Precision Wirewound Resistors

(BWW)

Introduction (BWW)

Precision Axial Moulded Wirewound Power Resistors - BWW Series

Precision Wirewound Resistor (BWW)

(BWW) Precision Power Resistors Operate in Harsh Environments.

The new BWW series moulded axial leaded wirewound resistors from Token use high-purity alumina ceramic cores with wire winding which are spot welded by precision CNC machine tools to ensure total operational consistency throughout.

Also, using advanced encapsulation die/mould technologies, this precision power resistors are encapsulated with epoxy molding compound.

The BWW models possess a wide resistance value from 0.1Ω to 39KΩ and meets the stringent requirements of MIL-R-93. Ayrton Perry noninductive windings are available on request. The BWW precision version has low ohmic values for current sensing applications.

All versions are miniaturised for better power to dimension ratios and are available in 0.5W to 10W rated power at 25°C. Tolerance is available in ±0.1%, ±0.25%, ±0.5%, ±1% and ±2% with TCR ±25PPM/°C, ±50PPM/°C and ±150PPM/°C which makes them ideally suited for use in precision applications.

The BWW series is RoHS compliant with 100% Sn (lead free) coated terminals. To address your need for technical and economic success in a timely manner, our custom solutions are the best option. Contact us with your specific needs.

Features :

Axial Moulded
Excellent load life stability
Insulation, Moisture Proof
High Precision and reliability
Meets the Standards of MIL-R-93
RoHS compliant with 100% lead free

Applications :

Electrical loads, Filament dropping
DC/DC converters, AC/DC inverters
High-voltage bleeders, Dynamic braking
Capacitor charging/discharging regulation
Motor speed controls, Voltage divider networks
Bias supply, Current shunts, Voltage dropping, Crow-bar circuits

Technical Specifications (BWW)

(BWW) Power Derating Curve

High Precision Wirewound Resistors (BWW) Dimensions

Precision Wirewound (BWW) Dimensions

Type

Rated Watts
at 25°C
(W)

Resistance Range
(Ω)

Tolerance
(%)

TCR
(PPM/°C)

Dimensions (Unit: mm)

Min

Max

A±0.25

ΦB±0.25

Φd

BWW-0.5

0.5

0.1

100

±0.1
±0.25
±0.5
±1
±2
±5

±25
±50
±150

7.0

3.0

0.8

27.0

BWW-1

1.0

0.1

11.0

3.0

0.8

31.0

BWW-3

3.0

0.1

10K

15.0

5.2

0.8

34.0

BWW-4

4.0

0.1

15K

18.0

6.5

0.8

38.0

BWW-5

5.0

24K

24.0

8.4

1.0

44.0

BWW-10

10.0

39K

46.5

10.0

1.0

66.0

Electrical Performance (BWW)

Test Items	Test Conditions	Specifications
Operating Temp. Range		-55°C ~ 175°C
Insulation Resistance	500V	>1GΩ
Dielectric Withstanding Voltage	500V AC 1 Min.	ΔR ≤ ±0.1%R
Load Life	70°C on~off cycle 1000 Hrs.	ΔR ≤ ±1%R
Moisture-Proof Load Life	40°C 95% RH on~off cycle 21 Hrs.	ΔR ≤ ±0.2%R
Resistance to soldering heat	350°C, 3.5s	ΔR ≤ ±0.1%R
Solderability	235±5°C, 5s(solder bath method)	IEC68-2-20(1968)

Application Notes of Precision Wire Wounds (BWW)

When being used in AC circuits, some wirewound structures give inductance ingredients or parasitic capacity, so they may cause unusual phenomena such as oscillations etc. Quorum deviations of other components should be carefully taken into account for use.
Application and Placement: Wire wound resistors use different gauges of wire as resistance elements. Sometimes the gauge is extremely thin (finer than a strand of human hair) and very susceptible to breakage in environments containing salts, ash, dust and corrosives. Avoid utilization in such environments.
Do not install in dusty areas because the accumulation will cause shorts and poor conductance.