Search coil by computer to determine displacement in multiple dimensions. Additionally, a second search coil can be added to measure torsional rotation. A more crude search coil also called exploring coil is also used in laboratory experiments in schools to measure the magnetic field in a certain region of space. In this case the search coil consists of a simple wire coil or solenoid connected to a sensitive ammeter or galvanometer. The coil is placed in the magnetic field to be measured and quickly withdrawn to a region of space with a negligible magnetic field. As the search coil moves the magnetic
Electric machine on to move stator further. Another name is step motor, and it is suited for low speed and accurate position control. Reluctance machines can be supplied with PMs in stator to improve performance. The “electromagnet” is then “turned off” by sending a negative current in the coil. When the current is positive the magnet and the current cooperate to create a stronger magnetic field which will improve the reluctance machine’s maximum torque without increasing the currents maximum absolute value. In "electrostatic machines", torque is created by attraction or repulsion of electric charge in rotor and stator. Electrostatic generators generate electricity