JPH08180990A - Discharge lamp lighting device - Google Patents

Abstract

PURPOSE: To provide a power source device, which can reduce the oscillation frequency of an inverter circuit and which is normally operated even in the case where wiring length and the number of load lamps is changed, by connecting an inductance in series to a load wiring circuit. CONSTITUTION: A choke L10 for inductance and current transformers CT1 -CT4 for each load are connected in series between output terminals X, Y of an inverter circuit 4. One of filaments of both ends of a fluorescent lamp FL1 is connected to one of both terminals of a secondary coil of one transformer CT1 , and the other filament is connected to the other terminal of the transformer CT1 through a capacitor C11 . Other transformers CT2 -CT4 are similarly connected. With this structure, resonance frequency of a load circuit is reduced, and the oscillation frequency of the inverter circuit is reduced, and switching loss of a switching element is reduced so as to improve the conversion efficiency of the circuit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge lamp lighting device in which a current supplied from a high frequency power source is received by a plurality of current transformers and each of the current transformers lights a discharge lamp.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 13, a high frequency constant current output from a high frequency power source A is supplied to a plurality of current transformers T.
Load FL1, which is supplied to the primary windings of 1, T2 and T3 and is connected to the secondary windings of the current transformers T1, T2 and T3,
A device that operates FL2 and FL3 at high frequency is known. Here, the constant current high frequency power source A,
Although not explicitly described in 9-46496, a power amplifier is generally conceivable as a concrete means for realizing it. However, in the case of the power amplifier, although it is considered that the output can be easily applied to the circuit of FIG. 13, in order to amplify the reference signal output from the high frequency oscillator or the like, the output power from the power amplifier is used. On the other hand, the input power supplied to the power amplifier becomes very large, which is not preferable in terms of efficiency in practical use.

Therefore, for example, as shown in FIG. 14, a DC voltage converter 3 for converting a DC voltage into an arbitrary voltage value by a switching operation, and a DC voltage converted by the DC voltage converter 3 at a high frequency by a switching operation. The output current of the inverter unit 4 is converted to a constant voltage by detecting the output current of the inverter unit 4 and controlling the switching operation of at least one of the DC voltage conversion unit 3 and the inverter unit 4. It is conceivable to use a high frequency power supply including an output current detection unit 6 (see Japanese Patent Application No. 5-113451).

Regarding the operation, a current detecting section 6 is provided at the output of the inverter section 4 which converts the DC voltage output from the DC voltage converting section 3 into a high frequency voltage by a switching operation, and the output is provided even if the state of the load 5 changes. Since the operating conditions of the DC voltage conversion unit 3 or the inverter unit 4 are controlled so as to keep the current constant, it is possible to control so that the load current becomes constant with respect to the state of the load 5 and the increase or decrease in the number thereof. You can
Further, the efficiency is improved as compared with the case where the power amplifier is used.

In this lighting system, a filament current condenser is provided in parallel with the fluorescent lamp in order to light the fluorescent lamp of the load. In addition, the wiring length changes depending on the number of fluorescent lamps in the load. As a result, the load and the inductance component of the wiring circuit viewed from the power supply side become a capacitive load. This phenomenon was verified by experiments. The wiring used is
The wiring length was 20 m and 40 m with VVF of 2.0φ, and the number of load lamps was 8 and 6. Further, the capacitances of the capacitors were C ₁₁ = 3900 pF and C ₁₂ = C ₁₃ = 0.1 μF. The measurement method is as follows. The pseudo load circuit shown in FIG. 15 is connected to the wiring and the impedance analyzer (41 by YHP) is used.
94A), and the pseudo lamp load resistance of 330Ω
The resonance frequency in the case where the above was removed was obtained. Table 1 shows the measurement results. In the table, m / n is pseudo resistance R = 33
It is the ratio of the number m of current transformers to which 0Ω is added and the total number n of current transformers connected in series to the load wiring circuit.

[0006]

[Table 1]

In Table 1, the case where the wiring length is 20 m is ◯,
If the wiring length is 40 m, it is plotted as □, and the result is as shown in the graph of FIG. As can be seen from this result, when the total number n of connected current transformers is large and the lamp which is the load is removed (for example, 0 load for 8 current transformers), the load and wiring are The resonance frequency of the circuit increases to 186 kHz. As a result, unless the oscillation frequency of the inverter circuit is set higher than the resonance frequency of the load circuit, a phase-advancing current flows through the inverter circuit, increasing the stress on the switching elements of the inverter circuit, leading to destruction. On the other hand, when the oscillating frequency of the inverter circuit is increased, the switching loss increases, the power conversion efficiency decreases, and the noise increases.

[0008]

To solve such a problem, we have proposed to reduce the resonance frequency of the wiring circuit by inserting an inductance choke in the wiring circuit. However, in that case, when the wiring length of the wiring circuit or the number of load circuits connected thereto changes, for example, when the wiring length becomes shorter and the number of load circuits increases,
The inductance value of the choke inserted until then becomes insufficient, and a phase-advancing current flows in the inverter circuit,
There is a problem that the conventional defects come out again. Further, when the wiring length is constant and the number of load circuits is reduced, the inductance value becomes excessive, and the circuit efficiency is reduced due to the power loss in the choke.

The present invention has been made in view of the above points, and an object of the present invention is to receive a current supplied from a high frequency power source by a plurality of current transformers and load the respective current transformers. It is an object of the present invention to provide a power supply device that operates normally even if the wiring length or the number of load lights (the number of circuits) changes.

[0010]

According to the present invention, in order to solve the above problems, a lumped inductance is provided between an inverter circuit and a load wiring circuit. As one of the means, an inductance choke may be inserted for each fixed wiring length, an inductance component may be provided for each load circuit, or a secondary side of a current transformer may be provided for each load circuit. A choke for inductance may be inserted in. Also, instead of the choke for inductance, a gap may be provided in the current transformer and the leakage inductance thereof may be used. Further, it is preferable that the inductance value provided between the inverter circuit and the load wiring circuit can be arbitrarily changed to an optimum value according to the state of the load wiring circuit.

[0011]

According to the present invention, by connecting an inductance in series with a load wiring circuit, the resonance frequency of the circuit is lowered,
The oscillation frequency of the inverter circuit can be reduced. Specifically,
In the load wiring circuit shown in the conventional example, as shown in FIG.
Table 2 shows the change in the resonance frequency when the lumped inductance L ₁₀ = 114 μH is inserted. In the table,
m / n is the ratio of the number m of current transformers to which the pseudo resistance 330Ω is added and the total number n of current transformers connected in series to the load wiring circuit.

[0012]

[Table 2]

In Table 2, the case where the wiring length is 20 m is ◯,
When the wiring length is 40 m, it is plotted with □, as shown in FIG. From this measurement result, it can be seen that the oscillation frequency of the inverter circuit can be reduced from 186 kHz to 78 kHz by inserting an inductance in the load wiring circuit. Further, it can be seen that when the inductance is inserted in the load wiring circuit, there is almost no influence of the wiring length, and the resonance frequency is determined by the number of current transformers.

Further, by inserting a choke for a predetermined inductance for each unit length of the wiring length or for each load circuit, the optimum inductance for the wiring length and the number of load circuits can be obtained. Furthermore, since an inductance component is added to each load circuit, the optimum inductance can always be obtained for the entire circuit.

[0015]

FIG. 1 shows a first embodiment of the present invention. Power supply part
Is basically the same as that of the conventional example of FIG.
Although not described, the filter circuit (inductor) of the output part
L₃ , Capacitor C_Five And C₆ , Inductor L_Four ,
Indexer C₇ ) And the isolation transformer Tf are deleted.
It has become. Between the output terminals of the inverter circuit 4,
Choke L for the above-mentioned inductance_TenAnd curry for each load
Front Trans CT ₁ ~ CT_Four Are connected in series
It One current transformer CT₁ Both terminals of the secondary winding
Is a fluorescent light FL₁ One of the filaments at both ends of is connected
And the remaining filament terminals are capacitors C₁₁
Connected through. Also, the fluorescent lamp FL₁ Of the
Capacitor C on each end of the lament₁₂, C₁₃Connected
Has been done. Other current transformer CT₂ ~ CT_Four Nitsu
The same is true. Regarding operation, the conventional example and action
Since it is explained, it is omitted.

A second embodiment of the present invention is shown in FIG. This embodiment is the same as the first embodiment of the present invention in that chokes L ₁₀ and L ₁₁ for inductance are added to both output terminals of the inverter circuit 4, and the other parts are exactly the same.
Although the step-down chopper circuit and the full-bridge inverter circuit are used in both the first and second embodiments, the step-up chopper circuit or the step-up / step-down chopper circuit may be used as the chopper circuit. Further, the inverter circuit may be a half bridge circuit.

A third embodiment of the present invention is shown in FIG. In the figure,
The terminals X and Y are connected to the terminals X and Y of the power supply circuit of FIG. Since the load circuit, which is a lighting fixture, is arranged at a constant interval on the ceiling surface, for example, lumped constant inductances La and Lb are provided for each wiring length d between adjacent load circuits.
Lc is installed. Each inductance L
If a, Lb, and Lc are equal, a lumped constant inductance La × n that automatically matches the number n of load circuits is obtained for each wiring length d.

A fourth embodiment of the present invention is shown in FIG. In the figure,
The terminals X and Y are connected to the terminals X and Y of the power supply circuit of FIG. Current transformers CT ₁ and C in each lighting fixture
Lumped constant inductances L ₁₁ , L ₁₂ , L in series with the primary windings of T ₂ , CT ₃ , CT ₄ , CT ₅ , CT ₆ , respectively.
₁₃ , ₁₃ , L ₁₄ , L ₁₅ , and L ₁₆ are connected. This allows
A lumped constant inductance corresponding to the number of load circuits is connected.

A fifth embodiment of the present invention is shown in FIG. In the figure,
The terminals X and Y are connected to the terminals X and Y of the power supply circuit of FIG. Current transformers CT ₁ and C in each lighting fixture
Lumped constant inductances L ₂₁ , L ₂₂ and L in series with the secondary windings of T ₂ , CT ₃ , CT ₄ , CT ₅ and CT ₆ , respectively.
₂₃ , L ₂₄ , L ₂₅ , and L ₂₆ are connected. This allows
A lumped constant inductance corresponding to the number of load circuits is connected.

A sixth embodiment of the present invention is shown in FIG. In the figure,
The terminals X and Y are connected to the terminals X and Y of the power supply circuit of FIG. Current transformers CT ₁ and C in each lighting fixture
T ₂ , CT ₃ , CT ₄ , CT ₅ , and CT ₆ are leakage transformers, each of which has a leakage inductance. As a result, lumped constant inductances corresponding to the number of load circuits are connected.

A seventh embodiment of the present invention is shown in FIG. The lumped inductance L ₁₀ is provided with taps A, B, and C, and each tap is connected to a plurality of terminal blocks A, B, and C at the output terminal of the power supply, as shown in the external view of FIG. Has been done. The installer optimizes the inductance value by connecting an arbitrary terminal block and load wiring in consideration of the wiring length and the number of load circuits during construction.

An eighth embodiment of the present invention is shown in FIG. 9 and its external view is shown in FIG. The lumped constant inductance is La, L
It is divided into b and Lc, and the middle point and the final end are A and
The switches B and C are connected to the changeover switch S and led out from the output terminal. The installer sets the changeover switch S to an arbitrary terminal in consideration of the wiring length and the number of load circuits at the time of construction.
Optimize the inductance.

The ninth embodiment of the present invention is shown in FIG. 11 and its external view is shown in FIG. The lumped constant inductance L ₁₂ is arranged outside the power source component as an adapter. (There are several types of lumped constant inductance L ₁₂ depending on the inductance.) The builder selects an optimum lumped constant inductance in consideration of the wiring length and the number of load circuits at the time of construction.

[0024]

According to the present invention, the inductance of the lumped constant is connected in series to the load circuit, so that the resonance frequency of the circuit is lowered, the oscillation frequency of the inverter circuit can be reduced, and the switching element is switched. The switching loss can be reduced and the conversion efficiency of the circuit can be improved.

According to the invention of claim 5, by dividing the inductance and inserting it into both of the output terminals of the inverter circuit, the noise generated from the inverter circuit is leaked to the ground through a loop. And a lighting device with a low noise level can be provided.

Further, according to the invention of claim 6, by inserting a predetermined inductance for each unit length of the wiring length or for each load circuit, an optimum inductance for the wiring length and the number of load circuits can be obtained. can get. Furthermore, since an inductance component is added to each load circuit, the optimum inductance can always be obtained for the entire circuit. Further, it is possible to obtain a lighting device which is always in an optimum state even when the wiring length or the number of load circuits changes. Furthermore, when the inductance is installed in the device, there is an effect that the number of construction steps can be reduced.

Further, according to the invention of claim 7, since a gap is provided in the current transformer instead of the lumped constant inductance, the inductance component exists in the secondary winding of the current transformer, and the current is small. Therefore, a highly efficient lighting system with low loss and low power loss can be obtained.

According to the present invention, the magnitude of the inductance component of the lumped constant is determined by providing a tap on the inductance to select a terminal, operating a changeover switch, or exchanging the inductance. By making it possible to switch, it is possible to obtain a lighting device that is always in an optimum state even when the wiring length or the number of load circuits changes.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a first embodiment of the present invention.

FIG. 2 is a circuit diagram of a second embodiment of the present invention.

FIG. 3 is a circuit diagram of a third embodiment of the present invention.

FIG. 4 is a circuit diagram of a fourth embodiment of the present invention.

FIG. 5 is a circuit diagram of a fifth embodiment of the present invention.

FIG. 6 is a circuit diagram of a sixth embodiment of the present invention.

FIG. 7 is a circuit diagram of a seventh embodiment of the present invention.

FIG. 8 is a perspective view of a seventh embodiment of the present invention.

FIG. 9 is a circuit diagram of an eighth embodiment of the present invention.

FIG. 10 is a perspective view of an eighth embodiment of the present invention.

FIG. 11 is a circuit diagram of a ninth embodiment of the present invention.

FIG. 12 is a perspective view of a ninth embodiment of the present invention.

FIG. 13 is a circuit diagram of a first conventional example.

FIG. 14 is a circuit diagram of a second conventional example.

FIG. 15 is an equivalent circuit diagram of a conventional load circuit.

FIG. 16 is a diagram showing a relationship between the number of discharge lamps and a resonance frequency in a conventional example.

FIG. 17 is an equivalent circuit diagram of the load wiring circuit of the present invention.

FIG. 18 is a diagram showing the relationship between the number of discharge lamps and the resonance frequency in the present invention.

[Explanation of symbols]

1 Filter circuit 2 Full wave rectifier 3 Chopper circuit 4 Inverter circuit L ₁₀ Inductance

 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Yasuhiro Kudo 1048, Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Works, Ltd. (72) Yoshinori Murakami, 1048, Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Works, Ltd.

Claims (10)

[Claims] 1. A commercial power supply, a constant-current high-frequency power supply fed from this commercial power supply, and a plurality of current transformers having primary windings connected in series to the output of the constant-current high-frequency power supply,
In a discharge lamp lighting device comprising a discharge lamp connected to the secondary winding side of each current transformer, a lumped inductance is inserted in series between the output terminals of the constant current high frequency power supply. Electric lighting device. 2. The load circuit includes a plurality of current transformers having primary windings connected in series, and a fluorescent lamp having one terminal of each electrode connected to both ends of the secondary windings of each current transformer. And a capacitor connected between the other terminals of both electrodes of each fluorescent lamp, respectively.
The discharge lamp lighting device described. 3. A separate capacitor is connected between the terminals of both electrodes of the fluorescent lamp.
The discharge lamp lighting device described. 4. The discharge lamp according to claim 2, wherein the resonance frequency due to the inductance of the first capacitor, the output wiring and the lumped constant inductance is set to 40 to 150 kHz. Lighting device. 5. The inductance of the lumped constant is divided into two, and is inserted between both output terminals of the constant current high frequency power supply and a load circuit. The discharge lamp lighting device according to. 6. A commercial power supply, a constant current high frequency power supply fed from this commercial power supply, and a plurality of current transformers having primary windings connected in series to the output of the constant current high frequency power supply,
In a discharge lamp lighting device including a discharge lamp connected to the secondary winding side of each current transformer, a plurality of lumped-constant inductances are installed at fixed distances in an output wiring circuit, or appliances are provided for each load circuit. A discharge lamp lighting device characterized by being installed inside. 7. A commercial power supply, a constant-current high-frequency power supply fed from the commercial power supply, and a plurality of current transformers having primary windings connected in series to the output of the constant-current high-frequency power supply,
2. A discharge lamp lighting device comprising: a discharge lamp connected to the secondary winding side of each current transformer, wherein a gap is provided in each current transformer. 8. The lumped-constant inductance is provided with a plurality of taps, and for each tap,
The discharge lamp lighting device according to claim 1, wherein the constant current high frequency power supply is provided with an output terminal. 9. The discharge lamp lighting device according to claim 1, wherein the lumped-constant inductance is provided with a plurality of taps, and each tap can be selected by a changeover switch. 10. The lumped-constant inductance is arranged outside the constant-current high-frequency power supply, and there are a plurality of lumped-constant inductance specifications, which can be arbitrarily converted. The discharge lamp lighting device according to 1.