CONTROL METHODS FOR SETTING A REFERENCE VOLTAGE IN AN AIR TREATMENT SYSTEM

• US 20100037679A1
• Filed: 10/21/2009
• Published: 02/18/2010
• Est. Priority Date: 07/14/2005
• Status: Active Grant

• Current Assignee: Access Business Group International LLC (Alticor Incorporated)
• Original Assignee: Access Business Group International LLC (Alticor Incorporated)
• Inventors: Niezgoda, Thomas A., Evans, Gregory K., Leppien, Thomas J.
• Granted Patent: US 8,689,603 B2
• Time in Patent Office: Days
• US Class Current: 73/31.20
• CPC Class Codes: B01D 2267/40 Different types of filters
• CPC Class Codes: B01D 46/0038 with means for influencing the odor, e.g. deodorizing substances
• CPC Class Codes: B01D 46/0086 Filter condition indicators
• CPC Class Codes: B01D 46/442 by measuring the concentration of particles
• CPC Class Codes: B01D 46/46 automatic
• CPC Class Codes: F24F 11/74 for controlling air flow rate or air velocity
• CPC Class Codes: G01N 21/53 within a flowing fluid, e.g. smoke

Abstract

A control system and associated methods for an air treatment system. In one aspect, the present invention provides a control system and method for controlling blower speed as a function of separately determined smoke and dust concentrations. In one embodiment, the control system and method provides a variable delayed between changes in motor speed to address undesirable rapid changes between speeds. In another aspect, the present invention provides a system and method for calibrating a sensor to provide more uniform operation over time. In yet another aspect, the present invention provide a system and method for calibrating motor speed to provide more consistent and uniform motor speed over time. The present invention also provides a system and method for tracking filter life by as a function of time, motor speed and/or a sensed variable, such as particulate concentration in the environment.

Claims

1. A method for setting the reference voltage for a sensor, comprising the steps of:

taking a plurality of sample readings from the sensor; and

setting the reference voltage as a function of the plurality of sample readings.

2. The method of claim 1 wherein said setting step includes the steps of:

maintaining data representative of the lowest sample reading; and

setting the reference voltage as a function of the lowest sample reading.

3. The method of claim 1 wherein said setting step includes the steps of:

individually maintaining data representative of the plurality of sample readings; and

setting the reference voltage as a function of the maintained data representative of the plurality of sample readings.

4. The method of claim 1 wherein said setting step includes the steps of:

maintaining data representative of the plurality of sample readings; and

setting the reference voltage as an average of the plurality of sample readings.

5. The method of claim 1 wherein said taking step includes the steps of:

taking a first sample reading from the sensor;

storing the first sample reading in a local variable;

taking an additional sample reading from the sensor; and

comparing each additional reading with the local variable and if the reading is lower than the local variable, then storing the sample reading in the local variable.

6. The method of claim 5 wherein said taking step includes repeating said taking an additional sample reading and said comparing steps a predetermined number of times, wherein said setting step is further defined as setting the reference voltage value to be the value stored in the local variable.

7. The method of claim 6 wherein said taking step includes repeating said taking an additional sample reading and said comparing steps 18 times.

8. The method of claim 6 further comprising performing said taking an additional sample reading and said comparing steps at 100 millisecond intervals.

9. A method for setting the reference voltage for a sensor, comprising the steps of:

taking a first sample reading from the sensor;

storing the first sample reading in a local variable;

taking an additional sample reading from the sensor;

adding the additional sample reading to the first sample reading to arrive at a sum and storing the sum in the local variable;

determining an average sample reading by dividing the sum by a total number of sample readings; and

using the average sample reading as the reference voltage.

10. The method of claim 9 including repeating said taking an additional sample reading and said adding steps a predetermined number of times.

11. The method of claim 10 including repeating said taking an additional sample reading and said adding steps 18 times, wherein the total number of readings is 20.

12. The method of claim 11 further comprising performing said taking an additional sample reading at 100 millisecond intervals.

13. The method of claim 12 further comprising adjusting the intervals in fixed segments of 5 to 10 millisecond segments.

14. A method for setting the reference voltage for a sensor, comprising the steps of:

taking a fixed number of sample readings at a sampling frequency;

comparing the lowest reading value with an acceptable range of values corresponding to an acceptable reference voltage;

in response to the lowest reading being higher than the acceptable range, increasing the sampling frequency.

15. The method of claim 14 further comprising repeating the taking, comparing and increasing steps.

16. The method of claim 14 further comprising decreasing the sampling frequency in response to the lowest reading being lower than the acceptable range.

17. The method of claim 14 further comprising performing the taking and comparing steps at 50 millisecond intervals.

18. The method of claim 17 further comprising adjusting the sampling frequency in fixed segments of 5 to 10 millisecond segments.

19. The method of claim 14 further comprising adjusting the sampling frequency as a function of the difference between the lowest sample reading and the acceptable range.

20. The method of claim 19 further comprising, in response to the lowest reading being within the acceptable range, leaving the frequency at its current value.