JPH08339891A - Discharge lamp lighting device - Google Patents

Abstract

PURPOSE: To suppress an unnecessary power loss in the case of removing a discharge lamp. CONSTITUTION: In a control part 4 of switching controlling a pair of switching elements Q1 , Q2 of an inverter part 2, an operating power supply of this control part is supplied from the first/second power supply parts 5, 6. A base of a power supply switching element Q3 for on/off operating the first power supply part 5 is connected to a connection point A between a DC cut capacitor C1 and a resonance capacitor C2 through a resistor R3 . Here during operating the inverter part 2, in the case of removing at least one discharge lamp 3a, 3b, by supplying a base current through the resistor R3 , the power supply switching element Q3 is turned on to operate the first power supply part 5. However, by charging the DC cut capacitor C1 , a base current is prevented from flowing consequrntly to be made capable of stopping operating the first power supply part 5. In the way, an unnecessary power loss in the first power supply part 5, in the case of removing the discharge lamp 3a, 3b, can be suppressed.

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 provided with an inverter section for lighting a discharge lamp at a high frequency, and more particularly to generation of operating power supply for a control section for controlling the inverter section.

[0002]

2. Description of the Related Art Conventionally, in a discharge lamp lighting device having an inverter unit for high-frequency lighting of a discharge lamp, the operating power source of a control unit for controlling the inverter unit is a DC power source for supplying power to the inverter unit or an inverter unit. It is proposed to generate from a high frequency output, and FIG. 8 is a circuit diagram showing an example of such a conventional discharge lamp lighting device.

The discharge lamp lighting device shown in FIG.
And a pair of switches connected in series at both ends of the DC power supply 1.
Holding element Q₁, Q₂Be switched alternately
Converting the DC output of DC power supply 1 to high frequency output
DC cut capacitor C ₁And resonance coil barrel
Primary winding n of the arc coil L₁And resonance capacitor C ₂
Supply to the two discharge lamps 3a and 3b via the series resonance circuit of
The so-called half-bridge type inverter unit 2 and the inverter
Switching element Q of data unit 2₁, Q₂On / off system
From the DC output of the DC power supply 1 and the control unit 4 that controls
A first power supply unit 5 that generates an operating power supply for the control unit 4;
Generates operating power for the control unit 4 from the high frequency output of the burner unit 2.
The second power supply unit 6 is provided. Two discharges
The lamps 3a and 3b have one filament fa₁,
fb₂When one end of is connected to the output end of the inverter unit 2,
The other end is a resonance capacitor C₂Connected through
The other filament fa₂, Fb₁Is a choke coil L
Secondary winding n₂And capacitor C₃Connected in series via
Has been done.

In the first power source section 5, a parallel circuit of a resistor R ₁ , a power source switching element Q ₃ , a diode D _{2, a} zener diode ZD ₂ and a smoothing capacitor C ₄ is serially connected in series from the positive electrode to the negative electrode of the DC power source 1. The Zener diode ZD ₁ connected in series with the resistor R ₃ at both ends of the DC power source 1 is connected to the base of the power source switching element Q ₃ , and the smoothing capacitor C ₄ is connected via the resistor R _1. It is charged to generate operating power for the control unit 4.

On the other hand, in the second power source section 6, the power source winding n ₃ which is the other secondary winding of the choke coil L has a resistance R.
_It is connected to both ends of the Zener diode ZD ₂ of the first power supply unit 5 through a series circuit of ₄ and the diode D ₁ . Next, the operation of the above conventional configuration will be described. First, when the power supply from the DC power supply 1 is started,
A base current is supplied to the power supply switching element Q ₃ via the resistor R ₃ to turn on the power supply switching element Q ₃ . Therefore, the smoothing capacitor C ₄ is charged via the resistor R ₁ , the power supply switching element Q ₃ , and the diode D _2, and the operating power supply for the control unit 4 is generated. As a result, the control unit 4 starts operating, and the switching elements Q ₁ and Q ₂ of the inverter unit 2 are alternately turned on and off periodically to generate a high-frequency rectangular wave, and the DC cutting capacitor C
_The series resonance circuit constituted by the resonance capacitor C ₂ and the resonance coil (the primary winding n ₁ of the choke coil L) starts the resonance operation through ₁ and at the same time, the secondary winding n _{2 of the} choke coil L is started. A high-frequency voltage is induced in each of the filaments fa ₁ , fa ₂ , fb of each of the discharge lamps 3a, 3b.
_A high-frequency voltage is applied between ₁ and fb ₂ so that the discharge lamps 3a, 3
b starts and lights up.

By the way, the inverter section 2 starts operating.
The primary winding n of the choke coil L₁Discharge lamps 3a, 3b
When a high-frequency current is supplied to the primary winding n₁Both
A voltage is generated at the end. As a result, the choke coil L
Power supply winding n₃Primary winding n₁Depending on the winding ratio with
Pressure is induced. This induced voltage is the diode D₁By
It is rectified and used as the operating power source for the control unit 4
Be done. Here, the voltage at which the control unit 4 starts the operation is Vth,
Power supply switching element Q₃Base-emitter voltage
To V_BE, Diode D₂ON voltage of V_D2, Zenada
Iodo ZD₁, ZD₂Zener voltage of V
_ZD1, V_ZD2And the following inequality holds
Sea urchin Zener diode ZD₁, ZD₂Zener voltage
V_ZD1, V _ZD2Are set respectively.

Vth + V _BE + V _D2 <V _ZD1 <V _ZD2 + V _BE + V _{D2 In} this case, the control unit 4 starts operating and the second power supply unit 6 generates the operating power for the control unit 4 and the smoothing capacitor C _Four
If the voltage across both ends exceeds the voltage of the rightmost term V _ZD2 + V _BE + V _{D2 in} the above equation (usually, this design is often done), the base current is not supplied to the power supply switching element Q ₃ . Therefore, the power supply switching element Q ₃ is turned off, the operation of the first power supply unit 5 is stopped, and the operating power supply of the control unit 4 is supplied only from the second power supply unit 6 and the discharge lamp 3a , 3b are turned on in a normal state, power loss in the resistor R ₁ of the first power supply unit 5 can be eliminated, and heat generation of the resistor R ₁ and a decrease in circuit efficiency can be prevented.

[0008]

Here, the above-mentioned conventional configuration
In, either one of the two discharge lamps 3a and 3b is discharged
When removed from the lamp lighting device, i.e.
If the discharge lamps 3a, 3b are disconnected from the output end of
Think of the case. In this case, the series resonance of the inverter unit 2
Circuit is resonance capacitor C₂And the resonance coil, Cho
Coil n primary winding n₁To be divided between
Therefore, the primary winding n of the choke coil L ₁High frequency
The current stops flowing. Therefore, the second power supply unit 6
The operation is stopped and the operating power supply to the control unit 4 is cut off.
The inverter unit 2 stops. Here, smoothing capacitor C
_FourThe voltage across both ends of the controller drops due to current consumption in the control unit 4.
Therefore, switching element Q for power supply₃DC power supply 1
The base power is supplied to turn on, and the first power supply unit 5 is turned on again.
Starts to work.

That is, in the above-mentioned conventional structure, while the discharge lamp 3a (or the discharge lamp 3b) is removed,
Always the first power supply portion 5 is current continues to flow in the resistor R ₁ is operating, not only consumes unnecessary power, other circuits present around the resistor R ₁ by the heat generation of the resistor R ₁ It may adversely affect the parts and cause deterioration of life.

The present invention has been made in view of the above points, and an object thereof is to provide a discharge lamp lighting device capable of suppressing unnecessary power loss when the discharge lamp is removed. To do.

[0011]

In order to achieve the above object, the invention of claim 1 is a DC power supply, an inverter section for converting a DC output of the DC power supply into a high frequency output and supplying the same to a discharge lamp, and an inverter. A control unit that controls the operation of the control unit, a first power supply unit that generates the operation power supply of the control unit from the DC output of the DC power supply, and a second power supply unit that generates the operation power supply of the control unit from the high frequency output of the inverter unit. A discharge lamp lighting device comprising: a control unit that controls the switching of the DC power supply so that the DC output of the DC power supply is intermittently connected to the positive electrode side of the DC power supply; A direct current cut capacitor for cutting a direct current component from a high frequency output intermittently connected by one or a plurality of switching elements;
A resonance circuit that has a resonance coil and a resonance capacitor and that resonates with a high-frequency output from which the direct current component is cut and supplies the resonance output to the discharge lamp is provided in the inverter section, and is controlled by the direct current output of the direct current power source. The first power supply unit is equipped with a power supply switching element for turning on and off the operation of the first power supply unit, and the control terminal of the power supply switching device is connected to the connection point between the DC cut capacitor and the resonance circuit via a resistor. It is characterized by being connected by.

According to a second aspect of the invention, in the first aspect of the invention, there is provided stop means for turning off the power supply switching element of the first power source section when operating power is being supplied from the second power source section to the control section. It is characterized by having. According to a third aspect of the present invention, in the first or second aspect of the invention, the DC power source is provided, which includes a power source and a chopper portion that generates a desired DC output from the power source.

According to a fourth aspect of the present invention, in the first to third aspects of the present invention, there is provided discharging means for discharging the charge of the DC cut capacitor and the resonance capacitor when the discharge lamp is connected to the output end of the inverter section. It is characterized by having.

[0014]

According to the present invention, the DC power supply, the inverter section for converting the DC output of the DC power supply into the high frequency output and supplying it to the discharge lamp, the control section for controlling the operation of the inverter section, and the DC power supply. A discharge lamp lighting device comprising: a first power supply unit that generates an operation power supply for a control unit from a DC output of the second power supply unit; and a second power supply unit that generates an operation power supply for a control unit from a high frequency output of an inverter unit, One or a plurality of switching elements that are switching-controlled by the control unit to periodically connect and disconnect the DC output of the DC power supply, and a high-frequency output that is DC-conductive with the positive side of the DC power supply and that is connected and disconnected by the one or more switching elements. Has a direct current cut capacitor that cuts the direct current component, a resonance coil and a resonance capacitor, and resonates with the high frequency output from which the direct current component has been cut, and supplies the resonance output to the discharge lamp. The oscillation circuit provided in the inverter unit,
The first power supply unit is equipped with a power supply switching element that turns on and off the operation of the first power supply unit under the control of the DC output of the DC power supply, and the control terminal of this power supply switching device is used as a DC cut capacitor. Since it was connected via a resistor to the connection point with the resonance circuit, the current supply from the DC power supply to the control terminal of the power supply switching element of the first power supply section was done by the DC cut capacitor when the discharge lamp was removed. This prevents the first power supply section from continuing to operate in a state where the switching element for power supply is turned off and the discharge lamp is removed.

According to the second aspect of the invention, since the stop means for turning off the power supply switching element of the first power supply section is provided when the operating power is being supplied from the second power supply section to the control section, The operation of the first power supply unit is stopped by the stopping means when the inverter unit starts operating, and the operation power supply to the control unit is performed only from the second power supply unit, which is unnecessary in the first power supply unit. Power consumption is suppressed, and furthermore, the first power supply unit stops operating even when the discharge lamp is removed, so that regardless of whether or not the discharge lamp is connected,
It is possible to efficiently supply the operating power to the control unit with low power loss.

According to the third aspect of the invention, since the DC power source having the power source and the chopper section for generating a desired DC output from the power source is provided, various power sources can be used by using the chopper section. Even if the desired DC power supply is obtained and the discharge lamp is removed and the chopper section becomes a light load and the output of the chopper section overshoots, excessive stress is applied to the circuit elements that make up each section. Can be prevented.

According to the fourth aspect of the invention, the discharge means is provided for discharging the charge of the DC cut capacitor and the resonance capacitor when the discharge lamp is connected to the output end of the inverter section. Current is supplied to the control terminal of the power supply switching element of the power supply unit via the DC cut capacitor, and the first power supply unit operates again to restart supply of operating power to the control unit. it can.

[0018]

【Example】

(Embodiment 1) FIG. 1 is a circuit diagram showing a first embodiment of the present invention. As shown in FIG. 1, the basic configuration of this embodiment is shown in FIG.
The same parts as those of the conventional example shown in FIG.

This embodiment is different from the conventional construction in that
Power supply switching element Q of the power supply unit 5 of₃Control terminal
(Base) is a capacitor C for cutting DC₁And series resonance times
Resonance capacitor C forming a path₂Resistance R at the connection point with
₃It is characterized by the fact that it is connected via
The configuration is common to the conventional example. Next, in this embodiment,
The operation will be described. First, two discharge lamps 3a and 3b
Is installed and connected in series to the output terminal of the inverter unit 2.
In normal condition, power supply from DC power supply 1 is open.
When started, DC power supply 1 positive electrode → DC cutting capacitor
SA C₁→ The filament fa of the discharge lamp 3a₁→ resistance R₃→
Zener diode ZD₁Of the DC power supply 1
Positive electrode → switching element Q₁Resistor R connected to both ends of
₂→ Primary winding n of choke coil L₁→ Discharge lamp 3b
Filament fb ₂→ Resonance capacitor C₂→ resistance R₃→
Zener diode ZD₁Direct current flows through the path
Be done. Therefore, the power supply switching of the first power supply unit 5
Element Q₃Base current is supplied to the power supply for switching
Element Q₃Turns on and the resistance R₁， Power supply switching element
Q₃, Diode D₂Smoothing capacitor C via_FourIs full
Then, the operating power of the control unit 4 is generated. At the same time
Capacitor C for DC cut by DC current₁And both
Swing capacitor C₂Is charged.

Here, as the DC cut capacitor C ₁ and the resonance capacitor C ₂ are charged by the DC current, the DC cut capacitor C ₁ (one end of the filament fa ₁ of the discharge lamp 3a) and the resonance capacitor C ₂ are charged. ₂ and resistance R
Potential of ₃ and the connection point (A point in FIG. 1) includes a DC blocking capacitor C ₁ and the resonance capacitor C ₂ resistor R
Gradually decreases with a time constant determined by each capacitance value and resistance value of ₃ . Then, when a predetermined time determined by this time constant elapses, the potential at the point A becomes the Zener diode ZD.
Below the Zener voltage of ₁ , the base current is no longer supplied to the power supply switching element Q ₃ and the power supply switching element Q ₃ is turned off, and the generation of operating power supply in the first power supply unit 5 is stopped.

However, as described above, it takes a predetermined time determined by the time constant from the start of the power supply from the DC power supply 1 to the stop of the first power supply unit 5, so that the first power supply unit 5 is in the meantime. The control unit 4 which receives the supply of the operating power from the device can activate the inverter unit 2, and the generation of the operating power is started in the second power unit 6 before the first power unit 5 stops. Therefore, the control unit 4 can be continuously operated. Regarding the operation after the generation of the operating power supply in the second power supply unit 6 is started,
Since the operation is the same as that of the conventional example described above, the description thereof will be omitted.

Next, a case will be described in which one of the two discharge lamps 3a and 3b which is directly connected to the DC-cutting capacitor C ₁ is removed. If the discharge lamp 3a is removed, the DC-cutting capacitor C ₁ and the point A are disconnected, and the inverter unit 2
Since no resonance loop is formed in the series resonance circuit of, the resonance current no longer flows in the primary winding n ₁ of the choke coil L. As a result, the operation of the second power supply unit 6 is stopped, and the operation power supply to the control unit 4 is stopped.

Here, as described in the conventional example,
When the generation of the operating power supply in the second power supply unit 6 is stopped, the potential across the smoothing capacitor C ₄ of the first power supply unit 5 also drops due to discharge. Therefore, the positive electrode of the DC power supply 1 → the resistance R
₂ → primary winding n ₁ of choke coil L → filament fb ₂ of discharge lamp 3b → resonant capacitor C ₂ → resistor R ₃ →
A current flows through the path of the Zener diode ZD _{1 and} the base current is also supplied to the power supply switching element Q ₃ to turn on the power supply switching element Q ₃ , and the first power supply unit 5 starts generating the operating power supply. However, as the resonance capacitor C ₂ is charged by the above current, the potential at the point A drops, and eventually falls below the Zener voltage of the Zener diode ZD ₁ , the supply of the base current to the power supply switching element Q ₃ is stopped again. Power supply switching element Q ₃ is turned off, and the first power supply unit 5
Operation stops.

Similarly, even when the other discharge lamp 3b is removed, the second power supply section 6 is stopped because the resonance loop of the series resonance circuit is not formed, and the voltage across the smoothing capacitor C ₄ drops, The positive electrode of the DC power supply 1 → the DC cut capacitor C ₁ → the fillant fa ₁ of the discharge lamp 3a → the resistance R ₃ → the Zener diode ZD ₁ causes a current to flow and the power supply switching element Q ₃ turns on once. As the DC cut capacitor C ₁ is charged,
Since the potential at the point drops, the power supply switching element Q ₃
Is turned off again, and the operation of the first power supply unit 5 is stopped.
In the case where two light discharge lamps 3a, 3b is also removed both, because the path the base current of the power switching element Q ₃ is supplied at all eliminated, the first power source unit 5 to work Absent.

As described above, according to the configuration of this embodiment,
2 lamp of the discharge lamp 3a, since it is possible to at least one of the discharge lamps 3a, turns off the power switching element Q ₃ of the first power supply portion 5 when 3b is removed out of 3b, a discharge lamp 3a, 3b In this state, unnecessary power loss does not occur due to the resistance R ₁ of the first power source section 5 and the like. Further, in the present embodiment, the operation of the first power supply unit 5 is stopped when the generation of the operating power supply of the control unit 4 is started in the second power supply unit 6. That is, since the second power supply unit 6 has priority over the first power supply unit 5 in generating the operating power supply to the control unit 4,
Even in a normal state in which the discharge lamps 3a and 3b are attached, it is possible to suppress unnecessary power consumption in the first power supply unit 5 and supply the operating power very efficiently.

(Embodiment 2) FIG. 2 is a circuit diagram showing a second embodiment of the present invention. In this embodiment, one end of a resistor R ₃ is connected to a DC cutting capacitor C ₁ and a filament fa of a discharge lamp 3a. The configuration and the operation are the same as those in the first embodiment except that they are connected between the _first and second embodiments. Therefore, common parts are denoted by the same reference numerals and description thereof is omitted.

Also in this embodiment, two discharge lamps 3a, 3
When at least one of b is removed, a current flows through the path of the positive electrode of the DC power supply 1 → the DC cutting capacitor C ₁ → the resistor R ₃ → the Zener diode ZD _{1 and} the power supply switching element Q ₃ is turned on once. However, due to the charging of the DC cut capacitor C ₁ , the DC cut capacitor C
_Since the potential at the connection point between ₁ and the resistor R ₃ drops, the power supply switching element Q ₃ is turned off and the operation of the first power supply unit 5 can be stopped.

(Embodiment 3) FIG. 3 is a circuit diagram showing a third embodiment of the present invention. This embodiment is the same as the first and second embodiments in the configuration and the operation except that one discharge lamp 3 is turned on, and the common portions are denoted by the same reference numerals and the description thereof will be omitted. In this embodiment, the discharge lamp 3 is connected to both ends of the switching element Q ₂ of the inverter unit 2 via the DC cut capacitor C ₁ , the primary winding n ₁ of the choke coil L and the resonance capacitor C ₂ . The base of the power supply switching element Q ₃ is connected between the DC cut capacitor C ₁ and the primary winding n ₁ of the choke coil L via a resistor R ₃ , and the other first power supply unit 5, The configurations and operations of the second power supply unit 6 and the control unit 4 are described in the first embodiment.
This is the same as No. 2 and its explanation is omitted.

Also in this embodiment, when the discharge lamp 3 is removed, the positive electrode of the DC power source 1 → the resistance R ₂ → the DC cutting capacitor C ₁ → the resistance R ₃ → the Zener diode ZD.
Power supply switching element Q due to the current flowing in the ₁ path
₃ is turned on once, but the potential at the connection point between the DC cut capacitor C ₁ and the resistor R ₃ drops as the DC cut capacitor C ₁ is charged, and the power supply switching element Q ₃ is turned off to turn the first switch ON. The operation of the power supply unit 5 can be stopped.

(Embodiment 4) FIG. 4 is a circuit diagram showing a fourth embodiment of the present invention. In this embodiment, one switching element Q ₁ and a parallel resonant circuit of an inductance L ₀ and a capacitor C ₀ are connected to both ends of a DC power supply 1, and a DC cutting capacitor C ₁ and a primary winding of a choke coil L. Line n
The configuration is substantially the same as that of the third embodiment except that a one-stone type inverter unit 2 ′ that supplies high-frequency power to the discharge lamp 3 via a series resonance circuit including the resonance capacitor ₁ and the resonance capacitor C ₂ is used. The common parts are denoted by the same reference numerals and the description thereof will be omitted.

In this embodiment, the base of the power supply switching element Q ₃ is connected to the connection point between _one filament f ₁ of the discharge lamp 3 and the resonance capacitor C ₂ via the resistor R ₃ , and the discharge lamp 3 in a state in which is properly installed, the first power supply unit 5 control unit 4 turns on the power switching element Q ₃ in the same manner as in example 1-3 power supply is started from the DC power source 1 The operating power is generated to activate the inverter unit 2 '. Then, the potential at the point B in FIG. 4 drops due to the charging of the DC cut capacitor C ₁ , and the power supply switching element Q ₃ turns off eventually, but at this point the inverter unit 2 ′ is activated. The second power supply unit 6 generates operating power.

Here, one filament f of the discharge lamp 3
_{When 1} is disengaged, the resonance loop of the series resonance circuit is broken, so that the second power supply unit 6 stops operating and
DC power source 1 positive pole → inductance L ₀ → choke coil L primary winding n ₁ → filament f ₂ → resonance capacitor C ₂ → resistor R ₃ → Zener diode ZD ₁ The element Q ₃ is turned on and the first power supply unit 5 operates. However, since the potential at the point B drops as the DC cut capacitor C ₁ is charged, the base current is no longer supplied to the power supply switching element Q ₃ and the power supply switching element Q _3
3 is turned off and the operation of the first power supply unit 5 is also stopped.

Similarly, the other filament f of the discharge lamp 3
_{When 2} is disengaged, a current flows through the path of the positive electrode of the DC power supply 1 → the DC cutting capacitor C ₁ → the filament f ₁ → the resistance R ₃ → the Zener diode ZD _{1 and} the power supply switching element Q ₃ is turned on once. Although the first power supply unit 5 operates, the power supply switching element Q ₃ is turned off as the DC cut capacitor C ₁ is charged, and the first power supply unit 5 is activated.
Also stops. When the discharge lamp 3 is detached and both filaments f ₁ and f ₂ are detached, no current flows in either the primary winding n ₁ of the choke coil L or the Zener diode ZD ₁ , so that the first and _second filaments f ₁ and f ₂ are detached. 2 power supplies 5, 6
Needless to say, all of them stop operating.

(Embodiment 5) FIG. 5 is a circuit diagram showing a fifth embodiment of the present invention. In order to share the inverter section 2 with different AC power supplies AC, different AC power supplies A are used.
It suffices that the input voltage to the inverter unit 2 in C be the same, and therefore, a chopper circuit that can obtain a desired DC power supply from the AC power supply AC is effective. A full-wave rectifier DB including a diode bridge and a step-up type chopper circuit 10 constitute a DC power supply 1. The configuration other than the DC power supply 1 is completely common to that of the first embodiment, and the common parts are denoted by the same reference numerals and the description thereof is omitted.

The AC output of the AC power supply AC is a capacitor C
_It is input to the full-wave rectifier DB through a low-pass filter 11 composed of ₅ , C ₆ and a filter coil Lf, and the pulsating flow output of the full-wave rectifier DB is input to the chopper circuit 10. The chopper circuit 10 includes a choke coil L ₂ and
A switching element Q ₄ composed of a MOSFET, a smoothing capacitor C _7, and a chopper control circuit 10 a composed of an integrated circuit for performing switching control of the switching element Q ₄ are main components. Hereinafter, a specific circuit configuration of the chopper circuit 10 will be described.

A choke coil is provided on the output side of the full-wave rectifier DB.
Le L₂And diode D_FiveThrough the series circuit of
Densa C₇Are connected. And this chokeco
IL L₂And diode D_FiveSwitching to the connection point with
Element Q_FourAnd resistance R_TenThe series circuit of is the capacitor C₇Parallel with
It is connected to the. The full-wave rectifier DB pulsating current output is full-wave
Voltage dividing resistor R connected in series between the output terminals of the rectifier DB₁₁,
R₁₂Is divided by and input to the chopper control circuit 10a
Has been done. Also, choke coil L₂Current flowing through
Is the choke coil L₂Secondary winding n₂Detected by
Resistance R₁₃Input to the chopper control circuit 10a via
Have been. The output of the chopper control circuit 10a is a resistor R₁₄
Through the switching element Q_FourIs input to the gate of
Switching element Q_FourCurrent flowing through the resistor R_TenBy
It is detected and input to the chopper control circuit 10a.
Also, smoothing capacitor C₇The voltage across the
SA C ₇Voltage dividing resistor R connected in series in parallel with₁₆, R₁₇By
Is divided and input to the chopper control circuit 10a.
It Here, the chopper control circuit 10a is
R₁₆, R₁₇Based on the voltage value detected by
Sensor C₇Switch so that the desired voltage is obtained across
Holding element Q_FourON / OFF control for switching element
Q_FourThe on-duty of is changed. Also full-wave rectification
Pulsation output of vessel DB and choke coil L₂Current value flowing in
Or switching element Q_FourThe current value flowing through
A light load is detected by the control circuit 10a.
It is also possible to protect the circuit at the time. The chopper
The operating power supply of the control circuit 10a is the first and second power supply units.
I got it from 5 and 6.

By the way, the operating power supply of the control unit 4 and the chopper control circuit 10a generated in the second power supply unit 6 is optimized in the resonance state of the inverter unit 2 when the chopper circuit 10 is operating. It is set. Therefore, when the power supply from the AC power supply AC is started, the first power supply unit 5 generates the operating power supply for the control unit 4 and the chopper control circuit 10a to start the operation of the chopper circuit 10, and at the same time, the inverter unit. A method of operating 2 to generate sufficient operating power by the second power supply unit 6 is very effective.

Here, when at least one of the two discharge lamps 3a and 3b is removed, the first power supply unit 5
If the chopper circuit 10 continues to operate and the chopper circuit 10 is operating, unnecessary power loss such as driving power of the switching element Q ₄ of the chopper circuit 10 increases, and at the same time, the chopper circuit 10 has a very light load. Therefore, the overshoot occurs and the circuit element is overstressed. However, in the configuration of the present embodiment, since the operation of the first power supply unit 5 can be stopped when the discharge lamps 3a and 3b are removed, such a problem can be prevented. The first
The same effect can be obtained by connecting the resistor R ₁ of the power supply unit 5 to the preceding stage of the chopper circuit 10, that is, the point C in FIG.

(Embodiment 6) FIG. 6 is a circuit diagram showing a sixth embodiment of the present invention. The present embodiment is different from the structure of the first embodiment in that the connection point between the DC cut capacitor C ₁ and the filament fa ₁ of the discharge lamp 3a is connected via the resistor Ra to the resonance capacitor C ₂ and the filament of the discharge lamp 3b. It is characterized in that it is connected to the connection point of fb ₂ , and since the other configurations are common to those of the first embodiment, common parts are designated by the same reference numerals and description thereof is omitted.

The resistance Ra in the present embodiment is temporarily removed.
Remove the removed discharge lamp 3a (or discharge lamp 3b) again.
Capacitor C for DC cut when installed₁There
Is the capacitor C for resonance₂For discharging the charge of
It becomes a discharge resistance. That is, the discharge lamp 3a (or the discharge
When the lamp 3b) is reattached,
Voltage V_AIs V_A≒ R₃/ (R₂+ Ra + R₃) ・ E
(However, E is the power supply voltage of DC power supply 1)
Therefore, this voltage V_AZener diode ZD ₁Notsu
If the voltage is higher than the
Itching element Q ₃The base current is supplied again to the first
The power supply unit 5 generates operating power and restarts the inverter unit 2.
Can be moved. In addition, as shown in FIG.
Resonance capacitor C in the configuration of Example 2₂In parallel with the above
Even if the resistor Ra as the discharge resistor is connected, the discharge lamp
3a (or discharge lamp 3b) can be installed again
The inverter unit 2 can be restarted.

[0041]

According to the invention of claim 1, a DC power source, an inverter unit for converting a DC output of the DC power source into a high frequency output and supplying it to a discharge lamp, a control unit for controlling the operation of the inverter unit, and a DC power source. A discharge lamp lighting device comprising: a first power supply unit that generates an operation power supply for a control unit from a DC output of the second power supply unit; and a second power supply unit that generates an operation power supply for a control unit from a high frequency output of an inverter unit, One or a plurality of switching elements that are switching-controlled by the control unit to periodically connect and disconnect the DC output of the DC power supply, and a high-frequency output that is DC-conductive with the positive side of the DC power supply and that is connected and disconnected by the one or more switching elements. A DC cut capacitor that cuts the DC component from the DC power supply and a resonance coil and a resonance capacitor that resonate with the high-frequency output with the DC component cut and supply the resonance output to the discharge lamp. And a switching element for a power supply, which is included in an inverter unit and is controlled by a DC output of a DC power supply to turn on and off the operation of the first power supply unit, and the switching element for the power supply. Since the control terminal of is connected to the connection point between the DC cut capacitor and the resonance circuit via a resistor, when the discharge lamp is removed, the DC power supply changes to the control terminal of the power supply switching element of the first power supply section. Current supply is blocked by the DC cut capacitor and the power supply switching element is turned off.
The first power supply unit does not continue to operate with the discharge lamp removed, and there is an effect that unnecessary power loss when the discharge lamp is removed can be suppressed.

According to the second aspect of the invention, since the second power source section is provided with the stopping means for turning off the power source switching element of the first power source section when the operating power is being supplied to the control section, the inverter is usually used. When the section starts operating, the operation of the first power source section is stopped by the stop means, and the operating power is supplied to the control section only from the second power source section, so that unnecessary power in the first power source section is not supplied. The first power supply unit stops the operation even if the consumption is suppressed and the discharge lamp is removed. Therefore, regardless of whether or not the discharge lamp is connected, the control unit is always efficient with a low power loss. There is an effect that the operating power of can be supplied.

According to the third aspect of the present invention, since the DC power source having the power source and the chopper section for generating a desired DC output from the power source is provided, it is possible to use various power sources by using the chopper section. Even when a direct current power source is obtained and the discharge lamp is removed, the chopper part becomes a light load and overshoot occurs in the output of the chopper part.
This has an effect of preventing excessive stress from being applied to the circuit elements forming each part.

According to a fourth aspect of the present invention, the first power source section includes the discharging means for discharging the charge stored in the DC cut capacitor and the resonance capacitor when the discharge lamp is connected to the output end of the inverter section. A current is supplied to the control terminal of the power supply switching element via the DC cut capacitor, and the first power supply unit operates again to restart the supply of operating power to the control unit to operate the inverter unit. The effect is that it can be restarted.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a first embodiment.

FIG. 2 is a circuit diagram showing a second embodiment.

FIG. 3 is a circuit diagram showing a third embodiment.

FIG. 4 is a circuit diagram showing a fourth embodiment.

FIG. 5 is a circuit diagram showing a fifth embodiment.

FIG. 6 is a circuit diagram showing a sixth embodiment.

FIG. 7 is a circuit diagram showing another configuration of the above.

FIG. 8 is a circuit diagram showing a conventional example.

[Explanation of symbols]

1 DC power source 2 inverter section 2a series resonant circuits 3a, 3b discharge lamp 4 control unit 5 first power source unit 6 and the second power supply unit R ₁ to R ₃ resistance ZD _1, ZD ₂ Zener diode Q ₃ power switching element

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takeshi Shibata 404-1 Nishinoue, Himeji City, Hyogo Prefecture Ikeda Electric Co., Ltd.

Claims (4)

[Claims] 1. A DC power supply, an inverter section for converting the DC output of the DC power supply into a high frequency output for supply to a discharge lamp, a control section for controlling the operation of the inverter section, and a DC output from the DC power supply for the control section. A first power supply unit that generates an operating power supply;
A discharge lamp lighting device comprising: a second power supply unit that generates an operating power supply for a control unit from a high frequency output of an inverter unit,
One or a plurality of switching elements that are switching-controlled by the control unit to periodically connect and disconnect the DC output of the DC power supply, and a high-frequency output that is DC-conductive with the positive side of the DC power supply and that is connected and disconnected by the one or more switching elements. In the inverter section, a DC cut capacitor that cuts the DC component from the power supply and a resonance circuit that has a resonance coil and a resonance capacitor and that resonates with the high frequency output from which the DC component is cut and supplies the resonance output to the discharge lamp are provided. In addition, the first power supply unit is equipped with a power supply switching element that is controlled by the DC output of the DC power supply to turn on / off the operation of the first power supply unit, and the control terminal of this power supply switching device is used for cutting the direct current. A discharge lamp lighting device characterized in that it is connected to a connection point between a capacitor and a resonance circuit via a resistor. 2. The stop means for turning off the power supply switching element of the first power supply unit when the operating power is being supplied from the second power supply unit to the control unit. Discharge lamp lighting device. 3. The discharge lamp lighting device according to claim 1, further comprising the DC power supply having a power supply and a chopper section for generating a desired DC output from the power supply. 4. The discharging means for discharging the charge stored in the DC cutting capacitor and the resonance capacitor when the discharge lamp is connected to the output end of the inverter section. Discharge lamp lighting device.