94
Introduction
Introduction
The application range of pulse transformers is very broad. In most
cases, a signal or a control pulse must be transmitted between
electrically isolated circuits. This problem exists in the activation of
thyristors and triacs, or in the operation of FETs or IGBTs in high-
power switching circuits.
Another application involves electrical isolation in telephone switch-
boards and data transfer systems.
High Insulation Rating
When used in power electronics, the secondary side of pulse
transformers is normally at a high voltage potential. This requires a
high insulation strength for pulse transformers.
Complying with VDE 110 b, Part 1, the following test voltages between
the primary and the secondary circuits are required for transformers
of Protection Class I and choke coils, as a function of the working
voltage:
The measurement is made with the following circuit. The load resistance
RL is given for each type.
For a turns ratio of «1:1», the test voltage is 10 V; for «2:1» it is 20 V,
and so on.
Trigger Current It
The maximum trigger current is a guide value. For a given current, the
drop in voltage over the secondary winding resistance is smaller than
one volt.
The Voltage-Time Integral Us••
••
• Tw
The voltage-time integral is the product of the pulse height and width,
measured at half pulse height. The voltage-time integral is measured
on the secondary side during operation under no load.
The voltage-time integral Us ••
••
• Tw is measured according to the principle
of the following circuit. The same voltages as used for measuring the rise
time are used.
Test Voltage Uisol
The test voltages for TIMONTA pulse transformers depend on the type
of winding and the coating on the coil wire. Exact information concerning
each type is available in the technical specifications. The test voltage
is in each case considerably higher than that prescribed by VDE 110 b.
Partial Discharge Voltage Ue
Partial discharges during normal operation have little effect on the
operation of the circuit, but can accelerate the ageing of the pulse
transformer.
The glow discharge and the intermittent voltages are at least 50%
higher than the approved working voltages for all TIMONTA pulse
transformers. This provides the best assurance against long-term
damage.
Definition of the Rise Time Tr
Over the almost straight-line in the lower 2/3 of the rise curve, i.e. in
the area where the semiconductor is triggered with certainty, we draw
a line and measure the time from 10% to 90% of the overall pulse
height.
Working Voltage Test Voltage Uisol
[V] [V]
250 V 1500 V
500 V 2500 V
1000 V 3000 V
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Primary and Secondary Inductances Lp, Ls
Primary and secondary inductances are measured with a low-power
signal of 0.1 mA/10 kHz at 25°C. The tolerance is −30% / +50%.
The measured value can also vary up to ± 25% under temperature
variation in the range 0°C to 70°C.
Coupling Capacity Cc
The coupling capacity is measured between the primary and one
secondary winding. This value varies depending on the type of
winding. Bifilar windings, designed for models with faster rise times,
have higher coupling capacitances than the layer or selection
windings.
In general, this value is not important with regards transmission
properties. To guarantee effective interference protection from
the control electronics, however, the smallest possible coupling
capacity is desired.
Turn Ratio N
In the given turn ratios, the first figure always refers to the primary
winding. Hence a «1:1» pulse transformer has the same number of
winding on both the primary and the secondary windings. The turn
ratio «3:1:1» stands for one primary and two secondary windings
with a transformation ratio of three to one between the primary
and the secondary windings.
On request, we can also supply pulse transformers with turn ratio
not specified in our products lists.
UL-Approbation
The plastic cases and the potting resin of all TIMONTA pulse trans-
formers are fire resistant in compliance with UL 94 V-0.
Abbreviations used in the technical data
Example of application
Power transistor in pulse operation
Code
Pulse transf.
T.. conventional
S.. SMD
N.. normal
R.. small rise time
A.. 1:1 / B.. 2:1/C.. 3:1
F.. 1:1:1 / H.. 3:1:1
Brandlabel TIMONTA
CK:1..≤10pF / 2..>10...≤100pF
Case code
Trigger current
Inductance
I T N F - 0 2 3 5 - D1 03
]
]
]
∫∫
∫∫
∫Udt Voltage-time integral (Us•Tw)
TrPulse rise time
PmPower dissipation at ambient 50°C
PPower dissipation at elevated temperature
ϑϑ
ϑϑ
ϑaAmbient temperature
ItTrigger current
CcCoupling capacity
RLTest load resistance (secondary)
RpPrimary resistance
RsSecondary resistance
LpPrimary inductance = Ls x N
2
LsSecondary inductance
Ueff Working voltage primary-secondary in VRMS
Uisol Test voltage
NTurns ratio
96
Pulse Transformer for Conventional Board Assemblies
IT Series, Turns Ratio 1:1, 2:1 and 1:1:1
TIMONTA pulse transformers have been specially developed for the
control of semi-conductors in power electronics.
Application possibilities are numerous and various and deal mainly
with triggering Thyristors, Triacs, power transistors and IGBTs.
In most cases there is a suitable model available from the bal-
anced component series for the development of dependable and
economical circuits.
The desired specifications are archived through specifically se-
lected materials and well-developed winding technology, and pro-
vide the following advantages:
•Electrical separation of circuit and power circuit, with a high
insulation rating of at least 3.2 kV between the primary and
secondary windings.
•Electrical separtion with high insulation rating (at least 500 V)
between secondary windings.
•Simple circuit layout, since there is sufficient power available
to the circuit. This makes special extra provision on the power
supply side unnecessary.
•Small coupling capacitances between primary and secondary
windings limit transient feedback from the power supply side
to the control electronics.
•The defined partial discharge voltage guarantees an effectively
unlimited serviceable life.
Voltage-time integral Us x Tw: 150 - 400 Vµs
Pulse rise time Tr: 0.05 - 1.5 µs
Working voltage: Ueff ≤≤
≤≤
≤ 600 VAC
Partial discharge voltage: Ue ≤≤
≤≤
≤ 1.5 x Ueff
Climatic category: 25/100/21 acc. to IEC 60068-1
Plastic case: UL 94 V-0
Potting resin: UL 94 V-0
On request, models with other turn ratios are available
Table data at ϑa 25°C
(1) Pm@ ϑa 50°C; Power derating over 50°C: P= Pm x (100 -ϑa) / 50
Technical Data
ITNF-0135-D101 150 0.9 100 0.1 0.5 0.5 10 3.5 0.5 35 - 4 1 : 1 : 1 1.1 Universal
ITRF-0235-D101 150 0.05 100 0.1 1 0.5 40 3.2 0.5 35 - 4 1 : 1 : 1 1.1 TR ≤ 0.05 µs
ITNF-0249-D101 250 1 100 0.1 0.5 0.5 20 3.5 0.7 49 - 4 1 : 1 : 1 1.4 Universal
ITRF-0249-D101 250 0.05 100 0.1 0.4 0.5 70 3.2 0.7 49 - 4 1 : 1 : 1 1.2 TR ≤ 0.05 µs
ITNF-0239-D202 350 1.5 60 0.17 0.4 0.4 20 3.5 1.0 39 - 4 1 : 1 : 1 1.6 Universal
ITRF-0239-D502 350 0.5 20 0.5 0.4 0.4 90 3.2 1.0 39 - 4 1 : 1 : 1 1.6 TR ≤ 0. 5 µs
Description ∫Udt TrRLItRPRSCcUisol Pm (1) Case Turn ratio LsApplication
[Vµs][µs][Ω][A][Ω][Ω][pF][kV~][W][N][mH]
ITNA-0235-D103 200 0.9 100 0.1 1 1 20 3.5 0.5 35 - 3 1 : 1 2.8 Universal
ITRA-0235-D103 200 0.05 100 0.1 1.5 1 80 3.2 0.5 35 - 3 1 : 1 2.8 TR ≤ 0.05 µs
ITNA-0249-D104 300 1 100 0.1 0.7 0.7 20 3.5 0.7 49 - 3 1 : 1 3.5 Universal
ITRA-0249-D104 300 0.05 100 0.1 0.7 0.7 90 3.2 0.7 49 - 3 1 : 1 3.5 TR ≤ 0.05 µs
ITNA-0239-D202 400 1 60 0.17 0.4 0.4 20 3.5 1.0 39 - 3 1 : 1 2.2 Universal
ITRA-0239-D502 400 0.1 20 0.5 0.4 0.4 100 3.2 1.0 39 - 3 1 : 1 2.2 TR ≤ 0. 1 µs
ITNB-0249-D101 250 1 100 0.1 1.0 0.5 20 3.5 0.7 49 - 3 2 : 1 1.6 Universal
ITRB-0249-D101 250 0.05 100 0.1 1.0 0.5 70 3.2 0.7 49 - 3 2 : 1 1.4 TR ≤ 0.05 µs
ITNB-0239-D202 350 1.5 60 0.17 0.8 0.4 20 3.5 1.0 39 - 3 2 : 1 1.8 Universal
ITRB-0239-D502 350 0.5 20 0.5 0.8 0.4 90 3.2 1.0 39 - 3 2 : 1 1.8 TR ≤ 0. 5 µs
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Case 35 35-3 35-4
Case 49 49-3 49-4
Case 39 39-3 39-4
Examples of applications
Firing of antiparallel Thyristors (SCR's) by means of unijunction and
transistor amplifiers
Triac phase angle control
Conventional Cases
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Pulse Transformers for SMD-Assemblies
IS Series, Turns Ratio 1:1, 2:1 and 1:1:1
Voltage time integral Us x Tw: 150 - 400 Vµs
Pulse rise timeTr: 0.05 - 1.5 µs
Working voltage: Ueff ≤≤
≤≤
≤ 600 VAC
Partial discharge voltage: Ue ≤≤
≤≤
≤ 1.5 x Ueff
Climatic category: 25/100/21 acc. to IEC 60068-1
Plastic case: UL 94 V-0
Potting resin: UL 94 V-0
On request, models with other turn ratios are available.
Table data at ϑa 25°C
(1) Pm@ ϑa 50°C; Power derating over 50°C: P= Pm x (100 -ϑa) / 50
Technical Data
TIMONTA pulse transformers have been specially developed for the
control of semi-conductors in power electronics.
Application possibilities are numerous and various and deal mainly
with triggering Thyristors, Triacs, power transistors and IGBTs.
In most cases there is a suitable model available from the bal-
anced component series for the development of dependable and
economical circuits.
The desired specifications are archived through specifically se-
lected materials and well-developed winding technology, and pro-
vide the following advantages:
•Electrical separation of circuit and power circuit, with a high
insulation rating of at least 3.2 kV between the primary and
secondary windings.
•Electrical separation with high insulation rating (at least 500 V)
between secondary windings.
•Simple circuit layout, since there is sufficient power available
to the circuit. This makes special extra provision on the power
supply side unnecessary.
•Small coupling capacitances between primary and secondary
windings limit transient feedback from the power supply side
to the control electronics.
•The defined partial discharge voltage guarantees an effectively
unlimited serviceable life.
Description ∫Udt TrRLItRPRSCcUisol Pm(1) Case Turn ratio LsApplication
[Vµs][µs][Ω][A][Ω][Ω][pF][kV~][W][N][mH]
ISNA-0235-D103 200 0.9 100 0.1 1 1 20 3.5 0.5 35 - 3S 1 : 1 2.8 Universal
ISRA-0235-D103 200 0.05 100 0.1 1.5 1 80 3.2 0.5 35 - 3S 1 : 1 2.8 TR ≤ 0.05 µs
ISNA-0249-D104 300 1 100 0.1 0.7 0.7 20 3.5 0.7 49 - 3S 1 : 1 3.5 Universal
ISRA-0249-D104 300 0.05 100 0.1 0.7 0.7 90 3.2 0.7 49 - 3S 1 : 1 3.5 TR ≤ 0.05 µs
ISNA-0239-D202 400 1 60 0.17 0.4 0.4 20 3.5 1.0 39 - 3S 1 : 1 2.2 Universal
ISRA-0239-D502 400 0.1 20 0.5 0.4 0.4 100 3.2 1.0 39 - 3S 1 : 1 2.2 TR ≤ 0. 1 µs
ISNB-0249-D101 250 1 100 0.1 1.0 0.5 20 3.5 0.7 49 - 3S 2 : 1 1.6 Universal
ISRB-0249-D101 250 0.05 100 0.1 1.0 0.5 70 3.2 0.7 49 - 3S 2 : 1 1.4 TR ≤ 0.05 µs
ISNB-0239-D202 350 1.5 60 0.17 0.8 0.4 20 3.5 1.0 39 - 3S 2 : 1 1.8 Universal
ISRB-0239-D502 350 0.5 20 0.5 0.8 0.4 90 3.2 1.0 39 - 3S 2 : 1 1.8 TR ≤ 0. 5 µs
ISNF-0135-D101 150 0.9 100 0.1 0.5 0.5 10 3.5 0.5 35 - 4S 1 : 1 : 1 1.1 Universal
ISRF-0235-D101 150 0.05 100 0.1 1 0.5 40 3.2 0.5 35 - 4S 1 : 1 : 1 1.1 TR ≤ 0.05 µs
ISNF-0249-D101 250 1 100 0.1 0.5 0.5 20 3.5 0.7 49 - 4S 1 : 1 : 1 1.4 Universal
ISRF-0249-D101 250 0.05 100 0.1 0.4 0.5 70 3.2 0.7 49 - 4S 1 : 1 : 1 1.2 TR ≤ 0.05 µs
ISNF-0239-D202 350 1.5 60 0.17 0.4 0.4 20 3.5 1.0 39 - 4S 1 : 1 : 1 1.6 Universal
ISRF-0239-D502 350 0.5 20 0.5 0.4 0.4 90 3.2 1.0 39 - 4S 1 : 1 : 1 1.6 TR ≤ 0. 5 µs
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Case 35S 35-3S 35-4S
Case 49S 49-3S 49-4S
Case 39S 39-3S 39-4S
Possible solder land pattern for SMD mounting
Case 35S 49-S 39-S
Case for SMD mounting
