176)
EN Approvals
TALEMA-NUVOTEM has the distinction
of being one of the very few toroidal
transformer manufacturers to have a
“General Approval” of custom designed
power transformers to EN61558.
• EN61588/VDE0570 -
Isolation
Transformers (Pri. 440V/Sec. 250V)
Family approval and custom designs
to 3000VA (“Non Short-circuit proof”)
Kema No. 2060938.02
• Safety Isolation Transformers
(Pri.440V / Sec. 50V) Family approval
and custom designs to 3000VA (“Non
Short-circuit proof”)
Kema No. 2060938.03
• Safety Isolation Transformers
(Pri.110-240V / Sec. 50V) Family
approval and custom designs to
300VA (“Non Inherently Short-circuit
proof”) Kema No. 2060938.01
•
EN60950/VDE0805/IEC950/
UL506/UL1950
- Family approval
for 70000K PCB Transformers (VDE
File No. 5803/ UL File No. E218027)
Talema toroidal transformers can
also be designed to meet the
following International Regulations
• VDE0750 (EN60601, IEC601)
Medical and Dental Equipment
• VDE0805 (EN60950, IEC950)
IT installations including office
equipment
• VDE0860 (EN60065, IEC65)
Electrical equipment for domestic
use
Delivery
Various production facilities allow fast
delivery and ensure continuity of supply
to our customers.
Germany: Int.+4989-841 00-0 • Ireland: Int.+35 374-954 8666 • Czech Rep: Int.+420 377 - 338 351 • India: Int.+91 427-244 1325
THE TALEMA GROUP
• Worldwide Toroidal Specialists
http://www.talema-nuvotem.com & www.talema.net
3
In-rush Current
Due to lack of air gaps, toroidal
transformers generally have a higher
inrush current than normal transformers.
For mains fuses we recommend the use
of slow blowing types, especially for
output power rates in excess of 500VA.
Frequency Range
TALEMA Standard Transformers are
designed for operating frequencies
between 48 Hz and 60Hz and operate
up to 450 Hz maximum. With
increasing frequency, the transformer
size decreases accordingly. Core
materials for frequencies up to 100kHz
are available in materials such as thin
tape wound nickel alloy, molded powder
or sintered ferrite.
Autotransformers
An autotransformer allows smaller
dimensions and a more economical over
all design in cases where galvanically
separated windings are not required
(graph 1)
Graph 1 (Autotransformers)
U max.
Transf. power rating
U min.
=
P
out
P
out
=
x
Duty Cycle
A smaller transformer can be used if the
load is intermittent. Because the output
power in this case significantly exceeds
the norminal power, the secondary
voltage drops below the voltages shown
on page 8. The voltage drop increases
proportionately with the current being
drawn (graph 3).
Graph 3 (Duty Cycle)
Efficiency
Graph 4 shows typical efficiency which
can be expected as a function of the
power relationship P
out
/ P
nom
and
transformer size.
Graph 4 (Efficiency)
η
%
100
90
80
70
1 kVA
300 VA
30 VA
t
T
Pnom <P
load
t
T
0.2
0.4
0.6
0.8
1.0
P
out
/ P
nom
Temperature rise
As can be seen from graphs 5 and 6,
TALEMA Standard Toroidal Transformers
are designed for a temperature rise of
60°C to 70°C at nominal load. When
choosing a transformer size, the ambient
temperature and heat sink coefficient of
the mounting place must be taken into
consideration. Graphs 5 & 6 show the
typical temperature change which
occurs as a function of output power or
overload.
Graph 5
(Ambient Temperature)
P
out
/ P
nom
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
20
40
60
80 100 120 °C
Graph 6
(Temperature Rise)
P
out
/ P
nom
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
20
40
60
80
100
^T °C
Umax. - Umin.
Umax.
Output Power
Umin.
Umax.
[VA]
[VA]
< 0.5
Optimal Size =
0
0
Rectifying
Graphs 7 and 8 give formulas for calculation of approximate
values of the transformers and are primarily dependent on
the size of the loading capacitor to be used. The applied
form factor “F” is rated between 1.1 for smaller capacitors
and up to 2.5 for for relatively large capacitors.
Voltage Drop
The secondary voltages and currents are valid as
shown on page 10 for normal output power. At partial
load the output voltage, as a function of transformer
size, will be accordingly higher. Graph 2 shows the
% voltage increase for TALEMA Standard Toroidal
Transformers at no load conditions.
Graph 2 (Voltage Drop)
% Voltage Drop
20
15
10
5
[VA]
15
100
300
500
1000
2000 5000
Graph 7
(Rectifying)
I
AC
C
U
AC
U
DC
I
DC
R
L
Graph 8
(Rectifying)
I
AC
U
AC
U
AC
C
I
DC1
U
DC1
R
L1
U
AC
~
U
DC
+ 2 [V
]
~
eff
2
C
I
AC
~
F • I
DC
[ A ]
I [A]
t • I [ Sec
-1
]
C
[F]
U
AC
F
U
DC2
I
DC2
R
L2
~
U
DC
+ 1 [V
]
~
eff
2
~
ripple
^
U
~
I•t
C
t Bridge = 1 / 100 at 50 Hz
t Bridge = 1 / 120 at 60 cycles
I
AC
~
~
I
DC12
+ I
DC22
[ A ]
2
THE TALEMA GROUP • Toroidal Transformers for Universal Application
4
Special Transformers
If we do not have a customer or stock
standard
which
meets
your
requirements, we can offer expert
engineering assistance to develop the
special transformer you need. We stock
the materials for the sizes shown on
table 2 (page 6) and can supply other
sizes as well on short notice.
Capabilities
• Power: 1VA - 7500VA / phase
• Assembled 3 phase sets
• Special sizes - extremely flat or small
diameter
• Static copper shielding
• Magnetic shielding
•
•
•
•
•
•
Operating frequencies to 20kHz
Potting in special housings tp 1200VA
Secondary voltages to 1000 V
Up to 8 primaries or taps
Up to 30 secondaries or taps
Reinforced dielectric to 5000V
eff
Table 1
C o p p e r L o ss
Power
VA
5
10
15
20
30
50
50
80
80
120
160
160
225
250
250
300
375
375
500
625
625
800
1000
1000
1300
1300
1600
1900
2200
2500
2500
2800
3200
3700
4400
5000
6000
7500
Core Loss
W
0.16
0.14
0.21
0.26
0.26
0.39
0.43
0.65
0.51
0.76
1.00
0.97
1.30
1.30
1.20
1.70
2.10
1.90
2.50
3.10
2.90
3.80
4.80
4.40
5.70
5.90
7.30
8.80
10.30
11.70
13.30
13.30
15.60
17.80
16.80
22.40
25.20
28.60
T=
20°C
W
0.6
1.1
1.8
2.4
3.6
4.7
4.7
8.4
8.4
9.9
14.9
14.9
15.2
15.7
15.7
16.1
20.0
20.0
22.1
27.9
27.9
30.0
30.7
30.7
42.9
44.3
45.0
47.1
55.3
59.3
59.3
68.0
70.0
73.0
84.0
87.0
97.0
110.0
Dimensions mm
(typical)
T=
120°C
W
0.8
1.6
2.5
3.3
5.0
6.6
6.6
11.8
11.8
13.9
20.8
20.8
21.3
22.0
22.0
22.5
28.0
28.0
31.0
39.0
420
42.0
43.0
43.0
60.0
62.0
63.0
66.0
76.0
83.0
83.0
95.0
97.0
102.0
116.0
120.0
135.0
153.0
O.D.
Ø
51
58
60
60
70
70
80
80
92
92
92
104
112
95
135
115
115
135
135
140
160
160
160
200
160
200
200
200
205
205
245
245
245
245
275
275
290
320
Height
27
29
31
36
32
44
35
45
36
45
58
44
48
69
38
58
68
48
60
70
48
60
72
48
82
65
75
85
90
105
80
80
90
100
95
105
120
100
Weight
kg
0.1
0.3
0.3
0.4
0.5
0.7
0.7
1.0
1.0
1.3
1.5
1.6
2.1
2.3
2.3
2.5
3.0
3.0
3.9
4.6
4.6
5.5
6.9
6.9
8.8
8.8
10.5
12.0
13.5
16.6
15.2
16.0
18.6
21.2
24.5
28.0
31.0
39.0
Germany: Int.+4989-841 00-0 • Ireland: Int.+35 374-954 8666 • Czech Rep: Int.+420 377 - 338 351 • India: Int.+91 427-244 1325
THE TALEMA GROUP
• Worldwide Toroidal Specialists
http://www.talema-nuvotem.com & www.talema.net
5
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