Abstract: An electromagnetic motor is provided with a samarium cobalt permanent magnet comprising a plurality of radially abutting segments. A combination of linear and non-linear springs with a force gradient larger than the magnetic force gradient facilitate motor operation in proportion to currents in electrical coils positioned on each side of the permanent magnet. Servoamplifiers independently control the current in each electrical coil in response to an input command signal, a motor position feedback signal and an actuator position feedback signal. A failure detection circuit detects coil failure by comparing current in each coil on one side of the magnet with the current in a corresponding coil on the opposite side of the permanent magnet. The circuit produces output signals to disconnect a defective coil and initiate an alarm. The circuit also detects power supply and motor position transducer failures by comparing their respective output voltage signals against predetermined reference voltages.

Abstract: An electromagnetic motor is provided with a samarium cobalt permanent magnet comprising a plurality of radially abutting segments. A combination of linear and non-linear springs with a force gradient larger than the magnetic force gradient facilitate motor operation in proportion to currents in electrical coils positioned on each side of the permanent magnet. Servoamplifiers independently control the current in each electrical coil in response to an input command signal, a motor position feedback signal and an actuator position feedback signal. A failure detection circuit detects coil failure by comparing current in each coil on one side of the magnet with the current in a corresponding coil on the opposite side of the permanent magnet. The circuit produces output signals to disconnect a defective coil and initiate an alarm. The circuit also detects power supply and motor position transducer failures by comparing their respective output voltage signals against predetermined reference voltages.