voltage of battery 16 the control circuitry will now be described in more detail heated dpf 12 can include one or more zones or regions that may be individually energized and heated for example each zone may be formed by an associated resistive heating element referring briefly to fig2 a cross section view a a of heated dpf 12 shows five heater zones the five zones are identified by numerals 1 5 zones 1 2 4 and 5 each have a quarter semicircle shape and are arranged to form a circle zone 3 has a circular shape and is positioned at the center of the circle formed by zones 1 2 4 and 5 it should be appreciated that a different quantity and or arrangement of zones may be used based on the cross sectional area of heated dpf 12 power available from the control circuit anticipated exhaust flow rates through heated dpf 12 and other factors that affect the ability of the heater to ignite soot in heated dpf 12 each zone is energized exclusive of the other zones the energized zone heats a portion of the accumulated soot to its combustion temperature once the soot ignites then the zone can be turned off the ignited soot propagates a flame or ember front through the remaining soot to regenerate a respective portion of the filter the zone is turned on for less than the duration of the regeneration cycle of the respective zone since a portion of the regeneration is fueled by the burning soot itself the zone heated dpf can use less electrical energy and provide improved fuel economy over other types of heated dpfs 12 an example of a zone heated dpf 12 is described in.