Ionisation current detector for IC engine ignition monitor - measures ionisation current through ignition coils during combustion of gas mixture

摘要

The ionisation current detector (11) for an IC engine comprises conventional circuitry for registering the successive ionisation currents. Such currents are generated during combustion as a result of the action of the ignition coils (1) and spark plugs (3) for each cylinder (1 to 4) when switched by the power transistors (2). The respective ionisation currents flow in the coil secondaries (1b) and appear as a voltage across the resistor (5) of the common detector unit (11). This voltage is coupled (8) to a comparator (9) for comparison with a reference level resulting in a pulse at the terminal (13) which confirms ignition. USE/ADVANTAGE - For high-speed multicylinder engines. Single detector unit serving all cylinders gives reduction in complexity and cost compared with usual one unit per cylinder.