BWT Series Through Hole Shunt Resistors
Product group: Current sensing (shunt) resistors
Mounting: Through hole
Power rating: 2W, 5W
Resistance range: 0.5mΩ to 10mΩ
Tolerance options: ±1%, ±5%
TCR: ±50ppm/°C
What are the BWT Series Through Hole Shunt Resistors?
The BWT is a through hole current sensing resistor, commonly known as a shunt resistor, designed for precise in-circuit measurement of electrical current by converting a current flow into a proportional and measurable voltage drop across its terminals. The resistor employs a low-resistance element — spanning from 0.5mΩ to 10mΩ — which is placed in series with the load circuit, allowing the sensing electronics downstream to read current magnitude without introducing significant impedance into the power path.
Available in 2W and 5W power ratings, the BWT is suited to applications carrying moderate to high currents where self-heating of the sensing element must remain within controlled limits. The low milliohm resistance values ensure that the voltage burden imposed on the monitored circuit remains negligibly small, preserving system efficiency while still generating a signal large enough for accurate downstream amplification and conversion.
Tolerance options of ±1% and ±5% accommodate both precision measurement and cost-sensitive general-purpose designs within the same product family. The temperature coefficient of resistance of ±50ppm/°C is notably low for a through hole shunt, ensuring that the relationship between sensed voltage and actual current remains stable over the operating temperature range of the equipment — an important characteristic in applications where current measurement accuracy must be maintained as the component self-heats under load.
The through hole form factor provides robust mechanical retention in the PCB, making the BWT well suited to environments subject to vibration or thermal cycling. Axial lead construction simplifies assembly, allows the component to be raised above the board surface for improved airflow if required, and supports both manual and automated insertion processes. The series addresses design requirements where board-mounted, low-value sensing resistors must combine measurement accuracy, power handling, and long-term stability in a compact and easily replaceable package.
BWT Series Through Hole Shunt Resistors Specifications
A practical overview for engineers and procurement teams evaluating resistive solutions.
Model: BWT
Resistor type: Current Sensing
Description: Through Hole
Power Rating: 2W, 5W
Resistance (Ω): 0.5m~10m
Tolerance (%): ±1, ±5
TCR (ppm/C): 50
Applications of the BWT Series Through Hole Shunt Resistors
Where RARA current sensing resistors are deployed in the field.
Motor drive and variable-speed drive systems — phase current measurement and overcurrent detection in inverter output stages, providing feedback for commutation control and protection functions.
Battery management systems — cell and pack current monitoring in lithium-ion and lead-acid battery stacks, enabling state-of-charge calculation and charge/discharge control.
Switching power supplies and DC-DC converters — output current sensing for load regulation, current-mode control loops, and overload protection circuits.
Uninterruptible power supply equipment — input and output current monitoring to manage power transfer, load sharing between parallel units, and fault detection.
Industrial control and automation panels — current feedback in servo amplifiers, programmable logic controllers, and field bus power conditioning circuits.
Automotive electronics — current sensing in DC-DC converters, on-board chargers, and electric power steering control units, where stable TCR over wide temperature ranges is critical.
Renewable energy systems — current measurement in solar inverters, maximum power point tracking circuits, and grid-tie converter stages.
Test and measurement equipment — reference load and current measurement elements in electronic loads, power analyzers, and calibration instruments.
Telecommunications power infrastructure — current monitoring in rectifier modules and -48V distribution systems used in base station and data centre power plants.
Related Products of the WCR500 / WCR1000 Series Water Cooled High Power Film Resistors
Model: BWH
Resistor type: Current Sensing
Description: Through Hole
Power Rating: 3W~5W
Resistance (Ω): 0.3m~3m
Tolerance (%): ±1, ±2, ±5
TCR (ppm/C): 100, 300
Model: CSR
Resistor type: Through hole shunt
Description: Through hole 2 terminal
Rated Current: 2A-12A
Resistance (Ω): 20m~200m
Tolerance (%): ±5, ±10
TCR (ppm/C): 260
Model: MPR
Resistor type: Current Sensing
Description: Through Hole
Power Rating: 3W~20W
Resistance (Ω): 5m~400m
Tolerance (%): ±1, ±5
TCR (ppm/C): 260 max.
Model: PCR4T
Resistor type: Current sensing
Description: Through Hole
Rated Current: 35-65A
Resistance (Ω): 0.5m-4m
Tolerance (%): ±0.5, ±1, ±5
TCR (ppm/C): 30
Why Choose RARA Current Sensing Resistors
What sets RARA apart for engineers and procurement managers in industrial and automotive markets.
01
8 Sub-Categories
No other single supplier covers AEC-Q200 chip shunts, milliohm precision types, four-terminal Kelvin shunts, power metering, and 12,000A panel shunts under one ISO-certified roof.
02
Extreme Precision
HPS, UHPS, and PSS precision shunts deliver ±0.05% tolerance and 3 ppm/°C TCR — meeting the accuracy demands of EV battery coulomb counting, precision power analyzers, and billing-grade energy metering.
03
Automotive Qualified
Multiple AEC-Q200 certified models (BCS, LRA, ECS, BWR, TCS, PCBS) with IATF 16949 manufacturing certification — covering EV battery management, motor control, and charging applications.
04
Global Track Record
Trusted by Tesla, GM Korea, Proterra, Siemens, Rockwell, and Schneider Electric — deployed in EV powertrains, industrial drives, and utility metering systems across six continents.
