JP2007114177A - Ion detector and ion generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ion detector detecting an ion by a simple configuration and to provide an ion generator having the ion detector. <P>SOLUTION: A collection electrode 19 collecting ions is connected to a gate terminal of a p-MOS type FET 181 via a rectifier diode 182, and direct current voltage is impressed to a drain terminal of the p-MOS type FET 181. When potential of the collection electrode 19 is increased, the p-MOS type FET 181 is turned into a ON condition, while source potential is increased to the impressed direct current voltage when the direct current voltage is impressed between a circuit GND and the drain terminal. It is determined whether an ion is generated or not when the source potential of the p-MOS type FET 181 is measured. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ion detector that detects ions with a simple configuration, and an ion generator that includes the ion detector.

  There are many devices called ion generators, but the principle is that most of them generate ions by applying a high voltage impulse between the needle electrodes and causing corona discharge at the discharge electrodes (for example, Patent Document 1).

  It is known that ions generated by electric discharge have various effects. For example, in a sealed room with low ventilation, such as an office or meeting room, if there are many people in the room, air pollutants such as carbon dioxide, cigarette smoke, and dust emitted by breathing increase. Negative ions, which have the effect of relaxing, decrease from the air. In particular, a large amount of negative ions may be lost due to cigarette smoke, and may be reduced to about 1/2 to 1/5 of the normal amount. Therefore, ion generators aimed at replenishing negative ions in the air have been put into practical use.

In recent years, needs for sterilization and sterilization are increasing, and ion generators that generate both positive ions and negative ions have been put to practical use in order to remove airborne bacteria. In such an ion generator, H ⁺ (H ₂ O) _m as positive ions and O ₂ ⁻ (H ₂ O) _n (where m and n are natural numbers) as negative ions are generated. When both positive ions and negative ions attach to the surface of airborne bacteria, these ions chemically react to generate hydrogen peroxide (H ₂ O ₂ ) and hydroxyl radicals (.OH), which are active species, in the air. To remove the floating bacteria.
Japanese Patent Laid-Open No. 61-14577

  However, since the ions themselves are tasteless and odorless and cannot be visually recognized, it cannot be confirmed whether or not they are actually generated. In the current ion generator, when the discharge electrode deteriorates due to long-time discharge or dust adheres to the electrode surface, the discharge may be unstable or stop compared to the initial state due to these factors. The problem is that there is no means for the user to confirm this from the outside.

  The present invention has been made in view of such circumstances, and the presence / absence of generation of ions with a simple configuration by including a conductor for collecting ions and a detection means for detecting the potential of the conductor. It is an object of the present invention to provide an ion detection device capable of detecting the ion and an ion generation device including the ion detection device.

  The ion detection apparatus according to the present invention includes a conductor that collects ions and a detection unit that detects a potential of the conductor.

  In the present invention, the presence or absence of ions is detected by detecting the potential of the conductor when ions are collected by the detection means.

  In the ion detector according to the present invention, the detection means includes a field effect transistor having a gate connected to the conductor, and detects ions collected by the conductor based on a source potential of the field effect transistor. It is made to do so.

  In the present invention, a conductor for collecting ions is connected to the gate of the field effect transistor. By applying a DC voltage to the drain terminal of the field effect transistor, when the potential of the conductor rises, the field effect transistor is turned on and the source potential rises to the DC voltage applied to the drain terminal. .

  The ion detection apparatus according to the present invention is characterized in that the detection means includes a rectifying element connected between the conductor and a gate of the field effect transistor.

  In the present invention, since the rectifying element is connected between the conductor for collecting ions and the gate of the field effect transistor, the polarity of the potential input to the gate is specified.

  The ion detector according to the present invention is characterized in that the detecting means is provided with a constant voltage element for limiting the absolute value of the gate potential of the field effect transistor to a predetermined value or less.

  In the present invention, since the constant voltage element is provided to limit the absolute value of the gate potential to a predetermined value or less, the magnitude of the potential input to the gate is limited.

  In the ion detection apparatus according to the present invention, the detection means includes a resistance element connected between a gate and a source of the field effect transistor.

  In the present invention, since the resistance element connected between the gate and the source of the field effect transistor is provided, the charge due to the ions accumulated in the gate is naturally discharged.

  The ion detector according to the present invention is characterized in that the type of the field effect transistor connected to the conductor is made different according to the polarity of the ion to be detected.

  In the present invention, a p-type field effect transistor can be used when the ion to be detected is a positive ion, and an n-type field effect transistor can be used when the ion to be detected is a negative ion. .

  The ion detector according to the present invention is characterized in that the conductor and the field effect transistor are connected by a wiring having an appropriate length.

  In the present invention, the length of the wiring connecting the conductor for collecting ions and the detection means including the field effect transistor can be freely adjusted, so that the ions can be detected in various places. And

  The ion detector according to the present invention includes a means for comparing the magnitude relationship between the absolute value of the source potential of the field effect transistor and a predetermined threshold value, and the detector detects ions when the magnitude relationship changes. And means for notifying that there is not.

  In the present invention, when the output obtained by detecting ions with a conductor and converting them to the source potential of a field effect transistor reaches a preset threshold value, for example, it is converted into light, sound, etc. It is notified that ions are not detected.

  An ion generator according to the present invention includes an ion generator that generates ions and the ion detector according to any one of the above-described inventions, and the ions generated by the ion generator are used as the ion detector. It is made to detect by.

  In the present invention, ion generating means for generating ions is provided, and ions generated by the ion generating means are detected by the ion detector described above.

  The ion generator according to the present invention is further characterized by further comprising a blowing means for diffusing ions generated by the ion generating means to the outside.

  In the present invention, since the air blowing means for diffusing the ions generated by the ion generating means to the outside is provided, the generated ions can be guided to the outside of the apparatus.

  The ion generator according to the present invention is characterized in that the ion detector is provided downstream of the ion generator in the ion diffusion direction.

  In the present invention, since the ion detection device is provided on the downstream side in the ion diffusion direction, the presence or absence of the generation of ions is reliably detected.

  In the case of the present invention, the presence or absence of ions can be detected by detecting the potential of the conductor when ions are collected by the detection means. For example, when the discharge is stopped due to dust or the like, it is possible to detect that no ions are generated, so it is possible to notify the user of an abnormality and to take measures such as prompting the electrode surface to be cleaned. Become.

  In the case of the present invention, a conductor for collecting ions is connected to the gate of the field effect transistor. By applying a DC voltage to the drain terminal of the field effect transistor, when the potential of the conductor changes, the state of the field effect transistor changes and the source potential changes to a potential corresponding to the potential of the conductor. Therefore, the presence or absence of ions can be detected by measuring the source potential of the field effect transistor.

  In the case of the present invention, since the rectifying element is connected between the conductor for collecting ions and the gate of the field effect transistor, the polarity of the potential input to the gate can be specified. In other words, it is possible to detect only one of the case where the ion collecting conductor is negatively charged or the case where the ion collecting conductor is positively charged, thereby enabling efficient detection of ions.

  According to the present invention, since the constant voltage element is provided to limit the magnitude of the gate potential to a predetermined value or less, the magnitude of the potential input to the gate can be limited. That is, even when a voltage higher than the gate breakdown voltage of the field effect transistor is accumulated in the conductor, the rise in potential can be limited and the field effect transistor can be protected by connecting a Zener diode.

  In the case of the present invention, since the resistor for naturally lowering the gate potential of the field effect transistor is provided, it is possible to constantly monitor the malfunction of the ion generator. That is, when the emission of ions from the ion generator stops, the gate potential can be lowered without any operation, so that ion detection can always be performed.

  In the case of the present invention, since the type of field effect transistor varies depending on the polarity of ions to be detected, both positive and negative ions can be detected. Therefore, it can be confirmed that bipolar ions are normally emitted in an ion generator that emits both positive and negative ions separately.

  According to the present invention, the length of the wiring between the conductor for collecting ions and the detection means including the field effect transistor can be freely adjusted. Therefore, by adjusting the length of the wiring and the shape of the conductor for collecting ions, it is possible to detect ions even when the ion generator is in a place where it is difficult to measure normally.

  In the case of the present invention, the output of the field effect transistor, which is the ion detection result, is converted into light, sound, etc., for example, to notify that the ions are not detected, so the user is more intuitively notified of the abnormality. be able to.

  In the case of the present invention, ion generation means for generating ions is provided, and ions generated by the ion generation means are detected by the ion detector described above.

  In the case of the present invention, since the air generating means for diffusing the ions generated by the ion generating means to the outside is provided, the generated ions can be guided to the outside of the apparatus.

  In the case of the present invention, since the ion detector is provided on the downstream side in the ion diffusion direction, the presence or absence of the generation of ions can be reliably detected. In addition, by arranging the ion generating means and the conductor approximately parallel to the ion diffusion direction, and further using a flat conductor, the number of ions released to the outside is reduced without blocking the generated ion wind. Only diffused ions can be detected without causing them to occur.

Hereinafter, the present invention will be specifically described with reference to the drawings showing embodiments thereof.
Embodiment 1 FIG.
FIG. 1 is a block diagram showing the internal configuration of the ion generator according to the present embodiment. The ion generator includes a control unit 10 composed of a microcomputer, a ROM, and the like. The control unit 10 receives power from the power supply circuit 12 and outputs control signals to each of the high-voltage drive circuit 11, the fan motor drive circuit 15, and the lamp circuit 20 according to a control program stored in the built-in ROM. To do.

  The high voltage drive circuit 11 is supplied with electric power from the power supply circuit 12 and outputs an alternating high voltage in accordance with a control signal output from the control unit 10. The alternating high voltage output from the high-voltage drive circuit 11 is applied to the discharge electrode 13 for generating ions. The fan motor drive circuit 15 is supplied with electric power through the power supply circuit 12 and performs PWM control based on a control signal output from the control unit 10 so that the fan motor 16 rotates at a predetermined rotation speed. The fan motor 16 rotates the fan 17. The lamp circuit 20 is supplied with power through the power supply circuit 12 and turns on or off the lamp 21 in accordance with a control signal output from the control unit 10.

  The ion generator of the present invention includes an ion detector for detecting ions generated through the discharge electrode 13. This ion detector is composed of an ion detection circuit 18A and a collection electrode 19. The ions generated at the discharge electrode 13 are diffused by the air flow generated by driving the fan 17 described above, and the potential of the collection electrode 19 when this ion is collected is detected by the ion detection circuit 18A. Thus, it is detected whether or not ions are generated.

  FIG. 2 is a schematic diagram for explaining an arrangement example of the discharge electrode 13 and the collection electrode 19. The ion generating apparatus is provided with a plastic ventilation path 100 serving as an air flow path, and the arrangement relationship between the fan 17 and the ventilation path 100 so that the air flow flows in the direction of the white arrow shown in the drawing. Has been adjusted. The ions generated by the ion generator are transported by the air flow generated by driving the fan 17 and are released to the external space through the ventilation path 100.

  The discharge electrode 13 and the collection electrode 19 are provided on the bottom side of the ventilation path 100. By disposing the discharge electrode 13 on the upstream side of the air flow and the collection electrode 19 on the downstream side of the air flow, the ions generated at the discharge electrode 13 are carried by the air flow and collected by the collection electrode 19. The Rukoto. As the discharge electrode 13, an electrode that is formed in a planar lattice shape and has a sharp portion inside the lattice can be used. The collecting electrode 19 may be a copper tape that is a conductor. In this way, the discharge electrode 13 and the collection electrode 19 are arranged substantially parallel to the air flow, and the discharge electrode 13 and the collection electrode 19 are provided in the same plane, so that the air flow carrying ions It is possible to collect only diffused ions without reducing the number of ions released to the outside without reducing the number of ions.

  FIG. 3 is a circuit diagram illustrating the internal configuration of the ion detection circuit 18A. The collection electrode 19 described above is connected to the gate terminal of the p-MOS type FET 181 through the rectifying diode 182 in the ion detection circuit 18A. The collecting electrode 19 and the rectifying diode 182 are connected by a wiring 19a adjusted to an appropriate length. In addition, a DC voltage is applied to the drain terminal of the p-MOS type FET 181, and the source terminal is connected to the circuit GND via the resistor 183. The magnitude of the DC voltage applied to the drain terminal is, for example, 12V. Further, a Zener diode 184 is connected between the gate terminal and the circuit GND in order to protect the p-MOS type FET 181. The Zener diode 184 has a Zener voltage of 16V.

  Since ions are charged particles, the potential of the collection electrode 19 is increased by the collected ions. When the collector electrode 19 is connected to the gate terminal of the p-MOS FET 181 to increase the potential of the collector electrode 19, the p-MOS FET 181 is turned on. At this time, by applying a DC voltage between the circuit GND and the drain terminal, the source potential rises to the applied DC voltage. The controller 10 can determine whether or not ions are generated by measuring the magnitude of the source potential of the p-MOS FET 181 through the ion detection circuit 18A.

  Further, in the ion generator, since ions of both positive and negative polarities can be generated, the potential of the collection electrode 19 can be either positive or negative depending on the balance of the generated ions. Therefore, in this embodiment, for the purpose of detecting positive ions, a rectifying diode 182 is connected between the collection electrode 19 and the p-MOS type FET 181 and input to the gate terminal of the p-MOS type FET 181. Specify the polarity of the potential. This circuit configuration makes it possible to quickly detect positive ions. Further, since there is a possibility that a potential higher than the gate breakdown voltage of the FET may be accumulated in the collecting electrode 19 during operation, the rise of the potential is restricted by connecting the Zener diode 184 to protect the p-MOS type FET 181.

  FIG. 4 is a graph showing the time change of the source potential in the p-MOS type FET 181. When the time change of the source potential is measured using the ion detection circuit 18A shown in FIG. 3, the source potential changes with time as shown in the graph. The abscissa indicates the elapsed time (seconds) after the AC voltage is applied to the discharge electrode 13 and the fan 17 starts to blow air, and the ordinate indicates the source potential (absolute value (absolute value) of the p-MOS FET 181). Bolt)). While the source potential rises to 12 V, which is the applied voltage of the drain terminal, during discharge, it can be seen that the potential does not change during non-discharge. Therefore, by measuring the source potential of the p-MOS type FET 181, it is possible to detect whether or not ions are generated in the ion generator.

  When it is detected that ions are not generated due to the stop of discharge or the like, the control unit 10 can give a control signal to the lamp circuit 20 to turn on the lamp 21 to notify the user of the abnormality. Therefore, when dust or the like adheres to the discharge electrode 13 and the discharge stops, it is possible to take measures such as prompting the electrode surface to be cleaned.

  In this embodiment, a copper tape is used as the collecting electrode 19 because it is easy to install, but the same effect can be obtained even if a conductive tape or plate electrode formed of another metal is used. Of course. In addition, in order to efficiently generate ions, the discharge electrode 13 assembled in a planar grid is used. However, a pair of needle electrodes are used, and a high voltage is applied to both ends of the needle electrodes to generate ions. It is good also as a structure to generate.

  Further, in the present embodiment, the wiring 19a connecting the collecting electrode 19 and the rectifying diode 186 can be adjusted to an appropriate length, and the shape of the collecting electrode 19 is also an arbitrary shape. Therefore, it is possible to detect discharge at various places.

Embodiment 2. FIG.
In the first embodiment, the configuration is such that positive ions are detected by the ion detection circuit 18A, but negative ions are detected by changing the p-MOS type FET 181 of the ion detection circuit 18A to an n-JFET 185 (see FIG. 5). Is possible. The overall configuration of the ion generator is completely the same as that of the first embodiment, and a description thereof will be omitted.

  FIG. 5 is a circuit diagram illustrating the internal configuration of the ion detection circuit 18B. The collection electrode 19 is connected to the gate terminal of the n-JFET 185 via a rectifying diode 186 in the ion detection circuit 18B. The collecting electrode 19 and the rectifying diode 186 are connected by a wiring 19a adjusted to an appropriate length. Further, a DC voltage is applied to the drain terminal of the n-JFET 185, and the source terminal is connected to the circuit GND via the resistor 185. The magnitude of the DC voltage applied to the drain terminal is, for example, 12V. Further, a zener diode 188 is connected between the gate terminal and the circuit GND to protect the n-JFET 185, and a resistor 189 is connected between the gate terminal and the source terminal of the n-JFET 185.

  When the negative ions emitted from the discharge electrode 13 are collected by the collection electrode 19, the potential of the collection electrode 19 decreases. When the potential of the collecting electrode 19 is reduced by connecting the collecting electrode 19 to the gate terminal of the n-JFET 185, the n-JFET 185 is turned off. At this time, the source potential is reduced to the GND level by applying a DC voltage between the circuit GND and the drain terminal. By measuring this potential, it can be determined whether or not negative ions are generated.

  FIG. 6 is a graph showing the time change of the source potential in the n-JFET 185. When negative ions are detected using the ion detection circuit 18B shown in FIG. 5 and the time change of the source potential is measured, the source potential changes with time as shown in the graph. The abscissa indicates the elapsed time (seconds) after the AC voltage is applied to the discharge electrode 13 and the fan 17 starts blowing air, and the ordinate indicates the source potential (absolute value (volt)) of the n-JFET 185. ). While discharging, the source potential decreases to 0 V, which is the GND voltage, while when not discharging, it can be seen that it does not change stably around 12 V, which is the drain terminal applied voltage. Therefore, by measuring the source potential of the n-JFET 185, it is possible to detect whether negative ions are generated in the ion generator.

  The resistor 189 connected between the gate terminal and the source terminal of the n-JFET 185 is for naturally discharging the charge due to the ions accumulated at the gate terminal. When the generation of ions is stopped, the resistor 189 is turned on. As a result, the ionic charges accumulated at the gate flow to GND with the passage of time, and the potential of the gate terminal is restored to the potential level at the time of non-discharge.

  FIG. 7 is a graph obtained by measuring the time change of the source potential when ion generation is stopped after detecting negative ions. Similar to the graph of FIG. 6, the horizontal axis indicates the elapsed time (seconds) after the AC voltage is applied to the discharge electrode 13 and the blowing by the fan 17 is started, and the vertical axis indicates the n-JFET 185. The source potential naturally rises with the passage of time to the same level as during non-discharge. That is, it is possible to detect the stop of ion generation without operating the n-JFET 185 from the outside.

  Also in the present embodiment, the wiring 19a connecting the collecting electrode 19 and the rectifying diode 186 can be adjusted to an appropriate length, and the shape of the collecting electrode 19 is also an arbitrary shape. Therefore, it is possible to detect discharge at various places.

Embodiment 3 FIG.
In the above-described embodiment, the control unit 10 gives control signals to the high-voltage drive circuit 11, the fan motor drive circuit 15, and the lamp circuit 20, and controls them. However, when detecting the stop of ion generation, It is good also as a structure which alert | reports that to a user, without going through the control part 10. FIG.

  FIG. 8 is a block diagram showing the internal configuration of the ion generator according to this embodiment. As in the above-described embodiment, the ion generator includes a high-voltage drive circuit 11 for applying an alternating high voltage to the discharge electrode 13 and a fan motor that performs PMW control on the fan motor 16 to rotate the fan 17. A drive circuit 15 is provided. The high-voltage drive circuit 11 and the fan motor drive circuit 15 are supplied with power from the power supply circuit 12 when the switch SW is turned on.

  The collection electrode 19 for collecting ions is connected to the ion detection circuit 18B by a wiring 19a having an appropriate length. Here, as the ion detection circuit 18B, the same circuit as that described in Embodiment 2 can be used. The output terminal of the ion detection circuit 18B is connected to the alarm circuit 30.

  FIG. 9 is a circuit diagram showing an example of the alarm circuit 30. The alarm circuit 30 includes a comparator 304, an alarm device 306, and the like. The comparator 304 receives the source potential of the n-JFET 185 input through the input terminal 301 and the voltage divided by the resistors 302 and 303 of the potential VCC. An alarm device 306 is connected to the output terminal of the comparator 304 via a resistor 305. Here, as the alarm device 306, for example, an LED lamp that emits light, a buzzer that emits sound, or the like can be used. Therefore, when the generation of ions stops and the source potential of the n-JFET 185 rises and reaches a partial pressure determined by the resistors 302 and 303, the alarm device 306 can be activated.

  As described above, in this embodiment, when the stop of ion generation is detected, the alarm device 306 can be operated without using the control unit 10, and the entire device can be downsized.

  In the present embodiment, the alarm circuit 30 is provided separately from the ion detection circuit 18B. However, it goes without saying that the alarm circuit 30 may be provided inside the ion detection circuit 18B.

It is a block diagram which shows the internal structure of the ion generator which concerns on this Embodiment. It is a schematic diagram explaining the example of arrangement | positioning of a discharge electrode and a collection electrode. It is a circuit diagram explaining the internal structure of an ion detection circuit. It is a graph which shows the time change of the source potential in p-MOS type FET. It is a circuit diagram explaining the internal structure of an ion detection circuit. It is a graph which shows the time change of the source potential in n-JFET. It is the graph which measured the time change of the source potential at the time of stopping ion generation after detecting a negative ion. It is a block diagram which shows the internal structure of the ion generator which concerns on this Embodiment. It is a circuit diagram which shows an example of an alarm circuit.

Explanation of symbols

10 Control unit
11 High voltage drive circuit
12 Power supply circuit
DESCRIPTION OF SYMBOLS 13 Discharge electrode 15 Fan motor drive circuit 16 Motor 17 Fan 18A, 18B Ion detection circuit 19 Collection electrode 20 Lamp circuit 21 Lamp 30 Alarm circuit 181 p-MOS type FET
182 Diode 183 Resistor 184 Zener diode 185 n-JFET
186 Diode 187 Resistor 188 Zener Diode 189 Resistor 304 Comparator 305 Resistor

Claims (11)

  An ion detector comprising: a conductor that collects ions; and a detection unit that detects a potential of the conductor.   The detection means includes a field effect transistor having a gate connected to the conductor, and detects ions collected by the conductor based on a source potential of the field effect transistor. The ion detector according to claim 1.   The ion detection apparatus according to claim 2, wherein the detection unit includes a rectifier element connected between the conductor and a gate of the field effect transistor.   4. The ion detection apparatus according to claim 2, wherein the detection means includes a constant voltage element so as to limit an absolute value of a gate potential of the field effect transistor to a predetermined value or less.   5. The ion detection apparatus according to claim 2, wherein the detection unit includes a resistance element connected between a gate and a source of the field effect transistor.   6. The ion detector according to claim 2, wherein the type of field effect transistor connected to the conductor is made different according to the polarity of ions to be detected.   The ion detector according to any one of claims 2 to 6, wherein the conductor and the field effect transistor are connected by a wiring having an appropriate length.   Means for comparing the magnitude relationship between the absolute value of the source potential of the field effect transistor and a predetermined threshold, and means for notifying that the detection means has not detected ions when the magnitude relation changes. The ion detection apparatus according to claim 2, wherein the ion detection apparatus is any one of claims 2 to 7.   An ion generation means for generating ions and the ion detection device according to any one of claims 1 to 8, wherein the ions generated by the ion generation means are detected by the ion detection device. An ion generator characterized by that.   The ion generating apparatus according to claim 9, further comprising a blowing unit that diffuses ions generated by the ion generating unit to the outside.   The ion generator according to claim 10, wherein the ion detector is provided downstream of the ion generator in the ion diffusion direction.

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