Vitreous Enamelled Wirewound Resistors
IRC Wire and Film Technologies Division
W20 Series
• Rugged all-welded construction
• High purity ceramic substrate
• Impervious lead-free vitreous enamel coating
• High stability and high reliability
• Suitable for harsh environments
• Overload charcteristics ideal for protection circuits
• Lead-free, RoHS-compliant construction
Specifications
Part
Number
Power rating
@25°C
Resistance
Range
(Ohms)
Tolerance
(±±)
TCR
(±ꢀꢀmꢁ°C)
Limiting Element
Voltage
Thermal
Imꢀedance1
(°Cꢁwatt)
(Watts)
(Volts)
W21
3.0
1 - 10K
1
2
5
1
2
5
1
2
5
1
2
5
1
2
5
Typical: <+75
Maximum: +200
100
160
200
500
750
88
58
44
29
22
0.5 - 10K
0.1 - 10K
1 - 15K
W215
W22
5.0
Typical: <+75
Maximum: +200
0.5 - 15K
0.1 - 15K
1 - 22K
7.0
Typical: <+75
Maximum: +200
0.5 - 22K
0.1 - 22K
1 - 60K
W23
10.0
14.0
Typical: <+75
Maximum: +200
1 - 60K
0.15 - 60K
1 - 100K
1 - 100K
0.15 - 100K
W24
Typical: <+75
Maximum: +200
Notes
1 See temperature rise graph
Application Notes
The terminations should not be bent closer than 1.6mm from the body of the resistor, and the recommended
bend radius is 1.2mm. Terminations are solderable to within 4mm from the resistor body.
When cold, vitreous enamel has excellent insulation resistance. In common with all insulation materials, the
specific resistance of the enamel decreases with increased temperatures. Therefore, resistors operated at
near-maximum temperature cannot be considered as insulated and should not be used in contact with any
conductive material.
Care must be taken when determining clearance distance between the resistor body and printed circuit board
or other components to ensure these are not overheated. Resistance is measured 6mm from the resistor body.
General Note
IRC reserves the right to make changes in product specification without notice or liability.
All information is subject to IRC’s own data and is considered accurate at time of printing.
A subsidiary of
TT electronics plc
W20 Series Issue November 2006
• 736 Greenway Road Boone, North Carolina 28607-1860
Telephone: 828 264 8861 • Facsimile: 828 264 8866 • Website: www.irctt.com
© IRC Wire and Film Technologies Division