Shunt resistors & Converters
Shunt resistors are current sensors that measure AC or DC electrical current. The voltage drops on the application of the current shunt, and such drop constitutes the basis of measurement. These devices may have either built-in or external DC current shunts. Current shunt resistors also have a variety of electrical and mechanical ranges and specifications, such as current rating, output voltage, resistance accuracy and resistance drift. The best stunt resistors are accurate, with zero inductance, and offer the claimed resistance in a precise manner, regardless of temperate or voltage variations. The efficiency of the current shunt also depends on its power rating. Current shunt resistors heat up owing to the dissipation of heat from the current flowing through the device. The heat can change the resistance and even damage the shunt irrevocably, and as such, a high power rating is essential for the integrity of these devices. The high power rating apart, it is important not to exceed the stated temperature measuring range of the device, to prevent overheating. Top-end shunt resistors are made of nickel plated copper rails and manganin resistor rods. Slip-on current transformers are a heavy-duty variant, used to measure high-quality AC current. Snap-in current transducers are used to detect the current flowing through wires and cables.