17721020 - 25W 20 Ohm Non-Inductive Aluminum Housed Resistor

Precision Power Resistor for Industrial Electronics

The 25W 20 Ohm Non-Inductive Wire Wound Resistor is a critical component designed for high-performance industrial applications, including the repair and maintenance of welding power sources. Encased in a durable aluminum housing, this resistor is engineered to handle significant power loads while maintaining exceptional stability. The aluminum shell not only protects the internal winding but also acts as a heat sink, allowing for efficient thermal dissipation when mounted to a chassis. This ensures the component operates within safe temperature ranges even during prolonged use in demanding environments.

Non-Inductive Design for High Frequency

One of the standout features of this resistor is its Non-Inductive (NI) construction. Standard wirewound resistors can act like inductors, creating unwanted reactance in high-frequency circuits. This "NI" version typically utilizes Ayrton-Perry winding or similar techniques to cancel out inductance. This makes it particularly suitable for high-frequency applications found in modern inverter welding machines, HF start circuits, and precision power supplies where signal purity and fast response times are paramount.

Reliability and Precision

With a tight 1% tolerance, this resistor offers precision that standard 5% or 10% components cannot match. This accuracy is vital for control circuits where specific resistance values dictate voltage drops or current limits. Whether you are troubleshooting a fault in a TIG welder's high-frequency board or replacing a burnt-out load resistor in a power supply unit, this component provides the reliability required for professional repairs. Its rugged construction resists vibration and thermal shock, common stressors in industrial workshop environments.

Applications

• Welding Machine Repair: Ideal for replacing failed resistors in HF circuits, snubber networks, and control boards.
• Power Supplies: Used for voltage dropping, bleeding, or current sensing applications.
• Test Equipment: Suitable for use as a dummy load or in calibration equipment due to its high precision.