JP7127025B2 - Control system for a balanced micropulse ionizing blower - Google Patents

Description

[Cross reference to related applications]
This international application claims priority to US patent application Ser. No. 15/362,280, filed November 28, 2016. The entirety of US patent application Ser. No. 15/362,280 is incorporated herein by reference.

Embodiments of the invention relate generally to ionizing blowers.

Static charge neutralizers are designed to eliminate or minimize static charge buildup. Static charge neutralizers remove static charge by generating air ions and delivering those ions to a charged target.

One specific category of static charge neutralizer is an ionizing blower. An ionizing blower typically uses a corona electrode to generate air ions and a fan (or fans) to direct the air ions toward a target of interest.

Monitoring or controlling fan performance utilizes two measurements.

The first measure is equilibrium. An ideal balance occurs when the number of positive air ions equals the number of negative air ions. The ideal reading is 0 on the charged plate monitor. In practice, static charge neutralizers are controlled within a narrow range centered around zero. For example, static charge neutralizer balance may be specified at about ±0.2 volts.

The second measurement is air ion flux. Higher air ion currents are useful because they can discharge static charges in a shorter period of time. A large air ion flux correlates with a short discharge time, which is measured with a charged plate monitor.

In one embodiment of the present invention, a method is provided for automatically balancing the ionized airflow created in a bipolar corona discharge. The method comprises providing an air movement device comprising at least one ion emitter and reference electrode connected to a micropulsed AC power source and a control system comprising at least one ion balance monitor and corona discharge regulation control. , generating a variable polarity group consisting of ionizing micropulses of short duration, said micropulses being predominantly asymmetric with respect to voltage amplitude and duration of both polarities, and ionizing pulses of at least one polarity being It has a magnitude exceeding (positive) the corona threshold.

In another embodiment of the present invention, an apparatus is provided for an automatically balancing ionizing blower. The apparatus comprises an air movement device, at least one ion emitter and reference electrode both connected to a high voltage source, and an ion balance monitor, wherein the transformer of the high voltage source, the ion emitter and the reference electrode are It is placed in a closed loop for the AC current circuit, said loop being grounded by a high value viewing resistor.

Various embodiments of the present disclosure, presented by way of example, are described in detail with reference to the following drawings, in which like numerals refer to like elements.

1 is a general block diagram of an ionizing blower, in accordance with one embodiment of the present invention; FIG. 1B is a cross-sectional view of the blower of FIG. 1A; FIG. FIG. 3 is a block diagram of a sensor included in an ionizing blower, according to one embodiment of the present invention; 1B is a block diagram of the ionizing blower of FIG. 1A and the ionized airflow from the blower, in accordance with one embodiment of the present invention; FIG. FIG. 4 is an electrical block diagram of the system within the ionizing blower, according to one embodiment of the present invention; 3 is a flow diagram of a feedback algorithm 300, according to one embodiment of the present invention; FIG. 4 is a flow diagram of a micropulse generator algorithm for micropulse generator control, according to one embodiment of the present invention; FIG. 4 is a flow diagram of system operation during formation of a negative pulse train, according to one embodiment of the present invention; 4 is a flow diagram of system operation during formation of a positive pulse train, according to one embodiment of the present invention; FIG. 4 is a flow diagram of system operation during the current pulse phase, according to one embodiment of the present invention; FIG. FIG. 4 is a flow diagram of system operation during sensor input measurement, in accordance with one embodiment of the present invention; FIG. FIG. 4 is a waveform diagram of micropulses, according to one embodiment of the present invention. FIG. 4 is a flow diagram of system operation during a balance alarm, according to one embodiment of the invention; FIG.

In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of various embodiments of the invention. Those skilled in the art will appreciate that these various embodiments of the present invention are illustrative only and are not intended to be limiting in any way. Other embodiments of the invention will readily occur to such skilled persons having the benefit of the disclosure herein.

An embodiment of the present invention can be applied to many types of air-gas ion generators configured, for example, as ionization bars, blowers or in-line ionization devices.

Wide area coverage ionizing blowers require highly efficient air ionization combined with short discharge times and tight ion balance control. FIG. 1A is a general block diagram of an ionizing blower 100, according to one embodiment of the present invention, while FIG. 1B is a cross-sectional view of the blower 100 of FIG. 1A along line AA. Efficient air ionization is produced between an array of emitter points 102 (ie, emitter point array 102) and two reference electrodes 104, 105 (shown as upper reference electrode 104 and lower reference electrode 105). achieved by a bipolar corona discharge. The emitter point 102 is mounted on a protective grille 106 (ie, air duct 106), which is similarly effective for increasing the velocity of the ionized airflow.

A fan 130 (FIG. 1A) is an air moving device that provides highly adjustable airflow in the space 130 between the emitter point array 102 (one or more ion emitters 102) and the two reference electrodes 104, 105. gives 125. The air duct 106 concentrates the airflow 125 and disperses it within the corona discharge space 130 . Positive and negative ions produced by the corona move between electrodes 102 , 104 , 105 . The airflow 125 can pick up and carry only a relatively small amount of the positive and negative ions produced by the corona discharge.

According to one embodiment of the present invention, air 125 is forced out of air duct (106) outlet 131 and air 125 passes through air ionization sensor 101 . Details of one embodiment of the design of sensor 101 are shown in FIG. 1C. A fan (shown as block 126 in FIG. 1B) provides airflow 125 . The air ionization voltage sensor 101 has a louver-type thin dielectric plate 109 that extends the full width of the duct 106 . The louver plate 109 redirects a portion 125a (or sample 125a) of the ionized airflow 125b (ionized airflow 125b) coming from the duct 106 and the upper electrode 104 (see also FIG. 2A), thereby Sensor 101 is capable of sensing and collecting some amount of the ionic charge within portion 125a of ionized airflow 125b. The collected ion charge then produces control signal 250 ( FIG. 2 ) for use by algorithm 300 ( FIG. 3 ) to balance the ions within ionizing blower 100 . The top side 132 of the plate 109 has a thin metal strip that acts as a sensitive electrode and the bottom side 133 has a wide grounded plane electrode 110 . This electrode 110 is normally shielded so that the air ionization sensor 101 is shielded from the strong electric fields of the emitter point array 102 . Electrode 108 collects some of the charge of the ions, resulting in voltage/signal 135 (FIG. 2A) proportional to the ion balance within ionized airflow 125b. Voltage/signal 135 from sensor 101 is used by control system 107 (shown as system 200 in FIG. 2) to monitor and adjust the ion balance within ionized airflow 125b (positive: is used). This signal 135 is also represented by signal 250, which is input to sample and hold circuit 205, as further discussed below. In other embodiments of the invention, other configurations of ion balance sensors may be used, for example, sensors in the form of conductive grids or wire mesh that are encased in the ion stream.

According to another embodiment of the present invention, ion current sensor 204 is used to monitor ionized flow balance. Accordingly, one embodiment of the present invention provides a system 200 (Fig. 2) that includes an ionization return current sensor 204 for monitoring ionized airflow balance. In another embodiment of the invention, system 200 includes an air ionization voltage sensor 101 for monitoring ionized air flow balance.

In yet another embodiment of the present invention, system 200 comprises dual sensors comprising air ionization voltage sensor 101 and ionization current feedback sensor 204, both sensors 101 and 204 monitoring ionized airflow balance. configured to

In some examples, ionization voltage sensor 101 and/or ionization current feedback sensor 204 are remote sensor(s) that are directly wired to control system 107 . In some other examples, ionization voltage sensor 101 and/or ionization current feedback sensor 204 are remote wireless sensor(s) using radio frequency (RF) communication, Bluetooth and/or any other wireless communication method. is). A remote sensor refers to a sensor external to the ionizing blower 100 . The exemplary ionization blower 100 is active (e.g., electrically processed) from a wired and/or wireless remote ionization voltage sensor 101 and/or an ionization current feedback sensor 204 in the control system 107 of the ionization blower 100 and/or Or it can receive passive (eg, not electronically processed) feedback signal(s).

The ionization blower 100 may be within wireless communication range of the ionization voltage sensor 101 and/or the ionization current return sensor 204, multiple or even greater numbers (e.g., tens, hundreds, or more) of the ionization blower 100 and In some examples, sensors 101, 204 and individual ionization blowers 100 are specifically labeled as they may be used in applications or environments in which wireless ionization voltage sensor 101 and/or ionization current feedback sensor 204 are used. , the ionization voltage sensor 101 and/or the ionization current feedback sensor 204 are individually addressable and have unique identifiers.

In examples where ionization voltage sensor 101 and/or ionization current feedback sensor 204 are remote sensor(s), exemplary control system 107 provides wired communication from ionization voltage sensor 101 and/or ionization current feedback sensor 204. and/or communication circuitry for receiving wireless communications.

Ionization feedback current sensor 204 includes capacitors C2 and C1, and resistors R1 and R2. Capacitor C2 bypasses the current sensing circuit and provides an AC current path to ground. Resistor R2 converts the ion current to a voltage (Ii*R2), and resistors R1 and R2 and capacitor C2 form a low-pass filter that filters out the induced current generated by the micropulses. A feedback current 210 flowing from the sensor 204 is shown as I2.

The current 254 flowing through emitter point 102 is the current sum Σ(Ii(+), Ii(-), I2, Ic1, Ic2), where currents Ic1 and Ic2 are the currents flowing through capacitors C1 and C2, respectively.

FIG. 2A shows an ion current 220 flowing between the emitter 102 and the reference electrodes 104,105. Airflow 125 from duct 106 converts a portion of these two ion streams 220 into an ionized airflow 125 b that travels to a charge neutralization target external to blower 100 . The target is shown generally as block 127 in FIG. 1B and can be positioned at different locations relative to ionizing blower 100 .

FIG. 2B shows an electrical block diagram of system 200 within ionizing blower 100, according to one embodiment of the present invention. The system 200 includes an ionization current sensor 204, a micropulse high voltage power supply 230 (micropulse AC power supply 230) (the power supply is formed by a pulse driver 202 and a high voltage (HV) transformer 203), and an ionization and the blower control system 201 . In one embodiment, control system 201 is microcontroller 201 . Microcontroller 201 receives power from voltage bias 256 , which may be, for example, approximately 3.3 DC volts, and is grounded at line 257 .

A power converter 209 may optionally be used in system 200 to provide the various voltages used by system 200 (eg, −12 VDC, 12 VDC or 3.3 VDC). A power converter 209 can convert a voltage source value 258 (eg, 24 VDC) to various voltages 256 for biasing the microcontroller 201 .

A micropulse high voltage power supply 230 has a pulse driver 202 controlled by a microcontroller 201 . A pulse driver 202 is connected to a step-up pulse transformer 203 . Transformer 203 produces short duration pulses (in the microsecond range) of positive and negative polarities with sufficient amplitude to produce a corona discharge. The secondary coil of transformer 203 is left floating relative to ground. A high voltage terminal 250 of the transformer 203 is connected to the emitter point array 102 and a low voltage terminal of the transformer 203 is connected to the reference electrodes 104,105.

As a result of short duration high voltage AC pulses (generated by high voltage power supply 230), significant capacitive or displacement currents Ic1 and Ic2 flow between electrodes 102 and 104,105. For example, current Ic1 flows between electrode (emitter point) 102 and upper reference electrode 104 and current Ic2 flows between electrode 102 and lower reference voltage 105 . Relatively small positive and negative ion corona currents labeled Ii(+) and Ii(-) exit this ion generation system 200, enter the environment external to the blower 100, and travel to the target.

In order to separate the capacitive and ionic currents, the secondary coil and corona electrodes 102, 104 and 105 of transformer 203 are left substantially floating with respect to ground to allow ionic currents Ii(+) and Ii(- ) has a return path to ground (and flows to ground), the ion generation system 200 is placed in a closed loop circuit for the high frequency AC capacitive currents labeled Ic1 and Ic2. AC currents have a significantly lower resistance than those that flow to ground to circulate within this loop.

The system 200 is an ion balance monitor that provides isolation of ion convective current from the pulsed AC current by placing a closed loop current path between the pulsed AC voltage source 230, the ion emitter 102 and the reference electrode 104 or 105. including.

In addition, ion balance monitoring is performed within system 200 during the period between micropulses. Additionally, ion balance monitoring is performed by integrating the differential signal of positive and negative convective currents.

The transformer 203, the ion emitter 102 and the reference electrode 104 or 105 of the high voltage power supply 230 are placed in a closed loop for the AC current circuit, which closed loop is grounded by a high value galvanometric resistor R2.

According to the law of conservation of charge, when the output of the AC power supply 230 (via transformer 203) is left floating, the ion current is equal to the sum of the positive ion current Ii(+) and the negative ion current Ii(-). . These currents Ii(+) and Ii(-) must return through the feedback current sensor 204 circuitry in system 200 . The amount of ionic current for each polarity is
[Number 1]
is. where Q is the positive or negative ion charge, N is the ion concentration, and U is the airflow. Ionic balance is achieved when the absolute values of the positive current Ii(+) and the negative current Ii(-) are the same. It is known in the art that air ions of both polarities carry roughly the same amount of charge (equal to one electron). Therefore, another condition for ion balance is equal concentrations of ions of both polarities. The air ionization voltage sensor 101 (ion balance monitor 101) is sensitive to variations in ion concentration, in contrast to the feedback current sensor 204 (ion balance monitor 204), which is sensitive to changes in ion current. Therefore, the response speed of air ionization voltage sensor (capacitor sensor) 101 is typically faster than the response of ionization feedback current sensor 204 .

As a result of the greater number of positive ions being detected by sensor 101 , sensor 101 produces a positive output voltage that is input to (and processed by) sample and hold circuit 205 . As a result of the greater number of negative ions being detected by sensor 101 , sensor 101 produces a negative output voltage that is input to (and processed by) sample and hold circuit 205 . In contrast, as similarly described above, the sensor 204 outputs a signal 250 for input to the sample-and-hold circuit 205 to determine and achieve the ion balance within the ionizing blower 100. Absolute values of positive Ii(+) and negative Ii(-) are used.

At times between micropulse trains, sample signal 215 will close switch 216 such that amplifier 218 is connected to capacitor C3, which then responds to input signal 250 to a value based thereon. charged.

The ion current suspended in the airflow is characterized by a very low frequency and can be monitored by flowing to ground through high megohm resistor circuits R1 and R2. To minimize the effects of capacitive currents and high frequency parasitic currents, the sensor 204 has two bypass capacitive paths comprising C1 and C2.

The difference between currents Ii(+) and Ii(-) is continuously measured by sensor 204 . The resulting current flow through the resistive circuits R1, R2 produces a voltage/signal proportional to the ion balance integrated/averaged over time of the airflow exiting the blower. This resulting current is shown as current 214 represented by the sum Σ(Ii(+), Ii(−)).

Ion balance monitoring is accomplished by measuring the voltage output of current sensor 204, or by measuring the output of voltage sensor 101, or by measuring the voltage from air ionization sensors 101 and 204. For clarity, the voltage output of current sensor 204 and the voltage output of voltage sensor 101 are each represented by the same signal 250 in FIG. This signal 250 is applied to the input of a sample and hold circuit 205 (sampling circuit 205 ), which is sampled by microcontroller 201 via sample signal 215 opening switch 216 which triggers a sample and hold operation on signal 250 . controlled.

In some instances or embodiments for corona systems, diagnostic signals from both sensors 101 and 204 can be compared. These diagnostic signals are input to sample and hold circuit 205 as signal 250 .

Signal 250 is then conditioned by low pass filter 206 and amplified by amplifier 207 before being applied to the input of an analog-to-digital converter (ADC) residing within microcontroller 201 . Sample-and-hold circuit 205 samples signal 250 between pulse times to minimize noise in reproduced signal 250 . Capacitor C3 holds the previous signal value between sampling times. Amplifier 207 amplifies signal 250 to a more useful level for microcontroller 201 and this amplified signal from amplifier 207 is shown as balanced signal 252 .

Microcontroller 201 compares balance signal 252 to setpoint signal 253 , which is a reference signal generated by balance potentiometer 208 . Setpoint signal 253 is a variable signal that can be adjusted by potentiometer 208 .

The setpoint signal 253 can be adjusted to compensate for different environments of the ionizing blower 100 . For example, the reference level (ground) near the output 131 (FIG. 1B) of the ionizing blower 100 may be approximately zero, while the reference level near the ionization target may be non-zero. For example, if the ionization target location has a strong ground potential value, more negative ions may be lost at that location. Therefore, the setpoint signal 253 can be adjusted to compensate for the non-zero reference level at the ionization target location. In this case, the microcontroller 201 drives the pulse driver 202 to control the HV transformer 230 to generate more positive ions at the emitter point 102 to compensate for the loss of negative ions at the ionization target location. The setpoint signal 253 can be lowered so that the HV output 254 (due to the lower setpoint value 253 used as a comparison to trigger the production of more positive ions) can be produced.

Reference is now made to FIGS. In one embodiment of the present invention, ionizing blower 100 operates based on one or more of the following: (1) by increasing and/or decreasing positive and/or negative pulse width values ( 2) by increasing and/or decreasing the time between positive pulses and/or the time between negative pulses; and/or (3) increasing the number of positive and/or negative pulses, as described below. and/or decrease, an ion balance within the ionizing blower 100 can be achieved. The microcontroller 201 outputs a positive pulse output 815 and a negative pulse output 816 (FIGS. 2 and 8) that feed into and control the pulse driver 202 . In response to outputs 815 and 816, transformer 230 produces ionization waveform 814 (HV output 814), which waveform is used to produce positive ion abundances and negative ion abundances based on ionization waveform 814. Applied to emitter point 102 .

As an example, if sensor 101 and/or sensor 204 detect an ion imbalance within ionizing blower 100 such that the amount of positive ions exceeds the amount of negative ions in blower 100, a balance is sent to microcontroller 201. Signal 252 will indicate this ion imbalance. Microcontroller 201 lengthens negative pulse width (duration) 811 of negative pulse 804 . As width 811 is lengthened, the amplitude of negative micropulse 802 increases. A positive micropulse 801 and a negative micropulse 802 are high voltage outputs delivered to the emitter point 102 . The increased amplitude of negative micropulses 802 will increase the negative ions generated from emitter point 102 . Ionizing waveform 814 produces a variable polarity group of short duration ionizing micropulses 801 and 802 . Micropulses 801 and 802 are predominantly asymmetric in terms of voltage amplitude and duration for both polarities, with at least one polarity ionizing pulse having a magnitude exceeding the corona threshold (positive).

If the maximum pulse width for the negative pulse width 811 is reached and the amount of positive ions still exceeds the amount of negative ions in the blower 100, the microcontroller 201 adjusts the positive pulse width of the positive pulse 803 ( duration) 810 will be shortened. As width 810 is shortened, the amplitude of positive micropulse 801 is reduced. The reduced amplitude of positive micropulses 801 will reduce positive ions generated from emitter point 102 .

Alternatively, or in addition, if the amount of positive ions exceeds the amount of negative ions in blower 100, microcontroller 201 may lengthen negative Rep-Rate 813 (the time interval between negative pulses 804). will lengthen the time between negative pulses 804 . As the negative Rep-Rate 813 is lengthened, the time between negative micropulses 802 is also increased. As a result, a lengthened or longer negative Rep-Rate 813 will increase the time between negative micropulses 802, thereby increasing the length of time that negative ions are produced from the emitter point 102. .

If the minimum negative Rep-Rate for negative Rep-Rate is reached and the amount of positive ions still exceeds the amount of negative ions in blower 100, microcontroller 201 sets positive Rep-Rate 812 ( By shortening the time interval between positive pulses 803 , the time between positive pulses 803 will be shortened. As the positive Rep-Rate 812 is shortened, the time between positive micropulses 801 is also increased. As a result, a shortened or shorter positive Rep-Rate 811 will decrease the time between positive micropulses 803, thereby decreasing the length of time that positive ions are produced from the emitter point 102. .

Alternatively or additionally, if the amount of positive ions exceeds the negative ions in blower 100 , microcontroller 201 reduces the number of negative pulses 804 in negative pulse output 816 . Microcontroller 201 has a negative pulse counter that can be incremented to increase the number of negative pulses 804 in negative pulse output 816 . As the number of negative pulses 804 increases, the negative pulse train in negative pulse output 816 increases, which increases the number of negative micropulses 802 in the HV output, ionizing waveform 814 applied to emitter point 102 .

If the maximum amount of negative pulses is applied to the negative pulse output 816 and the amount of positive ions still exceeds the amount of negative ions in the blower 100, the microcontroller 201 outputs a positive pulse on the positive pulse output 815. 803 will be reduced. Microcontroller 201 has a positive pulse counter that can be decremented to reduce the number of positive pulses 803 in positive pulse output 815 . As the number of positive pulses 803 decreases, the positive pulse train in positive pulse output 815 decreases, which reduces the number of positive micropulses 801 in the HV output, ionizing waveform 814 applied to emitter point 102 .

The following examples are directed to achieving ion balance within the blower 100 when the amount of negative ions exceeds the amount of positive ions within the blower.

Balance signal 252 to microcontroller 201 if sensor 101 and/or sensor 204 detects an ion imbalance within ionizing blower 101 such that the amount of negative ions exceeds the amount of positive ions within blower 101 . will show this ionic equilibrium. The microcontroller 201 will lengthen the positive pulse width 812 of the positive pulse 803 . As width 810 is lengthened, the amplitude of positive micropulse 801 increases. The increased amplitude of positive micropulses 801 will increase the positive ions produced from emitter point 102 .

If the maximum pulse width for positive pulse width 812 is reached and the amount of negative ions in blower 100 still exceeds the amount of positive ions, microcontroller 201 adjusts negative pulse width 811 for negative pulse 804 . will be shortened. As width 811 is shortened, the amplitude of negative micropulse 802 is reduced. The reduced amplitude of negative micropulses 802 will reduce negative ions generated from emitter point 102 .

Alternatively, or in addition, if the amount of negative ions exceeds the amount of positive ions in blower 100, microcontroller 201 increases the time between positive pulses 803 by lengthening positive Rep-Rate 812. it will be longer. As the positive Rep-Rate 812 is lengthened, the time between positive micropulses 801 also increases. As a result, a lengthened or longer positive Rep-Rate 812 will increase the time between positive micropulses 801, thereby increasing the length of time that positive ions are produced from the emitter point 102. .

If the minimum positive Rep-Rate for positive Rep-Rate is reached and the amount of negative ions still exceeds the amount of positive ions in blower 100, microcontroller 201 sets negative Rep-Rate 813 to By increasing it, the time between negative pulses 804 will be increased. As the negative Rep-Rate 813 is lengthened, the time between negative micropulses 802 is also increased. As a result, a lengthened or longer negative Rep-Rate 813 reduces the time between negative micropulses 802, thereby reducing the length of time negative ions are produced from the emitter point 102. Become.

Alternatively or additionally, if the amount of negative ions exceeds the positive ions in blower 100 , microcontroller 201 will increase the number of positive pulses 803 in positive pulse output 815 . Microcontroller 201 has a positive pulse counter that can be incremented to increase the number of positive pulses 803 on positive pulse output 815 . As the number of positive pulses 803 increases, the positive pulse train in positive pulse output 815 is lengthened and the number of positive micropulses 801 in the HV output, ionizing waveform 814 applied to emitter point 102 increases.

If the maximum amount of positive pulses is applied to the positive pulse output 815 and the amount of negative ions still exceeds the amount of positive ions in the blower 100, the microcontroller 201 will apply a negative pulse on the negative pulse output 816. 804 will be reduced. Microcontroller 201 has a negative pulse counter that can be decremented to reduce the number of negative pulses 804 in negative pulse output 816 . As the number of negative pulses 804 is reduced, the negative pulse train in negative pulse output 816 is shortened and the number of negative micropulses 802 in the HV output, ionizing waveform 814 applied to emitter point 102, is reduced.

If the ion imbalance (which is reflected in the balance current value 252) does not differ significantly from the setpoint 253, then a small adjustment of the ion imbalance may be sufficient and the microcontroller 201 controls the pulse width 811 and /or 810 can be adjusted to achieve ion balance.

If the ion imbalance (which is reflected in the balance current value 252) is somewhat different from the set point 253, then some adjustment of the ion imbalance may be sufficient and the microcontroller 201 will cause the Rep -Rate 813 and 812 can be adjusted to achieve ion balance.

If the ion imbalance (which is reflected in the balance current value 252) is significantly different from the set point 253, it may be sufficient to adjust the ion imbalance by a large amount, and the microcontroller 201 will cause the positive current at outputs 815 and 816, respectively. Pulses and/or negative pulses can be applied.

In yet another embodiment of the invention, the duration of at least one polarity (pulse width) of the micropulses in FIG. 8 is at least about 1/100th of the time interval between micropulses.

In yet another embodiment of the present invention, the micropulses in FIG. 8 are arranged in successive groups/pulse trains, one polarity pulse train comprising about 2 to 16 positive ionizing pulses, and a negative pulse train comprising: It contains about 2 to 16 positive ionizing pulses, with the time interval between positive and negative pulse trains equal to about twice the period of successive pulses.

The flow diagram of FIG. 3 illustrates a feedback algorithm 300 of system 200, according to one embodiment of the invention. The function of providing ion balance control through the use of feedback algorithm 300 is performed at the end of the ionization cycle. This algorithm is performed, for example, by system 200 of FIG. At block 301, the balance control feedback algorithm is initiated.

In blocks 302, 303, 304 and 305 the calculation of the negative pulse width control value is performed. At block 302, an error value (Error) is calculated by subtracting the desired ion balance (SetPoint) from the measured ion balance (BalanceMeasurement). At block 303, the error value is multiplied by the loop gain. At block 304, the control value is limited to limit the calculation of the control value to a minimum or maximum value so as not to go out of range. At block 305, a control value is added to the last negative pulse width value.

In blocks 306, 307, 308 and 309 the pulse width is incremented or decremented. At block 306, the negative pulse width is compared to the maximum pulse width (MAX). If the negative pulse width is equal to MAX, at block 307 the positive pulse width is decremented and the algorithm 300 proceeds to block 310 . If the negative pulse width is not equal to MAX, algorithm 300 proceeds to block 308 .

At block 308, the negative pulse width is compared to the minimum pulse width (MIN). If the negative pulse width is equal to MIN, block 309 decrements the positive pulse width and algorithm 300 proceeds to block 310 . If the negative pulse width is not equal to MIN, algorithm 300 proceeds to block 310 . When the negative pulse width reaches its control limit, the change in positive pulse width shifts the balance in such a way as to overshoot the balance set point, forcing the negative pulse towards its limit.

In blocks 310, 311, 312 and 313, the pulse repetition rate (Rep-Rate) is incremented or decremented when the pulse width limit is met. At block 310, the positive pulse width is compared to MAX and the negative pulse width is compared to MIN. If the positive pulse width equals MAX and the negative pulse width equals MIN, block 311 alternately increments the positive pulse repetition rate (Rep-Rate) or decrements the negative pulse Rep-Rate. be done. Algorithm 300 proceeds to block 314 . If the positive pulse width is not equal to MAX and the negative pulse width is not equal to MIN, algorithm 300 proceeds to block 312 .

At block 312, the positive pulse width is compared to MIN and the negative pulse width is compared to MAX. If the positive pulse width is equal to MIN and the negative pulse width is equal to MAX, block 313 alternately decrements the positive pulse repetition rate (Rep-Rate) or increments the negative pulse Rep-Rate. be done. Algorithm 300 proceeds to block 314 . If the positive pulse width is not equal to MIN and the negative pulse width is not equal to MAX, algorithm 300 proceeds to block 314 .

Positive and negative pulse width control are used when equilibrium is close to the set point. As the emitter point ages or is dictated by the environment, the positive and negative pulse width controls lose their range and reach control limits (positive to its maximum and negative to its minimum). (or vice versa). When this occurs, the algorithm changes the positive Rep-Rate or negative Rep-Rate, effectively increasing or decreasing the length of on-time for positive or negative ion production, shifting the balance towards the set point.

At blocks 314, 315, 316 and 317, the pulse repetition rate (Rep-Rate) is incremented or decremented when the pulse width limit is met. At block 314, the positive pulse Rep-Rate is compared to a minimum pulse repetition rate (MIN-Rep-Rate) and the negative pulse Rep-Rate is compared to a maximum pulse repetition rate (MAX-Rep-Rate). If the positive pulse Rep-Rate equals MIN-Rep-Rate and the negative pulse Rep-Rate equals MAX-Rep-Rate, then at block 315 one negative pulse is shifted to a positive pulse through the off time count. and then the algorithm 300 proceeds to block 318 where the balance control feedback algorithm 300 ends. Off time counts are the times when the ionizing waveform is off. Off time is the time between the negative group and the positive group (or pulse train) and between the positive group and the negative group (or pulse train), herein referred to as positive Rep-Rate or negative Rep-Rate. It is defined as a count equal to the pulse duration involved.

If the positive pulse Rep-Rate is not equal to MIN-Rep-Rate and the negative pulse Rep-Rate is not equal to MAX-Rep-Rate, algorithm 300 proceeds to block 316 .

At block 316, the positive pulse Rep-Rate is compared to MAX-Rep-Rate and the negative pulse Rep-Rate is compared to MIN-Rep-Rate). If the positive pulse Rep-Rate is equal to MAX-Rep-Rate and the negative pulse Rep-Rate is equal to MIN-Rep-Rate, block 317 shifts one positive pulse to a negative pulse through the OFF time count. and then the algorithm 300 proceeds to block 318 where the balance control feedback algorithm 300 ends. If the positive pulse Rep-Rate does not equal MAX-Rep-Rate and the negative pulse Rep-Rate does not equal MIN-Rep-Rate, algorithm 300 proceeds to block 318 where algorithm 300 ends.

When the Rep-Rate control reaches its limit, the algorithm triggers the next adjustment control level.

Shifting the micropulses from the positive pulse group to the off-time pulse group to the negative pulse group shifts the balance in the negative direction. Conversely, shifting the micropulses from the negative pulse group to the off-time pulse group to the positive pulse group shifts the balance in the positive direction. Using off-time groups reduces the impact, thereby providing finer control.

The flow chart of FIG. 4 shows an algorithm 400 for micropulse generator control. The waveforms of the drive pulse and high voltage output are illustrated in FIG. This algorithm 400 is executed, for example, by system 200 of FIG. At block 401, the Timer1 interrupt service routine is initiated. Algorithm 400 for the micropulse generator runs, for example, every 0.1 milliseconds.

At block 402, a micropulse repetition rate counter is decremented. This counter is the repetition rate divider counter for Timer1. Timer1 is a main loop timer and a pulse control timer that operates at 0.1 ms. Timer1 switches on the HVPS output and hence the start of the micropulse, Timer0 switches off the HVPS and ends the micropulse. Therefore, Timer1 sets the rep-rate and triggers the analog-to-digital conversion, and Timer0 sets the micropulse width.

At block 403 a comparison is made whether the micropulse repetition rate counter is equal to two. In other words, a test is performed to determine if the Rep-Rate divider counter is at two counts from the start of the next micropulse. The step of block 403 synchronizes the ADC (in microcontroller 201) to the time just prior to the next micropulse transmission. If the micropulse repetition rate counter equals two, the sample and hold circuit 205 is set to sample mode as shown in block 404 . At block 405 , the ADC within microcontroller 201 reads the sensor input signal from sample and hold circuit 205 .

If the micropulse repetition rate counter is not equal to two, algorithm 400 proceeds to block 406 .

Blocks 404 and 405 initiate and perform analog-to-digital conversions to allow microcontroller 201 to measure analog inputs received from sample and hold circuit 205 .

When sample and hold circuit 205 is enabled, typically about 0.2 milliseconds before the next micropulse occurs in block 403 using micropulses 803 and 804 having pulse widths 810 and 811 respectively, microcontroller 201 Signal 250 (FIG. 2) is conditioned by low pass filter 206 and amplified by amplifier 207 before being applied to the input of an analog-to-digital converter (ADC) present therein. Immediately after sample-and-hold circuit 205 enables the sample-and-hold operation (block 404), the ADC is signaled to begin conversion (block 405). The sampling rate of the resulting balanced signal is typically about 1.0 ms and is synchronous with the micropulse rep-rate. However, the actual sampling rate changes as Rep-Rate 812, 813 (FIG. 8) changes (indicated in blocks 310, 311, 312, 313), but always remains in sync with micropulse rep-rate 812, 813. is.

According to this embodiment, the method of sampling the signal before the next micropulse allows the system 200 to ignore noise and current surges (which are capacitively coupled) without corrupting the ion balance measurement. You can dodge conveniently.

At block 406, a test is performed to determine if Timer1's Rep-Rate divider counter is ready to start the next micropulse. A comparison is made whether the micropulse repetition rate counter is equal to zero. If the micropulse repetition rate counter is not equal to zero, algorithm 400 proceeds to block 412 . If the micropulse repetition rate counter equals zero, algorithm 400 proceeds to block 417 .

At block 417, the micropulse repetition rate counter is reloaded from the data register. This will reload the time interval for the start of the next pulse (micropulse). Algorithm 400 then proceeds to block 408 .

Blocks 408, 409 and 410 provide for determining whether a new pulse phase is to be started or whether to continue the current pulse phase.

At block 408, a comparison is made whether the micropulse counter is equal to zero (0).

If so, algorithm 400 proceeds to block 410 which calls the next pulse stage, and algorithm 400 proceeds to block 411 .

If not, the algorithm 400 proceeds to block 409 which calls for continuation of the current pulse phase.

At block 411, Timer0 (micropulse width counter) is started. Timer0 controls the micropulse width as discussed below with reference to blocks 414-417.

At block 412, all system interrupts are enabled. At block 413, the Timer1 interrupt service routine is terminated.

When Timer0 expires, the actual micropulse width is controlled based on blocks 414-417. At block 414, the Timer0 interrupt service routine is initiated. At block 415, the positive micropulse drive is set off (ie, the positive micropulse is switched off). At block 416, the negative micropulse drive is set off (ie, the negative micropulses are switched off). At block 417, Timer0's interrupt service routine is exited.

As also shown in portion 450 of diagram 400 , for micropulse drive signal 452 , Timer 0 duration is equal to micropulse width 454 of micropulse drive signal 452 . Micropulse width 454 begins at pulse rising edge 456 (triggered at the start of Timer0) and ends at pulse falling edge 458 (triggered at the end of Timer0).

Details of a method 700 for averaging ion balance sensor inputs are shown in the flow chart of FIG. Blocks 701 - 706 describe the operation of sample and hold circuit 205 and the ADC conversion of data from sample and hold circuit 205 . At the end of ADC conversion 701, after a delay of approximately 0.1 milliseconds, sample and hold circuit 205 is turned off to prevent noise and current surges from corrupting the balanced measurement. The resulting measurement 703 and sample counter 705 are added 704 to the preceding Raw Measurement Sum 704 value and saved awaiting further processing. Blocks 707-716 are an averaging routine for averaging the sensor 101 and/or 204 measurements to obtain the Ion Balance Measurement Average. The Ion Balance Measurement Average is then combined 714 using a finite impulse response calculation that combines the Balance Measurement Average with the preceding measurements to obtain the final Balance Measurement used in the balance control loop. The computation at block 714 computes a weighted average from the preceding series of sensor input measurements. At block 715 an event routine is called to make adjustments in ion production based on the calculations of block 714 .

The flow diagrams of FIGS. 5A, 5B and 6 illustrate system operation during formation of negative and positive pulse trains. An ionization cycle 531 consists of a series of positive pulses 502,602 followed by off time intervals 503,603 followed by a series of negative pulses 517,604 followed by off time intervals 518,605. When the specified number of ionization cycles has occurred (708), the Ion Balance Measurement Average is calculated (709) and the Raw Measurement Sum 710 and Sample Counter values are cleared (710, 711).

Reference is now made to FIGS. 5A, 5B and 6. FIG. These figures are flow diagrams of system operation during negative and positive pulse train formation, respectively, according to one embodiment of the present invention. At block 501, the next pulse phase routine for the negative pulse train is initiated. Blocks 502-515 describe steps for generating a series of negative pulses and off times of pulse duration. Blocks 517-532 describe steps for generating a series of positive pulses and off times of pulse duration. Blocks 601-613 describe the steps to generate the next pulse phase or if the current pulse phase continues.

The Balance Measurement Average is then combined with the preceding measurements 714 and combined using Finite Impulse Response calculations to yield the final Balance Measurement used in the balance control loop.

The balance control loop 301 compares (302) the Balance Measurement to the setpoint value to generate an error value. The Error signal is multiplied by the loop gain (303), checked if it exceeds the upper/lower limits of the range (304), and added to the current Negative Pulse Width value.

In the micropulse HV delivery system 202,203, the pulse width of the drive micropulses alters the peak amplitude of the resulting high voltage (HV) waveforms 814,801,802. In this case, the negative pulse amplitude is changed to affect the change in Ion Balance. If the error signal value is greater than 0, the negative pulse width is adjusted upwards, thereby increasing the negative HV pulse amplitude and shifting the balance in the negative direction. Conversely, if the balance is negative, the negative pulse width is adjusted downward, thereby changing the balance in the positive direction.

During continuous adjustment of the negative pulse width, the negative pulse width may reach its control limit under certain conditions. In this situation, the positive pulse width is adjusted downward for positive imbalance (307) or upward for negative imbalance (309) until the negative pulse width can resume control. . This control method using negative and positive pulse widths yields an average balanced control adjustment range of about 10V with less than 3V stability.

According to another embodiment, under conditions of large imbalance, e.g., during ionizing blower start-up, during significant contaminant build-up, or during emitter erosion as the emitter(s) ages, a negative pulse width and the positive pulse width will reach its control limits 310,312. In this situation, the positive and negative pulse repetition rates are adjusted (311, 313) to move the balance to the point where the positive and negative pulse widths are again within their respective control ranges. Therefore, for large positive imbalance conditions, the negative pulse repetition rate is increased (313), resulting in a negative shift of the balance. If the condition still exists, the positive pulse repetition rate is decreased (313), also resulting in a negative shift of the balance. This alternate method of changing the positive/negative rep-rate 313 continues until the negative and positive pulse widths are again within their control range. Similarly, for large negative imbalance conditions, the positive pulse repetition rate is increased (311) or, alternatively, the negative pulse repetition rate is decreased (311), resulting in a positive balance. shift to This continues until the negative and positive pulse widths are again within their control range, as described above.

If extreme imbalance conditions exist, both the negative/positive pulse width and positive/negative rep-rate adjustments may reach their respective control limits (310, 312, 314, 316), whereupon The positive and negative pulse counts are changed to move the balance to the point where the positive/negative rep-rates are again within their respective control ranges. Therefore, for extreme positive imbalance conditions, the positive pulse count is decreased (317) and the off time pulse count 317 is increased by one pulse count, resulting in a negative balance change.

If the condition still exists, the off-time pulse count is decreased (317) and the negative pulse count is increased by one pulse count (317), resulting in a more negative shift in balance. This one-pulse shift from negative packet/train to positive packet/train continues until the positive/negative Rep-Rate is again within its control range. Similarly, for extreme negative imbalance conditions, one pulse at a time shifts from the positive pulse 315 packets/train through the off-time pulse count to the negative pulse packet 315 so that the positive/negative Rep-Rate is again within its control range. , resulting in a positive change in equilibrium.

In parallel processes, the Balance Measurement is compared to the setpoint. If the Balance Measurement is determined to be outside its specified range, corresponding to an average CPM (charged plate monitor) reading of +/- 15 V measured at one foot from the ionizer, the ionizer control system will trigger an equilibrium alarm.

FIG. 9 is a method for providing a feedback routine that activates an ion balance alarm if there is an ion imbalance. Blocks 901-909 perform measurements that are compared to thresholds to determine if the balance alarm is tripped. Blocks 910-916 determine whether the balance alarm is activated.

At a time interval of once every 5 seconds, the Balance Measurement is evaluated (903) and when it is out of range, a '1' is left-shifted into the alarm register (904), otherwise a '0'. is left-shifted (902) into the alarm register. The Balance Measurement is declared in alarm when the alarm register contains a value of 255 (all '1's). Similarly, when the alarm register contains a value of 0 (all '0's), the Balance Measurement is declared not in alarm. Any value in the alarm register that is not 255 or 0 is ignored and the state of the alarm is not changed. It filters alarm notifications and prevents sudden notifications. As a by-product, the notification delay gives the balance control system enough time to recover from external stimuli.

Another parallel process, executed at the end of each ADC conversion cycle, monitors the balance control system, FIG. 9B, approximately every 1 millisecond. This routine 910 checks (911, 912) if the positive pulse count and negative pulse count are at the limit conditions. As noted above, the positive and negative pulse counts are adjusted when an imbalance condition exists and the positive/negative pulse width and positive/negative rep-rate are at their respective limits. However, if equilibrium could not be restored to specification and the positive/negative pulse count had reached its regulation limits (911, 912), by setting the alarm register to a value of all '1' The alarm state is forced (913), by setting the alarm flag (914), and by setting both alarm status bits (915).

The auto-balancing control methods and techniques discussed above are not limited to one type of ionizing blower. The method and technique can be used in different ionizing blower models with different emitter electrodes. Other applications of automated systems include models of ionization bars with micropulse high voltage power supplies.

The above description of the illustrated embodiments of the invention, including what is described in the Abstract, is not intended to comprehensively describe the invention or to limit it to the precise forms disclosed. do not have. Although specific embodiments of the invention and examples relating to the invention are described herein for purposes of illustration, various equivalent modifications are possible within the scope of the invention, as those skilled in the art will recognize. be.

These modifications can be made to the invention in light of the above detailed description. The terms used in the appended claims should not be construed to limit the invention to the specific embodiments disclosed in the specification and claims. Rather, the scope of the invention is to be determined entirely by the following claims, which are to be construed in accordance with established doctrines of claim interpretation.

Claims (11)

An apparatus for an automatically balancing ionizing blower comprising:
an ion balance control system configured to sample and compare output signals from the ionization current feedback sensor and the ionization voltage sensor at time intervals between ionization pulses;
The ionization current feedback sensor is internal to the ionization blower, the ionization voltage sensor is a remote sensor external to the ionization blower, and the ionization current feedback sensor and the ionization voltage sensor are specific to the ionization blower. A device that is individually addressable and has a unique identifier so that it can be combined. 2. The apparatus of Claim 1, wherein the ion balance control system is configured to receive the output signal from the ionization voltage sensor via a wireless connection. 3. The apparatus of claim 1 or 2, wherein the ion balance control system is further configured to compare the output signals from the ionization current feedback sensor and the ionization voltage sensor. A control system for a balanced micropulse ionizing blower, the control system comprising:
a micropulsed high voltage AC (alternating current) power supply configured to generate short duration positive ionizing pulses and short duration negative ionizing pulses;
A device according to claim 1;
a microcontroller configured to control the AC power supply based on the output signal;
A control system comprising: 5. The control system of claim 4, wherein the ion balance control system is configured to receive the output signal from the ionization voltage sensor via a wireless connection. 6. A control system according to claim 4 or 5, wherein the ion balance control system is further configured to compare the output signals from the ionization current feedback sensor and the ionization voltage sensor. The microcontroller is
increasing and/or decreasing positive and/or negative pulse width values of the ionizing pulse;
increasing and/or decreasing the time between positive and/or negative pulses of the ionizing pulse, or
increasing and/or decreasing the number of positive and/or negative polarity pulses of the ionizing pulse;
7. A control system according to any one of claims 4 to 6, wherein ionic balance is achieved by at least one of: A method of providing control in a balanced micropulse ionizing blower comprising the apparatus of claim 1, the method comprising:
generating a short duration positive ionization pulse and a short duration negative ionization pulse;
Generating the ionizing pulse includes:
receiving output signals from the ionization current feedback sensor and the ionization voltage sensor in the time intervals between the ionization pulses;
controlling an AC power supply that generates the ionizing pulse based on the output signal;
The method further comprising: 9. The method of claim 8, wherein said receiving said output signal from said ionization voltage sensor comprises receiving said output signal via a wireless connection. 10. The method of claim 8 or 9, further comprising comparing the output signals from the ionization current feedback sensor and the ionization voltage sensor. increasing and/or decreasing positive and/or negative pulse width values of the ionizing pulse;
increasing and/or decreasing the time between positive and/or negative pulses of the ionizing pulse, or
increasing and/or decreasing the number of positive and/or negative polarity pulses of the ionizing pulse;
11. The method of any one of claims 8-10, further comprising achieving ion balance based on controlling at least one of:

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