The disorder results from overproduction of collagen, a naturally occurring protein found in the skin. It is unknown what causes this overproduction of collagen to occur but the immune system is believed to play a significant role. Morphea is not contagious or passed down in families.
A typical US household voltage is 120/240 V, 60 hz, single phase. There is a tolerance and the actual measured voltage is rarely exactly 120 volts. A common reading at my house is 117 volts. Industrial motors are made and rated in multiples of 115V (115, 230, 460, and 550Vac) for use on line voltages in multiples of 120 V (120, 240, 480, and 600 Vac).
A current source is a piece of equipment that is used to produce or receive an electric current. It is related to the voltage source, which is the dual of the current source. Often, a current source will be used to power various machines, which can derive energy from the electric current produced. There is a wide range current sources available, such as resistor sources, active sources, radio frequency (RF) current sources, and direct current (DC) and alternating current (AC) sources.