FUSIBLE FILM RESISTORS, GENERAL PURPOSE 1/8 WATT to 3 WATT
RESISTORS CAPACITORS COILS DELAY LINES
BW/MBW SERIES
RoHS
Term.W is RoHS compliant & 260°C compatible
BW Series - Axial Lead
MBW Series - SM MELF
Industry’s widest selection of fusible film resistors 1/8W to 3W, .1Ω to 24KΩ, 1% to 5%, leaded & surface mount Low cost, quick delivery (available on SWIFTTM program) Flameproof (UL94V0), surface-mount versions available
Low Cost Circuit Protection!
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.
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!
←
H
→← L →
BW
↓D ↑
↓d
↓
←A→
MBW
↓
Dimensions BW Series (Axial Lead)
RCD Type BW1/8F BW1/4F, MBW1/4F BW1/2F, MBW1/2F BW1/2FS, MBW1/2FS BW1F, MBW1FS BW2F, MBW2F BW3F, MBW3F
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Dimensions MBW (MELF)
H (Min.) A ± .012[.3] B (Max.) N/A .118 [3] .118 [3] .197 [5] .040 [1] .040 [1] .080 [2] .080 [2] .154 [3.9] .060 [1.5] .154 [3.9] .060 [1.5] C (Min.)
Wattage Resistance Rating 1 Range 1 1/8W 1/4W 1/2W 1/2W 1.0W 2.0W 3.0W
2
Voltage Rating 1, 2 200V 200V 250V 250V 300V 300V 350V
L ± .032 [.8] .145 [3.7] .250 [6.4] .354 [9.0] .250 [6.4] .375 [9.5] .450 [11.4]
D ± .024 [.6] .067 [1.7] .090 [2.3] .128 [3.3] .090 [2.3] .135 [3.4] .162 [4.1]
d ±.003 [.07]
1Ω to 10K 0.1Ω to 10K 0.1Ω to 24K 0.2Ω to 20K 0.1Ω to 24K 0.1Ω to 24K 0.1Ω to 24K
.020 [.5] 1.00 [25] .022 [.55] 1.02 [26] .256 [6.5] .025 [.6] 1.02 [26] .374 [9.5] .022 [.55] 1.02 [26] .256 [6.5] .026 [.65] 1.02 [26] .374 [9.5] .031[.8] .031[.8] 1.02 [26] .441[ 11.2]
.60±.062[15.2±1.6] .22±.032[5.6±.8]
1.37 [35] .598 [15.2] .220 [5.6]
Expanded range available
Maximum working voltage is determined by E = (PR)1/2, E should not exceed value listed.
FUSING CHARACTERISTICS
FUSING TIME (SECONDS, TYP.)
60 50 40
1/2F, FS 1F, 1FS
30
1/8F
2F
10 0 5 10 15 20 30 40 50 60 80 100
APPLIED POWER (WATTS)
APPLICATION NOTES:
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 1Ω - 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.
TYPICAL PERFORMANCE
Temperature Coefficient Load Life Stability Operating Temp. Range Power Derating Dielectric Strength 200ppm/°C 5% -55 to +165°C 0.71%/°C >25°C 500V (300V BW1/8F)
P/N DESIGNATION: BW1F
RCD Type Options (leave blank if standard)
3F
20
1/4F
↑
Inch [mm]
↑
B
↑
C
- 101 J T W
Resis.Code 1%: 3 signif. figures & multiplier, (R100=.1Ω,1R00=1Ω,10R0=10Ω,1000=100Ω, etc.) Resis.Code 2%-10%: 2 signif. figures & multiplier, (R10=0.1Ω, 1R0=1Ω, 100=10Ω, 101=100Ω, etc.) Tolerance: J=5% (std.) G=2%, F=1% Packaging: B=Bulk, T=Tape & Reel Termination: W = Lead-free, Q = Tin/Lead (leave blank if either acceptable)
RCD Components Inc, 520 E.Industrial Park Dr, Manchester, NH, USA 03109 rcdcomponents.com Tel: 603-669-0054 Fax: 603-669-5455 Email:sales@rcdcomponents.com
FA037D Sale of this product is in accordance with GF-061. Specifications subject to change without notice.
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