Multiple sensor feedback for controlling multiple ionizers

Abstract

A feedback architecture for ionizers that allows simultaneous adjustment of positive and negative ionizer power supplies. Balance and swing data are fed back to the ionizer through an intermediate module, which permits an extra level of signal processing. Swing information is returned to both power supplies in negative feedback mode. If swing is too high, both power supplies lower output. Balance is fed back in both negative and positive feedback mode. This architecture is compatible with multiple sensors and multiple ionizers.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a schematic that shows a sensor receiving air ions from one or more ionizers. Balance signals and swing signals and are fed back to two ionizer power supplies through an intermediate module

FIG. 2 is a schematic that shows an invented feedback circuit. Information from the sensor is segmented into a balance signal and a swing signal, which are compared to set points. Differences from set points are used to generate feedback to the two ionizer power supplies.

FIG. 3 shows prototype data for a step perturbation of both balance and swing. The top line shows positive peak; the middle line shows balance; and the bottom line shows negative peak. A perturbation was applied at time unit 10. Both swing and balance settled to within 90% of their pre-perturbation values with 40 time adjustment units.

FIG. 4 shows the effects of the feedback loop on balance performance as measured on a reference CPM. A perturbation was purposely introduced.

FIG. 5 shows higher time resolution of FIG. 4 after the perturbation.

Claims

1. A method of monitoring and adjusting ionizers that contain a positive high voltage power supply and a negative high voltage power supply comprising: (a) receiving non-separated real-time balance signals and real-time swing signals from a sensor;(b) separating said real-time balance signal from said real-time swing signal with an intermediate module;(c) comparing said real-time swing signal to a swing set-point register, and calculating a swing difference;(d) comparing said real-time balance signal to a balance set-point register, and calculating a balance difference;(e) applying said swing difference as negative feedback to said positive high voltage power supply and to said negative high voltage power supply;(f) applying said balance difference as negative feedback to said positive high voltage power supply; and(g) applying said balance difference as positive feedback to said negative high voltage power supply.

2. Claim 1 where said swing difference is modified by a swing gain stage prior to the applying step (e).

3. Claim 2 where said swing gain stage affects the response time required to restore normal operation following a swing perturbation.

4. Claim 1 where said balance difference is modified by a balance gain stage prior to the applying steps (f) and (g).

5. Claim 4 where the balance gain stage affects the response time required to restore normal operation following a balance perturbation.

6. Claim 1 where said sensor has a low input impedance.

7. Claim 1 where said positive high voltage power supply and said negative high voltage power supply may not exceed a predetermined voltage level.

8. Claim 7 where an alarm is activated if said predetermined voltage level is exceeded.

9. Claim 1 where said swing set-point register and said balance set-point register are set at the time feedback is enabled.

10. Claim 1 where said real-time swing signal is defined as the peak-to-peak voltage produced by said sensor.

11. A method of monitoring and controlling an ionizer comprising: (a) measuring both real-time swing signals and real-time balance signals with one or more sensors;(b) forwarding said real-time swing signal and said real-time balance signal to an intermediate module;(c) generating two feedback signals within said intermediate module, where said two feedback signals comprise, a balance difference, anda swing difference; and(d) adjusting a positive high voltage power supply and a negative high voltage power supply that are components of said ionizer with said two feedback signals.

12. Claim 11 where said balance difference is defined as the difference between said real-time balance signal and a value stored in a balance set-point register.

13. Claim 11 where said swing difference is defined as the difference between said real-time swing signal and a value stored in a swing set-point register.

14. Claim 11 where said swing difference is input as a negative feedback to said positive high voltage power supply and to said negative high voltage power supply in adjusting step (d).

15. Claim 11 where said balance difference is input as negative feedback to said positive high voltage power supply.

16. Claim 11 where said balance difference is input as positive feedback to said negative high voltage power supply.

17. Claim 11 where said real-time swing signal is defined as the peak-to-peak voltage produced by said sensor.

18. Claim 11 where said one or more sensors are located within a work station.

19. Claim 11 where said intermediate module is positioned between said sensors and said ionizer.

20. Claim 11 where said generating step (c) employs a swing summing block and a balance summing block to calculate said swing difference and said balance difference, respectively.

21. Claim 11 where said two feedback signals are propagated through a positive HV register and a negative HV register.

22. Claim 11 where said generating step (c) employs a swing gain stage and a balance gain stage.

23. An intermediate module which is used to convert sensor data to ionizer feedback signals comprising: one or more swing input ports which receive real-time swing signals;one or more balance input ports which receive real-time balance signals;one or more balance summing blocks to detect changes in said real-time balance from a balance set-point register;one or more swing summing blocks to detect changes in said real-time swing from a swing set-point;one or more positive HV registers that send feedback to a positive high voltage power supply, wherein said positive high voltage power supply is a component of said ionizer;one or more negative HV registers that send feedback to a negative high voltage power supply, wherein said negative high voltage power supply is a component of said ionizer.

24. Claim 23 where said balance summing block calculates a balance difference.

25. Claim 24 where said balance difference is the difference between said real-time balance signal and said balance set-point register.

26. Claim 23 where said swing summing block calculates a swing difference.

27. Claim 26 where said swing difference is the difference between said real-time swing signal and said swing set-point register.

28. Claim 23 further comprising a swing gain stage or a balance gain stage.

29. Claim 23 further comprising a positive input summing block and a negative input summing block.

30. Claim 29 where said positive input summing block combines negative swing feedback and negative balance feedback.

31. Claim 29 where said negative input summing block combines negative swing feedback and positive balance feedback.

32. Claim 29 where said positive input summing block updates said positive HV register and said negative input summing block updates said negative HV register.

33. Claim 23 where said intermediate module is configured to interface with multiple sensors and multiple ionizers.

34. Claim 33 where a predetermined subset of said multiple sensors is linked to a predetermined subset of said multiple ionizers.

35. Claim 33 where said real-time swing signals and said real-time balance signals from said multiple sensors are combined into weighted feedback signals.

36. Claim 35 where said weighted feedback signals provide adjustments that are not the same for all ionizers.

37. Claim 23 further comprising a digital filter to remove irregular temporal perturbations.