Method and apparatus for generating a sustained arc at a sparking device

An apparatus for generating an arc at a spark generating device comprising:

• an output terminal connected to a spark-generating device;
• an ionizing circuit for developing a voltage to ionize the spark-generating device;
• a switch connected to the ionizing circuit and the output terminal that when closed provides an electrically conductive path to communicate the voltage to the output terminal, which ionizes an air gap of the spark-generating device;
• a power supply having on and off states for supplying energy to a spark generating device coupled to the output terminal;
• and,
• a logic circuit connected to the switch and the power supply for closing the switch to initiate an arc and to thereafter sustain the arc by continuing to connect the power supply to the output terminal after the ionizing circuit has fully discharged into the spark-generating device.

For a capacitive discharge ignition device, a method for generating and actively controlling an arc at a spark plug, the method comprising the steps of:

• supplying energy to a capacitor of the device;
• sensing a state of charge at the capacitor;
• discharging the capacitor into the igniter plug to ionize an air gap of the plug;
• and
• continuing to pump energy into the spark plug after the capacitor has been discharged to sustain the arc for a predetermined time period, where the predetermined time period is longer than a time period the arc would be sustained solely by the discharging of the capacitor.

An apparatus for generating an arc at a spark generating device comprising:

• an output terminal for connecting to a spark plug;
• an ionizing circuit that delivers energy to the output terminal in the form of a first pair of voltages and currents, where the voltage is sufficient to ionize an air gap of the spark plug;
• a switch that when closed connects the ionizing circuit and the output terminal and provides an electrically conductive path that communicates the energy of the ionizing circuit to the output terminal, which in turn delivers the energy to the connected spark plug, causing the air gap to ionize;
• a power supply having on and off states for supplying energy to the output terminal and the connected spark plug in the form of a second pair of voltages and currents after ionization of the air gap by the first pair, where the voltages of the first pair are higher than the voltages of the second pair, and the currents of the second pair are higher than the currents of the first pair.

An apparatus for generating a sustained arc at a spark generating device comprising:

• an output terminal connecting to a spark generating device;
• a power converter having on and off states for selectively supplying energy to the spark generating device connected to the output terminal;
• an energy storage device for storing a voltage sufficient to ionize an air gap of the spark generating device;
• a switch for selectively transferring the voltage at the energy storage device to the spark generating device by way of the output terminal;
• a sensor associated with the energy storage device that monitors an amount of energy stored by the energy storage device;
• and, a logic circuit connected to the sensor, the switch, and the power converter for (1) switching the switch to a conducting state so that the energy stored in the energy storage device ionizes the air gap of the spark generating device and (2) controlling the power converter to pump energy to the output terminal to sustain a plasma arc at the air gap of the connected spark generating device for a predetermined time period after which the logic circuit switches the power converter to its off-state, where the logic circuit limits the energy delivered to the output terminal by the power converter until a center of the plasma arc generated at the air gap of the spark-generating device moves away from a tip of the spark generating device.