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.
Application Notes
Radial Goalpost Lancet Z-form
Compact Flameproof Power
Wirewound Resistors
WP-S Series
Welwyn Components
© 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
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.
Packaging
Dimensions (mm) b c
WP1S 52 5
WP2S 52 5
WP25S 52 5
WP3S 67 10
WP4S 63 10
WP5S 63 10
WP7S 85 10
