General-Purpose Failsafe

Moulded Wirewound Resistors

General-Purpose Failsafe

Moulded Wirewound Resistors

SP20/SP20F Series

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

95

Type

F

0

2

P

S

0

2

P

S

EIA RS-344 Style

CRU 1

MIL-R-11 Style

RC20/RC32

k

1

o

t

1

R

0

2

k

1

o

t

1

R

0

s

m

h

o

e

g

n

a

R

e

c

n

a

t

s

i

s

e

R

0

1

±

,

5

±

%

e

c

n

a

r

e

l

o

T

C

°

0

5

t

a

1

C

°

0

5

t

a

1

s

t

t

a

w

g

n

it

a

r

r

e

w

o

P

0.75 at 70°C

0.75 at 70°C

-

C

°

0

0

1

t

a

5

.

0

Derating to 0 at 160°C

Derating to 0 at 160°C

Maximum continuous working voltage

√PR

g

e

M

0

0

0

,

0

1

y

r

d

e

c

n

a

t

s

i

s

e

r

n

o

it

a

l

u

s

n

i

m

u

m

i

n

i

M

g

e

M

0

0

1

t

e

w

V

0

0

7

M

T

A

s

tl

o

v

g

n

i

d

n

a

t

s

h

ti

w

c

ir

t

c

e

l

e

i

d

m

u

m

i

n

i

M

V

0

5

4

S

M

R

e

r

u

s

s

e

r

p

d

e

c

u

d

e

R

Hotspot temperature rise

120°C at 1 watt

Current noise

Negligible

Electrical Data

Issue B · 03.02

A subsidiary of

TT electronics plc

Welwyn Components

Dimensions (mm)

Type

L

D

d

f

SP20

9.91±0.25

3.56±0.20

0.813±0.05

38.1±3.2

SP20F

9.91±0.25

3.56±0.20

0.813±0.05

38.1±3.2

Physical Data

L

D

f

d

Resistive Element

All resistor types have resistance alloy winding on a braided

fibreglass substrate. Intermediate silicone coatings are used to

enhance processibility and to provide protection to the

resistive element.

Termination

The SP20 and SP20F resistors are terminated using an alloy

coated copper flashed steel lead welded to a cap of the same

material. This termination assembly is mechanically crimped,

utilizing an improved crimp design, to the resistive element.

Encapsulation

The SP20 and SP20F are encapsulated utilizing a compression

molded phenolic plastic material. The SP20F has a flame

resistance coating applied over the resistive element to

provide flammmability protection when destructive overloads

may occur.

Marking

All products are marked utilizing heat and solvent resistant

colour code bands consistent with EIA/MIL requirements. The

first band is double width to designate wirewound

construction. A fifth band, blue in colour, is used for

flameproof identification.

UL Recognised Range

ohms

N/A

1R0 to 470R

SP20 / SP20F Series

SP20F UL1412 recognised fusing *

0.1 ohm to 1200 ohms

Fversionhasflameresistantcoating

1wattratedwith1/2wattdimensions

Drop-inreplacementBW20/BW20F

Weldableandsolderablemagneticlead

TCR’saslowas±150ppm/°Cstandard(customTC’savailable)

Leadfree,RoHScompliantconstructionavailable

*ULfilenumberE234469

Make Possible

Resistors

07.14

General Note

TT Electronics reserves the right to make changes in product specification without notice or liability.

All information is subject to TT Electronics’ own data and is considered accurate at time of going to print.

© TT Electronics plc

www.ttelectronicsresistors.com

AllPb-freepartscomplywithEUDirective2011/65/EU(RoHS2)