Power resistor guide: metal oxide, thick film, braking resistors 1W-1kW. ADD stocks Vishay, Ohmite, TE Connectivity, Bourns. Buy power resistors online from HK.
Power Resistors: A Complete Guide to High-Power, Heat-Sink, and Braking Resistors
Power resistors are engineered to dissipate significant electrical energy as heat, operating from a few watts up to a kilowatt or more. They are the silent workhorses of power electronics, absorbing surge energy, providing dummy loads, and protecting circuits from fault currents. At ADD Components, we source high-power resistors across the full spectrum — metal oxide, thick film, wirewound, and heat-sink mountable types — from Vishay, Ohmite, TE Connectivity, and Bourns, supporting designers of power supplies, motor drives, and industrial equipment across global supply chains.
Product Types
Metal Oxide Power Resistors
Metal oxide film resistors are formed by depositing a tin-oxide resistive layer onto a ceramic core. They are a cost-effective choice for medium power levels, typically 1 W to 5 W, offering good pulse and surge withstand capability with flameproof construction. Their temperature coefficient is higher than metal film, but they excel in applications where transient overloads and elevated temperatures are expected, such as power supply inrush limiting, snubber circuits, and general power handling. ADD Components supplies metal oxide resistors in axial, cement, and chip packages from multiple manufacturers.
Thick Film Power Resistors (Heat-Sink Mountable)
Thick film power resistors bring surface-mount-style construction to high-power designs by printing a resistive element onto a ceramic or metal substrate mounted in a power package such as TO-220, TO-247, or TO-263 (D2PAK). When bolted to a suitable heat sink, these parts achieve ratings from 20 W to over 100 W in a compact footprint, with low inductance that suits high-frequency and fast-switching circuits. Vishay's RTO (TO-220) and LTO (TO-247) series are the industry references, joined by Ohmite's AP101 series and Bourns' PWR221T and PWR263S families, all available through ADD Components.
Wirewound and Cement Power Resistors
Wirewound resistors wind a resistive alloy wire — typically nickel-chromium or copper-nickel — around a ceramic or fibreglass core, offering the highest power ratings and excellent surge capability. They are available as axial/radial parts, vitreous-enamelled tubular types, and cement-filled ceramic boat packages, with ratings from a few watts to hundreds of watts. Wirewound parts dominate motor braking, load banks, and current sensing. Ohmite's L series tubular resistors and TE Connectivity's CGS aluminum-housed wirewound units are trusted choices for demanding industrial duty.
Braking Resistors
Braking resistors absorb the regenerative energy returned by a motor during deceleration, converting it to heat so a variable-frequency drive (VFD) does not trip on overvoltage. They must be specified for the drive's peak braking power, duty cycle, and resistance value, and are commonly supplied as aluminum-housed wirewound or high-power wirewound units rated from 50 W to several kilowatts. TE Connectivity's CGS aluminum-housed range, Vishay's high-power wirewound series, and Ohmite's chassis-mount offerings are standard braking resistor solutions ADD Components quotes daily for machine builders and automation integrators.
Typical Applications
Power Supplies: Inrush limiting, pre-charge, bleed, and snubber resistors from 1 W to 100 W protect bulk capacitors and semiconductors.
Motor Braking: VFD braking resistors dissipate regenerative energy during deceleration and e-stop, typically 100 W to 1 kW.
Load Banks: High-power resistor networks simulate electrical loads for testing generators, batteries, and power converters, often multi-kilowatt.
Current Sensing and Shunts: Low-value, low-inductance power resistors provide precise current measurement in drives and converters.
Key Selection Parameters
Power Rating: Continuous dissipation in watts, from 1 W to 1 kW and beyond. Always derate above the specified ambient and confirm heat-sink requirements for TO-220/TO-247 packages.
Resistance Value and Tolerance: Braking resistors typically fall between 10 Ω and 500 Ω matched to the drive's DC bus; tolerances of ±5% are common.
Mounting and Thermal Path: Through-hole axial, chassis/heat-sink mount, or SMD power packages. Heat-sink mountable types require a thermal interface for rated performance.
Pulse and Overload Capability: Verify surge energy rating for inrush and braking duty cycles, where peak power can far exceed continuous rating.
Inductance: Wirewound parts carry inductance that matters in fast-switching circuits; thick film and non-inductive windings are preferred for high-frequency applications.
Environmental Rating: Flameproof coatings, insulation voltage, and IP ratings matter for industrial and safety-critical installations.
Representative Resistors We Source
| Part Number | Brand | Type | Key Spec |
|---|---|---|---|
| LTO100F10000JTE3 | Vishay | Thick Film (TO-247) | 100 W, 1 kΩ, ±5%, heat-sink mount |
| RTO050F10000JTE3 | Vishay | Thick Film (TO-220) | 50 W, 1 kΩ, ±5%, heat-sink mount |
| RTO020F10000JTE3 | Vishay | Thick Film (TO-220) | 20 W, 1 kΩ, ±5%, heat-sink mount |
| L50J100E | Ohmite | Wirewound (Tubular) | 50 W, 100 Ω, ±5%, adjustable |
| AP101 100R J | Ohmite | Thick Film (TO-247) | 100 W, 100 Ω, ±5% |
| HSA50 100R J | TE Connectivity (CGS) | Wirewound (Aluminum Housed) | 50 W, 100 Ω, ±5%, chassis mount |
| SQP500JB-100R | Yageo | Cement Wirewound | 5 W, 100 Ω, ±5% |
| PWR221T-30-1000F | Bourns | Thick Film (TO-220) | 30 W, 100 Ω, ±1% |
| PWR263S-35-1000F | Bourns | Thick Film (D2PAK) | 35 W, 100 Ω, ±1% |
| PWR4412-2SBR1000F | Bourns | Wirewound Radial | 5 W, 100 mΩ, current sense |
Send Us Your Resistor Requirements
Whether you need heat-sink mountable thick film resistors for a compact power stage, aluminum-housed wirewound units for motor braking, or multi-kilowatt arrays for a load bank, ADD Components delivers competitive pricing and dependable lead times from Vishay, Ohmite, TE Connectivity, Bourns, and Yageo. Our procurement team can cross-reference existing part numbers, specify braking resistors to your VFD's parameters, and manage long-term supply agreements for your BOM. Submit your power resistor requirements today for a fast quotation.
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Last updated on August 19, 2026