Abstract: A drive circuit for a motor having a plurality of phases, comprising an input for a DC signal and a plurality of phase outputs, the circuit being arranged to provide at each of the phase outputs, in use, current to one phase of the motor, in which there is provided a converter for each phase output, each converter being arranged to take as an input a DC signal and output an signal having an AC component with a higher voltage magnitude than that of the DC signal input to the converter. Typically, the converters comprise ?uk converters.

Abstract: A motor drive circuit comprises positive and negative input terminals for connection of the motor circuit to a DC supply, a DC link filter connected between the input terminals: an electric motor having at least two phases, a plurality of motor drive sub-circuits, each connected to a respective phase of the electric motor and which each control the flow of current into or out of the respective phase of the motor that has been drawn from the supply through the DC link filter, and a switching means provided in the electrical path between the DC link filter and the electric motor drive sub-circuits, the switching means being movable between a closed position in which it connects the DC link filter to the motor drive sub-circuits, and an open position which isolates the DC link filter from the motor drive sub-circuits.

Abstract: A drive circuit for a motor having a plurality of phases, comprising an input for a DC signal and a plurality of phase outputs, the circuit being arranged to provide at each of the phase outputs, in use, current to one phase of the motor, in which there is provided a converter for each phase output, each converter being arranged to take as an input a DC signal and output an signal having an AC component with a higher voltage magnitude than that of the DC signal input to the converter. Typically, the converters comprise ?uk converters.

Abstract: A motor drive circuit comprises positive and negative input terminals for connection of the motor circuit to a DC supply, a DC link filter connected between the input terminals: an electric motor having at least two phases, a plurality of motor drive sub-circuits, each connected to a respective phase of the electric motor and which each control the flow of current into or out of the respective phase of the motor that has been drawn from the supply through the DC link filter, and a switching means provided in the electrical path between the DC link filter and the electric motor drive sub-circuits, the switching means being movable between a closed position in which it connects the DC link filter to the motor drive sub-circuits, and an open position which isolates the DC link filter from the motor drive sub-circuits.

Abstract: A vehicle anti-lock braking (ABS) system having a motor-driven pump (10) for providing a hydraulic supply to the ABS system. The pump motor (10) is controlled by a series device in the form of an electronic switch (16), such as a MOSFET, to enable frequent testing of the motor circuit by short pulses which produce no significant noise. Feedback to control motor speed is obtained by measuring the e.m.f. generated by the motor (16) after it has been switched off and after a delay to allow the back e.m.f., caused by switching off the motor, to decay (preferably to zero) before the measurement operation begins. The generated voltage is integrated during a motor switch-off period, the motor speed being established in this period by subtracting the measured integrated voltage when acting as a generator from the main supply voltage (B+) .

Abstract: In a control system, for instance forming part of a vehicle anti-lock brake system, a plurality of control processors provides similar or identical control signals of the system in response to a shared transducer input. An independent data correlation processor compares data generated in the control processors for correlation and, in the absence of proper correlation, provides an indication which may be used to disable anti-lock operation of the brake system. In preferred embodiments, a four wheel vehicle with an anti-lock brake system is monitored by dual microprocessors. Each wheel has a speed sensor which supplies an input to each microprocessor. The data correlation processor compares the outputs of the microprocessors for each wheel and sends and alarm or disables the anti-lock brake system if the difference in the microprocessors output is beyond a limit amount.