Abstract: In one aspect the invention provides a magnetic door position detection apparatus adapted to attach to a cabinet interior with a door arranged to transition between an open state where the interior of the cabinet is accessible, and a closed state. The door includes a magnetic field generating structure configured to magnetically engage the door with the cabinet in the closed state. The apparatus provided includes a housing configured to attach to the interior of the cabinet and one or more sensors configured to determine change in the magnetic flux field within the interior of the cabinet induced by motion of the magnetic field generating structure in at least one of three orthogonal axes. The sensor or sensors generate an output signal representing the sensed magnetic field change where the one or more axes is indicative of the cabinet door moved between the closed state and the open state.

Abstract: A refrigeration controller within a retail refrigeration cabinet controls the temperature (502) so that it approaches the maximum allowable temperature by using the most efficient fan speed for loading and time of day (507) but is varied by customer presence (505) to adhere to an algorithm reducing the noise (506) created by such machines while still creating sufficient cooling to remain within the maximum temperature while providing acceptable power economy.

Abstract: A refrigeration controller within a retail refrigeration cabinet controls the temperature (502) so that it approaches the maximum allowable temperature by using the most efficient fan speed for loading and time of day (507) but is varied by customer presence (505) to adhere to an algorithm reducing the noise (506) created by such machines while still creating sufficient cooling to remain within the maximum temperature while providing acceptable power economy.

Abstract: A beverage cooler has a low voltage DC supply (311) usable by the controller ancillaries, such as lighting (318), the DC supply also providing the supply voltage to a microprocessor (313) which electronically commutates at least one of the motors (305, 306, 307) associated with beverage cooling to provide a required speed or loading. The microprocessor also responds to and controls the cooler ancillaries, such as lighting, temperature and status reporting thereby allowing a reduced component count.

Abstract: A rotor for a motor or generator is produced by placing separated magnets around the diameter of the potential rotor, placing separated segments of magnetic backing material behind the magnets, and embedding the whole in molding material in a mold in such a way that the segments thrust outwards against the magnets and the magnets thrust outwards against the mold during placement of the molding material.

Abstract: A synchronous motor having phase windings which are split or tapped and in which the conduction angle of the applied alternating current is varied at one or more taps to allow the motor to start in a controlled direction and be torque controlled to synchronous speed.

Abstract: An electric motor or generator consists of a stator carrying pole pieces and their coacting coils, the stator being surrounded on one side by the field creating permanent magnets adjacent one face of the poles and on the other by a flux return path element positioned adjacent the other face of the poles. The stator coils are preferably bobbin mounted.

Abstract: A synchronous motor having phase windings which are split or tapped and in which the conduction angle of the applied alternating current is varied at one or more taps to allow the motor to start in a controlled direction and be torque controlled to synchronous speed.

Abstract: A winding for a toroidal electrodynamic machine is formed by providing a set of bobbins in a rectilinear array, winding the bobbins so that each phase is of one continuous wire, with each set of phases wound one bobbin at a time, the completed rectilinear array then being formed into a circular array for the machine. The rectilinear array has bobbins formed and is wired in such a way that bending into a torus is possible.

Abstract: A method and apparatus for production of stator windings for dynamoelectric mechines of different configurations is provided. The windings are preferably formed on a bobbin (10) or similar article, which may then be transferred onto an appropriate carrier such as a ferromagnetic core (24). The core (24) may be provided as a substantial linear article and then be bent into an appropriate shape, so that the assembly may be provided as the stator of a dynamoelectric machine. In this configuration, only a portion of each winding will face the magnetic poles of the rotor and thus be operative, as the return path of the windings will not be used. However, the invention as disclosed also shows it is possible to build a drum rotor (39) with both external and internal rotors in order to make use of both portions of the windings on the ferromagnetic core (24).

Abstract: A variable motor (1) having reduced audible noise. This advantage is achieved by reducing or eliminating ripple torque by making the individual phase torques follow a certain profile, so that when the torques are summed, they are substantially constant. Therefore, the motor (1) back EMF is used as a reference waveform to control the winding currents to achieve reduced ripple torque. The back EMF reference is amplified and provided to the motor windings, and may be derived in a number of ways including use of sense windings, electronic derivation, and approximation by sensing the voltage applied to the windings.

Abstract: A discoidal brushless DC motor having a stator (507) carrying windings (503) arranged in slots which radiate out from the center of the stator to the periphery. The depth of each slot increases towards the center of the stator. The slot, therefore, is wider (from side to side) and shallower towards the periphery of the stator, and narrower (from side to side) and deeper towards the center of the stator. This arrangement ensures that the windings are contained below the surface (504) of the stator (507). The magnetic circuit includes a backing of a ferromagnetic material (509). This ferromagnetic material (509) can be a watch spring core made from a long strip of soft iron tape.