This paper proposes a new short-circuit protection method for an IGBT. The proposed method is characterized by detecting not only gate charge but also gate voltage of the IGBT. This results in a shorter protection time, compared to the previous method that detects only the gate charge. A real-time monitoring system using an FPGA, A/D converters, and a D/A converter is used for the proposed prot...

Many of the current software systems rely on garbage collectors for automatic memory management. This is also the case for various software systems in realtime applications. However, a real-time application often requires an incremental working style of the underlying garbage collection, which renders the garbage collector more complex and less trustworthy. We present a formal verification of t...

To develop the organic Rankine-vapor compression ice maker driven by solar energy, a thermodynamic model was developed and the effects of generation temperature, condensation temperature, and working fluid types on the system performance were analyzed. The results show that the cooling power per square meter collector and ice production per square meter collector per day depend largely on gener...

The overall heat loss coefficient (U-value) of a vacuum tube solar collector is investigated experimentally and theoretically with regard to the pressure of the remaining gas inside the evacuated glass envelope. A number of collector tubes of same geometry are randomly selected from an installation of a solar based air-conditioning system and tested individually in the laboratory for the determ...

The maximum power cast on a collector from a source of finite angular extension by a concentrator of fixed position occurs when the collector sees the concentrator as a Lambertian source. Concentrators not fully meeting this requirement are evaluated using a parameter called the shape quality factor. Lambertian concentrators can be obtained with mirrors but not with lenses of finite n. In many ...

The Florida Solar Energy Center (FSEC), with the support of the National Renewable Energy Laboratory (NREL), has investigated the thermal performance of solar absorbers which are an integral yet indistinguishable part of a building’s roof. The first roof-integrated solar absorber (RISA) system was retrofitted into FSEC’S Flexible Roof Facility in Cocoa, Florida in September 1998. This “proof-of...

Current driven instabilities in the collector of III–V heterojunction bipolar transistors ~HBT! are investigated. Numerical simulations indicate that in a modified AlGaAs/GaAs HBT the collector current shows oscillatory behavior due to the transferred-electron ~Gunn–Hilsum! effect. Influence of the Kirk effect as well as conditions for oscillation are discussed. © 1995 American Institute of Phy...

Further computations are made on the traditional coupon collector’s problem when the collector shares his harvest with his younger brothers. When the book of the p-th brother of the collector is completed, the books of the younger brothers have certain numbers of empty spots. On the average, how many? Several answers can be brought to that question.

In this Application Note we show three system configurations for recovery collection with the Agilent 1100 Series purification system. One configuration uses a 12-position/13-port valve 3 in the waste line of the fraction collector, which offers up to twelve recovery locations. Another possibility is to use a third-party fraction collector, controlled by the ChemStation through external contact...

Schottky Collector Resonant Tunneling Diodes (SCRTDs) have potential for increased oscillator bandwidth, but may be prone to electron reflection at the semiconductor-metal interface of the Schottky collector. This reflection has been observed previously with in-situ MBE deposited collector metal, manifested as interference oscillations on the rising slope of the resonant current. This paper ext...