High Voltage
High Voltage
Thick Film Resistors
Thick Film Resistors
F
Series
F Series
F
Series
Welwyn Components
Screw Terminations:
Styles TU and KU
Screw Terminations:
Styles TU and KU
Material:
Turned brass
Material:
Turned brass
Screw Thread:
All caps are tapped UNF - 10 x 4.2
Screw Thread:
All caps are tapped UNF - 10 x 4.2
deep. UNF - 10 is 32 TPI, 60° thread
deep. UNF - 10 is 32 TPI, 60° thread
angle 4.72 ±0.07 mm outside diameter,
angle 4.72 ±0.07 mm outside diameter,
3.83 mm core diameter.
3.83 mm core diameter.
Coupling Stud:
Coupling Stud:
All KU & TU resistors are supplied with
All KU & TU resistors are supplied with
8 mm long screwed brass studs.
8 mm long screwed brass studs.
Construction
Construction
®
®
The Cermetox thick film is fired on to the surface of a high
The Cermetox thick film is fired on to the surface of a high
quality ceramic former. Turned brass end caps are fitted. A
quality ceramic former. Turned brass end caps are fitted. A
helical cut is made into the film to adjust its ohmic value and
helical cut is made into the film to adjust its ohmic value and
finally a sleeve is fitted to provide mechanical protection and
finally a sleeve is fitted to provide mechanical protection and
electrical insulation. Resistors for use in oil SF6 can be
electrical insulation. Resistors for use in oil SF6 can be
supplied with a lacquer protection instead of the sleeve.
supplied with a lacquer protection instead of the sleeve.
Terminations
Terminations
Three styles of termination are available to permit resistors to
Three styles of termination are available to permit resistors to
be screwed together in a series chain, with the end members
be screwed together in a series chain, with the end members
having axial wires for soldering.
having axial wires for soldering.
Wire Terminations:
Styles D and KU
Wire Terminations:
Styles D and KU
Non standard wire terminations
Non standard wire terminations
available upon request.
available upon request.
Material:
Solder coated copper wire
Material:
Solder coated copper wire
Strength:
The terminations meet the requirements
Strength:
The terminations meet the requirements
of IEC 68.2.21.
of IEC 68.2.21.
meet the requirements
Solderability:
The terminations
Marking
Marking
Type reference, resistance value, tolerance and date code are
Type reference, resistance value, tolerance and date code are
legend marked. The resistance values conform to IEC 62.
legend marked. The resistance values conform to IEC 62.
Solvent Resistance
Solvent Resistance
sleeve provide excellent resistance
The lacquer and protective
The lacquer and protective sleeve provide
suitable for printed
to all normal industrial cleaning solvents
excellent resistance
to all normal industrial cleaning solvents suitable for printed
circuits.
circuits.
Solderability:
The terminations meet the requirements
of IEC 115-1, Clause 4.17.3.2.
of IEC 115-1, Clause 4.17.3.2.
Performance Data
Performance Data
Load at rated power: 1000 hours at 20°C
Shelf life: 12
power:
at room temperature
Load at rated
months
1000 hours at 20°C
Derating
12 months at room
20°C
Shelf life:
from rated power at
temperature
Noise (µV/V in a decade of
at 20°C
Derating from rated power
frequency)
Voltage coefficient of resistance
Noise (µV/V in a decade of frequency)
∆R%
∆R%
∆R%
Maximum
5
Maximum
Typical
1
Typical
0.5
1
Zero at 100°C
5
Zero at 100°C
∆R%
ppm/V
0.5
<2.5
<25
<2.5
Application Notes
Mounting
Application Notes
Voltage coefficient of resistance
ppm/V
<25
Due to the high voltage which can appear between the end
Mounting
adjacent metal part, resistors should be mounted
cap and any
Due to the high
distance
which
other
appear between the end
at an adequate
voltage
from
can
conductors.
cap and any adjacent metal part, resistors should be mounted
Resistors may be screwed together
conductors.
at an adequate distance from other
to provide an assembly
which will be capable of withstanding any desired voltage,
Resistors may
individual resistor is subjected to
an
greater stress
providing no
be screwed together to provide
a
assembly
which will
dissipation than is recommended
desired
data sheet.
or power
be capable of withstanding any
in this
voltage,
providing no individual resistor is subjected to a greater stress
For some high voltage applications it is required to immerse
or power dissipation than is recommended in this data sheet.
the components in oil or gas to reduce the effects of corona
and surface tracking.
applications it is
is available, suitable
For some high voltage
A special lacquer
required to immerse
for
components
transformer oil of SF6.
the
immersion in
in oil or gas to reduce the effects of corona
Matched Sets
Matched
be screwed together to form sticks and, by
These may
Sets
Matched sets can be supplied for use as voltage dividers.
Matched sets
KU type
supplied for use
a wire connection can
selecting the
can be
of termination,
as voltage dividers.
These may be screwed together
stick.
be provided at each end of the
to form sticks and, by
selecting the KU type of termination, a wire connection can
Enquiries are welcomed
of
special resistors and sets when
be provided at each end
for
the stick.
resistor length, operating voltage or resistance vale is outside
Enquiries are welcomed for special resistors and sets when
the catalogued range.
resistor length, operating voltage or resistance vale is outside
Packaging
the catalogued range.
All components are supplied in boxes.
and surface tracking. A special lacquer is available, suitable
When resistors are required to be potted, the preferred
for immersion in transformer oil of SF6.
encapsulant is a silicone compound.
When resistors are required to be potted, the preferred
For voltage dividers with a low resistance section below the
encapsulant is a silicone compound.
resistors, it is entirely
minimum available value of an F43
suitable to use an RC Series resistor, available down to 1 ohm.
For voltage dividers with a low resistance section below the
minimum available value of an F43 resistors, it is entirely
suitable to use an RC Series resistor, available down to 1 ohm.
UK
© Welwyn Components Limited
Bedlington, Northumberland NE22 7AA,
General Note
Packaging
Standard Quantities Per Box
All components are supplied in boxes.
Standard Quantities Per Box
All Types
All Types
10 or 20 per box
10 or 20 per box
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© Welwyn Components Limited
Bedlington, Northumberland NE22 7AA, UK
Issue B · 03.02
Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com
© TT electronics plc
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