An ionization system for applying or removing charge to a moving object, the system comprising: (a) a power supply (22a, 22b); (b) at least one ionizer coupled to the power supply (22a, 22b) and receiving an output therefrom, the power supply (22a, 22b) having a first operating state such that one or more properties of the output are set to fixed non-zero baseline levels, and a second operating state such that the one or more properties of the output are set to neutralizing levels, the fixed baseline level for at least one of the one or more properties of the output being different than the neutralizing level for the at least one of the one or more properties; (c) a controller coupled to the power supply (22a, 22b) to control the output to the at least one ionizer; and (d) a charge sensor arranged downstream of the at least one ionizer and configured to measure a charge on the object; wherein the controller is coupled to an output of the charge sensor characterized in that the controller is configured to: (i) switch the power supply (22a, 22b) between the first and second states during a sequence of a plurality of alternating first and second time periods, (ii) during the first time period only, sense a current flow to the at least one ionizer with the power supply (22a, 22b) set to the first operating state, (iii) during the second time period only, set the power supply (22a, 22b) to the second state and receive measured charge data from the charge sensor, (iv) during the second time period only, adjust at least one of the neutralizing levels for the one or more properties of the output of the power supply (22a, 22b) in the second operating state based on the measured charge data from the charge sensor, (v) during one of the first and second time periods, perform at least one of a calculation of an upstream charge on the object based in part on the sensed current flow and a determination of a relative condition of the at least one ionizer, and (vi) periodically repeat steps (ii)-(v) for successive pairs of the first and second time periods, wherein the calculated upstream charge on the object is also based in part on a speed of the object and a width of the object as measured perpendicularly to the downstream direction of the object, the system further comprising: (e) a user input coupled to the controller and configured to receive data regarding the speed and width of the object. (a) a power supply (22a, 22b); (b) at least one ionizer coupled to the power supply (22a, 22b) and receiving an output therefrom, the power supply (22a, 22b) having a first operating state such that one or more properties of the output are set to fixed non-zero baseline levels, and a second operating state such that the one or more properties of the output are set to neutralizing levels, the fixed baseline level for at least one of the one or more properties of the output being different than the neutralizing level for the at least one of the one or more properties; (c) a controller coupled to the power supply (22a, 22b) to control the output to the at least one ionizer; and (d) a charge sensor arranged downstream of the at least one ionizer and configured to measure a charge on the object; (i) switch the power supply (22a, 22b) between the first and second states during a sequence of a plurality of alternating first and second time periods, (ii) during the first time period only, sense a current flow to the at least one ionizer with the power supply (22a, 22b) set to the first operating state, (iii) during the second time period only, set the power supply (22a, 22b) to the second state and receive measured charge data from the charge sensor, (iv) during the second time period only, adjust at least one of the neutralizing levels for the one or more properties of the output of the power supply (22a, 22b) in the second operating state based on the measured charge data from the charge sensor, (v) during one of the first and second time periods, perform at least one of a calculation of an upstream charge on the object based in part on the sensed current flow and a determination of a relative condition of the at least one ionizer, and (vi) periodically repeat steps (ii)-(v) for successive pairs of the first and second time periods,