Digital RLC analysis of CDU fireset x-units

An accurate and repeatable technique has been developed for quantitatively determining the dynamic resistance, inductance, and capacitance (RLC) of CDU Fireset X-units by digital analysis of the output current waveform. The waveform is digitized with 8 bit resolution at a 10 ns sample rate. A calibration file provides correction for attenuator and digitizer errors. Data accuracy is optimized by software filtering to minimize the digitizing noise component. R, L, and C are derived by selecting any four waveform coordinates as limits for a series of multiple numerical integrations. The integrals become coefficients for a system of linear equations which are solved simultaneously to obtain the circuit impedance. The approach is independent of circuit damping, eliminates the need for determining the waveform starting point, and is accurate to 1 percent in the presence of noise. The technique has been successfully employed at Bendix to identify defects and variations in components and processes used in the manufacture of X-unit assemblies