JP4338105B1 - High voltage generation circuit - Google Patents

Abstract

A high voltage generation circuit is provided that uses a relatively inexpensive part to reduce the current consumption and the risk of discharge, and that can output a high voltage with a positive and negative balance without lowering the output voltage.
A positive-side high voltage generator 10P having a first voltage doubler rectifier circuit 9P that outputs a positive voltage pulse and a negative high voltage generator 9N having a second voltage doubler rectifier circuit 9N that generates a negative voltage pulse. Voltage generator 10N, and a high-voltage generator circuit that adds and outputs the output voltages of positive and negative high-voltage generators 10P and 10N, and a final stage Zener in voltage doubler rectifier circuits 9P and 9N The connection points 21P and 21N between the diode and the capacitor are directly connected to each other and connected to the output terminal 23 through the current limiting resistor 8.
[Selection] Figure 1

Description

  The present invention relates to a high voltage generation circuit for generating a high voltage applied to, for example, a discharge electrode of an ionizer.

FIG. 3 is a circuit configuration diagram of an ionizer described in Patent Document 1.
In FIG. 3, the positive control signal output from the control circuit 1 is input to the positive oscillation circuit 2P via a switch 3P that is turned on by a main power supply (not shown). Further, the negative control signal output from the control circuit 1 is input to the negative oscillation circuit 2N as it is.

A high-frequency AC voltage is output from the positive-side oscillation circuit 2P, and this AC voltage is boosted and rectified by the voltage doubler rectifier circuit 5P via the transformer 4P in the positive-side high-voltage generator 6P. is output from the positive side terminal 21P to the connection point 22 as) shows such a positive voltage pulse (a + P ₁ amplitude). In the voltage doubler rectifier circuit 5P, C1 to C4 are capacitors, D1 to D4 are diodes, and ZD1 to ZD4 are zener diodes.

  On the other hand, a high-frequency AC voltage is output from the negative-side oscillation circuit 2N, and this AC voltage is boosted and rectified by the voltage doubler rectifier circuit 5N via the transformer 4N in the negative-side high voltage generator 6N, and the negative side Output from terminal 21N. Further, this rectified voltage is output to the connection point 22 through the resistor 7 as a negative DC bias voltage (with an amplitude of −N) as shown in FIG. In the voltage doubler rectifier circuit 5N, C5 to C8 are capacitors, and D5 to D8 are diodes.

Therefore, as shown in FIG. 4C, the voltage at the connection point 22 is an AC pulse voltage obtained by superimposing the negative DC bias voltage shown in FIG. 4B on the positive voltage pulse shown in FIG. The positive-side amplitude of this AC pulse voltage is + P, and the negative-side amplitude is -N, and P = P ₁ -N.
By applying the AC pulse voltage shown in FIG. 4C to the discharge electrode (not shown) from the output terminal 23 via the current limiting resistor 8 shown in FIG. 3, a corona discharge is generated between the counter electrode and the counter electrode. Thus, the air around the discharge electrode is ionized to generate positive and negative ions.

  In the above prior art, for example, by making the oscillation frequency of the positive oscillation circuit 2P variable, the frequency of the AC pulse voltage shown in FIG. 4C can be changed, and the negative frequency shown in FIG. If the magnitude of the DC bias voltage is changed, the amplitude of the AC pulse voltage shown in FIG. 4C can be changed.

Japanese Patent No. 4111348 ([0013] to [0026], FIG. 1, FIG. 2, etc.)

However, in the prior art shown in FIG. 3, a high breakdown voltage component must be used as the resistor 7 to which a negative high voltage is applied, and there is a concern that the cost may increase.
In addition, since the potential difference between the positive terminal 21P and the negative terminal 21N is a maximum value of | P ₁ + N |, which is a maximum value, there is a possibility of discharging between both terminals 21P and 21N.
Furthermore, since the current due to the DC bias voltage of FIG. 4B always flows through the resistor 7, the power consumption, that is, the loss due to the resistor 7 increases, and the voltage output from the output terminal 23 decreases accordingly. There was a problem such as.

  Accordingly, the problem to be solved by the present invention is that it can be configured by using relatively inexpensive parts, and it is possible to output a high voltage with good balance between positive and negative without reducing the risk of discharge and the like and without decreasing the output voltage. The object is to provide a voltage generation circuit.

In order to solve the above-mentioned problem, the invention described in claim 1 is directed to a positive high-voltage generator having a first voltage doubler rectifier circuit that receives an AC voltage and outputs a positive voltage pulse, and an AC voltage is input. And a negative high voltage generator having a second voltage doubler rectifier circuit for generating a negative voltage pulse, and adding the output voltages of the positive and negative high voltage generators to output the high voltage In the generator circuit,
The first and second voltage doubler rectifier circuits connect a series circuit formed by connecting a capacitor, a Zener diode, and a diode between the input terminals of the AC voltage, and at both ends of the series circuit of the Zener diode and the diode, A series circuit composed of a capacitor, a Zener diode, and a diode is connected in sequence, and the Zener diode and the diode in each series circuit are connected in the opposite direction, and the capacitors in each series circuit are not directly connected to each other. Is configured by placing each capacitor as
A connection point between the Zener diode and the capacitor in the series circuit at the final stage in the first voltage doubler rectifier circuit, and a connection point between the Zener diode and the capacitor in the series circuit at the final stage in the second voltage doubler rectifier circuit. Are connected directly to the output terminal via a current limiting resistor.

According to the second aspect of the present invention, a positive high voltage generator having a first voltage doubler rectifier circuit that receives an AC voltage and outputs a positive voltage pulse, and generates a negative voltage pulse when the AC voltage is input. A high-voltage generation circuit including a negative high-voltage generation unit including a second voltage doubler rectifier circuit, and adding and outputting the output voltages of the positive and negative high-voltage generation units.
In the first and second voltage doubler rectifier circuits, a series circuit formed by connecting a capacitor, a Zener diode, a resistor, and a diode is connected between the input terminals of the AC voltage, and the series circuit of the Zener diode, the resistor, and the diode is connected. A series circuit formed by connecting a capacitor, a Zener diode, a resistor, and a diode is sequentially connected to both ends of the capacitor, and the Zener diode and the diode in each series circuit are connected in the opposite direction, and Each capacitor is arranged so that the capacitors are not directly connected,
A connection point between the Zener diode and the capacitor in the series circuit at the final stage in the first voltage doubler rectifier circuit, and a connection point between the Zener diode and the capacitor in the series circuit at the final stage in the second voltage doubler rectifier circuit. Are connected directly to the output terminal via a current limiting resistor.

According to the present invention, it is possible to reduce the cost by eliminating the high withstand voltage resistance on the output side, and since the current does not always flow to the negative side high voltage generation unit in terms of operation principle, Current and loss can be reduced.
Furthermore, the circuit configurations of the positive and negative high voltage generators are substantially the same, and the potential difference between the output terminals of these high voltage generators is made smaller than in the prior art to reduce the risk of discharge, A high voltage generation circuit in which positive and negative output voltages are balanced can be realized.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a circuit configuration diagram showing an embodiment of the invention according to claim 1, and the following description will mainly focus on differences from FIG.
In FIG. 1, a positive control signal output from the control circuit 1 is input to the positive oscillation circuit 2P via a switch 3P that is turned on by a main power supply (not shown), and is output from the control circuit 1. The negative control signal is input to the negative oscillation circuit 2N via the switch 3N.

A high-frequency AC voltage is output from the positive-side oscillation circuit 2P, and this AC voltage is boosted and rectified by the first voltage doubler rectifier circuit 9P via the transformer 4P in the positive-side high voltage generator 10P. is output from the positive side terminal 21P to the connection point 22 as 2 (a) to indicate such a positive voltage pulse (and the + P ₁ amplitude). The voltage doubler rectifier circuit 9P has the same configuration as the voltage doubler rectifier circuit 5P in FIG. 3, C1 to C4 are capacitors, D1 to D4 are diodes, and ZD1 to ZD4 are zener diodes.

  The configuration of the voltage doubler rectifier circuit 9P will be described in detail. A capacitor C1, a Zener diode ZD1, and a diode D1 are connected in series to both ends (between AC voltage input terminals) of the secondary winding of the transformer 4P. The Zener diode ZD1 and the diode A capacitor C2, a Zener diode ZD2, and a diode D2 are connected in series to both ends of the series circuit with D1, and the series circuit of the capacitor C3, the Zener diode ZD3, and the diode D3, and the capacitor C4, the Zener diode ZD4, and the diode D4 are similarly connected. A series circuit is connected. A connection point (the anode of the Zener diode ZD4) between the final stage capacitor C4 and the Zener diode ZD4 is connected to the positive terminal 21P. Zener diode ZD1 and diode D1, ZD2 and D2, ZD3 and D3, and ZD4 and D4 are connected in opposite directions, respectively.

A high-frequency AC voltage is also output from the negative-side oscillation circuit 2N, and this AC voltage is boosted and rectified by the second voltage doubler rectifier circuit 9N via the transformer 4N in the negative-side high voltage generator 10N. 2B, a negative voltage pulse (with an amplitude of −N ₁ and | P ₁ | = | N ₁ |) is output from the negative terminal 21N to the connection point 22 as shown in FIG.
The voltage doubler rectifier circuit 9N has substantially the same configuration as the positive voltage doubler rectifier circuit 9P except for the zener diode and the polarity of the diode, C5 to C8 are capacitors, D5 to D8 are diodes, and ZD5 to ZD8 are A Zener diode is shown, and a connection point (a cathode of the Zener diode ZD8) between the capacitor C8 and the Zener diode ZD8 in the final stage is connected to the negative terminal 21N.
In this voltage doubler rectifier circuit 9N, a Zener diode ZD5 and a diode D5, ZD6 and D6, ZD7 and D7, and ZD8 and D8 are connected in opposite directions.

  The positive voltage pulse in FIG. 2A and the negative voltage pulse in FIG. 2B are added at the connection point 22 to generate an AC pulse voltage as shown in FIG. This AC pulse voltage is applied to the discharge electrode (not shown) from the output terminal 23 via the current limiting resistor 8 to cause corona discharge between the counter electrode and ionize the air around the discharge electrode, It generates positive and negative ions.

In the present embodiment, since there is no resistor 7 that requires a high breakdown voltage as shown in FIG. 3 on the output side of the negative high voltage generator 10N, the part cost can be reduced accordingly.
In addition, since no current always flows through the negative high voltage generator 10N, it is possible to reduce current consumption and reduce loss and improve efficiency.
Further, since the potential difference between the positive terminal 21P and the negative terminal 21N in FIG. 1 is | P ₁ | (= | N ₁ |) at the maximum, both terminals 21P, 21P, The potential difference between 21N can be reduced to reduce the risk of discharge.

  Here, Tables 1 and 2 below show the positive side high voltage generation unit and the negative side high voltage corresponding to the input voltage (DC power supply voltage of the control circuit 1) for the present embodiment of FIG. 1 and the prior art of FIG. The output voltage maximum value and peak-to-peak value of the voltage generator, and the peak-to-peak value ratio based on the prior art are shown. “Frequency” in Tables 1 and 2 is the output frequency (oscillation frequency) of the oscillation circuits 2P and 2N, which are equal to each other.

In Tables 1 and 2, according to the present embodiment, the positive and negative output voltage maximum values of the positive high-voltage generator 10P and the negative high-voltage generator 10N hardly change even when the oscillation frequency is changed. The change in the output voltage does not appear as large as the voltage change rate.
On the other hand, in the prior art, the positive high voltage generator 6P outputs a positive voltage pulse and the negative high voltage generator 6N outputs a negative DC bias voltage. When the oscillation frequency is changed, the input voltage However, the maximum positive and negative output voltage values vary, and the maximum positive output voltage value is significantly lower than that of the present embodiment. Furthermore, as is clear from the peak-to-peak value ratio based on the prior art, in the present embodiment, it is possible to output a larger peak-peak value than the prior art.

  Tables 3 and 4 show the positive side high voltage generator and the negative side high voltage generator according to the input voltage (DC power supply voltage of the control circuit 1) for the present embodiment of FIG. 1 and the prior art of FIG. The ratio of the output current and the average current, and the average current based on the prior art is shown. “Frequency” in Tables 3 and 4 is the output frequency (oscillation frequency) of the oscillation circuits 2P and 2N as described above. Furthermore, “Pog” indicates the output current of the positive high voltage generator, and “Neg” indicates the output current of the negative high voltage generator.

  In Tables 3 and 4, since current always flows through the negative high voltage generator 6N in the prior art, the average current increases. In other words, according to this embodiment, the current consumption is greatly reduced. I understand.

  Although not shown in the drawings, as an embodiment of the invention according to claim 2, between the Zener diode ZD1 and the diode D1 in the first and second voltage doubler rectifier circuits 9P and 9N, and similarly between ZD2 and D2 Between ZD3 and D3, between ZD4 and D4, between ZD5 and D5, between ZD6 and D6, between ZD7 and D7, and between ZD8 and D8, respectively. However, an equivalent effect can be obtained.

It is a circuit block diagram which shows embodiment of this invention. It is a figure which shows the voltage waveform of the principal part in FIG. It is a circuit block diagram which shows a prior art. It is a figure which shows the voltage waveform of the principal part in FIG.

Explanation of symbols

1: Control circuit 2P, 2N: Oscillation circuit
3P, 3N: Switch 4P, 4N: Transformer 8: Current limiting resistor 9P, 9N: Voltage doubler rectifier circuit 10P, 10N: High voltage generator 21P: Positive side terminal 21N: Negative side terminal 22: Connection point 23: Output terminal C1 C8: Capacitor D1-D8: Diode ZD1-ZD8: Zener diode

Claims (2)

A positive high voltage generator having a first voltage doubler rectifier circuit that outputs a positive voltage pulse when an AC voltage is input, and a second voltage doubler rectifier circuit that generates a negative voltage pulse when an AC voltage is input A high-voltage generating circuit having a negative-side high-voltage generating unit, and adding and outputting the output voltages of the positive-side and negative-side high-voltage generating units,
The first and second voltage doubler rectifier circuits connect a series circuit formed by connecting a capacitor, a Zener diode, and a diode between the input terminals of the AC voltage, and at both ends of the series circuit of the Zener diode and the diode, A series circuit composed of a capacitor, a Zener diode, and a diode is connected in sequence, and the Zener diode and the diode in each series circuit are connected in the opposite direction, and the capacitors in each series circuit are not directly connected to each other. Is configured by placing each capacitor as
A connection point between the Zener diode and the capacitor in the series circuit at the final stage in the first voltage doubler rectifier circuit, and a connection point between the Zener diode and the capacitor in the series circuit at the final stage in the second voltage doubler rectifier circuit. Are connected directly to the output terminal via a current limiting resistor. A positive high voltage generator having a first voltage doubler rectifier circuit that outputs a positive voltage pulse when an AC voltage is input, and a second voltage doubler rectifier circuit that generates a negative voltage pulse when an AC voltage is input A high-voltage generating circuit having a negative-side high-voltage generating unit, and adding and outputting the output voltages of the positive-side and negative-side high-voltage generating units,
In the first and second voltage doubler rectifier circuits, a series circuit formed by connecting a capacitor, a Zener diode, a resistor, and a diode is connected between the input terminals of the AC voltage, and the series circuit of the Zener diode, the resistor, and the diode is connected. A series circuit formed by connecting a capacitor, a Zener diode, a resistor, and a diode is sequentially connected to both ends of the capacitor, and the Zener diode and the diode in each series circuit are connected in the opposite direction, and Each capacitor is arranged so that the capacitors are not directly connected,
A connection point between the Zener diode and the capacitor in the series circuit at the final stage in the first voltage doubler rectifier circuit, and a connection point between the Zener diode and the capacitor in the series circuit at the final stage in the second voltage doubler rectifier circuit. Are connected directly to the output terminal via a current limiting resistor.

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