Differential Measurement of Fast Energy Discharge Capacitor, Inductance, and Resistance

A differential method to measure, simply and accurately, the equivalent series inductance (ESL) and the equivalent series resistance (ESR) of energy discharge capacitors is described and compared with other available methods. The differential method measures the ESL over a wide range of inductance, including extremely low inductance values, without elaborate equipment or intricate data interpretation. The differential method also determines the ESR of fast energy capacitors at frequencies approaching the capacitor self-resonant frequency.