JP5350098B2 - Pulse control power supply for static eliminator - Google Patents

Description

  The present invention relates to a power supply device for a static eliminator that applies a high-frequency high voltage to a static elimination electrode for generating positive and negative ions.

As described in Patent Document 1, a self-oscillation boosting circuit that self-oscillates with a DC voltage and boosts with a high-voltage transformer to generate a high-frequency high voltage as a continuous wave is used as a power supply device for a static eliminator. Things are generally widely used.
However, if the high-frequency high voltage applied to the static elimination electrode is a continuous wave, the capacitance of the cable connecting the output terminal of the self-excited oscillation booster circuit (secondary side of the high-voltage transformer) and the static elimination electrode increases. In this case, since the high-frequency voltage is continuously attenuated, there is a problem that the length of the cable to be used is limited.
In addition, the circuit configuration described in Patent Document 1 cannot be controlled arbitrarily according to the conditions of the static elimination target, and thus the plus / minus ion balance adjustment cannot be performed sufficiently.

In Patent Document 2, a high-frequency high voltage output from a self-excited oscillation booster circuit is superimposed with a positive voltage and a negative voltage that are charged in a capacitor in each of a positive half cycle and a negative half cycle. A power supply device for a static eliminator is disclosed in which an alternating current and a direct current can be used together by using an alternating voltage including
However, this adds a circuit for generating a direct current component to the output side of the self-oscillation boosting circuit, and the influence of capacitance according to the cable length cannot be improved.

Further, Patent Document 3 intermittently oscillates a self-oscillation boosting circuit to intermittently output a high-frequency high voltage, which is separately plus and minus by a plus side voltage doubler rectifier circuit and a minus side voltage doubler rectifier circuit. A power supply device for a DC type static eliminator is disclosed in which a positive DC high voltage and a negative DC high voltage are applied by rectification and amplification, and applied to a positive-side static elimination electrode and a negative-side static elimination electrode, respectively. ing.
Although this uses a self-excited oscillation booster circuit, a plus-side voltage doubler rectifier circuit and a minus-side voltage doubler rectifier circuit are added to the output side, and plus / minus DC high voltage is added to the plus / minus neutralization electrode. It is for DC type static eliminators to be applied respectively.

Further, Patent Document 4 discloses that a positive voltage transformer and a negative voltage transformer each of which is supplied with power from an external power source and generates a high voltage on each secondary side, and a high voltage generated on the secondary side of the positive voltage transformer is positive. A positive voltage doubler rectifier circuit for boosting to a high voltage, a negative voltage doubler rectifier circuit for boosting a high voltage generated on the secondary side of the negative transformer to a negative high voltage, and a positive voltage doubler rectifier circuit The first and second impedance elements connected in series to the diode and the diode of the negative voltage doubler rectifier circuit and each connected in series, and the first feeding path on the primary side of the positive transformer are opened and closed A first electronic switch for switching, a second electronic switch for opening and closing the second power supply path on the primary side of the negative transformer, and opening / closing times of the first electronic switch and the second electronic switch Control device to control The control device controls one of the first electronic switch and the second electronic switch to an open state and the other to a closed state, so that the static elimination electrode connected to the first and second impedance elements A power supply device for a static eliminator is disclosed in which a pulse voltage in which positive and negative polarities are reversed is repeatedly applied.
However, since this uses a voltage doubler rectifier circuit for each of the positive and negative, there is a limit from the responsiveness of the voltage doubler rectifier circuit to speed up the opening and closing operation of the first electronic switch and the second electronic switch. Yes, it is impossible to increase the repetition frequency of the positive and negative pulse voltage applied to the static elimination electrode (the cycle of the positive and negative pulse voltage must be low), and high performance static elimination with high frequency and high voltage. Cannot be done.

Japanese Patent Publication No.3-1798 Japanese Patent No. 2909893 Japanese Patent No. 2520839 Japanese Patent No. 4219451

  The object of the present invention is not only to perform high static elimination with high frequency and high voltage, but also to reduce the influence of the capacitance between the output terminal of the self-excited oscillation booster circuit and the static elimination electrode. It is to enable extension, and to allow sufficient adjustment of plus / minus ion balance.

To achieve the above object, a pulse control power supply for a static eliminator according to the present invention includes a self-excited oscillation booster circuit, a switching circuit for controlling a voltage from a DC power source input thereto, and a self-excited oscillation booster circuit A high frequency high voltage generation unit and a negative high frequency high voltage generation unit each including a rectifier circuit for half-wave rectification of the high frequency high voltage from, and a pulse width for varying the pulse for switching the switching circuit of both units A frequency variable unit and a synthesis circuit for synthesizing outputs from both units are provided.
The pulse width / frequency variable unit includes a low frequency pulse generation circuit that generates a low frequency pulse lower than the high frequency high voltage, a pulse width variable means that varies the pulse width, and a frequency variable means that varies the pulse frequency. It consists of.
Each switching circuit of the plus high frequency high voltage generating unit and the minus high frequency high voltage generating unit is switched by a pulse from the low frequency pulse generating circuit, and the voltage from the DC power source is changed according to the pulse width and the pulse frequency. By inputting to the self-oscillation boosting circuit, the high-frequency high voltage output from the self-oscillation boosting circuit is controlled to have an interval corresponding to the pulse frequency with a width corresponding to the pulse width. The switching circuit of the plus high-frequency high-voltage generation unit and the switching circuit of the minus high-frequency high-voltage generation unit perform switching operations reversed from each other.
The rectifier circuit of the positive high frequency high voltage generation unit and the rectifier circuit of the negative high frequency high voltage generation unit rectify the high frequency high voltage from the self-excited oscillation booster circuit in opposite directions, respectively, plus positive high frequency high voltage and negative high frequency High voltage.
The synthesis circuit synthesizes these plus high frequency high voltage and minus high frequency high voltage and applies them to the static elimination electrode.

In the invention according to claim 2, a capacitor is provided between the secondary side of the high-voltage transformer of each of the plus high-frequency high-voltage generation unit and the minus high-frequency high-voltage generation unit and the synthesis circuit.
The invention according to claim 3 has an ion balance adjusting circuit connected to the secondary coil of the high voltage transformer in each of the plus high frequency high voltage generating unit and the minus high frequency high voltage generating unit. A positive side circuit extending from the ground side of the secondary coil to the ground through the first fixed resistor, a second diode opposite to the first diode from the secondary side of the high-voltage transformer, and A negative circuit that reaches the ground via a variable resistor is connected in parallel, and at least one of the resistance of the positive circuit or the negative circuit is variable to adjust the resistance balance.

According to the present invention, the plus high frequency high voltage generating unit and the minus high frequency high voltage generating unit respectively generate a plus high frequency high voltage and a minus high frequency high voltage, and synthesize these to generate a plus high frequency high voltage and a minus high frequency high voltage. Since a high frequency high voltage obtained by synthesizing plus and minus having alternating repetition periods is applied to the static elimination electrode, static elimination with high performance by the high frequency high voltage can be performed.
In addition, each of the plus high frequency high voltage and the minus high frequency high voltage has an intermittent period instead of a continuous wave, and the attenuation due to the capacitance according to the length of the cable connected to the static elimination electrode can be reduced compared to the continuous wave. At the same time, the output pattern of each voltage can be made variable according to the pulse width and pulse frequency of the pulse from the low-frequency pulse generation circuit, so that the desired static elimination can be achieved while avoiding the influence of the length of the cable connected to the static elimination electrode. Appropriate charge removal depending on conditions can be performed.

In the case of an AC type static eliminator, the discharge characteristics are generally plus / minus asymmetric, and the minus discharge current is about 20% greater than the plus discharge current. However, according to the second aspect of the present invention, the DC discharge current is supplied to the plus high frequency high voltage generating unit and the minus high frequency high voltage. Since each of the generating units can be blocked by a capacitor, reverse charge is prevented and neutralization with a balance of positive and negative ions can be performed.
According to the invention of claim 3, in each of the plus high frequency high voltage generating unit and the minus high frequency high voltage generating unit, the discharge current flowing to the ground is divided into plus and minus, and the minus side can be varied by a variable resistor. Therefore, it is possible to finely adjust the plus / minus ion balance.

It is an electric circuit diagram of one Example of this invention. It is a timing chart of the operation.

Hereinafter, a pulse control power supply device for a static eliminator according to a preferred embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the pulse control power supply device X for static eliminator is roughly divided into a plus high frequency high voltage generation unit X1, a negative high frequency high voltage generation unit X2, a pulse width / frequency variable unit X3, And a synthesis circuit X4.

The plus high-frequency high-voltage generation unit X1 and the minus high-frequency high-voltage generation unit X2 are only slightly different from each other, so the same configuration will be described first.
Each of the plus high frequency high voltage generation unit X1 and the minus high frequency high voltage generation unit X2 has a self-oscillation boosting circuit 3 similar to the conventional one comprising two transistors Tr1, Tr2, a high-voltage transformer 1, and a self-excitation circuit 2. The self-excited oscillation booster circuit 3 uses an external DC power source connected to the power source terminal 4 of the pulse control power source device X for static eliminator of the present invention as a power source. The self-excited oscillation booster circuit 3 operates the two transistors Tr1 and Tr2 in the self-excited circuit 2 to self-oscillate and boosts the voltage by the high-voltage transformer 1, thereby generating a high-frequency high voltage. Yes.
The DC voltage from the DC power source is controlled by pulses as follows by the operation of the switching circuit 5.

  The switching circuit 5 is switched by a low frequency pulse from the low frequency pulse oscillation circuit 6 of the pulse width / frequency variable unit X3, and the pulse width can be varied by a pulse width variable resistor 7 which is a pulse width variable means. The pulse frequency can be varied by a frequency variable resistor 8 which is a frequency varying means (see the timing chart attached to FIG. 1). If the output frequency from the self-excited oscillation booster circuit 3, that is, the frequency of the high frequency and high voltage output from the secondary coil of the high voltage transformer 1, is 10 to 30 kHz, for example, the frequency of the pulse output from the low frequency pulse oscillation circuit 6 Is much lower than this, for example, 1 to 300 Hz.

The switching circuit 5 includes a constant voltage circuit that uses a voltage (for example, plus 24 V) from an external DC power supply as a constant voltage, and converts the constant voltage to the pulse width and pulse frequency of the pulse from the low frequency pulse oscillation circuit 6. In response, the self-excited oscillation booster circuit 3 is input.
Accordingly, since the self-oscillation boosting circuit 3 operates according to the pulse width and pulse frequency of the low frequency pulse, the high frequency high voltage output from the secondary coil of the high voltage transformer 1 An intermittent cycle with a width corresponding to the pulse width is repeated according to the pulse frequency.

The low frequency pulse width can be varied by the pulse width variable resistor 7, and the low frequency period can be varied by the frequency variable resistor 8. Therefore, the pulse width of the high frequency high voltage output from the secondary coil of the high voltage transformer 1 and the intermittent repetition period can be controlled by the pulse width variable resistor 7 and the frequency variable resistor 8.
A half-wave rectifying diode D0, which is a rectifier circuit, and a DC component removing capacitor C1 are connected in series between the secondary coil of the high-voltage transformer 1 and the synthesis circuit X4.
On the other hand, an ion balance adjusting circuit 10 is connected to the ground side of the secondary coil of the high-voltage transformer 1. The ion balance adjusting circuit 10 includes a positive side circuit extending from the ground side of the secondary coil to the ground through the first diode D1 and the first fixed resistor R1, and a first diode D1 from the ground side of the secondary coil. Is a parallel connection of a negative-side circuit that reaches the ground through the second diode D2, the second fixed resistor R2, and the variable resistor VR in the reverse direction. The first fixed resistor R1 is the resistor of the plus side circuit of the present invention, and the second fixed resistor R2 and the variable resistor VR are the resistors of the minus side circuit of the present invention.

  In addition, when the alarm control circuit 11 common to both units X1 and X2 is connected to the ground side of the secondary coil of the high-voltage transformer 1 via the discharge current abnormality detection capacitor C2, an abnormal discharge current flows. A load fluctuation control signal is output from the alarm control circuit 11 and input to the switching circuit 5. When this load fluctuation control signal is input to the switching circuit 5, the switching circuit 5 stops the power supply to the self-excited oscillation boost circuit 3, and the self-excited oscillation boost circuit 3 stops its operation. An alarm operation can be performed by the load fluctuation control signal.

  The above configuration is the same for both the plus high frequency high voltage generation unit X1 and the minus high frequency high voltage generation unit X2. However, only the plus high frequency high voltage generation unit X1 includes the inverter 13, and the low frequency pulse oscillation circuit 6 The pulse is inverted by the inverter 13 and input to the switching circuit 5, and the half-wave rectifying diode D0 of the plus high-frequency high-voltage generating unit X1 and the half-wave rectifying diode D0 of the minus high-frequency high-voltage generating unit X2 are rectified. The units X1 and X2 are different in that the direction is reversed between plus and minus.

Therefore, between the switching circuit 5 of the plus high frequency high voltage generation unit X1 and the switching circuit 5 of the minus high frequency high voltage generation unit X2, the pulses from the low frequency pulse oscillation circuit 6 are as shown by A1 and B1 in FIG. The patterns are reversed from each other. The outputs from the switching circuit 5 of both the units X1 and X2 are also inverted as shown by A2 and B2 in FIG.
Therefore, the high frequency high voltage output from the self-excited oscillation booster circuit 3 of the plus high frequency high voltage generation unit X1 is output intermittently from the self-excited oscillation booster circuit 3 of the minus high frequency high voltage generation unit X2. The high frequency high voltage is output alternately as indicated by A3 and B3 in FIG.

  The high-frequency high voltage from the self-oscillation booster circuit 3 of both units X1 and X2 having such a relationship is half-wave rectified by the respective half-wave rectifier diodes D0. Since the directions are opposite to each other, as shown in A4 and B4 of FIG. 2, the high frequency high voltage from the plus high frequency high voltage generation unit X1 is positive polarity, and the high frequency high voltage from the negative high frequency high voltage generation unit X2 is negative polarity. Become.

  The synthesizing circuit X synthesizes the plus / minus high frequency high voltage as shown by AB5 in FIG. 2 and outputs the synthesized voltage from the output terminal 9 of the static eliminator pulse control power supply device X to the outside. The neutralizing electrode Y is connected to the output terminal 9 via a cable or the like.

  As described above, since both the high frequency high voltage generation unit X1 and the negative high frequency high voltage generation unit X2 can change the width and repetition period of the output pattern, the high frequency high voltage from the self-excited oscillation booster circuit 3 can be changed. While avoiding the influence of the capacitance due to the length of the cable connected to the static elimination electrode Y, it is possible to realize the ion amount according to the desired static elimination conditions and perform appropriate static elimination. At that time, if a DC discharge current flows due to the asymmetry of plus / minus discharge characteristics on the charge removal electrode Y side, the DC discharge current is interrupted by the capacitor C1, so that the ion balance is maintained and the reverse of the charge removal target. Charge can be prevented.

Generally, as described above, due to the asymmetry of the plus / minus discharge characteristics on the static elimination electrode Y side, generally, the minus discharge current becomes larger than the plus discharge current as described above, and the ion balance is lost. Since the direct current flowing thereby can be interrupted by the capacitor C1, it is possible to prevent reverse charge by negative ions whose charge removal object is excessive.
Further, the negative discharge current, which is larger than the positive discharge current, is adjusted to the ground by adjusting the variable resistance VR in each of the positive high frequency high voltage generation unit X1 and the negative high frequency high voltage generation unit X2. The ion balance can be finely adjusted.

  The static elimination electrode Y to be used may be a general one in which the discharge electrode and the ground electrode are opposed to each other, and the ground electrode is connected to the ground terminal 12 prepared in the pulse control power supply device X for the static eliminator with a cable or the like. Can be connected and grounded.

  Further, if the pulse width / frequency variable unit X3 is provided for each of the plus high frequency high voltage generation unit X1 and the minus high frequency high voltage generation unit X2, the plus high frequency high voltage generation unit X1 and the minus high frequency high voltage generation unit X2 respectively. The width and repetition period of the high-frequency high-voltage output pattern from the self-oscillation boosting circuit 3 can be made variable.

X Discharger Pulse Control Power Supply Device X1 Plus High Frequency High Voltage Generation Unit X2 Negative High Frequency High Voltage Generation Unit X3 Pulse Width / Frequency Variable Unit X4 Synthesis Circuit Y Static Discharge Electrode Tr1, Tr2 Transistor C1 DC Component Removal Capacitor C2 Discharge Current Abnormality Detection Capacitor D0 Half-wave rectifier diode D1, D2 Diode R1, R2 Fixed resistor VR Variable resistor 1 High voltage transformer 2 Self-excited circuit 3 Self-excited oscillation booster circuit 4 Power supply terminal 5 Switching circuit 6 Low frequency pulse oscillation circuit 7 Pulse width variable resistor 8 Frequency variable resistor 9 Output terminal 10 Ion balance adjustment circuit 11 Alarm control circuit 12 Earth terminal 13 Inverter

Claims (3)

  A self-excited oscillation booster having a self-excited oscillation booster circuit that self-oscillates with a DC voltage and generates a high-frequency high voltage by boosting with a high-voltage transformer, and applying the output to a neutralization electrode. A plus high-frequency high-voltage generating unit and a negative circuit each including a circuit, a switching circuit for controlling a voltage from a DC power source input thereto, and a rectifier circuit for half-wave rectifying the high-frequency high voltage from the self-excited oscillation booster circuit A high-frequency, high-voltage generating unit, a pulse width / frequency variable unit for changing the pulse for switching the above switching circuits of both units, and a synthesis circuit for synthesizing outputs from both units are provided. The variable unit is a pulse having a frequency lower than the frequency of the high frequency high voltage output from the self-oscillation boosting circuit. Including a low frequency pulse generation circuit for generating a low frequency pulse, a pulse width variable means for changing the pulse width of the low frequency pulse, and a frequency variable means for changing the frequency of the low frequency pulse. The switching circuit of each of the negative high frequency high voltage generation unit is switched by a pulse from the low frequency pulse generation circuit, and the self-excited voltage is supplied from a DC power source according to the pulse width of the low frequency pulse and the frequency. By inputting to the oscillation booster circuit, the high frequency high voltage output from the self-excited oscillation booster circuit has a width corresponding to the pulse width of the low frequency pulse and an intermittent cycle corresponding to the frequency of the low frequency pulse. On the other hand, the switching circuit of plus high frequency high voltage generation unit and minus high frequency high voltage The switching circuit of the unit performs an inverted switching operation, and the rectifier circuit of the plus high frequency high voltage generating unit and the rectifier circuit of the minus high frequency high voltage generating unit are the high frequency high voltage from the self-oscillation boosting circuit. Are rectified in opposite directions to obtain a positive high-frequency high voltage and a negative high-frequency high voltage, respectively, and the synthesis circuit synthesizes the positive high-frequency high voltage and the negative high-frequency high voltage and applies them to the static elimination electrode. Pulse control power supply for static eliminator.   2. The pulse control power supply device for a static eliminator according to claim 1, wherein a capacitor is provided between a secondary side of each high-voltage transformer of each of the plus high frequency high voltage generation unit and the minus high frequency high voltage generation unit and the composite circuit.   Each of the plus high frequency high voltage generation unit and the minus high frequency high voltage generation unit has an ion balance adjustment circuit connected to the secondary coil of the high voltage transformer. The ion balance adjustment circuit is connected to the ground side of the secondary coil. The first diode, the plus side circuit that reaches the ground through the first fixed resistor, and the minus side that goes from the secondary side of the high-voltage transformer to the ground via the second diode and the variable resistor opposite to the first diode. 2. The pulse control power supply device for a static eliminator according to claim 1, wherein a resistance balance can be adjusted by connecting at least one of the resistance of the plus side circuit and the resistance of the minus side circuit while being connected in parallel with the side circuit.

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