WANT TO'PROBE'A VEHICLE'S EHT? You'll need this 1000:1 AC EHT Probe for Ignition Systems

摘要

Peak voltages from the ignition coil secondary windings are typically in die range of 10-30kV but can be higher-and can exceed 50kV in some circumstances.These high voltages occur for a very brief time across a spark plug's terminals before spark ionisation,or under any test condition when the spark plug is not connected.This'open-circuit'coil secondary voltage value is an important ignition system parameter.The rate that the voltage increases with time is another important parameter.A fast rise time to the spark ionisation voltage is thought to be beneficial in overcoming the ohmic resistance of fouled spark plugs,because less energy is dissipated due to a shorter time interval before spark ionisation.Also,a certain voltage threshold is always required to initiate spark ionisation(the spark's early phase,known as phase one).