Abstract: A method for controlling a reversible polyphase rotating electrical machine, wherein at least one coil circuit is supplied through a bridge of switches, including the following steps: controlling (P1) the bridge to deliver to the coil circuit a periodic voltage with a phase shift (d) relative to an electromotive force induced in the coil circuit, such that an operating torque is generated, the phase shift having initially a first value (d0); controlling (P2) the bridge to deliver to the coil circuit a periodic voltage with the phase shift (d) producing a torque ranging between the operating torque and the opposite of the operating torque, the phase shift taking on a plurality of values upon the control; flipping (T2) the bridge in rectifying mode.

Abstract: In a multi-phase motor drive that includes a bus capacitor, a multi-phase motor, a multi-phase inverter, multiple switches each having an on-state and an off-state, and multiple current sensors each being in series with respective phase winding, a method for checking the accuracy of circuit parameters of the motor drive, including using the switches to produce a first loop that includes the capacitor bank, a first phase winding, a first current sensor, a second phase winding, and a second current sensor, using the current sensors to determine a magnitude of current in the first and second phase windings, comparing a magnitude of current indicated by the first current sensor and the second current sensor, and determining a magnitude of a difference between the current in the first and second phase windings.

Abstract: A field effect transistor is provided between the ground and an H bridge circuit for rotating a motor in forward and reverse directions in a manner that the drain of the transistor is grounded and the gate thereof is coupled to a DC power source such as a battery serving as a bias source which supplies electric power to the H bridge circuit. Thus, when the DC power source such as a battery is reversely connected, the field effect transistor normally in an on state is turned off. A controller monitors the source voltage of the field effect transistor, and when the controller detects an excess current, the controller outputs a control signal to the high-side driver to prevent the supply of electric power to the motor.

Abstract: A rotating electric machine is provided which includes multiple independent control windings for compensating for rotor imbalances and for levitating/centering the rotor. The multiple independent control windings are placed at different axial locations along the rotor to oppose forces created by imbalances at different axial locations along the rotor. The multiple control windings can also be used to levitate/center the rotor with a relatively small magnetic field per unit area since the rotor and/or the main power winding provides the bias field.

Abstract: A reversible linear motor has a coil arrangement arranged alongside a conductive body such as a rotatable aluminium disc. The coil arrangement is made up of three separate coils: namely an inner coil and two interconnected outer coils on opposite sides of the inner coil. The coils are connected to a single phase a.c. supply and the drive of the disc can be reversed by reversing the connection of the inner coil relative to the two outer coils. The linear motor may be used for driving a reel of an entertainment machine of the fruit machine kind.

Abstract: A brushless DC motor includes a rotor adapted to rotate about an axis and having a plurality of magnets for generating a magnetic flux; a stator having at least two coils through which an alternating signal is applied for rotating the rotor about its axis; and a reversible drive circuit for regulating the alternating signal through the coils and which includes first and second switching transistors for energizing the coils with the alternating signal, a rotational position sensing circuit for generating a position signal corresponding to the rotational position of the rotor, a rotational direction selecting circuit for producing a control signal corresponding to a desired rotational direction of the rotor, an NPN switch control transistor responsive to the position signal and control signal for alternately switching the first and second switching transistors so as to rotate the rotor in the forward direction, and a PNP switch control transistor in parallel with the NPN switch control transistor and responsive