JP2007087932A - High voltage generation circuit and ionizer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high voltage generation circuit capable of efficiently applying high voltage to a discharging electrode without loss of voltage by a simple circuit configuration and to provide an ionizer. <P>SOLUTION: In this high voltage generation circuit 6 comprising positive polarity and negative polarity voltage doubler rectifier circuits 6a, 6b, and used for the ionizer generating positive and negative ions by corona discharge of the discharging electrode by applying positive or negative direct-current high voltage alternately between the discharging electrode 3 and a ground electrode, current-limiting resistances are provided between output terminals of the positive polarity rectifier circuit and between output terminals of the negative polarity rectifier circuit respectively, and the high voltage generation circuit 6 when it is connected with the positive polarity rectifier circuit and the negative polarity rectifier circuit in series and high voltage is applied to the discharging electrode becomes a circuit equivalent to a circuit wherein the discharging electrode and current-limiting resistances of one voltage doubler rectifier circuit generating the high voltage and the other voltage doubler rectifier circuit not generating the high voltage are connected in series. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ionizer used in a static eliminator and the like, and in particular, a high voltage generation circuit used in an ionizer that adjusts the generation amount of positive and negative ions according to the positive and negative ion balance around the object to be neutralized and blows air, and this circuit. It relates to the equipped ionizer.

  Electrostatic discharge (ESD) causes various obstacles in the manufacturing process and mounting process of precision electronic devices. With the miniaturization of semiconductor circuits, the permissible charge amount is reduced, and even with a slight charge, the silicon circuit and the oxide insulating layer are destroyed by ESD.

  Another problem is that the adhesion of dust is promoted by charging. In order to achieve high integration of semiconductor circuits, antistatic measures are indispensable. In general, the method of neutralizing charges by spraying positive and negative ions generated by a discharge device alternately on a static elimination object by a gas jet It has been. Such a device is called a static elimination device or an ionizer for static elimination (hereinafter referred to as an ionizer).

  Many of these ionizers generate a corona discharge localized at the tip by applying a high voltage to the discharge electrode. These ionizers generate positive and negative bipolar ions, so that an AC voltage is applied to the discharge electrode, a positive or negative DC voltage is applied to each of the electrodes, and the same discharge electrode is pulsed. There are various methods such as alternately applying positive and negative voltages.

  Conventionally, in an ion generation circuit (high voltage generation circuit) that controls the amount of positive and negative ions generated by applying an AC voltage, there is a method for boosting the voltage by making the positive and negative voltages on the primary side of the step-up transformer unbalanced (Patent Document 1). However, in this method, if the positive / negative of the primary side waveform of the step-up transformer is unbalanced by some method and input to the step-up transformer, the secondary side waveform is distorted due to the characteristics of the transformer, and positive / negative generated ions cannot be controlled over a wide range. There's a problem.

  In addition, there is a method of changing a positive / negative peak value by superimposing a DC bias voltage supplied from another DC power source on a secondary AC voltage of a step-up transformer (Patent Document 2). However, this method has a problem that the magnitude of the DC bias voltage is about 100V to 200V and the adjustment range of the ion balance is relatively narrow.

  In order to solve the above-described problems, a positive DC high voltage is applied to the discharge electrode to generate corona discharge on the discharge electrode, thereby generating positive ions. In addition, there is a method in which negative ions are generated by applying a negative direct-current high voltage to the discharge electrode and generating a corona discharge in the discharge electrode. Since this method is a direct current high voltage, the voltage control is relatively simple, and the amount of ion generation is easily controlled. However, since two positive and negative electrodes are provided separately, there is a problem that the number of electrodes increases and wiring becomes complicated. In addition, the deterioration of the discharge electrode to which a voltage of the same polarity is always applied has a problem that it is consumed faster than the electrode to which a positive voltage and a negative voltage are applied alternately.

  For this reason, there is an ion generation circuit (Patent Document 3) that controls generation of positive and negative ions by applying a DC high voltage to the same discharge electrode. FIG. 6 is a diagram showing a conventional ion generation circuit (high voltage generation circuit). The high voltage generation circuit 40 has a configuration in which a DC power source 41 is connected to a positive high voltage generation circuit 42a and a negative high voltage generation circuit 42b via switches 41a and 41b.

  The high voltage generation circuit 40 includes transformers 43a and 43b and voltage doubler rectifier circuits 44a and 44b. Equivalent resistors R1 and R1 are connected between the output terminals of the high voltage generation circuit 40 (voltage doubler rectifier circuits 44a and 44b), and an electrode needle 47 is connected to a connection point 46 of the resistors R1 and R1.

  The switches 41a and 41b are opened / closed by a control signal from the control device 48, and positive and negative high voltages are alternately applied from the electrode needle 47 to alternately output positive and negative ions. By controlling the opening and closing time of the switches 41a and 41b, the frequency of the voltage applied to the electrode needle 47 and the magnitude of the voltage of positive and negative polarity are controlled. The current flows from the resistor R1 to the connection point 46, the resistor R1, and a diode (voltage is applied in the forward direction) in the negative high voltage generation circuit 42b. As a result, a voltage that is ½ of the voltage (Em +) output from the positive high voltage generation circuit 42 a is applied to the electrode needle 47. The same applies to the case where the negative high voltage circuit 42b generates a negative high voltage. That is, in the conventional circuit, there is a problem that only half the voltage generated by the high voltage generating circuit is applied to the electrode needle 47.

JP-A-9-213493 Patent No. 2520311 JP 2000-058290 A

  Therefore, in view of such problems, the present invention has an object to provide a high voltage generation circuit and an ionizer that can apply a high voltage to a discharge electrode efficiently without losing a voltage with a simple circuit configuration. Is.

  The present invention relates to positive and negative voltage doubler rectification used in an ionizer that alternately applies positive or negative DC high voltage between a discharge electrode and a ground electrode and generates positive and negative ions by corona discharge of the discharge electrode. In the high voltage generation circuit including a circuit, current limiting resistors are provided between the output terminals of the positive rectifier circuit and between the output terminals of the negative rectifier circuit, respectively, and the positive rectifier circuit and the negative rectifier circuit Is connected in series, and when a high voltage is applied to the discharge electrode, the high voltage generation circuit includes the discharge electrode, any one of the voltage doubler rectifier circuits generating a high voltage, and a high voltage The circuit is equivalent to a circuit in which a current limiting resistor of another voltage doubler rectifier circuit that does not generate current is connected in series.

  Further, according to the present invention, when any one of the voltage doubler rectifier circuits generates a voltage, the other voltage doubler rectifier circuit includes a one-way energization element to which a reverse voltage is applied and the other voltage doubler rectifier circuit. The current limiting resistor is configured to be equivalent to a circuit connected in parallel.

  By adopting such a high voltage generation circuit configuration, the high voltage generated in the positive or negative high voltage generation circuit can be applied to the discharge electrode without drastically decreasing. For example, if a 20 MΩ resistor is provided between the output terminals of the high voltage generation circuit as a current limiting resistor, the resistance between the discharge electrode and the ground electrode is about 200 MΩ during discharge, so that the voltage generated by the high voltage generation circuit is 90%. % Can be applied to the discharge electrode.

  The voltage doubler rectifier circuit is preferably a billard circuit (Villard circuit) or a cockcroft-Walton circuit.

  The present invention is an ionizer including the above-described high voltage generation circuit.

  According to the present invention, positive and negative DC high voltages can be alternately applied to a single discharge electrode with a simple circuit configuration without significantly decreasing.

  EXAMPLES Hereinafter, although preferable embodiment of this invention is described in detail based on an Example, this invention is not limited to this.

  FIG. 1 is a schematic exploded view of an ionizer that is an embodiment of the present invention. This ionizer causes corona discharge by a large number of electrodes arranged in parallel in a direction perpendicular to the paper surface, and blows an air flow containing positive and negative ions to the static elimination object. FIG. 1 shows a schematic exploded view near the center of a rectangular ionizer body. This apparatus includes an ionizer body 1, ion sensors 2a and 2b, a high voltage generation circuit 6 described later, and the like. The ionizer body 1 includes a discharge electrode 3, a grid 4 as a counter electrode, a blower fan 5 that forms an air flow, and the like. The grid 4 that is the counter electrode is grounded.

  FIG. 2 shows a high voltage generation circuit including a quadruple voltage rectifier circuit using two stages of billard circuits (Villard circuits) as voltage doubler rectifier circuits. The high voltage generation circuit includes a power supply control circuit 7 including a power source and a switch for alternately applying positive and negative high voltages, and a high voltage generation circuit 6. The power supply control circuit 7 is basically the same as that described in the above-described existing technology.

  The high voltage generation circuit 6 includes a positive high voltage generation circuit 6a and a negative high voltage generation circuit 6b. The positive high voltage generation circuit 6a is provided at the transformer Tra, the positive voltage doubler rectifier circuit, and the output terminal. The negative high voltage generation circuit 6b includes a transformer Trb, a negative voltage doubler rectifier circuit, and a current limiting resistor Rb provided at the output terminal.

  In the high voltage generating circuit 6 shown in FIG. 2, the discharge electrode 3 is connected to the positive output terminal of the positive voltage doubler rectifier circuit, and the negative electrode terminal is connected to the negative output terminal of the negative voltage doubler rectifier circuit. The positive terminal of the negative voltage doubler rectifier circuit is grounded.

  The operation of the high voltage generation circuit shown in FIG. 2 will be described. When a high voltage is applied to the positive high voltage generation circuit 6a by the power supply control circuit 7 and no high voltage is applied to the negative high voltage generation circuit 6b, a transformer Tra is generated at the output terminal of the positive voltage doubler rectifier circuit. 4 times the voltage Em (4Em) generated. As a result, a positive voltage is applied to the discharge electrode 3, corona discharge is started at the end of the discharge electrode, positive ions are generated, and a current flows from the discharge electrode 3 toward the counter electrode (ground electrode). Here, the negative voltage doubler rectifier circuit can be regarded as a circuit equivalent to a circuit in which reverse voltages are applied to the diodes Db1 to Db4 of this circuit and these diodes and Rb are connected in parallel. .

  Similarly, when the high voltage is applied to the negative polarity high voltage generation circuit 6b by the power supply control circuit 7 and no high voltage is applied to the positive polarity high voltage generation circuit 6a, the output voltage of the negative polarity high voltage generation circuit 6b is similarly applied. Generates a voltage (-4Em) that is four times the voltage -Em generated by the transformer Trb. As a result, a negative voltage is applied to the discharge electrode 3, corona discharge is started at the end of the discharge electrode, negative ions are generated, and current flows from the counter electrode (ground electrode) to the discharge electrode 3. Here, the positive voltage doubler rectifier circuit can be regarded as a circuit equivalent to a circuit in which reverse voltages are applied to the diodes Da1 to Da4 of this circuit and these diodes and Ra are connected in parallel.

  FIG. 3 shows an equivalent circuit when the positive voltage doubler rectifier circuit and the negative voltage doubler rectifier circuit operate. The equivalent circuit when a high voltage is applied to the positive voltage doubler rectifier circuit is as shown in FIG. 3A, and the equivalent circuit when a high voltage is applied to the negative voltage doubler rectifier circuit is as shown in FIG. The equivalent circuit shown in FIG. Here, if each of the current limiting resistors Ra and Rb is 20 MΩ, the resistance between the discharge electrode 3 and the counter electrode (ground electrode) is about 200 MΩ, so that the discharge electrode 3 has 4 Em generated in the voltage doubler rectifier circuit. A voltage of about 90% will be applied. Further, the circuit can be protected from overcurrent by the current limiting resistors Ra and Rb.

FIG. 4 shows a high voltage generation circuit including a quadruple voltage rectifier circuit using two stages of a Cockcroft-Walton circuit (Cockcroft-Walton circuit) instead of the billard circuit (Villard circuit) as a double voltage rectifier circuit. When a positive DC high voltage is applied to the discharge electrode 3 by the positive high voltage generating circuit 6c, the equivalent circuit shown in FIG. 3 (a) is obtained, and a negative DC high voltage is generated by the negative high voltage generating circuit 6d. When applied to the discharge electrode 3, an equivalent circuit as shown in FIG. Similarly to the case where a billard circuit (Villard circuit) is used as the voltage doubler rectifier circuit, a voltage can be applied to the discharge electrode 3 without reducing the voltage generated by the voltage doubler rectifier circuit.

  FIG. 5 is a diagram showing power supply waveforms of the circuit shown in FIG. In FIG. 5, input voltage waveform 1 is a waveform when a voltage of −10 V is input to Trb by power supply control circuit 7, and input voltage waveform 2 is a case where a voltage of +10 V is input to Tra by power supply control circuit 7. It is a waveform. The positive / negative reference voltage is a ground voltage.

  By alternately inputting + 10V and -10V to the positive high voltage generation circuit 6a and the negative high voltage generation circuit 6b, a high voltage as shown in the output voltage waveform 3 is applied to the discharge electrode 3 at about ± 4.5 KV. It was confirmed that it was output. The OFF state of the input voltage waveform 1 and the input voltage waveform 2 is slightly higher than the ground voltage (0V), and this gradually decreases. However, the voltage doubler rectifier circuit is on when the voltage is 5V or less. Therefore, it is substantially equivalent to the ground voltage and does not cause a problem.

  As shown in the output voltage waveform 3 shown in FIG. 5, positive and negative DC voltages of about 4.5 KV are alternately applied to the discharge electrodes 3. Although approximately 5 KV is generated between the output terminals by the high voltage generation circuit 6, as described above, the voltage drop due to the current limiting resistor Ra (20 MΩ) or Rb (20 MΩ) is a resistance between the discharge electrode 3 and the ground electrode. The voltage of ± 4.5 KV is applied to the discharge electrode 3 because it is about 10% in relation to (about 200 MΩ).

  According to the present invention, it is possible to create a circuit that can be applied to the discharge electrode with a simple circuit without significantly reducing the high voltage generated by the high voltage generation circuit. Further, it is possible to manufacture an ionizer equipped with this high voltage generation circuit, which has industrial applicability.

It is a schematic exploded view of the ionizer which is an Example of the present invention. It is a high voltage generation circuit diagram using a Billard circuit (Villard circuit) as a voltage doubler rectifier circuit. It is the figure which showed the equivalent circuit when the positive polarity voltage doubler rectification circuit and negative polarity voltage doubler rectification circuit of a high voltage generation circuit of a present Example each operate | move. It is a high voltage generation circuit diagram using a Cockcroft-Walton circuit (Cockcroft-Walton circuit) as a voltage doubler rectifier circuit. It is an input / output voltage waveform diagram of a high voltage generation circuit using a billard circuit (Villard circuit) as a voltage doubler rectifier circuit of the present embodiment. It is a high voltage generation circuit diagram in a prior art.

Explanation of symbols

1 Ionizer body 2a, 2b Ion sensor 3 Discharge electrode 4 Grid (counter electrode)
5 Fan 6 Ion generation circuit (high voltage generation circuit)
7 Power control circuit

Claims (5)

High voltage including positive and negative voltage doubler rectifier circuits used in ionizers that apply positive or negative DC high voltage alternately between discharge electrode and ground electrode to generate positive and negative ions by corona discharge of discharge electrode In the voltage generation circuit,
Current limiting resistors are provided between the output terminals of the positive rectifier circuit and between the output terminals of the negative rectifier circuit, and the positive rectifier circuit and the negative rectifier circuit are connected in series,
When a high voltage is applied to the discharge electrode, the high voltage generation circuit includes the discharge electrode, any one of the voltage doubler rectifier circuits that generate a high voltage, and another that does not generate a high voltage. A high voltage generation circuit, characterized in that the circuit is equivalent to a circuit in which a current limiting resistor of a voltage doubler rectifier circuit is connected in series.   When one of the voltage doubler rectifier circuits generates a voltage, the other voltage doubler rectifier circuit includes a one-way energization element to which a reverse voltage is applied and a current limiting resistor of the other voltage doubler rectifier circuit. 2. The high voltage generation circuit according to claim 1, wherein the high voltage generation circuit is equivalent to a circuit connected in parallel. 3. The high voltage generation circuit according to claim 1, wherein the current limiting resistance is 1/10 or less of a resistance value between the discharge electrode and the ground electrode. 4. The high voltage generating circuit according to claim 1, wherein the voltage doubler rectifier circuit is a billard circuit or a cockcroft-walton circuit. An ionizer comprising the high voltage generation circuit according to claim 1.

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