Abstract: The present invention provides an improved design of linear motor as well as an improved control strategy. The design allows for a shorted stator, where the armature magnets are controlled to reciprocate to a greater maximum displacement that for a equivalent conventional linear motor. The control strategy is such that a minimum of external sensors are required. The linear motor is driven at its resonant frequency ensuring optionally efficient operation. A determination of the maximum current is made based on a relationship with the resonant frequency and the evaporating temperature/pressure of the vapor entering the compressor. The current is then limited to control the maximum displacement to avoid damage.

Abstract: The present invention provides an improved design of linear motor as well as an improved control strategy. The design allows for a shorted stator, where the armature magnets are controlled to reciprocate to a greater maximum displacement that for a equivalent conventional linear motor. The control strategy is such that a minimum of external sensors are required. The linear motor is driven at its resonant frequency ensuring optionally efficient operation. A determination of the maximum current is made based on a relationship with the resonant frequency and the evaporating temperature/pressure of the vapour entering the compressor. The current is then limited to control the maximum displacement to avoid damage.

Abstract: A mouthpiece for oral delivery for oral delivery of CPAP treatment has a vestibular shield for location between the teeth and lips/cheeks of a wearer. The vestibular shield is formed from a very supple material and is dimensioned to extend laterally into the buccal vestibule and vertically to overlap the gums. A gases pathway is provided through the vestibular shield and may include a hard plastic insert through the shield. A connection for connecting the mouthpiece to a breathing circuit is provided which reduces the transfer of forces caused by movement therebetween.

Abstract: An electric linear motor for driving a reciprocating load includes a stator, a coil, an armature and a commutation circuit. The stator has a magnetically permeable core with an air gap. The coil is wound around a portion of the stator and energized with a non-constant voltage for producing a non-constant magnetic flux in the stator and the air gap. The armature supports a permanent magnet having a substantial portion located in the air gap. The interaction of the magnetic field of the magnet and the non-constant flux in the air gap produces a force on the armature. The armature is connected to the load and reciprocates with respect to the stator. The circuit controls the coil such that at least one end of the magnet passes outside the region of substantially uniform flux density within the air gap during a portion of the motion of the armature.

Abstract: An apparatus assists a user to move a door between closed and open states. The apparatus includes a permanent magnet provided on the door. An electromagnet is located on the door frame adjacent thereto when the door is closed and is energizable to provide a magnetic field which reinforces the permanent magnetic field or to provide a magnetic field in opposition to the permanent magnetic field. A detector detects the state of the door and an interface detects the presence of a user. A controller receives input from the detector and the interface and energizes the electromagnet to provide a reinforcing magnetic field if a user is attempting to open the door and provides an opposing magnetic field to the permanent magnetic field if the door is closed and the user is attempting to open the door.

Abstract: The present invention provides an improved design of linear motor as well as an improved control strategy. The design allows for a shorted stator, where the armature magnets are controlled to reciprocate to a greater maximum displacement than for a equivalent conventional linear motor. The control strategy is such that a minimum of external sensors are required. The linear motor is driven at its resonant frequency ensuring optionally efficient operation. A determination of the maximum current is made based on a relationship with the resonant frequency and the evaporating temperature/pressure of the vapor entering the compressor. The current is then limited to control the maximum displacement to avoid damage.

Abstract: A flow probe for use in a humidification system is disclosed. The flow probe is adapted to be positioned in a humidified gases flow (for example oxygen or anaesthetic gases) such as that which is provided to a patient in a hospital environment. The flow probe is designed to provide both temperature and flow rate sensing of the gases flow by incorporating two sensors (preferably thermistors) and the shape and alignment of the probe enables accurate readings by reducing the occurrence of condensation on the sensors.

Abstract: An electric linear motor for driving a reciprocating load includes a stator, a coil, an armature and a commutation circuit. The stator has a magnetically permeable core with an air gap. The coil is wound around a portion of the stator and energised with a non-constant voltage for producing a non-constant magnetic flux in the stator and the air gap. The armature supports a permanent magnet having a substantial portion located in the air gap. The interaction of the magnetic field of the magnet and the non-constant flux in the air gap produces a force on the armature. The armature is connected to the load and reciprocates with respect to the stator. The circuit controls the coil such that at least one end of the magnet passes outside the region of substantially uniform flux density within the air gap during a portion of the motion of the armature.

Abstract: A status indicator (4) for a transparent ceramic glass cook top is disclosed which is able to display a range of colors. Typically such indications are used with red or smoked glass cooktops and are limited to red. The present invention is positioned directly underneath the transparent glass (22) which has an opaque layer (23) on the underside and wherein a portion (24) of the opaque layer has been removed thereby allowing the light source (2) to be visible directly above said cook top. The indicator may be used for a range of functions, including indicating the element is on and also that the heating region is too hot to be safely touched.

Abstract: A laundry machine drum has a sheet material skin including an arrangement of a plurality of perforations therethrough. Each of one or more of the perforations includes a shear cut in the sheet material. The sheet is deformed in the region of the shear cut such that the edge of the sheet material of one side of the shear cut is offset from the edge of the sheet material of the other side of the shear cut over at least some of the length of the shear cut. An opening is formed between the offset edges. The apparent area of the opening is greater when viewed from at least one direction substantially parallel to the general plane of the drum skin in the region of the perforation than when viewed from a direction substantially perpendicular to the general plane of the drum skin in the region of the perforation.

Abstract: A spin tub of a washing machine is driven by an electronically commutated DC motor. The commutation devices are connected to a DC power supply and have free-wheeling diodes connected in parallel therewith. The washing machine includes other components having inductive windings. A controller terminates commutation of power to the motor windings. A voltage threshold detector monitors the voltage of the power supply. Switching structure connects the inductive winding of an unused component in the machine across the power supply when the detector detects that the voltage has exceeded a predetermined value and subsequently disconnects the inductive winding of the unused component from the power supply when the detector detects that the voltage has reduced below the pre-determined value.

Abstract: A washing machine incorporates a drain pump powered by an electric motor and a variable frequency variable duty cycle pulse width modulated inverter the output of which supplies power to the electric motor, a water level detection means for detecting low washing machine water levels, and a controller which in response to the water level detection means decreases the frequency of the inverter at low washing machine water levels to thereby reduce the effects of ventilation. The motor is driven with the output of the variable frequency pulse width modulated inverter, and the frequency of said inverter is decreased at low washing machine water levels to reduce the effects of ventilation.

Abstract: A direct current power supply for a washing appliance powered is disclosed. The power supply includes a switch mode power supply which supplies direct current at a low voltage level from a high direct voltage supply and a pair of commutation devices as a buck converter, an active switching device connected across the input of one of the commutation devices, a latching circuit which controls the active switching device to cause the commutation device to switch off to disable the buck converter, and a push button switch for disabling the latching circuit to cause the active switching device to switch off to allow the one commutation switch to function and thereby enable the buck converter.

Abstract: An optocoupler drive circuit for the high side of a totem pole power transistor pair in a bridge circuit for commutating a motor includes an optocoupler output device being directly connected to the upper power transistor in the totem pole, and series resistor of selected value for controlling the drive current to said upper power transistor to reduce its speed of turn on.

Abstract: A method of operating a drain pump in a laundry washing machine during the drain phase of the wash cycle to reduce pump blockages is disclosed. The method includes the steps of (a) starting the pump and running it for a first period of time to produce a discharge of a given flow rate, (b) stopping the pump and leaving the pump stopped for a second period of time, and repeating steps (a) and (b) for the duration of said drain phase, said second period of time being such that the flow rate reduces substantially to zero.

Abstract: A flow probe for use in a humidification system is disclosed. The flow probe is adapted to be positioned in a humidified gases flow (for example oxygen or anaesthetic gases) such as that which is provided to a patient in a hospital environment. The flow probe is designed to provide both temperature and flow rate sensing of the gases flow by incorporating two sensors (preferably thermistors) and the shape and alignment of the probe enables accurate readings by reducing the occurrence of condensation on the sensors.

Abstract: Apparatus and method for raising or maintaining the core temperature of a mammal during surgery is disclosed. The apparatus comprises a infrared radiant element with a double reflector design to provide a very narrow beam of radiation. In this fashion the apparatus is able to direct radiant energy at the mammal's skin in regions with a high concentration of Arteriovenous Anastomoses. The apparatus also includes a skin temperature sensor to allow closed loop control of the heat energy supplied to the mammal. The complete apparatus can be located in an unobtrusive position such that it does not interfere with the surgical team.

Abstract: A flow probe for use in a humidification system is disclosed. The flow probe is adapted to be positioned in a humidified gases flow (for example oxygen or anaesthetic gases) such as that which is provided to a patient in a hospital environment. The flow probe is designed to provide both temperature and flow rate sensing of the gases flow by incorporating two sensors (preferably thermistors) and the shape and alignment of the probe enables accurate readings by reducing the occurrence of condensation on the sensors.

Abstract: A flow probe for use in a humidification system is disclosed. The flow probe is adapted to be positioned in a humidified gases flow (for example oxygen or anaesthetic gases) such as that which is provided to a patient in a hospital environment. The flow probe is designed to provide both temperature and flow rate sensing of the gases flow by incorporating two sensors (preferably thermistors) and the shape and alignment of the probe enables accurate readings by reducing the occurrence of condensation on the sensors.

Abstract: A mouthpiece for oral delivery for oral delivery of CPAP treatment has a vestibular shield for location between the teeth and lips/cheeks of a wearer. The vestibular shield is formed from a very supple material and is dimensioned to extend laterally into the buccal vestibule and vertically to overlap the gums. A gases pathway is provided through the vestibular shield and may include a hard plastic insert through the shield. A connection for connecting the mouthpiece to a breathing circuit is provided which reduces the transfer of forces caused by movement therebetween.