General Purpose

Wirewound Resistors

SPP Series

Dimensions (inches)

Type

A max

B max

C±0.002

SPP-1

0.400

0.148

0.032

SPP-2

0.570

0.170

0.032

SPP-3

0.570

0.170

0.032

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 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

97

Type

SPP-1

SPP-2

SPP-3

Resistance range

ohms

0R1 - 1K2*

0R1 - 2K4

0R1 - 2K4

Standard Tolerance

±%

5, 10

5, 10

5, 10

1 @ 85°C

2 @ 85°C

3 @ 85°C

Power Rating

watts

0.75 @ 105°C

1 @ 140°C

2 @ 145°C

0.5 @ 125°C

-

1 @ 190°C

Derating to 0 @ 160°C

-

-

Load Life Stability

watts

1 @ 85°C ± 10%

2 @ 85°C ± 10%

3 @ 85°C ± 10%

Max. Continuous Working Voltage

√PR

Min. Insulation Resistance - Dry

10,000 megohm

Min. Insulation Resistance - Wet

100 megohm

Min. Dielectric Withstanding Voltage

600 volts RMS

Current Noise

Negligible

Temperature Rise at Rated Load, 25°C Ambient

Approx. 150°C

Approx. 200°C

Approx. 225°C

Electrical Data

Physical Data

Issue B · 03.02

A subsidiary of

TT electronics plc

Welwyn Components

A

max.

C

1.125 min

B

Fuse/Pulse Applications

SPP resistors normally fuse in less than one minute with five

to ten times rated wattage depending on the range. By

modifying the windings, using a different wire size or type,

they can be made to fuse much faster.

On the other hand, by using larger wire diameters and higher

melt temperature alloys they can handle from five to fifty

times overloads of film resistors depending on the range.