Abstract: A drive controller for a motor of a compressor includes a drive circuit that applies voltages to windings of the motor. The drive controller includes a speed control module that controls the drive circuit to rotate the motor at a requested speed. The drive controller includes a speed determination module that generates the requested speed. The drive controller includes a locked rotor protection module that identifies a locked rotor condition and, in response to identifying the locked rotor condition, instructs the speed determination module to power down the motor. The locked rotor protection module acquires an estimated speed of the motor upon expiration of a predetermined time interval that begins upon startup of the motor. The locked rotor protection module identifies the locked rotor condition in response to the estimated speed being lower than a threshold speed. The threshold speed is based on the requested speed.

Abstract: A drive controller for a motor of a compressor includes a drive circuit that applies voltages to windings of the motor. The drive controller includes a speed control module that controls the drive circuit to rotate the motor at a requested speed. The drive controller includes a speed determination module that generates the requested speed. The drive controller includes a defrost module that enables a defrost mode in response to a defrost command. While the defrost mode is enabled, the defrost module causes the speed determination module to (i) ramp the requested speed down from a speed demand to a defrost speed and (ii) maintain the requested speed at the defrost speed for a predetermined period of time.

Abstract: A drive controller for a motor of a compressor includes a drive circuit that applies voltages to windings of the motor. A speed control module controls the drive circuit to rotate the motor at a requested speed. A speed determination module generates the requested speed based on a speed demand from a system controller. A lost rotor control module identifies a lost rotor condition and, in response to identifying the lost rotor condition, instructs the speed determination module to set the requested speed to an override speed that is lower than the speed demand. The lost rotor control module identifies the lost rotor condition in response to a comparison of a speed error with an adaptive threshold. The speed error is based on a difference between requested and estimated speeds of the motor. During first and second system states, the adaptive threshold is set to first and second thresholds, respectively.

Abstract: A method is provided for determining a value for an electrical output of a converter of renewable energy. The method comprises obtaining a signal representing the electrical output of the converter wherein that electrical output has an initial value. The method further comprises applying a pulse signal to the signal representing the electrical output, wherein the pulse signal comprises a positive portion and a negative portion. The method further comprises obtaining a measurement of electrical power produced by the converter during application of the pulse signal, removing the pulse signal and then obtaining a measurement of electrical power produced by the converter in the absence of the pulse signal. An error value is determined from the obtained electrical power measurements and that error value is applied to the initial value to obtain a target value for the electrical output of the converter.

Abstract: This disclosure relates to an apparatus and method 10 for protecting an electronic circuit from an airflow. The apparatus 10 comprises a base 12, wherein said base 12 comprises a cover means for covering at least part of the electronic circuit. The apparatus further comprises a guide means for guiding an airflow around the electronic circuit.

Abstract: A drive system for an electrical load such as an electric motor or generator comprises a PWM converter and a controller therefore. A signal indicative of a condition of the converter outpost is used in a controller to drive an optimal value of PWM switching frequency based on a load characteristic that is used to control the pulse switching frequency. The system takes account of the overall system in deriving an efficient PWM switching frequency.

Abstract: A demountable electrical panel comprises a spring under tension that is easily assembled by being laid to rest in a recess in a mounting plate put under tension to make electrical contact with a circuit board when the device is assembled.

Abstract: A device for use with a printed circuit board, PCB, is provided. The device is arranged to electrically connect to a component on the PCB. The device comprises a first layer having a first hole therethrough and a second layer having a second hole therethrough. The second hole is arranged to receive a connector to connect the device to the PCB. Each of the first and second holes has a width in the plane of the respective first or second layer. The first and second holes are substantially coaxial. The width of the first hole is greater than the width of the second hole. Thus proper electrical clearance is provided between the component on the PCB an the device when the connector is not present.

Abstract: A clamp for a choke is provided, the clamp comprising a component configured to hold a choke and at least one electrical connector receiving element for receiving one or more electrical connectors of a choke. The clamp is fitted to the choke and then the assembly is fitted into a device, such as a chassis.

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: The invention relates to an enclosure 100 for a drive unit. The enclosure 100 has a plurality of faces and is arranged to house components. A first face of said plurality of faces comprises an outer portion and at least one recessed portion. A first projection is provided projecting from a recessed portion of the first face. Furthermore, the first projection is arranged for engagement with a structure to which the enclosure 100 is to be mounted.

Abstract: A drive unit for housing components of a drive system for an electrical machine, such as an electric motor, comprises a cabinet having opposed first and second relatively narrow faces and a wide face between them. An interface for inputting and deriving data is mounted on a bracket to the unit and faces in the same direction as the wide face. The unit can be installed conveniently in situations in which depth is limited, while at the same time enabling the drive unit to be programmed and set in a convenient way.

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: An apparatus is provided comprising an enclosure for enclosing a printed circuit board (PCB). The PCB has a tab extending therefrom. The enclosure comprises first and second portions, one of which includes a recess arranged to receive the tab of the PCB.

Abstract: An adapter is provided for adapting a Secure Digital (SD) card for use with a Smart Card reader. The adapter comprises an improved Smart Card with a memory device physically connected thereto. A controller may also be provided for use with the Smart Card reader, the controller being configured to identify whether a conventional Smart Card or an adapter that includes an SD card socket has been presented to the Smart Card reader. The controller may be arranged to control communication between the Smart Card reader and an SD card in the SD card socket and to control access to the SD card memory accordingly.

Abstract: A demountable electrical panel comprises a spring under tension that is easily assembled by being laid to rest in a recess in a mounting plate put under tension to make electrical contact with a circuit board when the device is assembled.

Abstract: A drive system for an electrical load such as an electric motor or generator comprises a PWM converter and a controller therefore. A signal indicative of a condition of the converter outpost is used in a controller to drive an optimal value of PWM switching frequency based on a load characteristic that is used to control the pulse switching frequency. The system takes account of the overall system in deriving an efficient PWM switching frequency.

Abstract: This disclosure relates to an apparatus and method 10 for protecting an electronic circuit from an airflow. The apparatus 10 comprises a base 12, wherein said base 12 comprises a cover means for covering at least part of the electronic circuit. The apparatus further comprises a guide means for guiding an airflow around the electronic circuit.

Abstract: An apparatus is provided for producing a compensated voltage output comprising at least one photovoltaic module biasing means connected in series with the at least one photovoltaic module. The biasing means is operable to generate a controllable bias voltage for modulating an output voltage of the at least one photovoltaic module to produce the compensated voltage output.

Abstract: A DC motor drive (100) including power electronics (120) and control electronics (130). The power electronics (120) are arranged to receive a high voltage power supply and to controllably output that supply to a DC motor to controllably operate the motor. The control electronics (130) are arranged to receive a low voltage power supply and to control operation of the power electronics (120) and hence of the motor at least partly in response to signals received by the control electronics (130) indicative of at least one potential difference across the power electronics (120). The drive further includes a microprocessor (150) and an opto-coupler (170) arranged to sense the output of the power electronics (120) and to generate based thereon the signals in a form for optical transmission via opto-coupler (170) between the output of the power electronics (120) and the control electronics (130), thereby allowing galvanic isolation of the control electronics (30) from the power electronics (120).