High Voltage
High Voltage
Thick Film Resistors
Welwyn Components
Thick Film Resistors
VRW Series
VRW Series
VRW37 approved to BS / EN / IEC 60065
s VRW37 meets the requirements of BS / EN /
High working voltage to 10kV in compact size
IEC 60065
High ohmic range to 68M
s High working voltage to 10kV in compact
High pulse load capability
size
Robust flameproof coating material
s High ohmic range to 68M
RoHS compliant
s High pulse load capability
s Robust flameproof coating material
s RoHS compliant
Electrical Data
VWR 25 VWR 37 VRW68
Pow re ing ta 70C awtts 5
1.0
eR sist na cer na eg (O mh s) Kto 03 M Kto 03 M
100K to 68M
Limitingelement ov ltage ov lts cd oracp
10000
Is loatoi n v lotage ov lts
T RC p mp /C
eR sist na ceToler na ce % 1
Standard Values
E24 or E96
rmalIm ce C/ awtt
70
Ambient et mp ure ar nge
- 55 to+ C
Physical Data (Dimensions (mm) & Weight (g)
Type L D f d PCB Min Wt.
d
Max Max min Nom mount bend nom
centres radius
VRW25
6.2 2.5 21 0.60.05 10.2 0.6 0.3
d
D
L
f
9.0 3.7 19.6 0.80.05 12.7 1.2 0.5
VRW37
VRW68
15.5 5.0 27 0.80.05 20.3 1.2 1.15
Construction Terminations
Resistive thick film material is applied to high-grade ceramic Material: Hot tin dipped copper wire
rods. Tin-plated steel caps are force fitted and the
Strength: The terminations meet the requirements
termination wires are welded to the caps. The value is
of IEC 68.2.21
obtained by a helical cut in the film and finally the resistor
Solderability: The terminations meet the requirements
body is protected by a cement coating.
of IEC 115-1 Clause 4.17.3.2
Solvent Resistance
Marking
The body protection and marking are resistant to all normal
1% tolerance resistors are colour coded with 5 bands. 2%
industrial cleaning solvents suitable for printed circuits.
and 5% tolerance have 4 bands. IEC62 colours are used.
Flammability
The resistor coating will not burn under any condition of
applied temperature or power overload.
General Note
General Note
TT electronics reserves the right to make changes in product specification without notice or liability.
Welwyn Components reserves the right to make changes in product specification without notice or liability.
All information is subject to TT electronics own data and is considered accurate at time of going to print.
All information is subject to Welwyns own data and is considered accurate at time of going to print. A subsidiary of
www.bitechnologies.com www.irctt.com www.welwyn-tt.com
TT electronics plc
Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK
TT electronics plc
05.08
Telephone: +44 (0) 1670 822181 Facsimile: +44 (0) 1670 829465 Email: info@welwyn-tt.com Website: www.welwyn-tt.com Issue C 07.06
09. 11
70
C
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211 041 nadep ehT
5, 2,
002
007
0053
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001 001
5.0 2.0 tarHigh Voltage
High Voltage
High Voltage
High Voltage
High Voltage
Thick Film Resistors
Thick Film Resistors
Thick Film Resistors
Thick Film Resistors Welwyn Components
Thick Film Resistors Welwyn Components
VSRQW SeriesP Series
VSRQW SeriesP Series
Welwyn Components
VRW Series
VSRQW SeriesP Series Welwyn Components
VSRQW SeriesP Series
Performance Data
Performance Data
Performance Data
Performance Data
Maximum Typical
Maximum Typical
Load at rated voltage (1000hrs at 70C) R% 1.5* 0.4
Maximum Typical
Load at rated voltage (1000hrs at 70C) R% 1.5* 0.4
Maximum Typical
Derating from rated power at 70 C zero at 155 C
Load at rated voltage (1000hrs at 70C) R% 1.5* 0.4
Derating from rated power at 70 C zero at 155 C
Load at rated voltage (1000hrs at 70C) R% 1.5* 0.4
Overload (10 x 5s on, 45s oOverload (10 x 5s at 6.25 x fPrf at 6.25 x Pr not exceeding 2 x LEV) not exceeding 2 x LEV) R% 1 0.15
2
Derating from rated power at 70 C zero at 155 C
Overload (10 x 5s on, 45s oOverload (10 x 5s at 6.25 x fPrf at 6.25 x Pr not exceeding 2 x LEV) not exceeding 2 x LEV) R% 12 0.15
Derating from rated power at 70 C zero at 155 C
Damp heat steady state (56 days, 40C, 90% RH) R% 1.5 0.1
Overload (10 x 5s on, 45s oOverload (10 x 5s at 6.25 x fPrf at 6.25 x Pr not exceeding 2 x LEV) not exceeding 2 x LEV) R% 12 0.15
Damp heat steady state (56 days, 40C, 90% RH) R% 1.5 0.1
Overload (10 x 5s on, 45s oOverload (10 x 5s at 6.25 x fPrf at 6.25 x Pr not exceeding 2 x LEV) not exceeding 2 x LEV) R% 1 0.15
2
Climatic sequence R% 1.5 0.2
Damp heat steady state (56 days, 40C, 90% RH) R% 1.5 0.1
Climatic sequence R% 1.5 0.2
Damp heat steady state (56 days, 40C, 90% RH) R% 1.5 0.1
Climatic category 55/155/56
Climatic sequence R% 1.5 0.2
Climatic category 55/155/56
Climatic sequence R% 1.5 0.2
Temperature rapid change R% 0.5 0.05
Climatic category 55/155/56
Temperature rapid change R% 0.5 0.05
Climatic category 55/155/56
Resistance to solder heat R% 0.5 0.05
Temperature rapid change R% 0.5 0.05
Resistance to solder heat R% 0.5 0.05
Temperature rapid change R% 0.5 0.05
Vibration R% 0.5 0.05
Resistance to solder heat R% 0.5 0.05
Vibration R% 0.5 0.05
Resistance to solder heat R% 0.5 0.05
Voltage Proof volts 700 min
Vibration R% 0.5 0.05
Voltage Proof volts 700 min
Vibration R% 0.5 0.05
* 2% for ohmic values above 24M
Voltage Proof volts 700 min
* 2% for ohmic values above 24M
Voltage Proof volts 700 min
* 2% for ohmic values above 24M
Pulse Performace
* 2% for ohmic values above 24M
Pulse Performace
Pulse Performance
Pulse Performance
Pulse Performace
100
Pulse Performace
Pulse Performance
100
Pulse Performance
100
100
VRW25
VRW25
VRW37
10
VRW37
10 VRW25
VRW25
VRW68
VVRRWW6387
10
VRW37
10
VRW68
VRW68
1
1
0.1 1 10 100
0.1 1 10 100
1
1
0.1 Va1lue (megohm10s) 100
Value (megohms)
0.1 1 10 100
Value (megohms)
Maximum peak voltage in accordance with IECVa l6u0e0 (65me cghoahptmesr) 14.1
Maximum peak voltage in accordance with IEC 60065 chapter 14.1
50 discharges from a 1nF capacitor charged to V max. 12 discharges/minute.
Maximum peak voltage in accordance with IEC 60065 chapter 14.1
50 discharges from a 1nF capacitor charged to V max. 12 discharges/minute.
Maximum peak voltage in accordance with IEC 60065 chapter 14.1
50 discharges from a 1nF capacitor charged to V max. 12 discharges/minute.
50 discharges from a 1nF capacitor charged to V max. 12 discharges/minute.
Application Notes
Application Notes
Application Notes
1. Due to operating temperature limits imposed by some PCB materials, derating may be necessary. An
Application Notes
1. Due to operating temperature limits imposed by some PCB materials, derating may be necessary. An
estimate of the temperature rise to be expected at the center of the body can be calculated using the
1. Due to operating temperature limits imposed by some PCB materials, derating may be necessary. An
estimate of the temperature rise to be expected at the center of the body can be calculated using the
1. Due to operating temperature limits imposed by some PCB materials, derating may be necessary. An
thermal impedance figures given under Electrical Data.
estimate of the temperature rise to be expected at the center of the body can be calculated using the
thermal impedance figures given under Electrical Data.
estimate of the temperature rise to be expected at the center of the body can be calculated using the
thermal impedance figures given under Electrical Data.
2. VRW resistors can be supplied with radial, goalpost or lancet pre-formed leads. The VRW37 is also
thermal impedance figures given under Electrical Data.
2. VRW resistors can be supplied with radial, goalpost or lancet pre-formed leads. The VRW37 is also
available in an SMD format with Z formed leads and packed in blister tape. Consult Factory for details.
2. VRW resistors can be supplied with radial, goalpost or lancet pre-formed leads. The VRW37 is also
available in an SMD format with Z formed leads and packed in blister tape. Consult Factory for details.
2. VRW resistors can be supplied with radial, goalpost or lancet pre-formed leads. The VRW37 is also
available in an SMD format with Z formed leads and packed in blister tape. Consult Factory for details.
available in an SMD format with Z formed leads and packed in blister tape. Consult Factory for details.
Type b c
Type b c
Packaging
Packaging
VRW25/37 52 2mm 5 0.5mm
Type b c
VRW25/37 52 2mm 5 0.5mm
Type b c
Packaging
Our standard packaging for VRW is taped and
Packaging
Our standard packaging for VRW is taped and 73 2mm 10 0.5mm
VRW25/37VRW68 52 2mm 5 0.5mm
73 2mm 10 0.5mm
VRW68
VRW25/37 52 2mm 5 0.5mm
boxed. The critical dimensions are shown in
Our standard packaging for VRW is taped and
boxed. The critical dimensions are shown in
73 2mm 10 0.5mm
Our standard packaging for VRW is taped and VRW68
73 2mm 10 0.5mm
Figure 1. The component wires will not VRW68
boxed. The critical dimensions are shown in
Figure 1. The component wires will not
boxed. The critical dimensions are shown in
protrude beyond the outside edge of the
Figure 1. The component wires will not
protrude beyond the outside edge of the
c
Figure 1. The component wires will not
c
tapes. Alternative packaging is available by
protrude beyond the outside edge of the
tapes. Alternative packaging is available by
protrude beyond the outside edge of the
c
request. Pre-formed resistors are supplied
c
tapes. Alternative packaging is available by
request. Pre-formed resistors are supplied
tapes. Alternative packaging is available by
loose packed in plastic bags or boxes.
request. Pre-formed resistors are supplied
loose packed in plastic bags or boxes.
f1 f2
request. Pre-formed resistors are supplied
f1 f2
loose packed in plastic bags or boxes.
loose packed in plastic bags or boxes. 6 6
f1 f2
6 6
b
mm f1 f2 mm
b
mm mm
Body location f1-f2 1.4mm
6 6
Body location f1-f2 1.4mm
6 b 6
mm mm
b
mm mm
Body location f1-f2 1.4mm
Body location f1-f2 1.4mm
General Note
TT electronics reserves the right to make changes in product specification without notice or liability.
Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK
Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK
Telephone: +44 (0) 1670 822181 Facsimile: +44 (0) 1670 829465 Email: info@welwyn-tt.com Website: www.welwyn-tt.com 05.08
All information is subject to TT electronics own data and is considered accurate at time of going to print.
Telephone: +44 (0) 1670 822181 Facsimile: +44 (0) 1670 829465 Email: info@welwyn-tt.com Website: www.welwyn-tt.com 05.08
www.bitechnologies.com www.irctt.com www.welwyn-tt.com
Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK
Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK
Telephone: +44 (0) 1670 822181 Facsimile: +44 (0) 1670 829465 Email: info@welwyn-tt.com Website: www.welwyn-tt.com 05.08
71
T TT electrelephone: +44onics plc (0) 1670 822181 Facsimile: +44 (0) 1670 829465 Email: info@welwyn-tt.com Website: www.welwyn-tt.com 05.08 71
09. 11
71
71
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