The Weller Magnastat system operates through a ferro-magnetic sensing device which changes its characteristics when specific temperatures are reached. This causes it to either attract or repel a permanent magnet which operates a power supply switch. In this way power to the heating element can be quickly switched on or off to either provide extra power for soldering operations or reduce power when idling. Various pre-selected tip temperatures are available to permit different types of soldering to be undertaken. Working temperature selection is achieved by simply changing the “;temperature sensing”; soldering tip. These are available in temperature ratings of 260°C, 310°C, 370°C, 425°C and 480°C.