Abstract: A method and a control system for a multiphase-phase inverter system, the control system comprising an electric current detection circuit and a processor, wherein each phase of an electrical cycle is separated into a plurality of sections, inputs from the electric current detection circuit are received, each input indicating a measured phase current, and a phase current is calculated in each section, wherein the phase current calculation in at least one of the sections is determined from a changing ratio of the value of the phase current calculated from the measured values of the other phase currents in the multiphase system and the measured value of the phase.

Abstract: There is provided a method and control system for controlling a switching device in a power converter according to a modulation scheme. The switching device couples a direct current (DC) source to provide an alternating current (AC) output at a particular switching frequency. The method comprises the step of, in each switching period, switching the switching device between active configurations providing a finite voltage at the output and inactive configurations providing a zero voltage at the output. The ratio between the total period of time in which the switching device is in an active configuration and the total period of time in which the switching device is in an inactive configuration is the same for each switching period and is determined according to the desired voltage at the AC output.

Abstract: The present disclosure relates to a method of determining an offset between a detector and a point on a motor, the movement of the point on the motor being impeded in at least one direction. In particular, this disclosure relates to a method of determining a commutation offset for an encoder that works in conjunction with a synchronous motor. The commutation offset is an offset between the detector and the north pole of a permanent magnet within the motor. The method comprises setting a test value for the offset, causing a displacement of the detector based on the test value and measuring that displacement. The method further comprises repeatedly increasing the test value, and causing and measuring a displacement for each so increased test value until it is determined that the test value has crossed a threshold.

Abstract: A ground fault detection circuit comprising a fuse and a fuse detect circuit. The fuse and the fuse detect circuit are arranged to be coupled in parallel between a reference point and a second point of a monitored circuit for which ground faults are to be detected. The fuse detect circuit is further arranged to detect a fuse break indicative of a ground fault condition and disable at least a portion of the monitored circuit.

Abstract: Conducting emission suppression in a power circuit for an electric motor comprises a negative temperature co-efficient resistor and capacitor connecting one of the power lines to ground. The NTC resistor is self-stabilizing so that changes in the load current are automatically compensated for.

Abstract: The present disclosure relates to a power conversion system comprising a transformer comprising first, second, and third inductive coupling elements, a first power supply arranged to provide a voltage across the first coupling element, a second power supply arranged to provide a voltage across the second coupling element, an output arranged to receive a voltage from the third coupling element. In use, the voltage across the first coupling element and the voltage across the second coupling element are arranged to induce a voltage in the third coupling element. The system also comprises a control arrangement arranged to independently control the operation of the first and second power supplies.

Abstract: There is described an electronic assembly comprising a structure and a printed circuit board (PCB) connected to the structure to form a duct. The PCB has a first side arranged to receive one or more heat-generating components, and a second side. The PCB comprises one or more apertures formed therein. The electronic assembly further comprises airflow generating means arranged to generate an airflow along the duct and along the second side of the PCB such that air is forced through the one or more apertures. By forming a duct beneath a PCB and allowing air to be forced through apertures formed in the PCB, more efficient cooling of components on the PCB may be achieved. For example, the position of the apertures may be tailored such that specific components, or specific parts of components, may be exposed to airflow through the apertures.

Abstract: An inverter circuit comprises an inverter which can be configurable for controlling the supply of mains current from a grid to an electric machine in a start-up mode whereby the machine drives the prime mover for initialization. Thereafter the same inverter is reconfigurable as part of the circuit to supply reactive power to the grid when the machine is running as a generator powered by the prime mover.

Abstract: A voltage measurement is made between two points in a circuit. If the measured voltage exceeds a predetermined amount, a switch is operated to electrically connect the two points.

Abstract: A device for locking to a DIN rail includes a shaft defining an axis of rotation and first and second rail-engaging members connected to the shaft. The rail-engaging members are each shaped to engage a DIN rail in a respective engaging position. The shaft is rotatable about the axis of rotation and thereby arranged to urge each rail-engaging member into its respective engaging position with a DIN rail positioned between the first and second rail-engaging members. Other example devices for locking to a DIN rail and methods of mounting component(s) to a DIN rail are also disclosed.

Abstract: A method arranged to control a motor for driving a load is disclosed. The motor and load form at least a part of a system and the motor comprises a stator arranged to produce a varying magnetic field responsive to an applied AC voltage and a rotor arranged to rotate responsive to the varying magnetic field produced by the stator, the rotor rotating at a speed synchronized to a frequency of the applied AC voltage. The method comprises receiving a target rotor speed, determining a voltage level for the applied AC voltage for producing a magnetic field having magnetic flux of sufficient magnitude to maintain the rotor in synchronization with the frequency of the applied AC voltage when rotating at the target speed of rotation. The voltage level is determined in accordance with the target rotor speed and a model of the system.

Abstract: A method of controlling a current flowing through a component of a drive comprising the steps of: estimating the current flowing through a component; estimating the temperature of the component; comparing the estimated temperature with a desired maximum temperature for the component; and adjusting the current flowing through the component based on the result of the comparing step.

Abstract: A method of managing recovery from an event in an electrical circuit leading to a loss of control of an inverter in the electrical circuit is disclosed, the method comprising sampling a parameter of operation before the event, monitoring for occurrence of the event, calculating an estimated value of the parameter at a time after the event based on an extrapolation of the monitored parameter and controlling the inverter using the estimated value of the parameter.

Abstract: A sealing element (1) comprising, in cross-section, a body (7a) and a first sealing part (8a).The first sealing part (8a) providing a sealing face (12a), the first sealing part being connected to and angularly and resiliently displaceable relative to a first surface of the body (7a).

Abstract: A method of reducing periodic disturbances in the feedback quantity of a controlled system is disclosed. The method includes receiving a feedback signal and repeatedly deriving respective magnitudes of harmonic components of the feedback signal to produce corresponding error signals. The error signals and harmonic components are used to generate harmonic control signals. The harmonic control signals are used to create a plurality of negative feedback loops acting to reduce the error signals. The present disclosure thus provides negative feedback control in the frequency domain. In one specific disclosed embodiment, the control is tied to the periodic domain resulting from the rotation of an actuator motor shaft.

Abstract: A desaturation detection circuit for use between the desaturation detection input of an optocoupler and the output of a power switching device, the desaturation detection circuit comprising: a threshold setting element having an input and an output, the input for connection to the output of a power switching device via one or more diode(s), the threshold setting element being arranged to set a threshold voltage at the input at which the threshold setting element will provide an output at the output of the threshold setting element when the input voltage is exceeded, and a detector having an input connected to the output of the threshold setting element and an output connectable to a desaturation detection input of an optocoupler, the detector being arranged to detect an output at the output of the threshold setting element and in response to provide a control signal at the output of the detector for the desaturation detection input to trigger a desaturation routine in the optocoupler.

Abstract: Apparatus for preventing output of an input signal is disclosed. The apparatus comprises a signal control unit comprising a signal buffering unit having an input and an output, the signal buffering unit arranged to receive an input signal and pass the input signal to the output when the signal buffering unit is powered, wherein a negative power supply terminal of the signal buffering unit is arranged to be supplied by a first power source having a voltage. The signal control unit also comprises a boost circuit arranged to boost the voltage of the first power source to a boosted voltage higher than the voltage of the first power source and supply either the voltage of the first power source or the boosted voltage to a positive power supply terminal of the signal buffering unit.

Abstract: A latch mechanism is provided comprising a latch and a cover arranged for attachment to the latch. The latch includes a latch body and a projection extending therefrom wherein, when the latch and cover are attached to one another, the projection extends from an inner surface of the cover. The latch mechanism further comprises a docking area located on a device, the docking area being arranged to receive the latch such that the cover may be securely fixed to the device. When the cover is placed over the docking area, a sliding movement of the cover causes actuation of the latch to secure the cover to the docking area. When the cover is secured in the docking area, further sliding movement of the cover is prevented.

Abstract: The present disclosure relates to a plate for use with a heatsink. The plate is adapted to engage with the heatsink and a fan subassembly, and comprises a first substantially planar section which is adapted to engage with the heatsink and a second substantially planar section which is adapted to engage with the fan subassembly.

Abstract: A rectifier circuit comprising an AC input, at least one thyristor coupled to the AC input, a DC bus driven by the at least one thyristor, a controller arranged to: derive a first current in the DC bus, derive a maximum current demand on the DC bus, and provide a trigger signal to the at least one thyristor based on the derived maximum current and the derived first current.