Tubular Vitreous Enamelled
Wirewound Resistors
1600/1900 Series
Welwyn Components
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Impervious lead free vitreous enamel coating
Can be supplied with fixed, adjustable,
tapped or low inductance winding
Seven termination styles with choice of
mounting arrangements
Manufactured RoHS compliant
Pb-free terminations*
* Check status of stock when ordering
General Information
Vitreous enamelled wirewound resistors are capable of
withstanding a higher dissipation size for size, than any other
protected type; this is attributable to the higher operating
temperature which the wire and enamel can withstand.
Vitreous enamel provides exceptionally good protection to the
wire element and is essentially impervious to moisture. The
resistors can safely be used in harsh environmental conditions.
The Welwyn range is based on thirteen sizes of tube, each of
which has a recommended maximum dissipation which limits
operating surface temperature to a maximum of 375°C.
The stability and high reliability of Welwyn tubular vitreous
resistors is a direct result of the best quality materials being
used in their construction.
High purity ceramic tubes have been matched with nickel
chromium resistance wires and specially formulated enamel to
ensure that the resistors can withstand repeated heat cycling
without damage.
Connections between the resistance element and end
terminations are welded; other connections are brazed.
Mounting devices are available which permit resistors to be
mounted by both ends or by one end. Single ended mounting
is recommended for applications which do not subject the
resistor to shock or vibration.
Ferrules and the F type mounting plug are anchored into the
tubes with high temperature adhesive.
Special requirements, for types or styles not described
in this brochure, will be considered for economic
quantities.
Electrical Data
Power rating at 70°C
Resistance range
Limiting element voltage
TCR (-55 to +200°C)
Resistance tolerance
Values
Thermal impedance
Operating temperature range
watts
ohms
volts
ppm/°C
%
°C/watt
°C
1605
47
1601
11
1905
16
1602
1906
1603
1604
17
22
25
35
See Table 1
See Table 1
Typically: <+75
Maximum + 200
1, 2, 5, 10
See table 1 for value restrictions
E24 preferred
See fig. 1
-55 to +375
1908
54
1607
1606
76
91
See Table 1
See Table 1
1608
115
1609
165
1600
16.5
Power rating at 70°C
Resistance range
Limiting element voltage
TCR (-55 to +200°C)
Resistance tolerance
Values
Thermal impedance
Operating temperature range
watts
ohms
volts
ppm/°C
%
Typically: <+75
1, 2, 5, 10
°C/watt
°C-55 to +375
Maximum + 150
See table 1 for value restrictions
E24 preferred
See fig. 1
Note
See Figure 1 for curves of temperature rise / watts dissipation.
General Note
Welwyn Components reserves the right to make changes in product specification without notice or liability.
All information is subject to Welwyn’s own data, relates to current manufacture and is considered accurate at time of going to print.
A subsidiary of
TT electronics plc
Issue E · 10.05
© 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
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WELWYN [ WELWYN COMPONENTS LIMITED ]
