查看更多>>摘要：The dynamic characteristics imply the most important performance of semiconductor switching devices. Herein, a CPU-based instrument is designed for measuring the reverse recovery (R-R) time (T-rr) and RR charge (Q(rr)) of low power switching diodes. In the designed electrical system, the reverse voltage pulse is shaped by an emitter coupled logic (ECL) circuit constructed with microwave transistors to raise the pulse edges' commutating-rate, which is applied to the device under test to yield the RR current (I-rr) waveform. This waveform is converted into a voltage pulse with width equal to the RR time by voltage comparator consisted of the other ECL in the sampling circuit. This sampled pulse is sent to analog-digital converter and subsequently into an 89C2052-type CPU for calculating the values of T-rr and Q(rr), they are monitored by a liquid crystal displayer. The lowest metering range of about 3 ns of T-rr is demonstrated, the displayed T-rr value agrees with the one observed by oscilloscope, which verifies the design. Besides, the application of the ECL indicates a means of high-speed signal processing.
Perez-Garcia, G. F.Camas-Anzueto, J. L.Anzueto-Sanchez, G.Perez-Patricio, M....
8页
查看更多>>摘要：In this work, a spectroscopy study of lophine was carried out and the absorption spectrum was found to be in the wavelength range of 290 to 375 nm. Furthermore, the absorbance dependence of lophine as a function of temperature was studied . A fiber optic temperature sensor was built using an optical source with wavelength of 365 nm to improve sensitivity. The sensitivity at this wavelength was compared to the infrared wavelengths sensitivities. Finally, the sensor response was characterized and validated with a commercially available elec-tronic temperature sensor.
NSTL
Elsevier