A Miniature Blast-Gauge Charge Amplifier System

Abstract

Transducers whose outputs are characterized as a charge require signal conditioning to convert the charge produced to a voltage or current for use in instrumentation systems. Blast gauges, in particular, require processing which preserves the transient nature of the data and very fast risetimes, which would otherwise be degraded by long cable runs and parasitic capacitances. A charge amplifier which amplifies and converts a charge to a low-impedance voltage suitable for driving coaxial lines is described, along with theory of operation. Charge amplifiers of the type described are relatively unaffected by temperature and power supply variations, and occupy less than two square inches of printed circuit board space per channel.