Resistors are commonly found elements in electrical networks and circuits. These components are used to control electric current flow within electrical parts and circuit boards. One of the most common types of resistors is known as the wirewound resistor. Wirewound resistors are produced by winding metal wire around a plastic, fiberglass or ceramic core. Typically, this metal wire is comprised of nichromea nickel-chromium wire.
Optimized circuit designs often include wirewound resistors where precision is important. Wirewound resistors have tight resistance tolerances and are typically very stable. Since these resistor types can maintain their precision over time, they are extremely popular in electrical components. They are comprised of very stable materials and are very reliable and rugged. Modern circuits typically use wirewound resistors for this reason.
While electronic devices have become a way of life for much of the world, their presence have caused adverse effects on the health of many and the environment. In order to offset the risks that disposing of electronic parts creates, the European Union implemented the Restriction of Hazardous Substances (RoHS) Directive which went into effect July 1, 2006.
This directive is intended to regulate toxic materials in electronic devices and electrical systems. As such, RoHS restricts the use of lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyls and polybrominated diphenyl ether. These restrictions are intended to apply to the production of consumer electronic equipment, appliances, tools, toys and medical devices. While the directive is currently intended for the European Union, other countries around the world are adopting similar laws and regulations to reduce hazardous materials.