JPH0982477A - Pulse generation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pulse generating device which eliminates defect involved in the use of a semiconductor switch and can generate a stable pulse voltage despite dispersion in the core material of a magnet switch to a certain degree. SOLUTION: A capacitor 1 and the primary winding N1 of a pulse transformer 4 constitute a closed circuitry of a magnet switch 3, and it is saturated with the voltage of the capacitor 1 and will have a smaller inductance value, and the electric charges on the capacitor 1 are discharged with the closed circuitry when the device is turned on, and a high pulse voltage is impressed between the two ends of a high pressure discharge lamp 5 connected with the secondary winding N2 of the pulse transformer 4. The core material of the magnetic switch 3 is of amorphous or Faimet type in which the loss in the major loop at a frequency of 10kHz is less than 1000mW/cc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulse generator.

[0002]

2. Description of the Related Art Generally, in a high pressure discharge lamp lighting device used for a high pressure discharge lamp such as a mercury lamp, a metal halide lamp, a high pressure sodium lamp, a high voltage is required as a starting voltage, and a few kV generated by an igniter is required. Is applied to both ends of the high-pressure discharge lamp to start it.

Particularly, in order to instantly re-light a stable high-pressure discharge lamp immediately after it is turned off, a very high voltage of about several tens of kV is generally required, although it depends on the type of high-pressure discharge lamp. Become. As such a high pressure discharge lamp lighting device, there is one shown in Japanese Patent Application Laid-Open No. 2-77730 (shown in FIG. 8). In this high-pressure discharge lamp lighting device, when the commercial AC power supply 10 is turned on, the high-pressure discharge lamp 5 is not started, so that the voltage of the commercial AC power supply 10 is generated between the points a and b. In addition, since no lamp current flows, no voltage is generated on the secondary side of the lamp current detecting current transformer T _{4 that} causes the lamp current to flow on the primary side, and accordingly, the control circuit 13 determines that the lamp is not lit, An ON signal for turning on the 3-terminal AC control element Q ₁ for a predetermined time is applied to the gate of the 3-terminal AC control element Q ₁ at a predetermined phase of the commercial AC power supply 10. The control circuit 13 is supplied with power via the power transformer T ₃ .

Then, an oscillating current flows in the closed loop of the commercial AC power supply 10, the primary winding of the transformer T ₁ , the inductor 14, the capacitor 15, and the three-terminal AC control element Q ₁ . At that time, the voltage generated in the primary winding of the transformer T ₁ is boosted to a voltage of several kV by the secondary winding, and the boosted voltage of several kV is applied to the commercial AC power supply 10 between the points a and b. The superimposed voltage appears.

[0005] is charged charges in the capacitor 16 by the voltage, and reaches the voltage across two on-voltage terminal AC control element Q ₂ of the capacitor 16, two-terminal AC control elements Q
₂ , the oscillating current flows in the closed loop of the capacitor 16, the inductor 17, the primary winding of the transformer T ₂ , the two-terminal AC control element Q ₂ and the capacitor 18. At that time, the number voltage generated in the secondary winding of the transformer T ₂ are in trans T ₂ 1
The voltage is boosted to about 0 kV, a voltage in which the boosted voltage of several tens of kV is superimposed is generated at both ends of the high pressure discharge lamp 5, and the high pressure discharge lamp 5 is started and lit.

By the way, some high-pressure discharge lamps 5 require a high voltage having a very high peak value and a pulse width for instantaneous restart, but in the above conventional example, the withstand voltage of the capacitor 16 is limited. Therefore, there is a limit in increasing the ON voltage of the two-terminal AC control element Q ₂ . Therefore, the step-up ratio of the transformer T ₂ must be increased. For example, if the inductance of the primary winding of the transformer T ₂ remains the same, the shape of the transformer T ₂ becomes large, and conversely, if the shape is not made large. There is a problem that the inductance of the primary winding becomes small. Further, in order to secure the pulse width τ, it is necessary to increase the capacity of the capacitor 16, but the inductance value of the primary winding of the transformer T ₂ becomes relatively small, and at the same time, the capacity of the capacitor 16 becomes relatively large. When it becomes large, there is a problem that the oscillating current when the 2-terminal AC control element Q ₂ is turned on becomes large and exceeds the rated current of the 2-terminal AC control element Q _{2 which is} a semiconductor switching element.

As described above, the above-mentioned conventional example has various problems. Therefore, the magnetic switch 3 as shown in FIG.
It has been proposed to use a circuit using. This figure 9
In the circuit of, capacitor 1, load 19 and magnetic switch 3
And are connected in series to form a closed circuit, and the charging power source 20 is connected in parallel with the capacitor 1. Here, when the magnetic switch 3 is saturated, the charge accumulated in the capacitor 1 is discharged by the charging power supply 13, and a large current flows through the load 19.

Therefore, when the inductance of the magnetic switch 3 at the time of saturation is large, the cycle of the current I flowing through the magnetic switch 3 becomes long, and the current reducing action works, so that the core of the magnetic switch 3 is made larger, or Attempts have been made to reduce the inductance at the time of saturation, for example, by winding the coil once. Here, when the primary winding of the pulse transformer is connected in series with the capacitor 1 and the magnetic switch 3 as the load 19 and the high pressure discharge lamp is connected to the secondary winding of the pulse transformer, the high pressure discharge lamp can be started. It is necessary to apply a required energy, that is, a pulse voltage having a peak value required for dielectric breakdown of gas in the high-pressure discharge lamp and a pulse width for ensuring startability of the high-pressure discharge lamp.

Therefore, in the conventional magnetic switch 3, there is a possibility that this energy cannot be secured, so it is necessary to increase the discharge current, but there is a problem of noise due to discharge and a problem of current withstanding capacity of the capacitor used. . on the other hand,
A magnetic switch having an EE type core shape as shown in FIG. 10 has been conventionally used. However, in such an EE type core shape, since the winding is wound in a laminated winding, the toroidal core is further improved. Since the magnetic path 12 is shorter than when wound, there is a problem that the inductance at the time of saturation becomes large.

[0010]

Generally, the maximum value V _max of the starting voltage of a high pressure discharge lamp such as an HID lamp is 1.2 which is the minimum value V _min of the starting voltage in consideration of the life of the high pressure discharge lamp.
It is suppressed within 2 times, that is, the fluctuation of the starting voltage is ± 1
It is kept within 0%. Therefore, it is necessary to suppress the variation in the starting voltage within ± 10%. Therefore, it is necessary to reduce variations in the characteristics of the parts, particularly in magnetic devices such as magnetic switches and the like. However, the variation of the loss of the magnetic material is about 30%, which causes the variation of the starting voltage. Further, since the pulse generator for obtaining the starting voltage of the discharge lamp lighting device is arranged around the discharge lamp and the maximum operating temperature is about 120 ° C, the temperature characteristics of the electromagnetic device such as the magnetic switch are stable. You will also need to

The load of the pulse generator is provided with a transformer or a pulse transformer before the high-pressure discharge lamp. To prevent noise from these transformers, the human audible frequency range is 2 kHz or less. Therefore, the drive frequency of the pulse voltage generator must be 10 kHz or higher. Further, in the magnetic switch having the EE type core shape, if the magnetic flux of the magnetic switch 3 is made constant and the inductance at the time of saturation is reduced, the number of windings is reduced to increase the cross-sectional area of the core, or It is necessary to lengthen the magnetic path of the core, which causes a problem that the magnetic switch becomes large.

The present invention has been made in view of the above problems, and an object of the present invention is to solve the drawbacks of using a semiconductor switch and to disperse the core material of the magnetic switch. (EN) It is possible to provide a pulse generator capable of generating a stable pulse voltage even if there is some. The object of the invention of claim 3 is to claim 1
In addition to the object of the invention of claim 2, the inductance at the saturation of the magnetic switch can be reduced without increasing the size,
It is to provide a pulse generator capable of securing sufficient energy.

The object of the invention of claim 4 is to provide a low noise pulse generator in addition to the objects of the inventions of claims 1 to 3. An object of the invention of claim 5 is to provide a pulse generator for realizing a starting device of a high pressure discharge lamp in addition to the objects of the inventions of claims 1 to 4. The object of the inventions of claims 6 and 7 is that, in addition to the object of the invention of claim 5, there is provided a pulse generator capable of obtaining the energy necessary for surely starting the high pressure discharge lamp. To provide.

The object of the inventions of claims 8 and 9 is that, in addition to the objects of the inventions of claims 6 and 7, it is possible to suppress the withstand current of the capacitor for charging and discharging and to discharge the capacitor. It is an object of the present invention to provide a pulse generator capable of suppressing the generation of accompanying noise.

[0015]

In order to achieve the above object, according to the invention of claim 1, a closed circuit is constituted by a capacitor, a primary winding of a pulse transformer and a coil of a magnetic switch,
In a pulse generator that discharges the electric charge of a capacitor in a closed circuit when a magnetic switch is saturated to generate a high-voltage pulse in a secondary winding of a pulse transformer, the loss of a major loop at a frequency of 10 kHz is used as a core material of the magnetic switch. It is characterized by using a core material of 1000 mW / cc or less.

The invention of claim 2 is characterized in that, in the invention of claim 1, amorphous or fine met is used as a material of the core of the magnetic switch. A third aspect of the invention is characterized in that, in the first and second aspects of the invention, the core of the magnetic switch is formed of a toroidal core, and the coil is wound around the core in a single turn.

The invention of claim 4 is characterized in that, in the inventions of claims 1 to 3, the frequency of capacitor discharge by the closed circuit is 2 kHz or more. A fifth aspect of the present invention is characterized in that, in the first to fourth aspects, the pulse voltage generated in the secondary winding of the pulse transformer is applied to the high pressure discharge lamp. In the invention of claim 6, in the invention of claim 5, the high-voltage discharge lamp is supplied with lighting power by a lighting means, and a secondary output voltage of the lighting means is a pulse voltage generated in a secondary winding of a pulse transformer. Is applied, the frequency of the charging means for charging the capacitor is made higher than the frequency of the power source of the lighting means, and the discharging frequency of the capacitor in the closed circuit is higher than the charging frequency. When the saturation of the magnetic switch is high, a pulse voltage having a high pulse width and a sufficient pulse width for ensuring the startability of the high pressure discharge lamp and a peak value sufficient for dielectric breakdown of the gas in the high pressure discharge lamp is obtained. It is characterized by setting the inductance.

According to a seventh aspect of the present invention, in the fifth aspect of the present invention, the high-pressure discharge lamp is supplied with lighting power by the lighting means, and the secondary output voltage of the lighting means is generated in the secondary winding of the pulse transformer. A voltage superposed with a pulse voltage is applied, the frequency of the charging means for charging the capacitor is made higher than the frequency of the power source of the lighting means, and the discharging frequency of the capacitor in the closed circuit is charged. The frequency is set higher than the frequency, and the air-core coil is inserted between the magnetic switch and the primary winding of the pulse transformer, and the sum of the inductance when the magnetic switch is saturated and the inductance of the air-core coil is set to the high voltage discharge. A value that can obtain a pulse voltage having a pulse width sufficient to secure the startability of the electric lamp and a peak value sufficient to cause the dielectric breakdown of the gas in the high-pressure discharge lamp. Characterized in that the set.

According to the invention of claim 8, in the invention of claim 6
And the inductance of the magnetic switch at saturation is L
_MSAnd a pulse width sufficient to secure the startability of the high pressure discharge lamp.
Τ _minFor the dielectric breakdown of the gas in the high pressure discharge lamp.
Minute peak value is V_2PminAnd one of the pulse transformers
The inductance of the next winding is L₁And the capacitor
Let C be the capacity and the peak of the voltage charged in the capacitor.
The pulse value is Vc, the primary winding and the secondary winding of the pulse transformer
When the winding ratio to the winding is n, (τ_min/ Π)²・ (1 / C) -L₁≤L_MS ≦ [(n ・ V_C/ V_2pmin) -1) ・ L₁ It is characterized by satisfying the relationship.

According to the invention of claim 9, in the invention of claim 7
And the inductance of the magnetic switch at saturation is L
_MSAnd a pulse width sufficient to secure the startability of the high pressure discharge lamp.
Τ _minFor the dielectric breakdown of the gas in the high pressure discharge lamp.
Minute peak value is V_2PminAnd one of the pulse transformers
The inductance of the next winding is L₁And the capacitor
Let C be the capacity and the peak of the voltage charged in the capacitor.
The pulse value is Vc, the primary winding and the secondary winding of the pulse transformer
The winding ratio to the winding is n, and the inductor of the air-core coil is
L to₀Then, (τ_min/ Π)²・ (1 / C) -L₁≤L_MS+ L₀ ≦ [(n ・ V_C/ V_2pmin) -1) ・ L₁ It is characterized by satisfying the relationship.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment using the present invention will be described with reference to the drawings. (Embodiment 1) FIG. 1 is a circuit diagram of this embodiment which constitutes a pulse generator for starting a high pressure discharge lamp lighting device.

The magnetic switch 3 constituting the electromagnetic device of this embodiment forms a closed circuit with the coil 7, the capacitor 1 and the primary winding N _{1 of the} pulse transformer 4, and is saturated by the voltage of the capacitor 1. The inductance value becomes smaller and the device turns on. By this ON operation, the electric charge of the capacitor 1 is discharged in a closed circuit, and the secondary winding N of the pulse transformer 4 is discharged.
A high-voltage pulse voltage is applied to both ends of the high-pressure discharge lamp 5 connected to ₂ . The capacitor 1 is adapted to be charged by a charging power source (not shown). The resistor 2 connected in parallel to the coil 7 of the magnetic switch 3
Is the loss resistance of the magnetic switch 3. Magnetic switch 3
If the loss is large, the resistance 2 becomes small. Here, when the resistance 2 is small, that is, when the loss of the magnetic switch 3 is large, the leakage current Ie flows from the capacitor 1 through the resistance 2 before the magnetic switch 3 is saturated. Therefore, the charging speed of the capacitor 1 due to the voltage supplied from the charging power source is delayed, the magnetic switch 3 is saturated at a low voltage, and the voltage generated on the primary side of the pulse transformer 4 is lowered. The pulse voltage supplied to the high pressure discharge lamp 5 connected to the secondary side of the pulse transformer 4 also drops.

In FIG. 2, the core material of the magnetic switch 3 is modified.
Well, for each core material, unit volume at 10 kHz
The results of examining the relationship between the loss per hit and the pulse voltage are shown.
You. Here, the pulse voltage in the figure is the pulse voltage of the pulse transformer 4.
Next voltage V₂The maximum value of the starting voltage V _maxDivided by and standardized
The loss per unit volume is
It is the loss when driven. The core is close to the saturation magnetic flux density
Since it is magnetized to the end, it causes a loss of the major loop.

From FIG. 2, when the loss of the core material of the magnetic switch 3 is, for example, at the point A, there is almost no variation in the pulse voltage V ₂ / V _max even if the variation in the material loss is ± 30%. If the loss of the core material is at point B and the variation of loss is ± 30%, the pulse voltage V ₂ /
A variation of ± 20% occurs in V _max . Therefore, from FIG. 2, the loss of the core material at a frequency of 10 kHz needs to be 1000 mW / cc or less. Further, in order to prevent noise generation of the pulse transformer 4, it is necessary to set the driving frequency to an audible frequency or higher, preferably 10 kHz or higher. Therefore, core materials corresponding to A, C, D, and E are desirable, and specifically, C Mn-Z type ferrite, D
It was found that it is limited to the case of Finemet of No. 2 and the Fe type amorphous of E. When the core material of the magnetic switch 3 is ferrite, amorphous, or fine met, the variation of the pulse voltage V ₂ / V _max should be within several percent even if the variation of the material loss is ± 30%. You can In FIG. 2, F shows the case of 80% Ni permalloy, and B shows the case of silicon steel plate.

The relationship of the pulse voltage V ₂ / V _max with the ambient temperature of the core materials of Mn-Z type ferrite, fine met, and Fe type amorphous is shown in FIG. The magnetic switch 3 controls the ambient temperature to 120
Although it has to be considered up to ℃, the pulse voltage V ₂ / V _max decreases at 120 ℃ for ferrite (A) with a Curie temperature of about 200 ℃ from Fig. 3, and this also increases the variation of the pulse voltage. I understand. It can be said that the pulse voltage V ₂ / V _max is stable in amorphous (B) and fiment (C), which have high Curie temperatures.
From FIG. 3, the pulse voltage V
It can be said that the Curie temperature of the core material of the magnetic switch 3 capable of stabilizing ₂ / V _max is 300 ° C. or higher shown by the broken line in FIG.

Thus, in the magnetic switch 3 of this embodiment, the core material is a material having a major loop loss of 1000 mW / cc or less at a frequency of 10 kHz. In particular, a core made of amorphous or phimet is used. (Embodiment 2) As the shape of the core 6 of the magnetic switch 3, there is an EE type as described in the prior art. In this case, as shown in FIG.
The inductance after saturation is large because the magnetic path 12 is short.

Therefore, in the magnetic switch 3 of this embodiment,
As shown in FIG. 4, the coil 7 is wound one layer using the toroidal core 6 ′ made of the core material of the first embodiment. That is, it is possible to reduce the inductance of the magnetic switch 3 at the time of saturation, to improve the so-called disconnection of the switch operation, to be suitable for high frequencies, and to prevent an increase in size. In order to reduce the inductance of the magnetic switch 3 using the EE type core 6 as shown in FIG. 10, the number of turns of the coil 7 is reduced to increase the cross-sectional area of the core, or the magnetic path length of the core 6 is reduced. Should be larger, in this case
The magnetic switch 3 will be very large.

Therefore, it is preferable to use the toroidal core 6'as in this embodiment. The circuit configuration of the pulse generator used is, for example, the circuit shown in FIG. (Embodiment 3) This embodiment is used for a high pressure discharge lamp lighting device, and a magnetic switch 3 as an electromagnetic device comprises the magnetic switch 3 having the core material and structure in Embodiment 1 or 2, as shown in FIG. The coil 7 is used by inserting the coil 7 between the capacitor 1 connected between the output terminals of the high-frequency power source 10 constituting the charging circuit and the primary winding N ₁ of the pulse transformer 4.

When the magnetic switch 3 is saturated by the output voltage of the high frequency power source 10 (the inductance of the magnetic switch 3 at this time is L _MS ), the magnetic switch 3 is turned on and the charge accumulated in the capacitor 1 is transferred to the capacitor 1 and the pulse transformer 4. The primary winding N ₁ , the magnetic switch 3, and the capacitor 1 are discharged in a closed circuit. Due to this discharge, a current I flows in the closed circuit,
A voltage is generated in the primary winding N ₁ of the pulse transformer 4 by this current I, and this voltage is boosted by the secondary winding N ₂ and applied as a pulse voltage to the load side. That is, the pulse voltage is superimposed on the voltage of the commercial AC power source 10 and applied to the high-pressure discharge lamp 5 to start the high-pressure discharge lamp 5.

When the high pressure discharge lamp 5 is started, the commercial AC power source 10 switches the ballast 9 to the secondary winding N _{2 of} the pulse transformer 4,
A lamp current flows in the closed circuit of the high pressure discharge lamp 5, and the high pressure discharge lamp 5 is lit stably. Here, the energy required to start the high-pressure discharge lamp 5 is determined by the peak value V _{2P of the} voltage required for the dielectric breakdown of the gas in the high-pressure discharge lamp 5 and the pulse width τ of the pulse voltage for ensuring the start. . Minimum required energy to determine the condition of V _2Pmin, as tau _{mi n,} given the conditions for obtaining the peak value V _2P, first voltage applied from a high-frequency power source 8 is determined by the breakdown voltage of the capacitor 1 to receive it. When the voltage of the capacitor 1 is Vc, after the magnetic switch 3 is saturated, a peak value of a voltage substantially equal to the voltage Vc is applied to the primary winding N ₁ of the pulse transformer 4. Therefore, the winding ratio of the primary winding N ₁ and the secondary winding N ₂ of the pulse transformer 4 must satisfy n = N ₂ / N ₁ ≧ V _2Pmin / Vc (1). However, the secondary winding N ₂ has an impedance voltage due to the lamp current flowing during the lighting of the high pressure discharge lamp 5. If this impedance voltage is too large, it becomes difficult for the lamp current to flow near the zero cross, and the problem of the high-pressure discharge lamp 5 extinguishing occurs, so the impedance voltage can be limited. That is, the number of turns of the secondary winding N ₂ can be limited. Due to these factors, each winding N ₁ ,
The number of turns of N ₂ is approximately determined. At this time, the inductance of the primary winding N ₁ is L ₁ .

Next, consider the condition for obtaining the pulse width τ.
When the inductance L _MS of the magnetic switch 3 at saturation is negligibly small, the pulse width τ is determined by the resonance frequency of the capacitor 1 (the capacitance value is C) and the inductance L ₁ . Therefore, the following expressions (2) and (3) must be satisfied.

[0032]

[Equation 1]

However, if the capacitance C of the capacitor 1 is too large, the current I ₀ from the high-frequency current becomes large and the power source capacitance is lost, so the maximum value of the capacitance C of the capacitor 1 is determined. ) Is difficult to satisfy. If the capacitance C of the capacitor 1 is large, the current I ₁
The peak value of 1 increases, and the current withstanding capacity of the capacitor 1 is exceeded. In addition, noise due to discharge also increases.

Here, in the circuit of FIG. 5, the inductance L _MS of the magnetic switch 3 at the time of saturation is varied to apply a pulse voltage to the high pressure discharge lamp 5, and the peak value V of the pulse voltage is applied.
I examined _2P and pulse width τ. FIG. 6 shows the result. As can be seen from FIG. 6, as the inductance L _MS increases, the peak value V _2P decreases and the pulse width τ increases. The reason why the peak value V _2P decreases when the inductance L _MS increases is that when the magnetic switch 3 is saturated,
This is because the voltage Vc of the capacitor 1 is _divided between the primary winding N ₁ (inductance L ₁ ) of the pulse transformer 4 and the magnetic switch 3 (inductance L _MS ) and the value of the inductance L _MS is V _2Pmin . It must be within _LMSmax . Further, as the inductance L _MS increases, the pulse width τ also increases. This is because the value of the inductance L _{1 in} the equation (2) becomes L ₁ → L ₁ + L _MS , and the value of the inductance L _MS is pulsed. It is necessary to make it _{equal to} or more than L _MSmin which can secure the width τ _min .

The following equations (4) to (6) show the condition of the inductance L _MS when the magnetic switch 3 is saturated.

[0036]

[Equation 2]

As a result, the capacitance C of the capacitor 1 can be reduced, and the withstand current of the capacitor C and the generation of noise can be suppressed. As described above, in the present embodiment, the inductance L _MS of the magnetic switch 3 when saturated is V
_The energy required to start the high-pressure discharge lamp 5 can be obtained only by _setting L _{MSmax which is 2 Pmin} or less and L _MSmin which is τ _min or more to suppress the current withstanding capacity of the capacitor 1 and to reduce noise. Can be suppressed.

(Embodiment 4) In this embodiment, as shown in FIG. 7, in the circuit of FIG. 5, an air-core coil 11 is inserted in series between the magnetic switch 3 and the primary winding N ₁ of the pulse transformer 4. The magnetic switch 3 and the air-core coil 11 form an electromagnetic device. The present embodiment is characterized in that the inductance L ₀ of the air-core coil 11 supplements the inductance L _MS when the magnetic switch 3 is saturated. The condition of the inductance L _MS and the inductance L ₀ is expressed by the following equation (7).

[0039]

(Equation 3)

That is, the same effect as that of the third embodiment can be obtained by _setting L _MS + L ₀ to be equal to or smaller than the inductance that can secure V _2Pmin and be equal to or larger than the inductance that can secure the pulse width τ _min .

[0041]

According to the first aspect of the invention, the closed circuit is constituted by the capacitor, the primary winding of the pulse transformer, and the coil of the magnetic switch, and the electric charge of the capacitor is discharged by the closed circuit when the magnetic switch is saturated, thereby causing the pulse transformer. In the pulse generator for generating a high-voltage pulse in the secondary winding, the semiconductor switch is used because the core material of the magnetic switch has a major loop loss of 1000 mW / cc or less at a frequency of 10 kHz. It is possible to generate a stable pulse voltage even if there is some variation in the core material of the magnetic switch, and since the pulse voltage is stable, it is necessary to increase the number of secondary windings of the pulse transformer. There is an effect that there is no.

Particularly, in the invention of claim 2, in the invention of claim 1, amorphous or fine met is used as a material of the core of the magnetic switch, so that a stable pulse voltage can be generated even at a high ambient temperature. There is an effect. According to the invention of claim 3, in the invention of claims 1 and 2, the core of the magnetic switch is formed of a toroidal core, and the coil is wound around the core in a single layer, so that the magnetic switch is not increased in size. There is an effect that the inductance at the time of saturation is reduced and sufficient energy can be secured.

According to a fourth aspect of the present invention, in the first to third aspects of the invention, the frequency of the capacitor discharge by the closed circuit is 2 kHz or more, so that a low noise pulse generator can be realized. According to the invention of claim 5, in the invention of claims 1 to 4, since the pulse voltage generated in the secondary winding of the pulse transformer is applied to the high pressure discharge lamp, a starting device for starting the high pressure discharge lamp can be realized. effective.

According to a sixth aspect of the present invention, the high-pressure discharge lamp is supplied with lighting power by the lighting means, and the secondary output voltage of the lighting means is superposed with the pulse voltage generated in the secondary winding of the pulse transformer. Is applied,
The frequency of the charging means for charging the capacitor is made higher than the frequency of the power source of the lighting means, the discharge frequency of the capacitor in the closed circuit is made higher than the charging frequency, and the startability of the high pressure discharge lamp is ensured. The inductance at saturation of the magnetic switch is set to a value that gives a pulse voltage having a sufficient pulse width and a peak value sufficient for dielectric breakdown of the gas in the high-pressure discharge lamp. In the high pressure discharge lamp, lighting power is supplied by lighting means, and a voltage in which a pulse voltage generated in a secondary winding of a pulse transformer is superimposed on a secondary output voltage of the lighting means is applied. The frequency of the charging means for charging the capacitor is set higher than the frequency of the power source of the lighting means, and the capacitor in the closed circuit is discharged. The frequency is set higher than the charging frequency, and the air-core coil is inserted between the magnetic switch and the primary winding of the pulse transformer to calculate the sum of the inductance of the magnetic switch at the time of saturation and the inductance of the air-core coil. Since the pulse voltage having a pulse width sufficient for ensuring the startability of the high-pressure discharge lamp and a peak value sufficient for dielectric breakdown of gas in the high-pressure discharge lamp is set to a value that can be obtained, the high-pressure discharge lamp is started. There is an effect that it is possible to realize a starting device that can obtain the energy necessary for reliable operation.

The invention of claim 8, the inductance at saturation of the magnetic switch and L _MS, the sufficient pulse width to start ensuring the high-pressure discharge lamp as tau _min, the insulating gas of the high pressure discharge lamp The peak value sufficient for destruction is V _2Pmin , the inductance of the primary winding of the pulse transformer is L ₁ , the capacitance of the capacitor is C, and the peak value of the voltage charged in the capacitor is Vc. (Τ _min / π) ² · (1 / C) −L ₁ ≦ L _MS ≦ [(n · V _C / V _2pmin ), where n is the winding ratio between the primary winding and the secondary winding. −1] · L ₁ is satisfied, and the invention of claim 9 sets the inductance when the magnetic switch is saturated to L _MS ,
Make _sure that the pulse width sufficient to secure the startability of the high-pressure discharge lamp is τ _min.
Where V _2Pmin is a peak value sufficient for dielectric breakdown of gas in the high pressure discharge lamp, L ₁ is the inductance of the primary winding of the pulse transformer, and C is the capacitance of the capacitor.
And the peak value of the voltage charged in the capacitor is V
c, the winding ratio between the primary winding and the secondary winding of the pulse transformer is n, and the inductance of the air-core coil is L.
_{When 0} , the relationship of (τ _min / π) ² · (1 / C) −L ₁ ≦ L _MS + L ₀ ≦ [(n · V _C / V _2pmin ) −1] · L ₁ is satisfied. It is possible to realize a starting device that can obtain the energy necessary for surely starting the high-pressure discharge lamp, and it is possible to suppress the current withstanding capacity of the capacitor that performs charging and discharging and suppress the generation of noise due to discharge. There is an effect.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram of a first embodiment.

FIG. 2 is an explanatory diagram showing the relationship between the loss of the core material of the magnetic switch and the pulse voltage of the magnetic switch.

FIG. 3 is a diagram for explaining the relationship between the temperature of the core material of the above magnetic switch and the pulse voltage.

FIG. 4 is a perspective view of a magnetic switch according to a second embodiment.

FIG. 5 is a circuit configuration diagram of a third embodiment.

FIG. 6 is a characteristic explanatory view of the magnetic switch of the above.

FIG. 7 is a circuit configuration diagram of a fourth embodiment.

FIG. 8 is a circuit configuration diagram of a conventional example.

FIG. 9 is a circuit configuration diagram of another conventional example.

FIG. 10 is an explanatory diagram of an example of a magnetic switch.

[Explanation of symbols]

1 Capacitor 2 Resistor 3 Magnetic Switch 4 Pulse Transformer 5 High Pressure Discharge Lamp N ₁ Primary Winding N ₂ Secondary Winding Ie Leakage Current

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroyasu Eriguchi, 1048 Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Works Co., Ltd. (72) Takeshi Kamoi, 1048, Kadoma, Kadoma City, Osaka Matsushita Electric Works, Ltd.

Claims (9)

[Claims] 1. A closed circuit is constituted by a capacitor, a primary winding of a pulse transformer, and a coil of a magnetic switch, and when the magnetic switch is saturated, the electric charge of the capacitor is discharged by the closed circuit to generate a high voltage in the secondary winding of the pulse transformer. In the pulse generator for generating the pulse, the core material of the magnetic switch has a major loop loss of 1000 mW / cc or less at a frequency of 10 kHz. 2. The pulse generator according to claim 1, wherein amorphous or fine met is used as a material of the core of the magnetic switch. 3. The pulse generator according to claim 1, wherein the core of the magnetic switch is formed of a toroidal core, and the coil is wound around the core in a single layer winding. 4. The frequency of the capacitor discharge by the closed circuit is 2 kHz or more.
The pulse generator described. 5. The pulse generator according to claim 1, wherein the pulse voltage generated in the secondary winding of the pulse transformer is applied to a high pressure discharge lamp. 6. The high-pressure discharge lamp is supplied with lighting power by a lighting means and is applied with a voltage obtained by superimposing a pulse voltage generated in a secondary winding of a pulse transformer on a secondary output voltage of the lighting means. The frequency of the charging means for charging the capacitor is higher than the frequency of the power source of the lighting means, the discharge frequency of the capacitor in the closed circuit is higher than the charging frequency, and The inductance when the magnetic switch is saturated is set to a value that provides a pulse voltage having a pulse width sufficient for ensuring startability and a peak value sufficient for dielectric breakdown of gas in the high-pressure discharge lamp. The pulse generator according to claim 5. 7. The high-pressure discharge lamp is supplied with lighting power by a lighting means and is applied with a voltage obtained by superimposing a pulse voltage generated in a secondary winding of a pulse transformer on a secondary output voltage of the lighting means. The frequency of the charging means for charging the capacitor is higher than the frequency of the power source of the lighting means, and the discharge frequency of the capacitor in the closed circuit is higher than the charging frequency, and the air-core coil is Inserted between the switch and the primary winding of the pulse transformer, the sum of the inductance when the magnetic switch is saturated and the inductance of the air-core coil,
6. A pulse voltage having a pulse width sufficient for ensuring the startability of the high pressure discharge lamp and a peak value sufficient for dielectric breakdown of gas in the high pressure discharge lamp is set to a value that can be obtained. Pulse generator. 8. The inductance when the magnetic switch is saturated is L _MS , the pulse width which is sufficient for ensuring the startability of the high pressure discharge lamp is τ _min, and the peak which is sufficient for dielectric breakdown of the gas in the high pressure discharge lamp. The value is V _2Pmin , the inductance of the primary winding of the pulse transformer is L ₁ , the capacitance of the capacitor is C, the peak value of the voltage charged in the capacitor is Vc, and the primary winding of the pulse transformer is When the winding ratio to the secondary winding is n, (τ _min / π) ² · (1 / C) −L ₁ ≦ L _MS ≦ [(n · V _C / V _2pmin ) −1] · L 7. The pulse generator according to claim 6, wherein the relationship of ₁ is satisfied. 9. The saturation inductance of the magnetic switch is L _MS , the pulse width sufficient to secure the startability of the high pressure discharge lamp is τ _min, and the peak sufficient for dielectric breakdown of the gas in the high pressure discharge lamp. The value is V _2Pmin , the inductance of the primary winding of the pulse transformer is L ₁ , the capacitance of the capacitor is C, the peak value of the voltage charged in the capacitor is Vc, and the primary winding of the pulse transformer is When the winding ratio to the secondary winding is n and the inductance of the air-core coil is L ₀ , (τ _min / π) ² · (1 / C) −L ₁ ≦ L _MS + L ₀ ≦ (( _{n · V C / V 2pmin)} -1 ] · L pulse generator according to claim 7, characterized by satisfying the relationship of _1.