Abstract:
A reversible chest protector includes internal padding configured to absorb impacts against both the front and rear-facing surfaces of the chest protector. The chest protector includes inner and outer layers of fabric that are molded to an internal foam core. The foam core may include outer layers of closed-cell foam molded to the fabric layers, and an internal layer of open-cell foam molded to the closed-cell foam layers, such that the padding layup is symmetrical. Other features and advantages will appear hereinafter.
Abstract:
A load control device is adapted to be disposed in series with an AC voltage source and an electrical load and is operable to provide substantially all voltage provided by the AC voltage source to the load. The load control device comprises a controllably conductive device, a controller, a zero-crossing detector, and a power supply for generating a substantially DC voltage for powering the controller. The power supply is operable to charge an energy storage device to a predetermined amount of energy each half-cycle. The controller is operable to determine when the power supply has stopped charging from the zero-crossing detector each half-cycle, and to immediately render the controllably conductive device conductive to conduct the full load current. Before the controllably conductive device begins to conduct each half-cycle, only a minimal voltage develops across the power supply to allow the energy storage device to charge.
Abstract:
An electrical component includes a capacitive impedance and a shunt path inductance cancellation feature provided by coupled windings. A filter having a capacitor with capacitor-path inductance cancellation provides enhanced performance over frequency compared with conventional capacitors.
Abstract:
A switched mode dc-dc converter enables increases in switching frequency over conventional architectures. In one embodiment, a dc-dc converter has a Vernier-regulated architecture having unregulated cells and a regulating cell coupled to a controller. In another embodiment, a dc-dc-converter has a cell-modulation-regulated architecture.
Abstract:
A chest protector includes rows of padding protruding inwardly from a base section. The pads are arranged to rest against the body of a wearer. Ventilation channels are located between neighboring rows of padding to provide multiple paths for heat dispersion. The rows of padding are able to flex relative to one another such that the chest protector may conform to the body of the wearer.
Abstract:
A power supply adapted to be coupled in series electrical connection between an AC voltage source and an electrical load for generating a DC voltage, the power supply comprising an energy storage capacitor, the DC voltage produced across the capacitor; a charging circuit adapted to be coupled in series electrical connection between the source and the load and to conduct a load current from the source to the load, the charging circuit coupled to the energy storage capacitor for charging the energy storage capacitor; a controllably conductive device coupled in parallel electrical connection with the charging circuit and having a control input for rendering the controllably conductive device conductive, the controllably conductive device adapted to carry the load current from the source to the load when the controllably conductive device is conductive; and a triggering circuit coupled to the control input of the controllably conductive device for causing the controllably conductive device to become conductive when the energy storage capacitor has charged to a desired maximum value; wherein the charging circuit is adapted to conduct the load current from the source to the load when the controllably conductive device is non-conductive, the charging circuit imposing a low voltage drop relative to the peak value of an AC voltage of the AC voltage source, such that substantially all of the AC voltage is available to the load during the time when the controllably conductive device is non-conductive.
Abstract:
A resistance compression network substantially decreases the variation in effective resistance seen by a tuned rf inverter as loading conditions change. Circuits can include resistance compression networks and rectifiers to form rf-to-dc converters having narrow-range resistive input characteristics.
Abstract:
A power supply for a load control device is disposed in series with an AC voltage source and a load and generates a substantially DC voltage for powering a controller of the load control device. The power supply is operable to provide substantially all voltage provided by the AC voltage source to the load and includes a controllably conductive device, a triggering device, and a charging circuit. The charging circuit is operable to charge an energy storage device and to conduct current to the load when the controllably conductive device is non-conductive. The controllably conductive device begins conducting the full load current when the energy storage device has charged to a predetermined amount of energy. Before the controllably conductive device begins to conduct, only a minimal voltage, which is substantially the same as the break-over voltage of the triggering circuit, develops across the power supply to allow the energy storage device to charge.
Abstract:
High power output may be obtained from a photovoltaic (PV) system by controlling each photovoltaic cell of a solar array individually to operate at its maximum power point. Each cell may have associated power electronics and control circuitry that may be integrated together on a chip which may be advantageously implemented in CMOS, enabling reductions in cost and size. A perturb and observe algorithm may be used to find the maximum power point by measuring the power produced at different operating points, and modifying the operating point in the direction of increased power production. In one aspect, performance of a perturb and observe algorithm may be improved in the presence of noise.