JP3768938B2 - High voltage generator circuit for ion generator and high voltage generator circuit for both ion generator and igniter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a high voltage generation circuit for an ion generator and a high voltage generation circuit for both ion generation and ignition (igniter) such as an oil heater.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an igniter using spark discharge using a high voltage generation circuit using a battery as a power source is known as an ignition device for a light core of oil burning equipment (see, for example, Japanese Patent Laid-Open No. 06-341644).
[0003]
An example of this type of igniter high voltage pulse generation circuit is shown in FIG. The high-voltage pulse generation circuit 1 uses a DC power source 2 made of a battery as an operation source, an astable multivibrator MV that oscillates, switching transistors Q3 and Q4 that are switched by the output thereof, and switching of the transistor Q4 And a pulse transformer T that generates a high voltage by operation. Astable multivibrator MV includes transistors Q1 and Q2, resistors R1 to R4, and capacitors C2 and C3. A capacitor C4 is connected in parallel to the primary coil N1 of the pulse transformer T, and ignition electrodes 3 are connected to both ends of the secondary coil N2. A smoothing capacitor C1 is connected in parallel to the DC power source via a switch SW.
[0004]
In the high voltage pulse generation circuit 1, the transistor Q4 is turned on and on according to the oscillation cycle of the multivibrator MV, and the primary current of the pulse transformer T is intermittently connected. An oscillating current is generated in a closed circuit composed of N1. Due to this oscillating current, a high voltage is generated at both ends of the secondary coil N2 of the pulse transformer T, and a spark discharge is generated between the electrodes 3 for ignition.
[0005]
By the way, a high voltage pulse generation circuit for generating ions is also used in an ion generator as an air cleaning device. The negative ions generated by this ion generator relax humans and the positive ions have the effect of sterilizing. If both positive and negative ions are generated simultaneously, the indoor atmosphere is improved. In view of this, it has been proposed to use an igniter high-voltage pulse generation circuit as described above for ion generation and to incorporate an ion generator in an oil combustion device.
[0006]
[Problems to be solved by the invention]
However, when the conventional high voltage pulse generation circuit for an igniter 1 using a battery as a power source as shown in FIG. 11 is used for an ion generator, there are the following problems. The voltage pulse VN2 for the igniter appearing in the secondary coil N2 of the pulse transformer T vibrates to the same extent, for example, as shown in FIGS. 12 and 13, and has a one-side amplitude of 5 to 6 kV and a pulse period of 1.2 msec. It has a waveform. The oscillating voltage of the pulse appearing in the secondary coil N2 attenuates with time according to the dissipation of energy, but in this circuit, it does not attenuate uniformly during the period indicated by the arrow a in the figure, but a voltage of a certain value or more. The pulse lasts and becomes noise during discharge. When ions are generated by such a voltage pulse VN2, the amount of ions varies, and if the peak value of a pulse that lasts for a period exceeds -2kV due to too much current, harmful ozone is likely to be generated. For this reason, it is not preferable to apply the conventional high voltage pulse generation circuit for an igniter as shown in FIG. 11 to the ion generator as it is. In addition, since the operation is performed with a low-voltage battery power source, the switching trigger is easily affected by external noise.
[0007]
In the above description, a high voltage pulse generation circuit using a battery power supply is shown, but there is also a high voltage pulse generation circuit using a 100V commercial AC power supply. In this case, a thyristor is generally used for the switching operation, and since the trigger operation voltage is high, it is relatively less susceptible to external noise. However, when such a high-voltage pulse generation circuit using a commercial AC power supply is applied to an ion generator, if there is a voltage fluctuation of the commercial AC power supply, the amount of ions generated varies accordingly, and the voltage is too high. There is a problem that ozone is easily generated. Further, when the commercial AC power supply is provided with a stabilized power supply circuit, the cost becomes high.
[0008]
In addition, the output voltage of the high voltage pulse generation circuit used in the ion generator needs to be about ± 4 kV or less in order to suppress the generation of ozone, whereas the output voltage of the high voltage pulse generation circuit for the igniter is It is necessary to make it about 10 kV for ignition. Thus, since the output voltage to be used is different between the ion generator and the igniter, it is difficult to use one high voltage pulse generation circuit for both.
[0009]
The present invention solves the above-mentioned problems, and with a simple and inexpensive configuration using a battery power source, generation of ozone can be suppressed for an ion generator, without being affected by noise, and voltage fluctuations. It is an object of the present invention to provide a high voltage generation circuit for an ion generator that can stabilize the amount of ion generation. Further, it is possible to easily obtain a high voltage pulse suitable for ion generation and igniter by switching circuit operation, and to provide an inexpensive high voltage generation circuit that can be used for both ion generation and igniter. With the goal.
[0010]
[Means for Solving the Problems and Effects of the Invention]
In order to achieve the above-described object, the invention of claim 1 is directed to an astable multivibrator, a switching element switched by a pulse output of the astable multivibrator, and a current flowing through the primary coil by the switching element. A pulse transformer which is controlled and outputs a high voltage pulse to the secondary side, and a capacitor connected in parallel to the primary side coil of the pulse transformer, the high voltage pulse obtained on the secondary side of the pulse transformer In the high voltage generation circuit used for the ion generator, the driving power source of the pulse transformer is a direct current power source, and a diode is inserted in series in the primary side coil of the pulse transformer in the forward direction.
[0011]
In the above configuration, the pulse transformer is driven by the pulse output of the astable multivibrator using the battery as the drive source, and the noise component appearing in the primary side coil of the pulse transformer is serially forwarded to the primary side coil of the pulse transformer. Cut off by inserted diode. As a result, the waveform of the high voltage pulse appearing in the secondary coil of the pulse transformer is monotonously attenuated while oscillating positively and negatively, and there is no noise component sustained in the high voltage pulse. For this reason, the variation in the amount of generated ions is eliminated, and the generation of ozone is suppressed. Therefore, this high voltage generation circuit is suitable for an ion generator. In addition, since a stable DC power source using a battery as a driving source is used, the output is stable, the amount of ion generation is stable, and ozone generation is eliminated as compared with the case where a commercial AC power source is used.
[0012]
The invention according to claim 2 is a non-stable multivibrator, a switching element that is switched by a pulse output of the non-stable multivibrator, and a current flowing through the primary coil is controlled by the switching element, and a high voltage is applied to the secondary side. A high voltage generation circuit comprising a pulse transformer for outputting a pulse and a capacitor connected in parallel to a primary coil of the pulse transformer, and using a high voltage pulse obtained on the secondary side of the pulse transformer for an ion generator The driving power source of the pulse transformer is a DC power source, a diode is inserted in a forward direction in series with the primary coil of the pulse transformer, and the pulse output width of the unstable multivibrator is switched to at least two stages. The high voltage voltage output from the pulse transformer when the pulse output width is short is possible. The scan and ion generation dexterity, in which said high voltage pulse output from the pulse transformer also serves to the use and for ion generation, wherein an igniter to igniter when the longer pulse output width.
[0013]
In the above configuration, in addition to obtaining the same effect as that of the first aspect, by switching the pulse output width of the astable multivibrator, the high voltage pulse obtained at the short pulse output width is used for the ion generator. The high voltage pulse obtained with a long pulse output width is used for the igniter. Thereby, the high voltage generation circuit can be used for both the ion generator and the igniter. As a result, a battery type igniter and a stable ion generator can be mounted at low cost on a wick type oil combustor.
[0014]
According to a third aspect of the present invention, there is provided a high voltage generating circuit for both ion generation and igniter according to the second aspect, wherein the astable multivibrator is connected to each other by the outputs of the two transistors from each collector. The base of each transistor is positively fed back through a capacitor, and each base is connected to a power supply line through a resistor that determines a charge / discharge time constant, and the pulse output width of the unstable multivibrator is two-staged. The configuration that enables switching to each other includes a resistor and a switch for switching each of the resistors to a resistor having a different value.
[0015]
In the above configuration, the resistance that determines the charge / discharge time constant of the astable multivibrator can be switched between the one suitable for the ion generator and the one suitable for the igniter simply by operating the changeover switch. Therefore, one high voltage generation circuit can be switched between an ion generator and an igniter with a simple configuration and operation.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a high voltage generation circuit for an ion generator according to an embodiment of the present invention will be described with reference to FIG. The high voltage generating circuit 10 for the ion generator is switched by an unstable multivibrator MV that oscillates with a DC power source 2 composed of a battery as an operating source and the output thereof, as in the circuit of FIG. Switching transistors Q3 and Q4, and a pulse transformer T that generates a high voltage by the switching operation of the transistor Q4. The difference from the circuit shown in FIG. 11 is that the diode D1 is inserted on the positive power supply side of the primary coil N1 of the pulse transformer T so as to be in the forward direction with respect to the power supply.
[0017]
In the astable multivibrator MV, the outputs of the two transistors Q1 and Q2 are positively fed back to the bases of the other transistors through capacitors C2 and C3, with each base determining the charge / discharge time constant. It is connected to the power supply line via resistors R3 and R2. The collectors of the transistors Q1 and Q2 are connected to the positive power supply line via resistors R1 and R4, and the emitters are connected to the negative power supply line.
[0018]
The output of the astable multivibrator MV is taken out to the collector of the transistor Q2 and input to the base of the transistor Q3. The base and collector of the transistor Q3 are connected to the positive power supply line via resistors R5 and R6, respectively, and the emitter is connected to the base of the transistor Q4. The collector of the transistor Q4 is connected to the positive power line via the primary coil N1 of the pulse transformer T, and the emitter is connected to the negative power line. These transistors Q3 and Q4 are switching elements that intermittently connect the primary side of the pulse transformer T. A capacitor C4 is connected in parallel to the diode D1 and the primary coil N1 of the pulse transformer T. An ignition electrode 3 is connected to the secondary coil N2.
[0019]
In the high voltage generation circuit 10 configured as described above, when the switch SW is turned on, the capacitor C1 is charged and the multivibrator MV is activated, and a positive pulse potential having a substantially constant magnitude is applied to the collector of the transistor Q2. Appear periodically. The transistors Q3 and Q4 are cut off while the pulse potential is off or low, and the transistors Q3 and Q4 are conductive while the pulse potential is high. In the primary coil N1 of the pulse transformer T, a current that rises with the conduction of the transistor Q4 and falls with the cutoff of the transistor Q4 flows in the same cycle as the oscillation frequency of the multivibrator MV. Further, electric charge is accumulated in the capacitor C4 when the transistor Q4 is turned on. As described above, the primary current of the pulse transformer T is intermittently interrupted by the multivibrator MV via the transistors Q3 and Q4. When the current of the primary coil flowing through the transistor Q4 is cut off by the cutoff of the transistor Q4, the capacitor C4 and the diode are caused by the charge accumulated in the capacitor C4 and the back electromotive force of the primary coil N1. A large current flows through the closed circuit composed of D1 and the primary coil N1, and this current generates a high voltage at both ends of the primary coil N1, and therefore, the winding ratio of the coil is present at both ends of the secondary coil N2. According to (for example, N1: N2 = 1: 100), a higher voltage is output. The current flowing through the primary coil N1 of the pulse transformer T is only in one direction because the diode D1 exists, but the current in the secondary coil N2 is a current that vibrates positively and negatively due to the counter electromotive force generated in the coil. It becomes. Positive and negative ions can be generated by this positive and negative current (discharge current).
[0020]
2 and 3 show the voltage pulse VN2 for the igniter appearing in the secondary coil N2 of the pulse transformer T. FIG. The voltage pulse VN2 vibrates in the same degree, positive and negative, and has a waveform with a one-side amplitude of about 4 kV and a pulse period of 1.2 msec. In the pulse waveform of this oscillating voltage, no continuous noise component as seen in FIG. 12 or FIG. 13 due to the above-described conventional circuit is seen at all, and as shown by the arrow b, it is a clean decay that monotonously attenuates with time. It is a shaped waveform. In this way, the harmful voltage component that does not attenuate can be removed because the diode D1 is inserted into the primary coil N1 of the pulse transformer T. When this circuit is applied to an ion generator, it is possible to output a voltage pulse VN2 having a shaped waveform and a longer pulse period. Is done.
[0021]
FIG. 4 shows a high voltage generation circuit 11 for an ion generator according to another embodiment. The high voltage generation circuit 11 of this embodiment is different from the embodiment shown in FIG. 1 in that the diode D1 is inserted on the negative power supply line side of the primary coil N1 of the pulse transformer T. Even in this configuration, the same effect as the previous embodiment can be obtained.
[0022]
FIG. 5 shows a high voltage generation circuit 12 according to still another embodiment. The high voltage generation circuit 12 can be used for both an ion generator and an igniter. The high voltage generation circuit 12 is configured such that the pulse output width of the astable multivibrator MV (hereinafter simply referred to as pulse output width) can be switched to at least two stages in addition to the configuration of the embodiment of FIG. It is. The high voltage pulse output to the secondary coil N2 of the pulse transformer T when the pulse output width is short is used for the ion generator, and the high voltage pulse output to the secondary coil N2 of the pulse transformer T when the pulse output width is long. The voltage pulse is used for the igniter.
[0023]
As a configuration for switching the pulse output width in two stages, the resistance values of the resistors R2 and R3 that determine the charge / discharge time constant in the embodiment of FIG. 1 can be switched. In the present embodiment shown in FIG. 5, resistors 21 and 31 are inserted in series into the resistors R2 and R3, and short-circuiting open / close switches SW1 and SW2 are connected in parallel to the resistors 21 and 31, respectively. Yes. By switching the switches SW1 and SW2, switching between the igniter and the ion generation can be performed.
[0024]
Here, when the switches SW1 and SW2 shown in FIG. 5 are in a solid line state, one resistor R21 is not short-circuited by the switch SW1, so that the time constant of the resistors R2 and R21 and the capacitor C2 becomes large (the other resistor 31). Is short-circuited by the switch SW2, so that the time constant of the resistor R3 and the capacitor C3 is small. Therefore, the output high period of the astable multivibrator MV is relatively long within one period (with respect to one period). The duty ratio which is the ON time ratio changes), the pulse width for driving the pulse transformer T becomes long, the current amount is large, and the igniter is used. The output waveform of the unstable multivibrator MV at this time is shown in FIG. On the other hand, when the switches SW1 and SW2 are in the broken line state, the above is reversed and the switch is used for the ion generator. The output waveform of the unstable multivibrator MV at this time is shown in FIG.
[0025]
As described above, the charge and discharge time constants related to the capacitors C2 and C3 are switched by the switches SW1 and SW2, so that the voltage and the pulse period of the high voltage pulse generated in the secondary coil N2 of the pulse transformer T will be described below. Are optimized for igniters and ion generators. FIGS. 5 (a) and 5 (b) show temporal changes in the collector voltage VCQ2 (output of the multivibrator MV) of the transistor Q2, and H1, L1 and T1 (T1 = H1 + L1) are respectively off of the transistor Q2 of the igniter circuit. H2, L2, and T2 (T2 = H2 + L2) are the off time, the on time, and the multivibrator MV, respectively, of the transistor Q2 of the ion generator circuit. Since H1 and H2 are the conduction time of the transistors Q3 and Q4, they are the charge accumulation time in the capacitor C4. Further, the voltage generated in the secondary coil N2 of the pulse transformer T increases or decreases depending on the amount of charge accumulated in the capacitor C4. Therefore, the level of the voltage generated in the secondary coil N2 of the pulse transformer T can be switched by switching the off times H1 and H2 of the transistor Q2. Further, according to the general theory of the multivibrator MV, H1≈0.7 · C2 · (R2 + R21) and H2≈0.7 · C2 · R2, and therefore, H1> H2, so that the igniter circuit The high pulse voltage can be reduced to a low pulse voltage in the ion generator circuit.
[0026]
The adjustment of the pulse period can be adjusted by the conduction times L1 and L2 of the transistor Q2, in other words, the off time of the transistor Q1, according to the general theory of the multivibrator MV, and L1≈0.7 · C3 · R3. Since L2≈0.7 · C3 · (R3 + R31), and L1 <L2 and T1 <T2, it is possible to set a short pulse period in the igniter circuit and a long pulse period in the ion generator circuit.
[0027]
As shown in FIGS. 7 and 8, the above-described pulse voltage switching is performed as a result of changing the off time of the transistor Q2 from H1 = 400 μs to H2 = 100 μs (see the waveform of the collector voltage VCQ2 in the lower stage in the figure). It can be seen that the pulse voltage is lowered from the pulse voltage 4 kV for the igniter to the pulse voltage 2 kV for the ion generator (see the waveform of the secondary coil pulse voltage VN2 in the upper stage in the figure). Further, the pulse cycle is switched, and the voltage pulse obtained for ion generation has a positive and negative oscillation waveform that is attenuated cleanly with a pulse voltage of 2 kV and a pulse cycle of 3.5 msec, as shown in FIGS.
[0028]
The present invention is not limited to the configuration of the above embodiment, and various modifications can be made. For example, the configuration for switching the resistance values of the resistors R2 and R3 is not limited to the configuration of whether or not the resistors R21 and R31 shown in FIG. 5 are inserted in series. For example, separate resistors are connected in parallel. The configuration may be such that whether or not to insert is switched by a switch circuit. Further, a photocoupler may be used in place of the transistor Q3 in order to electrically insulate between the transistor Q3 and the transistor Q4 which are switching elements. Furthermore, the high voltage generation circuit may be automatically switched to an ion generator after an ignition operation as an igniter of a wick type oil burning device.
[Brief description of the drawings]
FIG. 1 is a circuit diagram of a high voltage generation circuit according to an embodiment of the present invention.
FIG. 2 is a pulse voltage waveform diagram generated by the circuit.
FIG. 3 is a pulse voltage waveform diagram showing an enlarged time axis of the pulse voltage waveform.
FIG. 4 is a circuit diagram of a high voltage generation circuit according to another embodiment of the present invention.
FIG. 5 is a circuit diagram of a high voltage generation circuit that is used as a circuit for both ion generation and igniter according to still another embodiment of the present invention.
6A is an output waveform diagram of an unstable multivibrator when used for an igniter, and FIG. 6B is an output waveform diagram of an unstable multivibrator when used for an ion generator.
FIG. 7 is an output waveform diagram showing a relationship between a pulse voltage waveform when used for an igniter and an output waveform of an astable multivibrator.
FIG. 8 is an output waveform diagram showing a relationship between a pulse voltage waveform when used for an ion generator and an output waveform of an astable multivibrator.
FIG. 9 is a pulse voltage waveform diagram generated when ions are generated.
FIG. 10 is a pulse voltage waveform diagram in which the time axis of the waveform is enlarged.
FIG. 11 is a circuit diagram of a conventional high voltage generating circuit for an igniter.
FIG. 12 is a pulse voltage waveform diagram generated by the circuit.
FIG. 13 is a pulse voltage waveform diagram in which the time axis of the waveform is enlarged.
[Explanation of symbols]
10, 11, 12 High voltage generation circuit 2 DC power supply 3 Electrode MV Astable multivibrator C2, C3 Capacitors R2, R3, R21, R31 Resistors Q1, Q2 Transistors Q3, Q4 Switching element T Pulse transformer N1 Primary coil N2 Secondary Coil D1 Diode SW1, SW2 selector switch

Claims (3)

An astable multivibrator, a switching element that is switched by a pulse output of the astable multivibrator, a pulse transformer that controls a current flowing through the primary coil by the switching element and outputs a high voltage pulse to the secondary side; A high-voltage generating circuit including a capacitor connected in parallel to a primary coil of the pulse transformer and using a high-voltage pulse obtained on the secondary side of the pulse transformer for an ion generator,
The driving power source of the pulse transformer is a DC power source,
A high voltage generation circuit for an ion generator, wherein a diode is inserted in series in a forward direction with a primary coil of the pulse transformer. An astable multivibrator, a switching element that is switched by a pulse output of the astable multivibrator, a pulse transformer that controls a current flowing through the primary coil by the switching element and outputs a high voltage pulse to the secondary side; A high-voltage generation circuit including a capacitor connected in parallel to a primary coil of the pulse transformer, and using a high-voltage pulse obtained on the secondary side of the pulse transformer for an ion generator,
The driving power source of the pulse transformer is a DC power source,
A diode is inserted in the forward direction in series with the primary coil of the pulse transformer;
The pulse output width of the astable multivibrator can be switched to at least two stages, and a high voltage pulse output from the pulse transformer is used for the ion generator when the pulse output width is short, and when the pulse output width is long A high voltage generation circuit for both ion generation and igniter, wherein the high voltage pulse output from the pulse transformer is used for an igniter. The astable multivibrator is configured such that the outputs of two transistors are positively fed back to each other via a capacitor as a result of the respective collectors, and each base supplies power via a resistor that determines a charge / discharge time constant. Is connected to the line,
The configuration enabling switching of the pulse output width of the astable multivibrator in two stages includes a resistor and a switch for switching each of the resistors to a resistor having a different value. High voltage generator for both ion generation and igniter.

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