DocumentCode :
2575846
Title :
Low-noise, high-bandwidth amplification of prebreakdown current pulses in liquid dielectrics
Author :
Wintenberg, A.L. ; Pace, M.O. ; Blalock, T.V.
Author_Institution :
Dept. of Electr. & Comput. Eng., Tennessee Univ., Knoxville, TN, USA
fYear :
1988
fDate :
5-8 Jun 1988
Firstpage :
383
Lastpage :
386
Abstract :
Results of prebreakdown current measurements made with a low-noise, high-bandwidth preamplifier (0.4-μA minimum detectable current and 58-MHz bandwidth) are summarized. These waveforms demonstrate that low-noise, high-bandwidth preamplifiers are needed in order to observe the shape of prebreakdown current pulses, including the earliest pulses which are extremely small and fast. These and other factors influencing the design of an improved preamplifier are considered. Data collected indicate that at least a 50-MHz bandwidth is desirable to see the higher frequency components of the current pulses and that the noise level should be as low as possible so very small currents will be detectable. A major constraint on the design is the need to protect the preamplifier from a complete breakdown of the test sample while still maintaining bandwidth and noise performance. Another important consideration is the tradeoff between bandwidth and noise level. In general an increased bandwidth implies higher noise levels and, hence, higher minimum detectable currents. In light of these considerations, the relative merits of current-sensitive (transimpedance) preamplifiers and voltage-sensitive preamplifiers (where current develops a voltage across the input impedance) are examined, and the possibility of greater current sensitivity is considered
Keywords :
dielectric properties of liquids and solutions; electric breakdown of liquids; electric current measurement; preamplifiers; 0.4 muA; 58 MHz; bandwidth; current sensitive preamplifiers; high-bandwidth amplification; high-bandwidth preamplifier; liquid dielectrics; minimum detectable current; noise level; prebreakdown current pulses; voltage-sensitive preamplifiers; Bandwidth; Current measurement; Frequency; Noise level; Preamplifiers; Protection; Pulse amplifiers; Pulse shaping methods; Shape; Voltage;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Electrical Insulation, 1988., Conference Record of the 1988 IEEE International Symposium on
Conference_Location :
Cambridge, MA
ISSN :
1089-084X
Type :
conf
DOI :
10.1109/ELINSL.1988.13946
Filename :
13946
Link To Document :
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