Analog Filtering in Instrumentation Using Posicast
Keywords:
lightly damped systems, Posicast, input shapers, analog filters.Abstract
Analog filters are essential in industrial environments for noise reduction. The filter approximation that presents the best performance in noise reduction is Tchebyshev. This approximation introduces distortions in pulsed signals due to overshoot. The analysis and design of analog filters using a Posicast element are presented. Posicast is a feedforward compensator that eliminates overshoot in system response. The authors present a straightforward method to design analog filters, using knowledge of the step response overshoot and system's damped time response period. Simulated results for two filters (Tchebyshev and Bessel) indicates that the new method eliminates distortion in pulsed signals, without affecting its performance in frequency.
