Trådresistors

Trådresistors, also known as wirewound resistors, are a type of electrical resistor that uses a long length of resistive wire wound around a core to create a specific resistance value. The wire is typically made of an alloy such as nichrome (nickel-chromium) or Manganin (copper-manganese-nickel), chosen for its stable resistance over a range of temperatures. The core is usually made of ceramic or a similar insulating material, providing structural support and heat dissipation.

The construction of a trådresistor involves carefully winding the resistive wire onto the core. The length and diameter of the wire, along with its material properties, determine the final resistance. Once wound, the ends of the wire are connected to terminals, which allow the resistor to be integrated into an electrical circuit. For higher power applications, trådresistors are often coated with a protective glaze or cement to improve durability and heat management.

Trådresistors are known for their high power handling capabilities and excellent stability, making them suitable for applications where continuous high currents are present or where precise resistance values are critical over time and temperature fluctuations. They are commonly used in power supplies, motor controls, and test equipment. However, they tend to be larger and more expensive than other resistor types like film resistors, and can exhibit significant inductance due to the coiled wire, which may be a disadvantage in high-frequency circuits.