W21-1K2JI WELWYN Resistor (Resistors, Axial Diameter Horizontal Mounting) In Stock
WELWYN W21-1K2JI is a wirewound resistor with 1.2 kΩ resistance, ±5% tolerance, and 3 W power rating in an axial horizontal mounting package. Features robust wirewound construction for high power dissipation and stability in demanding applications. Available from authorized distributors with worldwide shipping.
- Manufacturer
- WELWYN
- Package
- Resistors, Axial Diameter Horizontal Mounting
- Pin Count
- 2
- Lifecycle
- ACTIVE
- Datasheet
- W21-1K2JI Datasheet PDF
- Category
- Resistor
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- 3 W power rating with wirewound construction enabling reliable high-power dissipation in compact axial package
- 1.2 kΩ resistance with ±5% tolerance for robust motor control, load, and power supply applications
- Axial horizontal mounting style compatible with standard through-hole PCB and chassis assembly
- Wirewound technology providing low noise, high stability, and excellent thermal performance
Applications
The W21-1K2JI is used in power supply circuits, motor control resistor networks, and load banks where 3 W continuous power dissipation at 1.2 kΩ is required. Its wirewound construction makes it ideal for inrush current limiting, braking resistors in servo drive systems, and dummy load applications in industrial power electronics. The axial horizontal mount package suits through-hole PCB designs and chassis-mounted assemblies in power conversion equipment operating across wide ambient temperature ranges.
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
Alternate & Equivalent Parts
No known alternates. Submit an RFQ and our team can suggest alternatives.
Frequently Asked Questions
What maximum current can W21-1K2JI handle continuously at its rated power?
At 3 W rated power and 1.2 kΩ resistance, the W21-1K2JI can handle a maximum continuous current of approximately 50 mA (using I = √(P/R) = √(3/1200) ≈ 0.05 A). The corresponding maximum voltage across the resistor is approximately 60 V DC, making it suitable for medium-voltage power supply bleeder and load resistor applications.
What advantages does wirewound construction give the W21-1K2JI over carbon film resistors at 3 W?
Wirewound construction in the W21-1K2JI provides superior power handling at 3 W with lower thermal resistance than carbon film alternatives, which are typically limited to 0.25 W to 0.5 W in similar package sizes. Wirewound resistors also exhibit lower noise, better long-term stability (typically ±1% drift over lifetime), and can withstand short-term power surges up to 5× rated power, making them ideal for industrial and power electronics applications.
In which motor control or braking applications is the W21-1K2JI 1.2 kΩ wirewound resistor typically specified?
The W21-1K2JI is specified in DC motor speed control bleeder circuits, servo drive dynamic braking resistor banks, and regenerative braking energy dissipation networks. Its 1.2 kΩ resistance at 3 W handles braking currents up to 50 mA in low-power servo systems operating from 24 V to 48 V DC bus voltages, providing reliable energy dissipation without exceeding thermal limits in enclosed enclosures.
How does the ±5% tolerance of W21-1K2JI affect its suitability for precision versus power applications?
The ±5% tolerance (J grade) of W21-1K2JI means the actual resistance can range from 1.14 kΩ to 1.26 kΩ, making it unsuitable for precision voltage dividers or calibration circuits requiring better than 1% accuracy. However, for power dissipation applications such as load resistors, bleeder circuits, and motor braking where exact resistance is less critical than power rating, the ±5% tolerance is fully adequate and provides a lower-cost solution than ±1% wirewound alternatives.
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About WELWYN
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