JPH02159279A - Air-ionizing apparatus of - Google Patents

Abstract

PURPOSE: To provide an air ionization equipment which can maintain the planned total ion output and is easy to be used by generating a constant ratio of positive and negative ions. CONSTITUTION: An ionization unit 13 has a external case 19 and a positive and negative ion emitter 22 and 23 is supported by a pair of insulated hollow bar extended downward from the external case, above zone where static charge should be suppressed. In each emitter 22 and 23, electrodes 24 and 26 are installed and the ionization unit has a positive high voltage generator 28 connected with the electrode 24 and a negative high voltage generator 29 connected with the electrode 26. And positive and negative voltage control and feedback circuits 31 and 32, a feedback signal addition circuit 33, an instruction and alarm circuit 35 and a direct voltage source is also included. The voltage control and feedback circuit 31 and 32 maintain the planned ion output at the emitter 22 and 23. The voltage control and feedback circuit 31 and 32 maintain the ratio of ion at each electrode 24 and 26 as planned by controlling the voltage generated by the high voltage generator 28 and 29 which detect returning electric current and keep the current constant.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to devices for increasing the ion content of air, and in particular to regulating the ion output of air ionization devices.

Air ionizers have one or more pointed electrodes to which a high voltage is applied. The resulting strong electric field near the tip of the electrode ionizes nearby air molecules into positive and negative ions. Ions with a polarity opposite to that of the high voltage are attracted to the electrode and neutralized. Ions of the same polarity as the high voltage are repelled by the electrodes and repelled by each other and diffuse outward from the ionizer into the surrounding atmosphere.

BACKGROUND OF THE INVENTION Air ionization devices of the type described above have been designed primarily to provide beneficial effects to people breathing the air and/or to remove pollutant particles from the air, such as dust, smoke, etc. Although ions of either positive or negative polarity are effective in removing contaminant particles by applying an electric charge to the contaminant particles as described above, negative air ions are particularly physically advantageous. Charged particles precipitate on nearby walls or other objects as a result of electrostatic adsorption.

The ion output rate of such an air ionization device is fundamentally determined by the magnitude of the high voltage and the area and shape of the electrodes. Ion output adjustment in early ionizers was usually limited to the use of voltage regulators in the high voltage generator power supply. The regulator effectively maintained the high voltage at the electrodes at a fixed or, in some cases, selectable level. This does not guarantee that the ion output remains constant over a period of time. As a result of the corona discharge that occurs at the tip of the electrode, the electrode deteriorates and changes shape. As a result, the ion generation rate is gradually reduced. Deterioration of other components may also change ion output.

It may be desirable to more precisely adjust the ion output. In particular, air ionization devices have been recognized as extremely effective means for suppressing static charges from accumulating on indoor items. Items and people tend to become charged with electrostatic charges in the range of thousands of volts due to friction, dielectric effects, and discharges from other items as they move and move. A sudden discharge of such static electricity may cause discomfort to humans and may damage various devices and articles. In particular, for example, combinators and recording devices can be disturbed by electrostatic discharges.

Extreme care must be taken within a so-called clean room where semiconductor electronic components are manufactured. Electrostatic discharge can destroy tiny conductive components in microcircuits.

A problem has also arisen in which semiconductor wafers and the like attract dust and other contaminant particles due to electrostatic charging, resulting in defective products. Maintaining high levels of air ions around such products helps minimize the occurrence of rejects, as static charges of intended polarity are neutralized by charge exchange with air ions of opposite polarity. This is an extremely effective method.

Air ionization devices for suppressing static build-up are typically configured to generate both positive and negative ions. Charge accumulation on the article is possible with ions of either polarity. This requires precisely adjusting the output of ions of each polarity.

The desired generation of positive and negative ions can be equal or other ratios depending on the electrostatic charge build-up tendency of the particular clean room. In either case, changes in the ratio of positive and negative ion output caused by electrode deterioration or other reasons can have adverse effects. Ionizers tend to build up static charges on articles rather than suppress them. For this reason, changes in the combined output ratio of positive and negative ions also have negative effects.

The rate of air ion generation at a particular electrode can be controlled by adjusting the magnitude of the high voltage applied to the electrode, with higher voltages applied to the electrodes increasing the ion output and lower voltages increasing the ion output. If so, the ion output will be reduced. In order to maintain the desired amount of ions generated by controlling the voltage in this way, it is necessary to monitor the ion output and detect the amount of ions generated.

Conventional monitoring systems for such purposes employ ion detection devices that are typically placed in areas of the article away from the ionizing electrodes and in areas where static charges are to be suppressed. Ion sensors output signals that indicate changes in the amount of ions in the air near them.

This signal can be input into a meter to read the ion content and manually adjust the electrode voltage, or it can be fed back to the high voltage generator's servo controller for automatic adjustment of the voltage.

Systems controlled by ion sensors are subject to various limitations and have various drawbacks. Ion sensors pick up ambient noise and have a limited spatial range. Also, ion sensors are expensive. This is extremely disadvantageous in systems where a large number of ionization electrodes are arranged spaced apart from each other to control over a wide area. Requires multiple ion sensors to detect imbalances in positive and negative ions or changes in total ion content throughout the chamber. Ideally, an ion sensor control system would include one air ion sensor for each ionization electrode, but this is often not practical due to the high cost of the equipment. be.

The present invention 1 is capable of maintaining a desired high ion concentration in an adjacent atmosphere and maintaining a desired ratio of negative to positive ions in an accurate and reliable manner without the need for expensive costs. By configuring the air ionization device so that it can be controlled without any problems, the air ionization device is intended to be extremely easy to use.

For this reason, an air ionization device according to the invention comprises at least one electrode exposed to the air to be ionized, a high voltage generator for applying a high voltage of a predetermined polarity to the electrode, and a ground return electrical resistance. A charge of opposite polarity is drawn from the high voltage generator via this electrical resistance at a rate corresponding to the rate of air ion generation by the electrode. The sensing means generates an electrical feedback signal that varies in magnitude in response to variations in the voltage drop across the electrical resistance.

The air ionization device according to the invention further receives a feedback signal and applies a higher voltage to the electrode in response to a reduction in the feedback signal, and applies a lower voltage to the electrode in response to an increase in the feedback signal. Voltage regulating means is provided for regulating the high voltage generator so as to cause the high voltage generator to

The device according to the invention further includes control means for generating a voltage control signal indicative of a desired ion output rate. The voltage regulating means varies the high voltage generated by the high voltage generator in accordance with changes in the voltage control signal and inversely with changes in the feedback signal.

The present invention also provides an air ionization device comprising a plurality of spaced apart ion emitters, a power source, and a plurality of high voltage generators.

Each high voltage generator is connected to a power source and to each of the ion emitters, with each high voltage generator having an electrical resistance path of opposite polarity to the high voltage generated by the high voltage generator. A return current having a magnitude corresponding to a proportion of the ion output from the ion emitter connected to the high voltage generator flows through the electrical resistance path in a direction away from the high voltage generator. A first part of the high voltage generator generates a positive high voltage and a second part generates a negative high voltage. The return current sensing means generates a plurality of feedback signal voltages that each vary in accordance with variations in the return current from each of the high voltage generators. The ionization device according to the invention further comprises means for varying the high voltage produced by each generator in an inverse relationship to variations in the feedback signal voltage from a particular generator. The air ionizer according to the present invention maintains a predetermined total ion output and generates positive and negative ions in a substantially constant ratio.

The air ionization device according to the present invention also includes a plurality of spaced apart air ionization units each having at least one ion emitting electrode exposed to the atmosphere. The high voltage output of each of the plurality of high voltage generators provided in the air ionization unit is connected to a respective electrode and each has means for varying the output voltage in response to a voltage control signal. The first part of the high voltage generator is a negative high voltage generator, and the other part generates a positive high voltage. The control box is connected to the power supply and the first to negative high voltage generator.
means for alternately generating a voltage control signal and a separate second voltage control signal for the positive high voltage generator. A multi-conductor cable extends from the control box to each ionization unit, the cable having an input conductor connected to each high voltage generator, first and second voltage control signal conductors, and a high voltage generated by the generator. has a ground return conductor that receives a ground return current of opposite polarity from each high voltage generator, the ground return current having a magnitude equal to the ion output at the electrode connected to the generator. The device according to the invention further comprises a plurality of feedback circuits,
Each feedback circuit is respectively connected between the high voltage generator, the ground return conductor, and one of the first and second voltage control signal conductors. Each feedback circuit includes means for operating a generator connected to the feedback circuit in response to a received voltage control signal and means for varying the voltage output of the generator in an inverse relationship to variations in return current from the generator. and has.

Air ionization devices according to the present invention have unique properties that allow them to maintain a substantially constant total scheduled ion output even when the electrodes deteriorate or when the input voltage fluctuates. Furthermore, in the air ionization apparatus according to the present invention having a plurality of ion emitters with different polarities, the ion output of each ion emitter is self-adjusted independently of the ion output of other ion emitters, so that negative and the predetermined power ratio of positive ions is maintained substantially constant. Even if a particular electrode degrades more rapidly than an electrode of opposite polarity located nearby, an imbalance of negative and positive air ion amounts in a localized area will not occur.

In one embodiment of the invention, means are provided for varying the voltage applied to each electrode to compensate for the neutralization of air ions occurring at other adjacent electrodes.

According to the present invention, air ion content is accurately and reliably adjusted without the need to use expensive air ion sensors that continuously monitor the ion content of the air.

Next, embodiments of the present invention will be described with reference to the drawings.

First, an air ionization device 11 according to an embodiment of the present invention shown in FIG. 1 is configured to be installed in a room 12 to suppress static charges generated on objects and people in the room. In this example, a plurality of bipolar ionization units 13 are connected to the ceiling 1.
4 mounted spaced from each other and connected to each other by a number of conductor sections 16 of a multi-conductor electrical cable, one of the conductor sections 16 extending to a control box 17 mounted in a readily accessible position on a wall 18. are doing.

In FIG. 1, two ionization units 13 are shown as an example.
However, one ionization unit may be sufficient in some cases, and in a room with a large area, it may be necessary to arrange more ionization units to suppress static charges.

Each ionization unit 13 has an outer case 19 from which a pair of spaced apart insulating hollow rods 21 extend downward a predetermined distance to provide positive and negative ion emitters 22 above the area where static charge is to be suppressed. 23 respectively. The emitters 22, 23 are each provided with an electrode 24, 26 with a downwardly pointed tip, which is exposed to the atmosphere and is preferably provided with an annular insulating protective ring 27 of large diameter around its outer periphery. Although thoriated tungsten needles are used for the electrodes 24 and 26 shown in this example, other electrode materials and various other shapes including a fruit end shape can also be used.

Therefore, the physical structure of the ionization unit 13, including the emitters 22, 23, is similar to the Sequence Controlled Bipolar Air Ionization System of Scott G. Nis. Gehalke et al. The corresponding components of the apparatus described in ``Methods and Apparatus'' may be similar. Similar to that US patent, each ionization unit 13 has a positive high voltage generator 28 connected to an electrode 24 and a negative high voltage generator 29 connected to an electrode 26. The present invention differs from the above US patent in that, among many other differences, each ionization unit 13 also has a positive voltage control and feedback circuit 31 and a negative voltage control and feedback circuit 3.
2, a feedback signal summation circuit 33, an indication and alarm circuit 35, and a separate DC power supply 40 for the other circuits of the ionization unit.

As will be described in more detail below, voltage control and feedback circuits 31 and 32 are capable of controlling individual electrode degradation,
Regardless of fluctuations in supply voltage or other changes, a predetermined ion output is maintained at each individual emitter 22,23 in the system. This automatically maintains the ideal predetermined ratio of positive and negative air ions throughout the area where static charge generation is to be suppressed without the need for external air ion monitoring sensors for control purposes. If the ion output of each electrode in the system is maintained constant, local imbalances in ion polarity due to degradation of a particular electrode 24 or 26 will not occur.

As shown in FIG. 2, a low voltage AC power supply 34 and a timing pulse generator 36 are provided within the control box 17, and this pulse generator controls the ion emitters 22, 23, as will be explained in detail later. It can be activated and deactivated, and predetermined levels of positive and negative ion output can be selected.

The low voltage power supply 34 in this embodiment has a voltage step-down transformer 37 whose second winding 28 is e.g.
Turns on 5 volt standard utility line alternating current.
It is received via off switch 39 and protection fuse 41. Varistor 42 is connected in parallel with primary winding 38 to protect the circuit from power surges generated on the power line. An indicator lamp is also connected in parallel to the primary winding 38,
It provides a visible signal indicating that the ionizer 11 is in operation.

The secondary winding 44 of the transformer 37 is connected to a pair of low voltage AC conductors 46° 4 of the cable 16 connected to the ionization unit 13.
7. A high resistance 45 is connected across windings 38.44 of transformer 37 and is specifically configured to serve as a common or chassis ground conductor for the electrical components of ionization unit 13. If the conductor 46 is directly earthed, the earthing resistor 45 is not required. Although it is not necessary in all cases to operate the ionization unit 13 with a stepped down low voltage input, operating in this manner allows the use of light and inexpensive cables 16 to interconnect the units in the system. There are advantages that can be achieved.

Cable 16 includes two additional conductors 48, 49 which connect the output channels of timing pulse generator 36 to separate them. Conductor 48 receives a first voltage control signal that determines the ion output of positive ion emitter 22, and conductor 49 receives a second voltage control signal that determines the ion output of negative ion emitter 23, as will be explained in more detail below. receive.

Although the voltage control signals 51 and 52 may be continuous voltages of selectable magnitude to cause the positive and negative ion emitters 22 and 23 to operate continuously, preferably the pulse generator 36 Preferably, it is of a known type for generating pulse signals 51, 52 of selectable waveforms. In this example, signals 51 and 52 alternately drop from a predetermined maximum voltage to a selectable low voltage for a selectable period of time. Besides the controller 53 for selecting the lower voltage level of each signal 51 and 52, the pulse generator 36 has an additional controller 54 for separately selecting the duration of the voltage drop of each signal 51 and 52; Also, the off time between each voltage drop of signal 51 and the successive voltage drop of signal 52 and the off time between the voltage drop of signal 52 and the successive voltage drop of signal 51 are also selected. An example of an adjustable pulse timing circuit applicable for this purpose is shown in U.S. Pat. No. 4,542,434, column 9, lines 64 to 12.
It is disclosed in column 11. The alternating operation of the positive and negative ion emitters 22, 23 with off-times is extended to the range of the ionizer 11 for reasons explained below.

Operating power for pulse generator 36 is provided by a DC power supply 56 of known construction which receives AC input power from conductor 47. Cable 16 includes an additional conductor 57, which is a component of an alarm circuit 58, described below.

In the illustrated example, transformer 37 provides 48 volts, 60 cycles of alternating current to ionization unit 13 via power conductor 47 . Pulse generator 36 outputs +15 volts direct current through conductor 48, 49, except during periodic voltage drops;
During the periodic voltage drop, the DC voltage drops to a selected value within the range of +2 volts to +10 volts, depending on the setting of the ion power controller 53. Controller 5 in this example
4 allows independent adjustment of the off period after the voltage drop of the voltage control signal 51 and the off period after the voltage drop of the signal 52, and can also adjust the time of the voltage drop,
In this example, each voltage drop time can be selected within the range of 0 to 9.9 seconds. These specific values for voltage and duration are provided by way of example only, and other values and ranges of values may be suitably selected and used in other embodiments.

As shown in FIG. 3, the positive high voltage generator 28, negative high voltage generator 29 and DC power supply 40 of each ionization unit 13 are connected between the AC conductor 47 of the cable 16 and the chassis ground conductor 46, respectively. .

The positive and negative high voltage generators 28 and 29 may be of identical construction except that the components of the type described below are grounded in opposite orientations. Each such generator includes a voltage step-up transformer 64;
Its secondary winding 66 is connected in series with a charge storage capacitor 68 between circuit junction 67 and ground conductor 46. Circuit junction 67 receives the positive half cycle of alternating current from conductor 47 via capacitor 69, diode 71 and charging resistor 72. Diode 71 blocks negative half cycles from circuit junction 67. In this manner, a positive charge is stored on capacitor 68 during each positive half cycle of AC. Capacitor 68 is discharged through primary winding 66 of voltage step-up transformer 64 during each positive half cycle of alternating current, as will be described in detail below.

Another diode 73 connects the ground conductor 46 and the capacitor 69
and a circuit junction 74 between diode 71 and enable positive charging of capacitor 69 during the negative half cycle of the alternating current. When this charging is combined with the additional positive charging of capacitor 69 during the positive half cycle of AC, capacitor 69 and diode 73 function as a voltage multiplier. As a result, in this embodiment, a maximum voltage of approximately 135 volts charges capacitor 68 during each positive half cycle.

An SCR (silicon controlled rectifier) 76 is connected between circuit junction 67 and ground conductor 46 to discharge capacitor 68 through the primary winding at specific times during each positive half-cycle of the alternating current. This induces a high voltage pulse in the secondary winding 74. The magnitude of the voltage developed across the secondary winding depends on the timing of the discharge of the capacitor with respect to the positive half-cycle, since the capacitor's own voltage gradually increases during the initial part of the half-cycle. The output voltage of transformer 64 is relatively low when capacitor 68 is discharged early in the positive half cycle of AC, and highest when discharged at or after the peak of the positive half cycle of AC. becomes.

The gate terminal 77 of the 5CR76 is connected to the ground conductor 46 via a gate resistor 78 and receives a trigger signal voltage pulse from an associated voltage control and feedback circuit 31 or 32, the circuit 31 or 32 determining the timing of the short circuit of the 5CR76; This controls the output voltage of transformer 64. An additional diode 79 is connected across the 5CR 76 in an opposite polarity orientation to enable repeated cycles of damped oscillation in the resonant circuit formed by winding 66 and capacitor 68.

The voltage developed across the secondary winding 74 depends on the positive and negative peak voltages of this vibration.

One output terminal 81 of the transformer 64 is connected to the air ionization electrode 2
4 or 26 through a capacitor 97, a circuit junction 83, another capacitor 93, a circuit junction 86, and a current limiting resistor 87, which resistor is connected to a strong discharge when an external conductive object contacts the electrode. prevent this from occurring. The other terminal 88 of the secondary winding 74 is connected to an associated voltage control and feedback circuit 31, as described in detail below.
or is connected to ground via an electrical resistance at 32.

Ground terminal 88 also connects capacitor 94 to circuit junction 86.
Connected via another circuit junction 92 and diode 84. Another diode 91 is connected between junctions 83 and 92, and yet another diode 82 is connected between junctions 83 and 88.

Diodes 91, 82 and 84 have opposite orientations in the two high voltage generators 28 and 29. The diodes 91, 82 and 84 of the negative high voltage generator 29 can negatively charge the capacitors 93, 94 and 97 with the output current from the secondary winding 74 through the winding if the winding voltage is reversed. are oriented to prevent the discharge of electricity. During the first negative half cycle of the output of winding 74, capacitor 97 connects diode 82 to the peak output voltage.
After that, it becomes negatively charged. Capacitor 94 is charged to twice the peak voltage through capacitor 97 and diode 91 during the next positive half cycle. During the next negative half cycle, capacitor 97 charges again to the peak voltage and as the charge on capacitor 94 is transferred to capacitor 93, capacitor 93 charges to twice the peak voltage via capacitor 94 and diode 84. Because capacitors 93 and 97 are in series relationship between electrode 26 and the ground terminal, a negative voltage that is substantially three times greater than the peak voltage from winding 74 is applied to ionizing electrode 26.

Diodes 91, 82 and 8 of the positive high voltage generator 28
4 are negative high voltage generator diodes 91, 81 and 84
is oriented in the opposite direction. Capacitors 93, 94 and 97 of the positive high voltage generator 28 therefore obtain a positive charge from the winding 74 and apply a positive voltage to the air ionizing electrode 24 to which the high voltage generator is connected.

Next, in particular, the negative high voltage generator 29 will be explained.
A strong electric field adjacent the tip of electrode 26 breaks up the air component gas molecules into ions, and these ions exhibit an electrical charge. Decomposition produces equal amounts of negative and positive charges. The negative ions are repelled by the electrode 26 and diffuse outward into the surrounding atmosphere. The positive charge is attracted to the electrode 26 and neutralized by charge exchange with the electrode. Such charge exchange tends to reduce the voltage on capacitors 93, 94 and 97, so that a compensating positive current flows from high voltage generator 29 through terminal 88, return current conductor 96 and feedback signal summation circuit 33 to chassis ground. leak. This return current has a magnitude proportional to the electrode 26 and the generation rate of air ions.

Viewed in another way, it is clear that the outward diffusion of negative charge from electrode 26 should be matched by an equal flow of positive charge to ground. Otherwise, the accumulating positive charge is rapidly neutralizing the negative high voltage.

Positive high voltage generator 28 generates a return current to feedback signal summation circuit 33 via return current conductor 96, albeit a negative current, for the same reason. Since the air ion outputs from the electrodes 24 and 26 are not the same, the two generators 28.
The return currents from 29 are not necessarily of the same magnitude.

Voltage control and feedback circuits 31 and 32 are
Schedule the rate of ion generation at each electrode 24 and 26 by detecting the return current and adjusting the voltage generated by the high voltage generators 28-29 required to maintain the return current substantially constant. functions to maintain the ratio of

The DC power supply 40 for the components of the ionization unit 13 may be of known construction and is connected to an AC power conductor 46.47. The power supply 40 in this example has output B
+ and B-, which are +15 volts and -1
Give 5 volts each. Supply bypass capacitor 5
0 is connected between each output and ground to suppress vibrations in the power supply circuit.

As shown in FIG. 4, the return current from the voltage generators 28, 29 is routed through resistors 99, 101, respectively, to a summing junction 98, which is connected to ground through a high resistor 103 to the chassis. , the high resistance 103 also functions as a return current detection resistor. The voltage drop across resistor 103 at a particular time is proportional to the return current from whichever high voltage generator 28 or 29 is activated at that particular time. The summing circuit 33 includes as another component an amplifier 104 which sends a feedback signal output via a resistor 106 to the voltage control and feedback circuits 31 and 32. The positive or non-inverting input of amplifier 104 is connected to summing junction 98 and the inverting input terminal is connected to ground through resistor 107 to the chassis. amplifier 1
A feedback resistor 108 connected between the output of 04 and the inverting input fixes the gain of the amplifier, and a capacitor 109 connected in parallel with the resistor 108 suppresses the influence of circuit noise by slightly delaying the response of the amplifier. Teru.

In practicing the invention, a separate return current resistor 103 is provided for each high voltage generator 28 and 29 which separately inputs the feedback signal into the two voltage control and feedback circuits 31 and 32. It can also be configured without the circuit 33.

An advantage of the summing circuit 33 is that it compensates for air ion loss, which can significantly reduce the effective ion output of systems with pairs of ionizing electrodes 24,26 located close to each other. In particular, a significant portion of the ions generated by each electrode 24,26 are attracted to and neutralized by the other electrodes.

As a result, the high voltage generator 28 connected to the other electrode
or 29, charge flows out through the return current conductor of this generator, and this flow is proportional to the rate at which such air ion neutralization occurs.

The summing circuit 33 transfers this charge flow to the active generator 2.
It combines at summing junction 98 with the return current from B or 29. Since the voltage input to junction 98 from an inactive generator 28 or 29 is of opposite polarity to the voltage input from an active generator, the result is that the feedback signal voltage transmitted by amplifier 104 is inactive. is reduced by an amount proportional to the rate of ion neutralization at the electrode.

The voltage control and feedback signal 31 or 32 in the active state cannot distinguish between the reduction in feedback signal due to reduced ion generation and the reduction in feedback signal proportional to the rate of ion neutralization described above, It counteracts by increasing the voltage generated by the active high voltage generator by an amount that compensates for ion neutralization.

Positive voltage control and feedback circuit 31 has an input amplifier 112 whose non-inverting input receives a feedback signal from summing circuit 33 . The inverting input of amplifier 112 is connected to ground through resistor 113 to the chassis. A variable feedback resistor 114 is connected in series with a fixed resistor 116 between the non-inverting input and the output of amplifier 112 to allow selective adjustment of the gain of the amplifier. This selects a positive ion output rate at electrode 24 that is different from a negative ion output rate at electrode 2G within the desired environment.

A trigger pulse is generated by a comparator 117 with a timing that determines the magnitude of the voltage generated by the positive high voltage generator 28, which comparator determines whether the voltage at one input is equal to the reference voltage applied to the other input. It shall be of a type that outputs an output voltage when the voltage is exceeded. The inverting input of comparator 117 is connected to cable conductor 48 through resistor 147A and to the chassis through resistor 14B to ground, thereby receiving the aforementioned positive voltage control signal, which voltage control signal varies from a fixed maximum value to a desired value. periodically drops to a selected low value representing the ion output percentage of +1
5 volts, and the lowest value is within the range of +2 volts to +10 volts.

As shown in FIGS. 3 and 4, the positive input of comparator 117 is connected to circuit junction 67 of positive high voltage generator 28 through circuit junction 118 and resistor 119, thereby supplying the generator. It receives an alternating current voltage that rises and falls in response to the alternating current. Voltage-dropping resistor 119 reduces the maximum value of the AC voltage at junction 118 to +10 volts, which occurs during each positive AC half-cycle at generator node 67. This is also the voltage applied from cable conductor 48 to the inverting input of comparator 117 when a positive voltage control signal is selected to obtain maximum ion output.

Amplifier 112, which inverts the return current feedback signal from summing circuit 33, is connected to circuit junction I18 via resistor 122.
It has an output 121 connected to. A capacitor 120 is connected in parallel with a resistor 122 to suppress circuit noise. Thus, the AC voltage signal input to comparator 117 is modulated in combination with the inverted return current feedback signal from positive high voltage generator 28. This causes a rise in voltage at the positive input of comparator 117 during six positive half-cycles of alternating current by an amount that is inversely dependent on the magnitude of the feedback signal from positive high voltage generator 28 indicative of the ion output at electrode 24. Definitely delay. A reduced feedback signal indicating a reduction in ion output causes comparator 117 to send a trigger signal after each positive half-cycle of AC, and the increased feedback signal advances the timing of the trigger signal.

Positive feedback resistor 123 Comparator 117
The comparator output is connected to the aforementioned SCR gate terminal 77 of the positive high voltage generator 28 via a resistor 124 and a diode 126.

As mentioned above, the SCR for the positive half cycle of AC
The timing of the trigger signal at gate terminal 77 determines the magnitude of the high voltage generated by generator 28.

Thus, the voltage control force and feedback circuit 31 functions to maintain a substantially constant positive ion output by varying the timing of the trigger signal as required for the desired purpose.

During the period between each actuation of high voltage generator 28, the voltage control signal from cable conductor 48 increases to, for example, +15 volts, so that generation of the trigger signal by comparator 117 is stopped. For this reason, during the above period, AC
Since the voltage signal is continuously received through resistor 119, it is preferable to connect circuit junction 118 to ground to quickly terminate the trigger signal and also for a period of time to dissipate the high voltage on electrode 24. is required and a return current feedback signal is continuously received during this period.

For this purpose, in this example, the NPN transistor 12
A collector emitter circuit of 9 is connected between junction 118 and chassis ground. The base of transistor 1290 is connected to ground through resistor 131 to the chassis and to positive voltage control signal conductor 48 through Zener diode 132 and resistor 133.

Zener diode 132 conducts in response to the full power supply voltage present on conductor 48 during the off period, applying a bias voltage to the base of transistor 129.

This causes the transistor to become conductive and the voltage at the positive input of comparator 117 immediately decreases to substantially zero. A diode 134 is connected between junction 118 and ground to protect comparator 117 from negative voltage transients.

The negative voltage control and feedback circuit 32 can be similar in most respects to the positive circuit 31 described above, but because the return current has the opposite polarity during operation of the negative high voltage generator 29. , adding circuit 33 without inversion
input amplifier 13 to output a feedback signal from
6 is connected. In particular, the positive or non-inverting input of the input amplifier 136 is connected to the output resistor 106 of the summing circuit 33;
On the other hand, the inverting input is connected to chassis ground via a resistor 137.

A variable feedback resistor 138 is connected between the output and the inverting input of amplifier 136 to allow independent adjustment of the negative ion output percentage and connects the output of the amplifier to circuit junction 140, resistor 141, and other circuit junctions 142. A capacitor 143 is connected in parallel with a resistor 141 . A resistor 144 is connected to carry the AC voltage signal from terminal 67 of negative high voltage generator 29 to junction 142, and a diode 146 is connected between the junction and chassis ground. The other input of comparator 139 is connected through a resistor 147 to negative voltage control signal conductor 49 and through another resistor 148 to chassis ground. Feedback resistor 14
9 is connected between the positive input and output of the comparator 139, and the comparator 139 sends the trigger signal to the negative high voltage generator 29 S through the resistor 145 and the diode 150.
It is connected to send to the CR gate terminal 77.

The function and operation of the components of circuit 32 described above are similar to the function and operation of the corresponding components of positive voltage control and feedback circuit 31 described above.

As in circuit 31, transistor 151 is connected between circuit junction 142 and chassis ground to quickly terminate the trigger signal at the end of each voltage control pulse, and the base of the transistor is connected to the negative voltage control signal conductor. 49 through a Zener diode 152 and a resistor 153, and to chassis ground through a resistor 154.

If the operation of the air ionizer can be easily monitored to ensure that it is operating properly, and if a malfunction occurs, it will provide a signal indicating that this malfunction has occurred. If so, it is advantageous. For this purpose, the fifth
An indication and alarm circuit 35 may be provided as shown.

A first light emitting diode 155 (hereinafter referred to as LIED) visually indicates the period of positive ion generation, and a second LED 156
indicates the negative ion generation period. The third LED 157 is
A visual indication of the loss of ion generation, if any, occurs during operation of the device. As shown in FIG. 2, LEDs 155, 156, 157 are mounted on the surface of the outer case 19 of the air ionization unit 13 in easily visible positions.

The LED 155 is also controlled by a comparator 158 whose positive input is connected to the positive voltage control signal conductor 48 of the cable 16 through an input resistor 159, as shown in FIG. The reference input of the comparator 158 is from the junction 161 between the voltage dividing resistors 162 and 163, for example
10 volts and these voltage divider resistors 162
．． 163 is connected in parallel between the OC power supply terminal B+ and chassis ground with another junction 164 and a pair of diodes 166, 167 which serve as other resistors. A positive feedback resistor 168 is connected between the positive input and output of comparator 158, and the output is connected to resistor 169.
and is connected to the DC power supply terminal B+ via the LBD 155.

As previously mentioned, the positive voltage control signal from conductor 48 is +15 volts except when positive ions are generated and drop to a lower value selected within the range of +2 to +10 volts. Thus, during periods when positive ions are not being generated, the voltage at the positive input of comparator 158 is equal to or exceeds +10 volts at the reference input from junction 161. Therefore, during such a period, when the output of the comparator 158 is high<, the LED 15
No current flows through 5.

During positive ion generation, the output of comparator 158 is low as a result of the drop in the positive voltage control signal.

This causes current to flow through LIED 155 and emit light.
Therefore, it can be visually recognized that positive ions are being generated.

LED 156 that indicates that negative ions are being generated
Generation of the visible signal by is performed by a similar circuit.

In particular, one input of the other comparator 171 is connected to the resistor 17
2 receives a negative voltage control signal, while the reference input receives, for example, +10 volts from circuit junction 161. Positive feedback resistor 173 is connected to comparator 171
It is connected between the input and output of , and is connected via the output to the DC power terminal B+ via the resistor 174 and the LED 156.

Alarm LεD157 that visually indicates loss of ion output
can be activated by either of two additional comparators 176 and 177. Both comparators 1
The reference inputs of 76 and 177 are connected to junction 164 to receive a low DC voltage, for example 1.2 volts. The positive input of comparator 176 is connected to the aforementioned terminal 121 of positive voltage control and feedback circuit 31 to receive a return current feedback signal during the positive ion generation period, and is also connected to comparator 15 via diode 178.
I am trying to receive the output from 8. Comparator 1
The positive input of 77 is connected to receive a return current feedback signal from the aforementioned terminal 140 of circuit 32 during negative ion generation and is connected via diode 179 to the output of comparator 171. Connect capacitors 181 and 182 to chassis ground and comparator 176
and 177, respectively, to slow the comparator's response to changes in input voltage, for example, by about 174 seconds. Both comparators 176 and 177 have positive feedback resistors 183 that connect the outputs of both comparators to LIED 157 and resistor 184.
It is connected to the DC power supply terminal B+ through the terminal.

During positive ion generation, the output of comparator 176 is typically high because the feedback signal voltage received from circuit 31 exceeds the low reference voltage from junction 164. Therefore, during the positive ion generation period, sufficient current does not flow through the alarm LεD157, and the alarm remains stopped. This condition continues to occur normally after the positive ion generation period ends, because the high input voltage from comparator 158, which increases when the positive voltage control signal from conductor 48 rises to +15 volts as described above, is applied to comparator 176. This is because they receive it. If no feedback signal voltage is received during the period when the output of comparator 158 is low indicating that positive ions are being generated, then the output of comparator 176 will be low. When the output of the comparator 176 is low, current flows to the alarm LεD157, and Lt! D flashes to visually notify the occurrence of an error. Positive feedback ensures circuit activation by preventing unwanted vibrations from occurring when an alarm condition occurs.

When the voltage on conductor 49 drops indicating the generation of negative ions, comparator 177 is activated to activate alarm LED 157 in a similar manner when it should not receive a negative feedback signal voltage from circuit 32.

In the illustrated example, it is advantageous if the alarm LED 157 in a particular one of the ionization units is activated in conjunction with the activation of the main alarm 186 provided in the control box 17, as shown in FIG. In the illustrated example, the alarm 186 is a beaver (alarm generator) that generates an acoustic signal.
However, any of a variety of other forms of electrically actuated audible or visual warning devices may be used.

Alarm 186 is connected in series between AC power conductors 46 and 47 with a normally closed relay 187, preferably of a type that exhibits a short delay before closing in response to the extinguishment of the drive current. . Under normal conditions, relay 186 is held open to prevent drive current from cable conductor 57, which is connected to DC power source 56 through resistor 185, from activating the alarm. As shown in FIG.
and an NPN junction transistor 188 having an emitter-collector circuit connected between chassis ground and chassis ground.

The PNP junction transistor 189 has a voltage drop resistor 19 between the DC power supply terminal B+ and the base of the transistor 188.
It has an emitter collector circuit connected in series with 0.

The outputs of both comparators 176 and 177 are connected to the base of transistor 189 via a resistor 191.

If the output of comparator 176 or 177 goes low as described above, indicating a loss of ion power, transistor 189 is biased into conduction and applies a base bias voltage to transistor 188, which also causes transistor 188 to become conductive. . This grounds cable conductor 57 and reduces the voltage on this conductor to substantially zero. Referring again to FIG. 2, grounding of conductor 57 closes relay 187 and applies actuation current to alarm 186.

Referring again to FIG. 1, the output rate of the device 11 is first adjusted in the control box 17 to increase the concentration of air ions and the ratio of positive to negative ions to the articles in a particular chamber 12. It should be effective in suppressing static charges. The ideal concentration and ratio can vary from chamber to chamber, but after detecting the charge in a local area using a charge detector of known construction, the output of ions of opposite polarity is increased to increase the accumulation of such ions. Ideal concentrations and ratios can be determined during initial adjustment by eliminating Any one ion emitter 22 or 23 can be modified by adjusting the amplifier feedback resistor 114 or 138 to change the gain of the feedback circuit amplifier (see FIG. 4) coupled to the ion emitter.
The relative power of the ion emitter relative to other ion emitters can be raised or lowered as required for this purpose.

Referring again to FIG. 1, the device 11 uses an ion sensor to generate a static charge on articles within the chamber 12 over an extended period of time without the need for constant monitoring of the ion content of the air by its ground-like detection means. can be extremely effectively prevented from occurring. Electrode deterioration and line voltage fluctuations do not adversely affect the ion output of each ion emitter 22, 23. Even if the electrodes 24 or 26 of a particular ion emitter 22.23 were to degrade to a greater extent than nearby electrodes of opposite polarity, no local imbalance of positive and negative ions would occur. Each ion emitter 22.23
The ion output of remains constant regardless of such variables. Although it may be desirable to readjust the device 11 if there is a significant change in the content of ions in the air within the chamber 12 or in the activity within the chamber, it is not usually necessary to perform such readjustments frequently.

The embodiments of the invention described herein alternately generate positive and negative ions in periods separated by periods of inactivity during which no ions are generated. The effective range of ionizer 11 is expanded because ions of each polarity can diffuse farther from ion emitters 22 and 23 before the positive and negative ions substantially mix and neutralize each other. The present invention can also be applied to systems where there is no delay between periods of alternating generation of positive and negative ions, or where ions of both polarities are generated simultaneously.

Single-electrode air ion generators that generate ions of only one polarity tend to apply a charge to nearby articles and are therefore not typically used for the purposes of the embodiments described above.

Such monopolar ion generators are widely used for other purposes such as improving the physiological effects of air, and if it is desired to maintain a constant ion output, such ion generators may also include a single feedback circuit 31 or 32 according to the invention.

Although the present invention has been described with reference to one embodiment, the present invention is not limited to the illustrated embodiment, and can be implemented with various modifications within the scope of the present invention.

[Brief explanation of the drawing]

1 is a perspective view showing a preferred embodiment of the device of the invention installed in a room in which electrostatic accumulated charges are to be neutralized; FIG. 2 is a schematic diagram showing the control components of the device shown in FIG. 1; Figure 4 is a circuit diagram of the individual ionization units of the apparatus shown in Figure 1; Figure 4 is a detailed circuit diagram of the summing circuit, positive and negative voltage control and feedback circuitry shown in block form in Figure 3; Figure 5 is a detailed circuit diagram of the 1 is a circuit diagram of an indication and alarm circuit installed in the apparatus shown; FIG. 11... Air ionization device 12... Chamber 13...
Ionization unit 16...Conductor portion 17...Control box 22.23...Ion generators 24, 26
... Electrodes 31, 32 ... Voltage control and feedback circuit 3
3... Addition circuit 35... Indication and alarm circuit 40... Power supply

Claims (1)

[Claims] 1. An electrode exposed to the air to be ionized, a high voltage generator connected to the electrode to apply a high voltage of a predetermined polarity to the electrode, and a ground return electrical resistance. Ingredients,
In an air ionization device configured to lead out charges of opposite polarity from the high voltage generator via this electrical resistance at a rate corresponding to the rate of air ion generation by the electrode, the voltage drop across the electrical resistance varies. sensing means for generating an electrical feedback signal of varying magnitude in response to the feedback signal; and detecting means for receiving the feedback signal and applying a higher voltage to the electrode in response to a reduction in the feedback signal; and voltage adjustment means for adjusting said high voltage generator to apply a lower voltage to said electrode in response to said high voltage generator. 2. further comprising control means for generating a voltage control signal indicative of a desired ion output rate, the voltage control signal being generated by the high voltage generator in accordance with changes in the voltage control signal and inversely related to changes in the feedback signal; 2. The apparatus of claim 1, wherein said voltage regulating means is configured to vary the high voltage applied to said voltage. 3. The high voltage generator is configured to receive input power having a periodic voltage that increases and decreases periodically, and is responsive to relative variations in the timing of a repetitive trigger signal to the increase and decrease of the periodic voltage. further comprising means for varying the high voltage at the electrodes, the high voltage regulating means transmitting the trigger signal to the high voltage generator and adjusting the timing of the trigger signal in response to a change in the magnitude of the feedback signal. 2. The apparatus of claim 1, wherein the apparatus is configured to change. 4. a comparator having first and second inputs and an output connected to the high voltage generator for applying the trigger signal, and another signal increasing and decreasing in response to the feedback signal and the periodic voltage; 4. The apparatus of claim 3, wherein said voltage regulating means includes means for applying a combined signal to said first input; and means for applying a reference signal of selectable magnitude to said second input. 5. A plurality of the electrodes and a plurality of the high voltage generators, each high voltage generator being connected to each of the electrodes, each high voltage generator having an independently adjustable high voltage output. further comprising control means for directing an input current to each of said high voltage generators, said detection means generating a plurality of said feedback signals, each feedback signal being indicative of ion output at each of said electrodes. and further comprising a plurality of said voltage regulating means, each voltage regulating means being connected to a respective one of said high voltage generators and configured to be responsive to a respective one of said feedback signals generated from a respective one of said generators. 1. The device according to 1. 6. The apparatus of claim 5, wherein at least a first of said high voltage generators generates a positive high voltage and at least a second of said high voltage generators generates a negative high voltage. 7. The control means operates the first and second high voltage generators intermittently and alternately, and the detection means combines and combines the charge flows from both the first and second high voltage generators. a summing circuit connected to send a charge flow to said electrical resistor so that said voltage regulating means regulates the voltage produced by each generator during operation of each generator to the other generator; 7. The device of claim 6, further comprising compensation for neutralization of ions at the electrodes. 8. The summing circuit includes a circuit junction and a pair of resistors connected between the circuit junction and each high voltage generator to direct the charge flow from each generator to the circuit junction; 8. The apparatus of claim 7, including means for feeding from said junction to said electrical resistance, and an amplifier having an input connected to said circuit junction and an output connected to apply a feedback signal to each voltage regulating means. 9. The control means generates a positive voltage control signal relating to the magnitude of the selectable quantity and a negative voltage control signal relating to the magnitude of the independently selectable quantity, and the first and second voltage adjusting means generate the positive voltage control signal and the negative voltage control signal relating to the magnitude of the independently selectable quantity. 5. The method of claim 5, wherein the voltage produced by the first and second high voltage generators is changed in response to a change in each of the negative voltage control signals, and further configured to change the voltage in response to the feedback signal.
The device described. 10, comprising at least one pair of high voltage generators and at least one pair of electrodes connected to each of the high voltage generators, the first generator being a positive high voltage generator;
the generator being a negative high voltage generator, and comprising first and second voltage regulating means connected to each of said generators, further comprising intermittently alternating the positive and negative high voltage generators; and means for deactivating each voltage regulating means during intermittent periods during which a generator connected to the voltage regulating means is deactivated by the control means. Device. 11. said control means alternately generating first and second voltage control signals, and said first voltage regulating means responsive to said first voltage control signal by activating said first generator;
11. The apparatus of claim 10, wherein said second voltage regulating means is configured to respond to said second voltage control signal by activating said second generator. 12. further comprising an alarm circuit, the alarm circuit comprising an electrically damped signal generator and alarm control means to compare the feedback signal and the voltage control signal;
12. The apparatus of claim 11, wherein the signal generating device is energized if the feedback signal drops to a predetermined value during a period in which the control means is generating the voltage control signal. 13. further comprising an alarm signal conductor, a power source connected to deliver a predetermined voltage to the conductor, and means for activating the signal generating device in response to a drop in voltage on the conductor, the control means controlling the voltage. 13. The apparatus of claim 12, wherein said alarm control means is configured to drop the voltage on said conductor if said feedback signal drops to said predetermined value during a period of signal generation. 14. A plurality of ion emitters installed at a distance from each other, a power source, and a plurality of high voltage generators, each high voltage generator being connected to the power source and the ion emitters being connected to the power source. an ion emitter connected to each high voltage generator, each high voltage generator having an electrical resistance path, the return current having an opposite polarity to the high voltage generated by the high voltage generator; a return current having a magnitude corresponding to a proportion of the ion output from the high voltage generator flows through an electrical resistance path in a direction away from the high voltage generator, the first part of the high voltage generator being a positive high voltage generator; , a second portion of which is a negative high voltage generator, comprising: return current detection means for generating a plurality of feedback signal voltages each varying in accordance with variations in the return current from each of the high voltage generators; , means for varying the high voltage produced by each generator in an inverse relationship to variations in feedback signal voltage from a particular generator, thereby causing the air ionizer to maintain a predetermined total ion output. and generating positive and negative ions in a substantially constant ratio. 15. The apparatus of claim 14 further comprising means for selectively varying the high voltage produced by each generator independently of the high voltage produced by other generators. 16. a plurality of spaced apart air ionization units each having at least one ion emitting electrode exposed to the atmosphere; and a high voltage output provided on the air ionization unit and connected to each of the electrodes; a plurality of high voltage generators, each having means for varying the output voltage in response to a voltage control signal, the first portion being a positive high voltage generator and the second portion being a negative high voltage generator; a power supply and a first voltage control signal for the positive high voltage generator and a second voltage control signal for the negative high voltage generator.
a control box having means for generating an alternating cycle of voltage control signals; an input conductor extending from the control box to each ionization unit and connected to each high voltage generator; and an input conductor connected to each high voltage generator; a ground return conductor receiving a ground return current from each generator of opposite polarity to the generated high voltage and having a magnitude equal to the ion output at the connected electrode; and a first and second voltage control signal; a multi-conductor electrical cable having a conductor; and a plurality of feedback circuits respectively connected between each high voltage generator and the ground return conductor and one of the first and second voltage control signal conductors, each feedback an air circuit having means for activating a connected generator in response to a voltage control signal received by the circuit and means for varying the voltage output of the connected generator in an inverse relationship to variations in said return current; Ionization device. 17. Each of said ionization units has a pair of said electrodes and a high voltage generator, one of said pair of generators being a positive high voltage generator and the other being a negative high voltage generator; said unit including a pair of said feedback circuits, each feedback circuit connected to a respective one of a pair of high voltage generators to detect a neutralization condition resulting from charge exchange of ions from one of said electrodes with the other of said electrodes; 19. The apparatus of claim 18, further comprising means for adjusting the high voltage generated by the generator connected to said one electrode in an amount sufficient to compensate for this neutralization.