What are the categories of high-power resistors?

High power resistors are key components used in electronic circuits to carry high power, convert energy, or limit current. Their categories can be systematically classified from four dimensions: material technology, packaging form, application scenarios, and functional characteristics. The following provides a detailed analysis of the classification system of high-power resistors based on technical principles and typical cases:
1、 Classified by materials and processes
1. High power metal film resistor
Structure: A nickel chromium (NiCr) alloy film is sputtered onto a ceramic substrate, and precise resistance values are formed through laser impedance tuning.
characteristic:
High accuracy (± 0.1%), low temperature coefficient (± 5ppm/℃).
The rated power is usually between 1W and 10W, suitable for precision industrial control.
Application: Current sampling circuit for medical equipment and testing instruments.
Case: Vishay's PWR series metal film resistors have a power of 5W and an accuracy of ± 0.5%.
2. Thick film high-power resistor
Structure: Made of ruthenate based conductive paste through screen printing and sintering processes.
characteristic:
Low cost, strong pulse resistance (able to withstand 3 times the rated power impact).
Power range of 1W~50W, surface mount packaging (such as 2512).
Application: Consumer electronics power supply, LED driver circuit.
Case: Guoju's RCW series thick film resistors, with a power of up to 10W, are suitable for fast charging adapters.
3. Wire wound high-power resistor
Structure: Copper or nickel chromium alloy wire is wound around a ceramic tube or metal frame.
characteristic:
The power carrying capacity is extremely strong (up to several kW), but the volume is relatively large.
Accuracy ± 1%~± 5%, temperature coefficient ± 50ppm/℃.
Application: Industrial power supply, motor drive, braking resistor.
Case: Ohmite's RXLG series wire wound resistors, with a power of up to 3kW, are used in industrial frequency converters.
4. Ceramic high-power resistors
Structure: Using aluminum oxide (Al ₂ O3) or aluminum nitride (AlN) ceramics as the substrate, a resistance layer is formed after surface metallization.
characteristic:
High temperature resistance (up to 300 ℃), corrosion resistance, suitable for harsh environments.
Power range of 1W~100W, mainly in plug-in packaging.
Application: High reliability circuits for aerospace and military equipment.
Case: AVX's TCR series ceramic resistors have a power of 50W and meet MIL-STD-202 military standards.
2、 Classified by packaging form
1. Plug in high-power resistor
Typical packaging: TO-220, TO-247, KEC (square ceramic packaging).
characteristic:
Equipped with heat sinks or metal pins, with low thermal resistance (usually<10 ℃/W).
Suitable for high-power scenarios such as industrial power supplies and motor drives.
Case: BOURNS' CR25 series TO-247 packaged resistor, with a power of up to 25W.
2. Surface mounted high-power resistors
Typical packaging: 2512, 2920, 3628.
characteristic:
Compact in size, suitable for SMT process, but with high thermal resistance (up to 50 ℃/W).
Power range of 1W~10W, suitable for portable devices.
Case: Fenghua High tech's FH series 2512 packaged resistor, with a power of up to 3W, is used for laptop power supply.
3. Specially packaged high-power resistors
Integrated design of heat sink: The resistor and heat sink are integrated to improve heat dissipation efficiency.
Water cooled type: dissipate heat through circulating coolant, suitable for extremely high power scenarios (such as electric vehicle charging stations).
Case: Vishay's WSN series water-cooled resistors, with a power of up to 10kW, are used for new energy charging equipment.
3、 Classified by application scenario
1. Industrial control category
Typical products: wire wound resistors, metal film resistors.
Application:
Motor drive: As a braking resistor, it absorbs the back electromotive force of the motor.
Power module: Thick film resistors are used for current sampling in DC-DC converters.
Case: TE Connectivity's PWR221 series, with a power of up to 20W, is used for servo drive of industrial robots.
2. New energy category
Typical products: ceramic resistors, thick film resistors.
Application:
Photovoltaic inverter: Metal film resistor as voltage sampling element, capable of withstanding high voltage of 600V.
Energy storage system: Milliohm level resistors are used for battery pack current detection, with an accuracy of ± 0.5%.
Case: Panasonic ERJ series thick film resistors with a power of 5W, used for photovoltaic inverters.
3. Automotive electronics
Typical products: Surface mounted high-power resistors, metal film resistors.
Application:
BMS system: monitors battery cell voltage and operates at temperatures ranging from -40 ℃ to 125 ℃.
Motor controller: The power resistor serves as a pre charging resistor to limit the starting current.
Case: ROHM's MCR series automotive grade resistors, with a power of up to 3W, have passed AEC-Q200 certification.
4. Aerospace category
Typical products: ceramic resistors, metal film resistors.
Application:
Satellite power supply: The thin-film resistor can withstand a total radiation dose (TID) of up to 100krad (Si).
Rocket propulsion: Special resistors withstand extreme vibrations and temperature shocks (-55 ℃~150 ℃).
Case: Vishay's SQP series, with a power of up to 10W, is used for satellite communication equipment.
4、 Classified by functional characteristics
1. Braking resistor
Features: Fast response to motor back electromotive force, high power carrying capacity.
Applications: Industrial servo systems, elevator traction machines.
Case: KOA's RK73H series, with a power of up to 50W, is used for industrial robot braking.
2. Current sampling resistor
Features: milliohm resistance, high precision (± 0.5%), low temperature coefficient (± 20ppm/℃).
Applications: Battery Management System (BMS), Electric Vehicle Motor Controller.
Case: ISABELLENH ü TTE's PVB series, with a power of 3W, is used for Tesla Model 3 battery packs.
3. Load resistance
Features: Adjustable power (0-100% continuous adjustment), high stability.
Application: Testing equipment, aging test bench.
Case: Chroma's 63800 series, with a power of 4kW, is used for power module testing.
5、 Technological Trends and Innovation
Material Innovation:
Carbon nanotube (CNT) resistance: With a resistivity as low as 10 Ω· cm and a thermal conductivity of 3000W/m · K, it is suitable for high-frequency and high-power scenarios.
Graphene resistor: a two-dimensional material that enables flexible and transparent design, suitable for wearable devices.
Structural optimization:
3D integration: Vertical stacking of resistive layers through TSV (silicon via) technology to enhance power density.
Intelligent resistor: integrates temperature sensor and MCU to achieve real-time health monitoring and self-protection.
Technological breakthrough:
Laser Resistance Adjustment: Femtosecond lasers achieve nanometer level accuracy, with resistance control up to ± 0.01%.
Atomic Layer Deposition (ALD): Deposition of a single atomic layer resistive film with thickness uniformity<1nm.
summarize
High power resistors form a complete product system covering industrial, new energy, automotive, aviation and other fields through diversified combinations of materials, packaging, application scenarios and functional characteristics. Its technological evolution direction focuses on higher power density, smaller size, stronger environmental adaptability, and intelligent functional integration. With the rapid development of cutting-edge fields such as 5G, electric vehicles, and aerospace, high-power resistors will continue to innovate and provide more efficient and reliable energy management solutions for electronic devices.