Abstract: This invention relates to a power converter (1) comprising a converter input (3), a converter output (5), a power factor correction (PFC) stage (7) and an isolation stage (9). The PFC stage (7) is implemented by way of a buck PFC with low side drive and low side current sensing, There is provided a third stage, an intermediate buck pre-regulation stage (11), intermediate the buck PFC stage (7) and the isolation stage (9), Control of the power converter output voltage is achieved by varying the duty cycle of the intermediate buck pre-regulation stage (11) and therefore the isolation stage (9) may be an unregulated stage operated as a fixed DCDC voltage converter. The isolation stage (9) is operated as a 50%-50% duly cycle double ended stage. The configuration of power converter allows for a relatively inexpensive, highly efficient converter with 90%+ efficiency and simplified control.

Abstract: This invention relates to a transformer (1) for multi-output power supplies such as those commonly found in electronic equipment. The transformer comprises a magnetic core (3) and a plurality of windings (5, 7, 9) at least some of which are fractional windings, arranged about the magnetic core. The transformer comprises a dual transformer structure with a pair of transformers, a main transformer (11) and an auxiliary transformer (13). In a preferred embodiment, the main transformer and the auxiliary transformer are connected together. In this way, readily available magnetic components may be used in the construction of the transformer and the simple construction allows for a large cross-sectional area of transformer to be deployed so that reduced turn counts of windings may be used.

Abstract: There is illustrated the assembly of a dual inductor (1) on to a printed circuit board (2). A printed circuit board (2) has a through hole (3). Then the first winding (5), formed from a stamping, is mounted across the hole (3). Then, the first winding (5) is connected to the first face (7) of the PCB (2). Then, a core assembly (10) is inserted into the hole (3) from the direction of a second face (8) of the PCB (2). Then, at some stage, for example as shown, the second winding (6) is inserted into the core assembly (10) and affixed to the bottom face (8) of the PCB (2).

Abstract: A heavy duty cycle power converter (2) has current mode control in which the closed loop control is carried out by a controller (5) using a desired signal (11) which is a function of the difference between the desired duty cycle (7) and the measured duty cycle (6). This fluctuates current mode control without voltage feedback.

Abstract: A PCB assembly (1) in this case a DC-DC converter comprising a single layer board (2), mounts power semi-conductor devices forming high heat generating components (3) and various cores of magnetic material forming heat dissipating components (4). Tracks of heat conductive coupling material (6) lie above or below each heat generating component (3) and project into one of the heat dissipating components (4) and beside the others. In one embodiment, the heat generating components (3) are housed within a heat dissipating component (3). In another PCB assembly, there is an additional plug-in PCB which may itself carry heat generating components (3) or only heat dissipating components (4). In the latter case, the heat generating components (3) are mounted on the PCB assembly below the additional plug-in PCB.

Abstract: A heavy duty cycle power converter (2) has current mode control in which the closed loop control is carried out by a controller (5) using a desired signal (11) which is a function of the difference between the desired duty cycle (7) and the measured duty cycle (6). This fluctuates current mode control without voltage feedback.

Abstract: There is illustrated the assembly of a dual inductor (1) on to a printed circuit board (2). A printed circuit board (2) has a through hole (3). Then the first winding (5), formed from a stamping, is mounted across the hole (3). Then, the first winding (5) is connected to the first face (7) of the PCB (2). Then, a core assembly (10) is inserted into the hole (3) from the direction of a second face (8) of the PCB (2). Then, at some stage, for example as shown, the second winding (6) is inserted into the core assembly (10) and affixed to the bottom face (8) of the PCB (2).