Measurement of the effect of parasitic capacitance in minimum ignition energy spark generation circuits

Abstract

To accurately measure electrostatic discharge energy, a resistive-capacitive voltage discharge approach was used to measure the parasitic capacitance in a circuit. As a result, an output-stage parasitic capacitance in the circuit during the discharge process and a non-negligible storage-stage parasitic capacitance during the charging process were identified. By comparing the data obtained from the resistive-capacitive discharge voltage model and spark current RCL circuit model, the maximum relative deviation from the total circuit capacitance was 5.4% for both approaches. A model based on graded-stage parasitic capacitance was established to analyze the effect of this capacitance on discharge energy. The energy stored in the charging process increased because of the storage-stage parasitic capacitance, and the discharge energy decreased because of the output-stage parasitic capacitance. The energy calculated by the graded parasitic capacitance model was larger than that calculated by the single-stage parasitic capacitance model, with a maximum relative deviation of 36.7% under the test conditions. The smaller the charging capacitor, the more evident the effect of the parasitic capacitance on the discharge energy.