Resistors
CARBON FILM RESISTORS
The WCF Series Carbon Film Resistors are manufactured using mechanised high vacuum carbonising plants. This ensures a stable resistive film. The resistors are insulated with layers of light brown lacquer. The WCF series offer a wide range of power ratings (0.125 W, 0.25W, 0.4W, 0.5W, 1W, 2W & 3W) with a tolerance of ± 5%. and TCR ±1000 ppm/ºC.

MPN

SPECIFICATION

Type No.

WCF 12 / WCF 25 M WCF 25 / WCF 33 / WCF 40/ WCF50 M WCF 50 / WCF 100 M WCF 100 / WCF 200 M WCF 200 / WCF 300 M

Rated Power at 70'C

0.125 W / 0.25 W 0.25 W / 0.40 W / 0.50 W 0.50 W / 1 W 1 W / 2 W 2 W / 3 W

Resistance Range (E 24 series)

0.1 E to 10 Meg 0.1 E to 10 Meg 0.1 E to 10 Meg 0.1 E to 10 Meg 0.1 E to 10 Meg

Tolerance

± 5% ± 5% ± 5% ± 5% ± 5%

Maximum working voltage at 70'c at normal air pressure

200V 250V 350V 500V 500V

Maximum Over Load Voltage

400V 500V 700V 1000V 1000V

Operating Temperature Range

-40ºC to + 150ºC -40ºC to + 150ºC -40ºC to + 150ºC -40ºC to + 150ºC -40ºC to + 150ºC

Dielectric Strength

400V No break down

ΔR.max. ± 0.5%

500V No break down

ΔR.max. ± 0.5%

700V No break down

ΔR.max. ± 0.5%

1000V No break down

ΔR.max. ± 0.5%

1000V No break down

ΔR.max. ± 0.5%

CHARACTERISTICS

Terminal Strength

no damage
Δ R max. ± 0.5%

Resistance to soldering heat (350ºC)

Δ R max. ± 1%

Solderability

good tinning
no damage

Temperature Cycling
-40 ºC to ± 150 ºC

Δ R max. ± 1%

Life 1000 hours at Rated Power

Δ R max. ± 3%

Short time overload

Δ R max. ± 1%

Resistance to solvents

no damage
E 24 Series

10

11 12 13 15 16 18 20 22 24 27 30

33

36 39 43 47 51 56 62 68 75 82 91
DIMENSIONS (in mm)

TYPE WCF 12 / WCF 25M

H = 26 ± 2 L = 3.3 ± 0.2 D = 1.7 ± 0.1 d = 0.45 ± 0.05

TYPE WCF 25 / WCF 33 / WCF 40M/ WC 50M

H = 26 ± 2 L = 6.0 ± 0.4 D = 2.2 ± 0.1 d = 0.50 ± 0.05

TYPE WCF 50 / WCF 100M

H = 26 ± 2 L = 9.0 ± 0.5 D = 3.2 ± 0.2 d = 0.55 ± 0.05

TYPE WCF 100 / WCF 200M

H = 26 ± 2 L = 11 ± 1.0 D = 4.3 ± 0.5 d = 0.65 ± 0.05

TYPE WCF 200 / WCF 300M

H = 26 ± 2 L = 15 ± 1.0 D = 5.0 ± 0.5 d = 0.75 ± 0.05
Colour lst figure 2nd figure Multiplier Tolerance
Black 0 0 1
Brown 1 1 10 ± 1%
Red 2 2 100 ± 2%
Orange 3 3 1,000
Yellow 4 4 10,000
Green 5 5 100,000 ± 0.5%
Blue 6 6 1,000,000 ± 0.25%
Violet 7 7 10,000,000 ± 0.1%
Gray 8 8
White 9 9
Gold 0.1 ± 5%
Silver 0.01 ± 10%