Abstract: A modular dc-dc boost converter system is provided that can substantially improve efficiency over a wide range of input and output voltages. The system includes three modules: a buck module, a boost module, and a dc transformer module. These modules are interconnected such that the system output voltage is equal to the sum of the output voltages of adc-dc converter module and a dc transformer module. Depending on the operating point, one or more modules may operate in passthrough mode, leading to substantially reduced ac losses. The required capacitor size and the transistor voltage ratings are also substantially reduced, relative to a conventional single dc-dc boost converter operating at the same input and output voltages.

Abstract: The disclosed embodiments and principles provide a way to integrate high-efficiency, low-profile power electronics with localized maximum power point tracking (MPPT) into a rooftop shingle-based photovoltaic power system. DC-DC power converters having a height, or profile, as low as ¼ inch for a 200 W power output, are able to be included in a building-integrated photovoltaic (BIPV) roof shingle. The DC-DC power converters increase the relatively low voltage produced by two rows of series-connected photovoltaic shingles, each including photovoltaic cells, to a high voltage used by a DC-AC inverter. For example, DC-DC power converter increases the voltage produced by two rows of series-connected photovoltaic shingles from several tens of volts to approximately 400 volts. Thus, the DC-DC power converters provide a large voltage step-up using a low profile and with very high efficiency.

Abstract: A modular dc-dc boost converter system is provided that can substantially improve efficiency over a wide range of input and output voltages. The system includes three modules: a buck module, a boost module, and a dc transformer module. These modules are interconnected such that the system output voltage is equal to the sum of the output voltages of adc-dc converter module and a dc transformer module. Depending on the operating point, one or more modules may operate in passthrough mode, leading to substantially reduced ac losses. The required capacitor size and the transistor voltage ratings are also substantially reduced, relative to a conventional single dc-dc boost converter operating at the same input and output voltages.

Abstract: A modular dc-dc boost converter system is provided that can substantially improve efficiency over a wide range of input and output voltages. The system includes three modules: a buck module, a boost module, and a dc transformer module. These modules are interconnected such that the system output voltage is equal to the sum of the output voltages of adc-dc converter module and a dc transformer module. Depending on the operating point, one or more modules may operate in passthrough mode, leading to substantially reduced ac losses. The required capacitor size and the transistor voltage ratings are also substantially reduced, relative to a conventional single dc-dc boost converter operating at the same input and output voltages.

Abstract: A modular dc-dc boost converter system is provided that can substantially improve efficiency over a wide range of input and output voltages. The system includes three modules: a buck module, a boost module, and a dc transformer module. These modules are interconnected such that the system output voltage is equal to the sum of the output voltages of adc-dc converter module and a dc transformer module. Depending on the operating point, one or more modules may operate in passthrough mode, leading to substantially reduced ac losses. The required capacitor size and the transistor voltage ratings are also substantially reduced, relative to a conventional single dc-dc boost converter operating at the same input and output voltages.

Abstract: The disclosed embodiments and principles provide a way to integrate high-efficiency, low-profile power electronics with localized maximum power point tracking (MPPT) into a rooftop shingle-based photovoltaic power system. DC-DC power converters having a height, or profile, as low as ¼ inch for a 200 W power output, are able to be included in a building-integrated photovoltaic (BIPV) roof shingle. The DC-DC power converters increase the relatively low voltage produced by two rows of series-connected photovoltaic shingles, each including photovoltaic cells, to a high voltage used by a DC-AC inverter. For example, DC-DC power converter increases the voltage produced by two rows of series-connected photovoltaic shingles from several tens of volts to approximately 400 volts. Thus, the DC-DC power converters provide a large voltage step-up using a low profile and with very high efficiency.

Abstract: The disclosed embodiments increase the power generated by a photovoltaic (PV) array, when the PV panels within the PV array are not uniformly illuminated or oriented or when PV panels are mismatched (e.g., have varying performance characteristics) and/or operate at non-uniform temperatures. It also provides simpler interconnection and wiring of the elements (e.g., PV panels) of the array. A dc-dc converter comprised of a DC transformer is coupled to each PV panel in a photovoltaic array to generate an increased dc voltage from a lower dc voltage produced by the PV panel. The outputs of the dc-dc converters are connected in parallel to a dc bus, which distributes the resulting voltage. As a result, the energy generated by the PV array is increased, the costs of system design and installation are reduced, and it becomes feasible to install PV arrays in new locations such as on gabled or non-planar roofs.

Abstract: An apparatus and method for draining fluid from a patient. A drainage line is connected to a vacuum bottle. The vacuum is transferred into the drainage line by piercing a seal over the bottle mouth. The indicator in the form of a collapsible bulb or other deformable element confirms the presence of the vacuum at the time of use.

Abstract: An apparatus and method for draining fluid from a patient. A drainage line is connected to a vacuum bottle. The vacuum is transferred into the drainage line by piercing a seal over the bottle mouth. The indicator in the form of a collapsible bulb or other deformable element confirms the presence of the vacuum at the time of use.

Abstract: An improved ultrasonic surgical instrument is disclosed having a design that extends horn or tip life and minimizes instrument breakage and disintegration during use. The instrument comprises an ultrasonic tip having a distal working end and a metal sheath around the tip; the tip further having projections located in the vicinity of nodal points near the tip working end, said tip radially extending from the tip towards the sheath so as to provide the tip with radial inward support. The instrument can further comprise said tip with a substantially flat or convex end and said sheath with an inwardly projecting portion located distally of said tip projection and extending sufficiently radially inward so as to capture the tip with its projection should a tip break occur.