A microprocessor-based dynamic inductance/capacitance meter

A microprocessor-based dynamic inductance/capacitance meter has been developed. Two different approaches are examined utilizing the frequency response of the circuit where the unknown reactive element is included. One procedure uses an LC oscillator which generates a frequency that is proportional to the reactive elements, while the other employs the resonance response of an RLC circuit from which the unknown element can be determined by the phase relationship. An 8088 processor detects the frequency counts in the first procedure, monitors the phase relationship in the second, and performs the required calculations for both. The microprocessor periodically samples the output of the LC oscillator at its input port to dynamically monitor the changes in the reactive circuit elements. Within 5% error over the frequency range of 100 Hz to 256 kHz, a wide range of inductance and capacitance values for both approaches were determined.<>