Compact Flameproof Power
Wirewound Resistors
WP-S Series
Welwyn Components
Application Notes
1. If the resistors are to dissipate full rated power, it is recommended that the terminations should not be soldered closer than
4mm from the body.
2. 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 thermal impedance figures given under
Electrical Data.
3. WP-S resistors can also be supplied with radial, goalpost or lancet pre-formed leads. WP2S, WP3S, WP4S and WP5S are also
available in an SMD format with Z formed leads and packed in blister tape. Consult factory for details.
Radial
Goalpost
Lancet
Z-form
Packaging
The standard packaging for WP-S is taped. The critical dimensions are shown in Figure 1. The component wires will not
protrude beyond the outside edge of the tapes. Taped product is then packed into boxes or onto reels; see Ordering Procedure
for details. Alternative packaging is available by request. Pre-formed resistors are supplied loose packed in plastic bags or boxes.
Figure 1
Dimensions (mm)
WP1S
WP2S
WP25S
WP3S
WP4S
WP5S
WP7S
b
52
52
52
67
63
63
85
c
5
5
5
10
10
10
10
C
f1
6
b
f2
6
Body location f1 - f2 < 1.4mm
© 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
Issue E · 07.06
WELWYN [ WELWYN COMPONENTS LIMITED ]
