Digital Instrumentation of Slowly Moving Arcs

The slowly moving arc has been instrumented for position and velocity. A practical arc model has been used that has particular application to the needs of industry. Analog circuitry has been developed that interfaces the arc plant with a digital computer. A computer strategy has been applied for time-average filtering without losing the resolution capability of the computer´s A/D converter. Through digital differentiation, arc velocity signals are obtained of a quality adequate for industrial control. The entire system is oriented towards the low-priced computer increasingly available in industry. Appendix I contains the flow chart for implementing this instrumentation on a computer. Appendix II presents a simple mathematical model of the instrumentation system.