BW/MBW SERIES

FA037D Sale of this product is in accordance with GF-061. Specifications subject to change without notice.

Industry’s widest selection of fusible film resistors -

1/8W to 3W, .1

Ω to 24KΩ, 1% to 5%, leaded & surface mount

Flameproof (UL94V0), surface-mount versions available

OPTIONS

Modified fusing characteristics (fast blow, slow blow, etc.)

Increased pulse capability (Option P)

Dozens of additional options are available...

Mil-spec screening/burn-in, special marking, non-standard

values, custom lead forming, increased power or voltage, etc.

Customized components are an RCD specialty!

RCD pioneered fusible film resistors in the early 1970’s as a

low cost approach to circuit protection in case of overload or

component failure. The component is designed to act as a

conventional resistor under normal operating conditions, but

open quickly under fault conditions. Series BW meets the

requirements of EIA RS-325 and can be useful in eliminating

circuit board damage and fire hazards. Standard fusing

characteristics can be altered to customer requirements.

Low Cost Circuit Protection!

TYPICALPERFORMANCE

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FUSING CHARACTERISTICS

APPLIED POWER (WATTS)

60

50

40

30

20

10

0

5

10

15

20

30

40

50

60

80

100

1. Fault level must be suitable to safely open the resistor quickly, especially surface mount

MBW models. If insufficent, the resistor may reach elevated temp. For this reason, the

fusing overload must be relatively large compared to rated W, 20 to 50x is common for

most axial-lead applications, 40 to 100x for most SM circuits. SM fusing times vary due to

mounting geometry/materials, so each application needs to be evaluated by user. The fault

condition must be at least equal to the minimum W indicated in each of the above curves,

and preferably double for SM applications. Fusing may still occur at W levels below the

levels graphed above but not consistently (fast-blow models available). Don’t exceed volt

rating or 200x W rating, whichever is less (increased levels available).

2. For customized models, complete RCD’s Fuse Questionnaire or advise the desired fusing

wattage or current, min.& max. blow time, continuous wattage, ambient temp., pulse

conditions, physical constraints, voltage to be interrupted, frequency, etc.

3. Maintain clearance from any heat-sensitive or flammable materials.

4. Fusing times vary depending on resistance value. Typical fusing times are given above

for 1

Ω - 3.9K. Low values tend to fuse slower. Consult factory for assistance.

5. Residual resis. is

≥50x initial value after fusing at 20x rated W (30x for BW1/8F & MBW)

6. Verify selection by evaluating under the full range of fault conditions. Place resistors

inside a protective case when testing.

APPLICATION NOTES:

FUSIBLE FILM RESISTORS,

GENERAL PURPOSE 1/8 WATT to 3 WATT

RESISTORS CAPACITORS COILS DELAY LINES

81

d

↓

↑

↑

BW

C

↑

↓

B

MBW

Termination: W = Lead-free, Q = Tin/Lead

(leave blank if either acceptable)

BW Series - Axial Lead

MBW Series - SM MELF

- 101 J T W

RCD Type

Tolerance: J=5% (std.) G=2%, F=1%

Packaging: B=Bulk, T=Tape & Reel

Options (leave blank if standard)

Resis.Code 1%: 3 signif. figures & multiplier,

(R100=.1

Ω,1R00=1Ω,10R0=10Ω,1000=100Ω,etc.)

Resis.Code 2%-10%: 2 signif. figures & multiplier,

(R10=0.1

Ω, 1R0=1Ω,100=10Ω, 101=100Ω, etc.)

Term.W is

RoHS

compliant

& 260°C

compatible

RoHS