JPH0896982A - Lighting system - Google Patents

Abstract

PURPOSE: To obtain the lighting system, which can improve the input power factor and which can restrict the in-rush current and which can be easily downsized and which is provided with a preheating timer and a starting function. CONSTITUTION: At the time of closing an alternating current power source Vs , a capacitor C1 is charged in a loop of a positive terminal of a rectifier DB-an inductance element L1 -a primary coil n1 -an inductance element L2 -a filament f1 -a resistor R4 -a filament f2 -a diode D8 -a capacitor C1 -the ground. After closing the alternating current power source Vs , when a switching element Q2 is turned off, the capacitor C1 is charged in a loop of the positive terminal of the rectifier DB-the inductance element L1 -a built-in diode Da-a capacitor C3 -the diode D8 -the capacitor C1 -the ground.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lighting device for lighting a lighting load (for example, a discharge lamp).

[0002]

2. Description of the Related Art As a first conventional example according to the present invention, Japanese Patent Laid-Open No.
FIG. 7 shows a circuit diagram thereof and FIG. 8 shows an operation waveform diagram thereof.

This circuit uses a half-bridge inverter.
When lighting the lighting load (for example, discharge lamp) La by using
AC power supply V_SInput current over the entire period of one cycle
I_in(Or input current when a filter circuit is added
I_in′) Flows, the input power factor is improved and the input current I is increased.
_in(Or input current I when a filter circuit is added
_in′) Harmonic components can be reduced.
Is characterized by the inductance element L₂And switching element
Q₂And the series circuit with the inductance element L₃And Conde
Sensor C_FourParallel to the output terminal of the rectifier DB through a series circuit with
It is a column connection. Therefore, switching element Q₂
Turns on, the positive side terminal of the rectifier DB → inductance
Element L₃→ Capacitor C_Four→ Inductance element L₂→
Switching element Q₂Loop of input current I_inSome of
Current I_ZFlows. Inductance element L₃， Conden
SA C_Four, Inductance element L₂Forms a vibration system
Current I_ZThe direction of will be reversed. Reversed current I_Z
Is the capacitor C_Four→ Inductance element L₃→ Dio
-D₃→ Capacitor C₁→ Capacitor C₃→ Lighting load
La → Capacitor C_FourFlow through the condenser C_Four
Releases the electric charge charged to.

As a second conventional example according to the present invention, Japanese Patent Laid-Open No. Sho 60
There is one disclosed in Japanese Patent Publication No.-134776, and a circuit diagram thereof is shown in FIG. This circuit is a type of lighting device that also serves as an inverter circuit and a chopper circuit, and improves the input power factor and harmonics of the input current I _in (or the input current I _in 'when a filter circuit is added). The components can be reduced, and the feature of this circuit is that the capacitor C ₁ is charged and smoothed by the boost chopper circuit composed of the switching element Q ₂ , the diode D ₂ , and the inductance element L ₃ . A DC voltage is obtained, and the DC voltage smoothed by the capacitor C ₁ is converted into a high frequency voltage by alternating high frequency switching of the switching elements Q ₁ and Q ₂ , and is supplied to the lighting load La.

FIG. 10 is a circuit diagram of a third conventional example according to the present invention.
Shown in. This circuit includes a series circuit composed of a resistor R ₃ and a capacitor C ₄ connected in parallel to both ends of the capacitor C ₁ , a contact B _{1 of the} resistor R ₃ and the capacitor C ₄ , and a gate terminal of the switching element Q ₂ . The current transformer CT having the secondary windings n ₂₁ and n ₂₂ is provided with the starting circuit 1 including the bidirectional switching element DIAC connected in series between the switching element Q _{1 and the} switching element Q ₂ . The secondary windings n ₂₁ and n ₂₂ are connected in series between the contact B ₂ and one end of the inductance element L ₂ , and the secondary windings n ₂₁ and n ₂₂ respectively connect the switching element Q ₁ and the switching element Q ₂ via the resistors R ₁ and R ₂ , respectively. -A parallel connection between the gate and the source.

This circuit uses an AC power source V_SAll with rectifier DB
Wave rectification and inductance element L ₁， Switching element
Child Q₁Capacitor C via built-in diode Da of₁To
Inductance element L₁， Switchon
Element Q₁Built-in diode Da, resistor R₃Through
Indexer C_FourTo charge the capacitor C_FourVoltage V across
_C4Is a break of the bidirectional switching element DIAC.
When the voltage reaches the voltage, the bidirectional switching element DIAC
Turns on, switching element Q₂Between the gate and source
Capacitor C_FourVoltage V across_C4Is applied, switch
Element Q₂Turns on and starts. And after starting,
Secondary winding n of current transformer CT_{twenty one}, N_{twenty two}Secondary power generated in
Switching element Q due to pressure₁, Switching element Q₂
Drive.

[0007]

However, in the first conventional example, a part of the input current I _in (or the input current I _in 'when the filter circuit is added) is a diode D.
_As shown in FIGS. 8 (d) and 8 (e), the current waveform has a protruding portion in the vicinity of the peak of the input current I _in (or the input current I _in 'when the filter circuit is added), as shown in FIGS. A is generated and the input power factor is improved and the input current I _in (or the input current I _in 'when a filter circuit is added) is generated.
There is a first problem that there is a limit to the reduction of the higher harmonic component.

In the first conventional example and the second conventional example, the output voltage of the rectifier DB is applied to the capacitor C ₁ through the diode D ₃ when the AC power source V _S is turned on, and the capacitor C ₁ In order to increase the life of the lighting load La, the second problem that the contacts of the power switch are welded because a large value of inrush current (inrush current) for charging the capacitor C is generated, and the capacitor C There is a third problem in that a preheating timer for starting the lighting load La after separately supplying a preheating current to both filaments of the lighting load La via ₂ is required, resulting in an increase in size of the apparatus.

Further, in the above-mentioned third conventional example, there is a fourth problem that the device becomes large in size because the starting circuit 1 for starting the device is required.

The present invention has been made in view of the above problems. An object of the present invention is to easily improve the input power factor, suppress the inrush current, and reduce the size, as well as the preheat timer. An object of the present invention is to provide a lighting device having a function and a starting function.

[0011]

In order to solve the above problems, according to the invention of claim 1, a rectifier for rectifying an AC power supply and a first rectifier connected in series to the positive output terminal of the rectifier. An inductance element, a first switching element connected to the output terminal of the rectifier via the first inductance element, a second switching element connected in series with the first switching element, and a second resonance element at least for resonance. Of the inductance circuit, the capacitor for filament heating of the lighting load, and the first capacitor for removing the DC component, and at least the resonance circuit and the first and second switching elements, and the DC power. An inverter device for converting the power into high frequency power and supplying it to a lighting load, and a first and a second switching element connected in parallel at both ends of a series circuit. And a discharging diode for supplying a DC power to the inverter device, and a second charging capacitor for supplying a charging current to the second capacitor. And an impedance element connected in the charging circuit of the capacitor, and the second capacitor is charged from one end of the resonance circuit through a charging diode.

According to the second aspect of the present invention, the filament preheating capacitor is provided in the charging circuit of the second capacitor.

According to a third aspect of the present invention, the impedance element is connected in parallel between the non-power supply side terminals of the lighting load.

According to a fourth aspect of the present invention, the impedance element is at least one filament of a lighting load.

According to the fifth aspect of the invention, the first and second aspects are provided.
The driving means for the switching element is characterized in that it detects the current flowing in the resonance circuit and in the charging circuit to drive the first and second switching elements.

According to the invention of claim 6, the first and second
The switching element driving means is provided in the resonance circuit and in the charging circuit, has a secondary winding, and drives the first and second switching elements by the electric power generated in the secondary winding. It is characterized by being a transformer.

[0017]

According to the first aspect of the present invention, when the AC power supply V _S is turned on, the second inductance element, the resonance circuit, the filament of the illumination load, the impedance element, and the second charging element are used. The capacitor is charged. At this time, the impedance element reduces the inrush current when the AC power supply V _{S is} turned on.

After the AC power supply V _S is turned on, the second capacitor is charged, and the DC voltage charged in the second capacitor is converted into an AC high frequency voltage by the inverter device and supplied to the lighting load.

According to the second aspect of the invention, the AC power source V
_{When the S} is turned on, the second capacitor is charged, the voltage across the filament preheating capacitor is gradually increased, and is increased until the filament is sufficiently preheated.

According to the third aspect of the invention, the AC power source V
The second capacitor is charged when _{S is} turned on, and a preheat timer is configured by the impedance element and the filament preheating capacitor to gradually increase the voltage across the filament preheating capacitor and preheat the filament sufficiently. Rise until you.

According to the invention of claim 4, the AC power source V
_{When the S is} turned on, the second capacitor is charged, and at least one filament and the filament preheating capacitor constitute a preheating timer to gradually increase the voltage across the filament preheating capacitor and fully preheat the filament. Rise until you.

According to the invention of claim 5, the AC power supply V
_{When the S} is turned on, the second capacitor is charged, the charging current is detected, and the first switching element is turned on to start the inverter device.

After the AC power source V _S is turned on, the second capacitor is charged by charging the second capacitor and detecting the current flowing in the resonance circuit to alternately turn on and off the first and second switching elements. The charged DC voltage is converted into an AC high frequency voltage and supplied to the lighting load.

According to the invention of claim 6, the AC power source V
_{When the S} is turned on, the second capacitor is charged, a charging current flows in the primary winding of the current transformer, and a voltage is generated in the secondary winding of the current transformer to turn on the first switching element, Start the inverter device.

After the AC power source V _S is turned on, the second capacitor is charged and a resonance current flows in the primary winding of the current transformer to generate a voltage in the secondary winding of the current transformer. , The second switching elements are alternately turned on and off to convert the DC voltage charged in the second capacitor into an AC high frequency voltage and supply it to the lighting load.

[0026]

【Example】

 (Embodiment 1) FIG. 1 is a circuit diagram of a first embodiment according to the present invention.
Is different from the circuit diagram of the second conventional example shown in FIG.
Is the secondary winding n_{twenty one}, N_{twenty two}A current transformer CT having
Switching element Q₁And switching element Q₂Contact
Point B₂And inductance element L ₂In series with one end of
Secondary winding n_{twenty one}, N_{twenty two}Is the resistance R₁, Resistance R
₂Through the switching element Q₁, Switching element Q
₂Connected in parallel between the gate and source of₂of
High resistance R on both ends_FourAre connected in parallel and the capacitor C₃
And the filament f of the lighting load La₂Contact X and die
Code D₈Connect to the anode terminal of₈
Cathode terminal and diode D₉Connect to the anode terminal of
Continuing, and the diode D₉Anode terminal and
Sensor C₁Connect to the non-ground side terminal of
₉Cathode terminal and switching element Q₁The drain edge
Connect the child to the diode D from the lighting load La side.₈To
Through capacitor C₁By charging the
The same components as those of the second conventional example are designated by the same reference numerals.
Therefore, the description is omitted.

When the AC power source V _{S is} turned on, the positive side terminal of the rectifier DB → the inductance element L ₁ → the primary winding n ₁ of the current transformer CT → the inductance element L ₂ → the filament f ₁ → the resistor R _{4 with a} high value → the filament f ₂ → dio-
The capacitor C ₁ is charged by the loop of D ₈ → capacitor C ₁ → ground. Since the resistor R ₄ has a high resistance value, the inrush current when the AC power supply V _{S is} turned on is reduced. At this time, the resistor R ₄ and the capacitor C ₂ form a preheat timer. That is, the voltage across V _C2 of the capacitor C ₂ is gradually increased by the time constant of the resistor R ₄ and the capacitor C ₂ Prefecture, and rises to sufficiently preheat the filament f _1, f _2.

When the switching element Q ₂ is turned off after the AC power source V _S is turned on, the positive side terminal of the rectifier DB → the inductance element L ₁ → the built-in diode Da → the capacitor C.
_The capacitor C ₁ is charged even in the loop of ₃ → diode D ₈ → capacitor C ₁ → ground.

The capacitor C ₃ is, as shown in FIG.
It may be connected between the drain of the switching element Q ₁ and the cathode terminal of the diode D ₂ , and as shown in FIG. 3, the capacitor C ₁ is shared and two lighting loads La ₁ and La ₂ are provided. The number of lights may be three or more, and as shown in FIG. 4, the driving of the switching element Q ₁ and the switching element Q ₂ after startup may be separately excited, and instead of the resistor R ₄ . The filaments f ₁ and f ₂ having several ohms may be used, or other impedance elements may be used.

(Embodiment 2) FIG. 5 is a circuit diagram of a second embodiment according to the present invention. The difference from the first embodiment shown in FIG. 1 is that the capacitor C _{3 is connected} to the current transformer CT and the filament f _1. This is because the resistor R ₄ is omitted by connecting the anode terminal of the diode D ₈ to the non-power source terminal of the filament f ₂ by connecting in series with the power source side terminal of the diode D _8. The same components as those in FIG.

When the AC power supply V _{S is} turned on, the positive terminal of the rectifier DB → the inductance element L ₁ → the primary winding n ₁ of the current transformer CT → the inductance element L ₂ → the capacitor C.
₃ → filament f ₁ → capacitor C ₂ → diode D
_The capacitor C ₁ is charged by a loop of ₈ → capacitor C ₁ → ground. By the way, since the filament f ₁ is several ohms, the inrush current when the AC power supply V _S is turned on is reduced. At this time, the filament f ₁ and the condenser C ₂ constitute a preheat timer. That is, the voltage across V _C2 of the capacitor C ₂ is gradually increased by the time constant composed of filaments f ₁ and the capacitor C ₂ Prefecture, and rises to sufficiently preheat the filament f _1, f _2.

When the switching element Q ₂ is turned off after the AC power source V _S is turned on, the positive terminal of the rectifier DB → inductance element L ₁ → built-in diode Da → filament f ₂ → diode D ₈ → capacitor C _The capacitor C ₁ is charged even in the loop of ₁ → ground.

(Third Embodiment) FIG. 6 is a circuit diagram of a third embodiment according to the present invention. The difference from the second embodiment shown in FIG. 5 is that the primary windings n _{1 and} n of the current transformer CT are Connect the contact Y of the inductance element L ₂ and the terminal of the inductance element L ₁ not connected to the rectifier DB to the diode D
₈ is connected to the contact W between the inductance element L ₂ and the capacitor C ₃ , and the other first
The same components as those in the embodiment are designated by the same reference numerals and the description thereof will be omitted.

AC power supply V_SWhen throwing in,
A part of the current flows from the positive terminal of the rectifier DB to the inductance element
Child L₁→ Primary winding n of current transformer CT₁→ Built-in dio
-De Da → Capacitor C₂→ Capacitor C₃→ Dio
De D₈→ Capacitor C₁→ Flow in a loop called Grand
However, the other side of the inrush current is the positive side end of the rectifier DB.
Child → Inductance element L₁→ Inductance element L₂
→ Diode D₈→ Capacitor C₁→ Grand
-Capacitor C₁Is charged, so AC power
Source V_SThe inrush current at the time of making is reduced. Also,
Primary winding n of current transformer CT₁Inrush flowing in
Since the current is reduced, switching element Q₁， Su
Itching element Q₂2 is sufficient secondary voltage to turn on
Next winding n _{twenty one}, N_{twenty two}Can occur at any time. this
When filament f₁And capacitor C₂With preheat timer
-Constitute. That is, the capacitor C₂Voltage V across_C2
Is the filament f₁And capacitor C₂Timed consisting of
Gradually increases with the number, and the filament f₁, F₂To
Increase until fully preheated.

When the switching element Q ₂ is turned off after the AC power source V _S is turned on, the positive side terminal of the rectifier DB → the inductance element L ₁ → the primary winding n _{1 of the} current transformer CT →
Built-in diode Built-in diode Da → filament f ₂
→ capacitor C ₂ → filament f ₁ → capacitor C ₃
→ diode D ₈ → capacitor C ₁ → capacitor C ₁ is charged even in the loop of ground.

In the second and third embodiments described above,
The number of lights may be two or more, and switching element Q after startup
₁ , the switching element Q ₂ may be driven by a self-excited type or a separately excited type. Further, the switching elements shown in the above-mentioned first to third embodiments have a diode or a transistor.
The switching element may be an anti-parallel connection, a bidirectional switching element, or another switching element.

With the configuration as shown in the first to third embodiments, it is possible to easily improve the input power factor and suppress the inrush current with a simple configuration. Further, since the inrush current flows in the primary winding n ₁ of the current transformer CT, the secondary windings n ₂₁ and n ₂₂ of the current transformer CT are
The start-up can be performed via the control unit and the preheating timer can be easily configured by using the time constants of the filanment preheating capacitor and the filanment.

[0038]

According to the first aspect of the present invention, it is possible to provide an illuminating device capable of easily improving the input power factor, suppressing the inrush current, and downsizing.

According to the inventions of claims 2 to 4, it is possible to easily improve the input power factor, suppress the inrush current, and reduce the size, and to provide a lighting device having a preheating timer function. it can.

According to the fifth and sixth aspects of the present invention, it is possible to provide an illuminating device which is capable of easily improving the input power factor, suppressing the inrush current and downsizing, and having a starting function.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a first embodiment according to the present invention.

FIG. 2 is a diagram showing another circuit example according to the embodiment.

FIG. 3 is a diagram showing still another circuit example according to the embodiment.

FIG. 4 is a diagram showing still another circuit example according to the embodiment.

FIG. 5 is a circuit diagram showing a second embodiment according to the present invention.

FIG. 6 is a circuit diagram showing a third embodiment according to the present invention.

FIG. 7 is a circuit diagram showing a first conventional example according to the present invention.

FIG. 8 is a diagram showing operation waveforms according to the conventional example.

FIG. 9 is a circuit diagram showing a second conventional example according to the present invention.

FIG. 10 is a circuit diagram showing a third conventional example according to the present invention.

[Explanation of symbols]

 C capacitor CT current transformer D diode DB rectifier L inductance element La lighting load Q switching element R impedance element f filament n winding

Claims (6)

[Claims] 1. A rectifier for rectifying an AC power supply, a first inductance element connected in series to a positive output end of the rectifier, and an output end of the rectifier via the first inductance element. A first switching element,
A resonance composed of a second switching element connected in series with the first switching element, at least a second inductance element for resonance, a filament preheating capacitor for a lighting load, and a first capacitor for removing a DC component. An inverter including a circuit, at least the resonance circuit, and the first and second switching elements, and converting direct-current power into high-frequency power and supplying it to a lighting load.
In a lighting device including a switching device and a second capacitor connected in parallel at both ends of a series circuit of the first and second switching elements, a charging device for supplying a charging current to the second capacitor is provided. The resonance circuit is provided with a diode, a discharge diode for supplying DC power to the inverter device, and an impedance element connected in the charging circuit of the second capacitor. An illumination device, wherein the second capacitor is charged from one end of the battery via the charging diode. 2. The filament preheating condenser comprises:
The lighting device according to claim 1, wherein the lighting device is provided in a charging circuit of the second capacitor. 3. The lighting device according to claim 1, wherein the impedance element is connected in parallel between non-power supply side terminals of the lighting load. 4. The lighting device according to claim 1, wherein the impedance element is at least one filament of the lighting load. 5. The driving means for driving the first and second switching elements drives the first and second switching elements by detecting a current flowing in the resonance circuit and in the charging circuit. The lighting device according to claim 1, wherein: 6. The driving means for driving the first and second switching elements is provided in the resonance circuit and in the charging circuit, has a secondary winding, and is generated in the secondary winding. The lighting device according to claim 1, wherein the lighting device is a current transformer that drives the first and second switching elements with electric power.