The electric current passage during a few milliseconds into the coil (D) turns on the clamping system.

An inverse electric current passage turns off the system.

The electric current passage during a few milliseconds into the coil (F) permits to reverse the polarity of magnet (G).

The magnetic fields generated by magnets (G) and (E) are oriented to the polar face of the chuck, which becomes active and clamps the work piece to machine.

A new electric current passage turns off the system.