: A well accepted model for sprite production involves quasi-electrostatic fields (QSF)driven by large positive cloud-to-ground (+CG) strokes that can cause electricalbreakdown in the middle atmosphere. A new high voltage, high impedance, dou-ble Langmuir probe instrument is designed specifically for measuring these largelightning-driven electric field changes at altitudes above 30 km. This High Volt-age (HV) Electric Field Detector measured 200 nearby (< 75 km)) lightning-drivenelectric field changes, up to 140 V/m in.