A Guide to Wirewound Resistors
One of the oldest resistor types that is still used today is the wirewound resistor. A wirewound resistor is made by winding a metallic wire around a core of insulating material. The areas of application of a wirewound resistor differs from other resistor types. There are two types of wirwound resistor including the power wirewound resistor and the precision wirewound resistor. These resistors can be used in many different applications. These can be adapted for use in temperature and current sensors.
Precision wirewound resistors are used in accurate calibration devices and measuring bridges. These resistors are very accurate and could have a tolerance of under one tenth percent. Its temperature coefficient is considerably better than the majority of metal film resistors. It has good stability and is able to withstand increase in temperature to lower than 30 degrees. This is why they can be coated with epoxy materials. You can read more about a current shunt resistor or buy the best wirewound resistors.
Power wire wound resistors have a range which varies from 0.5 watts up till more than 1000 w. You can categorize these resistors by breaking them down according to the coating type. For the lowest dissipation ranges, silicon resins can be used. These small resistors are able to endure temperature increases up to a maximum of 300 degree Celsius above the normal level. A second kind of coating is porcelain enamel. This traditional coating type offers good insulation properties at low temperatures. AT high temperatures the insulation is considerably less. This makes it less common. 400 degrees is the maximum operating temp with this coating. The ceramic coating is the most standard type of coating. The resistors have a ceramic core and coating to protect the wire.
Effective energy dissipation is given by the coating yet it has good insulation properties. On top of that, it provides a good physical protection. These resistors can warm up to around three hundred degrees without problems. These are engineered with leads that allow for horizontal or vertical installation. Resistors have the largest power ratings that feature an aluminum case fins. It can give a larger surface area that can dissipate heat and permits the resistor handle more electrical power without getting weakened. The best insulating resistance is kept by the anodized resistors. To attain high power dissipation, the resistor has to be place on a metallic surface to achieve an ideal heat transfer. The highest outside temperatures are approximately 300 degrees with the TRC value quite small.