Abstract: A speaker assembly for good thermal management in loudspeakers such as planar magnetic drivers (PMDs). The assembly comprises a front panel with one or more sound openings, one or more PMDs each associated with a respective sound opening, one or more rear thermal plates each associated with a respective PMD structure plate, and a thermal spreader plate. The PMD structure plate is mounted to the front panel, the rear thermal plate is mounted to the associated PMD structure plate, and the thermal spreader plate is mounted to the one or more rear thermal plates, thereby forming a layered heatsink assembly. In a further development, the assembly has multiple PMDs and a circuit configured to modulate power handling and frequency response between the multiple PMDs.

Abstract: An automatic control system for a plurality of engine-driven alternator units arranged to supply a common electrical distribution system, the system monitoring the level of the load on each generating set so that a load analogue signal corresponds to the proportion of its load that its alternator is producing.