The Magnastat system works by means of a permanent magnet and a ferromagnetic temperature sensor. If the soldering tip is cold, the permanent magnet is attracted by the ferromagnetic temperature sensor. In this state the switch is closed and the heating is switched on. If the temperature sensor approaches its Curie point, i.e. the selected peak temperature, its magnetic behavior changes and the heating is switched off. If the tip cools down a little, the temperature sensor picks up again and the control cycle starts again.
The working temperature is selected by simply changing the soldering tip with the temperature sensor attached to it. The Weller Longlife soldering tips cover different temperature ranges.