JP2010165632A - Discharge lamp lighting device and lighting fixture - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device and a lighting fixture capable of shortening a generation interval of high-pressure pulses with the use of a small charging resistance of a rated voltage even in case an attenuation of the high-pressure pulses is alleviated by increasing capacity of a charging and discharging capacitor. <P>SOLUTION: If a charging voltage detected is yet below a given voltage smaller than a voltage value enough to make a two-terminal thyristor 21 conductive, in starting a high-pressure discharge lamp 17 of a load circuit, an output voltage of a boosting chopper circuit 5 is set at a first output voltage larger than a minimum voltage value to make the two-terminal thyristor 21 conductive, and, if a charging voltage detected reaches a given voltage smaller than a voltage value enough to make the two-terminal thyristor 21 conductive, an output voltage of the boosting chopper circuit 5 is to be set at a point higher than a lowest-limit voltage value to make the two-terminal thyristor 21 conductive, and that, at a second output voltage smaller than the first output voltage. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a discharge lamp lighting device and a lighting fixture including the same.

  The conventional discharge lamp lighting device is, for example, “When the high-pressure discharge lamp of the load circuit is started, the high-pressure discharge lamp is lit so that the charging voltage of the charge / discharge circuit becomes a voltage value for conducting the two-terminal thyristor. After that, "the DC power supply circuit is controlled so that the charging voltage becomes a voltage value that makes the two-terminal thyristor non-conductive" has been proposed (see, for example, Patent Document 1).

Japanese Patent Laying-Open No. 2007-200793 (Claim 1)

In a conventional discharge lamp lighting device, a charge / discharge capacitor is connected between both output terminals of a DC power supply circuit through a charge resistor and a diode in series, and the primary winding side of the step-up transformer is connected in parallel with the charge / discharge capacitor. It has an igniter starting circuit in which two-terminal thyristors such as Sydac are connected in series.
When starting the discharge lamp, the output voltage of the DC power supply circuit is set to a value exceeding the breakover voltage of the two-terminal thyristor to generate a high voltage pulse. When the discharge lamp is turned on, the high voltage pulse is reliably stopped by lowering the output voltage of the DC power supply circuit to a voltage lower than the breakover voltage of the two-terminal thyristor.
In a discharge lamp lighting device, it is desired to reduce the attenuation of a high-pressure pulse. The attenuation of the high-voltage pulse can be reduced as the capacity of the charge / discharge capacitor increases.

  However, when the capacity of the charge / discharge capacitor is increased, there is a problem that the start interval is deteriorated because the generation interval of the high voltage pulse becomes long.

On the other hand, even when the capacitance of the charge / discharge capacitor is increased, the generation interval of the high-voltage pulse can be shortened by decreasing the resistance value of the charging resistor.
However, when the resistance value of the charging resistor is reduced, the current flowing through the charging resistor increases, and thus there is a problem that it is necessary to use a resistor with a large rated power.

  The present invention has been made to solve the above-described problems. Even when the capacity of the charge / discharge capacitor is increased to reduce the attenuation of the high voltage pulse, the high voltage pulse is reduced by using a charging resistor having a small rated power. It is an object to provide a discharge lamp lighting device and a lighting fixture capable of shortening the generation interval.

  A discharge lamp lighting device according to the present invention includes a load circuit to which a discharge lamp is attached, a rectifier circuit that rectifies a commercial power supply, a boost chopper circuit that converts an output voltage of the rectifier circuit into a desired DC voltage, and the boost chopper An inverter circuit that converts a DC voltage from the circuit into an AC voltage and supplies the AC voltage to the load circuit, a step-up transformer in which a secondary winding is inserted into the load circuit, and a primary winding side of the step-up transformer A charge / discharge circuit provided between the outputs of the two-terminal thyristor and the step-up chopper circuit, and when the charge voltage of the charge / discharge circuit rises and the two-terminal thyristor becomes conductive, the secondary winding of the step-up transformer A starting circuit for generating a high voltage pulse on the wire, a control means for controlling at least the step-up chopper circuit, and a voltage detecting means for detecting a charging voltage charged in the charging / discharging circuit. The control means, when starting the discharge lamp of the load circuit, when the detected charging voltage does not reach a predetermined voltage smaller than a voltage value for conducting the two-terminal thyristor, The output voltage is set to a first output voltage larger than a minimum voltage value at which the two-terminal thyristor is conducted, and the detected charging voltage is set to a predetermined voltage smaller than a voltage value at which the two-terminal thyristor is conducted. When the voltage reaches, the output voltage of the step-up chopper circuit is set to a second output voltage that is equal to or higher than a minimum voltage value at which the two-terminal thyristor is conducted and smaller than the first output voltage.

  Further, a discharge lamp lighting device according to the present invention includes a load circuit to which a discharge lamp is attached, a rectifier circuit that rectifies commercial power, a boost chopper circuit that converts an output voltage of the rectifier circuit into a desired DC voltage, An inverter circuit that converts a DC voltage from a boost chopper circuit into an AC voltage and supplies the AC voltage to the load circuit, a boost transformer in which a secondary winding is inserted into the load circuit, and a primary winding side of the boost transformer And a charge / discharge circuit provided between outputs of the step-up chopper circuit, and when the charge voltage of the charge / discharge circuit rises and the two-terminal thyristor becomes conductive, the step-up transformer 2 A starting circuit for generating a high voltage pulse in the next winding, a control means for controlling at least the step-up chopper circuit, and a voltage detecting means for detecting a charging voltage charged in the charging / discharging circuit; The charge / discharge circuit includes a first charge resistor, a diode, and a charge / discharge capacitor connected in series between outputs of the boost chopper circuit, and a second connected in parallel with the first charge resistor. And a switch that is controlled by the control means to turn on / off the connection of the second charging resistor, and the second charging resistor has a resistance value smaller than that of the first charging resistor. Is.

  The present invention sets the output voltage of the boost chopper circuit to the first output voltage when the charging voltage does not reach the predetermined voltage, and sets the output voltage of the boost chopper circuit when the charging voltage reaches the predetermined voltage. Since the second output voltage is set, even when the capacity of the charge / discharge capacitor is increased to reduce the attenuation of the high-voltage pulse, the generation interval of the high-voltage pulse can be shortened using a charging resistor having a small rated power.

  Further, when a second charging resistor having a resistance value smaller than that of the first charging resistor is connected in parallel with the first charging resistor, and the charging voltage does not reach a predetermined voltage, the second charging resistor is connected. When the charging voltage reaches a predetermined voltage, the connection of the second charging resistor is turned off. Therefore, even when the capacity of the charging / discharging capacitor is increased to reduce the attenuation of the high voltage pulse, The generation interval of the high voltage pulse can be shortened by using a small charging resistance.

1 is a circuit diagram showing a configuration of a discharge lamp lighting device according to Embodiment 1. FIG. It is a figure which shows the waveform of the high voltage | pressure pulse generated when starting high pressure discharge lamp, and the igniter starting circuit. It is a figure which shows the high voltage | pressure pulse which concerns on Embodiment 1, and the waveform of an igniter starting circuit. 3 is a flowchart showing the operation of the control circuit according to the first embodiment. 5 is a circuit diagram of a discharge lamp lighting device according to Embodiment 2. FIG. It is a figure which shows the waveform of the high voltage | pressure pulse which concerns on Embodiment 2, and an igniter starting circuit. 6 is a flowchart illustrating an operation of a control circuit according to the second embodiment. It is a figure which shows the structure of the lighting fixture which concerns on Embodiment 3. FIG.

Embodiment 1 FIG.
1 is a circuit diagram showing a configuration of a discharge lamp lighting device according to Embodiment 1. FIG.
In FIG. 1, the discharge lamp lighting device of the present embodiment includes a DC power supply circuit 1, a half-bridge inverter circuit, a load circuit, an igniter start circuit, and a control circuit 22.

  The DC power supply circuit 1 includes, for example, a rectifier circuit 3 that rectifies AC power of an AC power supply 2 such as a commercial power supply into DC power, a capacitor 4 connected between both output terminals of the rectifier circuit 3, And a step-up chopper circuit 5 connected between both output terminals.

The step-up chopper circuit 5 has a switching element 7 connected in parallel to the output terminal of the rectifier circuit 3 via the inductor 6 and a diode 8 connected to the inverter circuit via the forward polarity.
The step-up chopper circuit 5 converts the output voltage of the rectifier circuit 3 into a desired DC voltage when the switching element 7 is ON / OFF controlled at a high frequency by the control circuit 22.

The inverter circuit includes a series circuit of a first electrolytic capacitor 9 and a second electrolytic capacitor 10 connected between outputs of the boost chopper circuit 5, and a series circuit of the first electrolytic capacitor 9 and the second electrolytic capacitor 10. And a series circuit of a first switching element 11 and a second switching element 12 connected in parallel.
This inverter circuit converts the DC voltage from the boost chopper circuit 5 into an AC voltage and supplies it to the load circuit.

  The load circuit includes an inductor 13, a capacitor 14, and a capacitor 15. A high pressure discharge lamp 17 is attached to this load circuit.

  The inductor 13 and the capacitor 14 are connected in series between the connection point of the first switching element 11 and the second switching element 12 and the connection point of the first electrolytic capacitor 9 and the second electrolytic capacitor 10. The

  The capacitor 15 is connected between the connection point of the inductor 13 and the capacitor 14 and the ground.

The high pressure discharge lamp 17 is connected in series with a secondary winding of a step-up transformer 16 described later, and is connected in parallel with the capacitor 14.
As the high-pressure discharge lamp 17, for example, an HID lamp (high-pressure mercury lamp), a high-pressure sodium lamp, a metal halide lamp, or the like is used.
The high pressure discharge lamp 17 corresponds to the discharge lamp in the present invention.

  The igniter starting circuit includes a charge / discharge circuit, a step-up transformer 16 and a two-terminal thyristor 21.

The charge / discharge circuit includes a charge resistor 18, a diode 19, and a charge / discharge capacitor 20.
The charging resistor 18, the diode 19, and the charging / discharging capacitor 20 are connected in series and are connected between both output terminals of the boost chopper circuit 5.

  The step-up transformer 16 has a secondary winding inserted between the connection point of the inductor 13 and the capacitor 14 of the load circuit and the high-pressure discharge lamp 17. One end of the primary winding is connected to a connection point between the diode 19 and the charge / discharge capacitor 20 of the charge / discharge circuit, and the other end is connected to the two-terminal thyristor 21.

The two-terminal thyristor 21 is connected in series with the primary winding of the step-up transformer 16. The two-terminal thyristor 21 is composed of, for example, Sidac.
The primary windings of the two-terminal thyristor 21 and the step-up transformer 16 are connected in parallel with the charge / discharge capacitor 20.

This igniter starting circuit generates a high voltage pulse in the secondary winding of the step-up transformer 16 when the charging voltage of the charging / discharging circuit rises and the two-terminal thyristor 21 becomes conductive.
The igniter starting circuit corresponds to the starting circuit in the present invention.

The control circuit 22 controls the boost chopper circuit 5 and the inverter circuit.
The control circuit 22 has means (not shown) for detecting the voltage and current of the high-pressure discharge lamp 17. Then, according to the detected voltage and current, the power of the high-pressure discharge lamp 17 is adjusted by controlling the switching elements 11 and 12 of the inverter circuit on and off at a high frequency.

Further, the control circuit 22 has means (not shown) for detecting the output voltage of the boost chopper circuit 5. Then, the output voltage of the boost chopper circuit 5 is adjusted by controlling the switching element 7 of the boost chopper circuit 5 on and off at a high frequency according to the detected output voltage.
In this way, the control circuit 22 performs voltage feedback control for controlling the output voltage of the boost chopper circuit 5 based on the detected output voltage.

  The control circuit 22 includes voltage detection means (not shown) that detects a charging voltage charged in the charging / discharging circuit.

Further, the control circuit 22 has a storage device, and stores voltage value information to be described later.
The control circuit 22 corresponds to the control means in the present invention.

The configuration of the discharge lamp lighting device has been described above.
Next, control of the output voltage of the step-up chopper circuit 5 when the high-pressure discharge lamp 17 is started and lit will be described.

  First, the relationship between the reduction in the attenuation of the high voltage pulse and the generation interval of the high voltage pulse will be described with reference to FIG.

  FIG. 2 is a diagram showing a high-pressure pulse generated when starting and lighting a high-pressure discharge lamp and a waveform of an igniter starting circuit.

As shown in FIG. 2A, the output voltage of the step-up chopper circuit 5 is set to a voltage value at which the two-terminal thyristor 21 becomes conductive, and the voltage charged by the charging resistor 18 and the charge / discharge capacitor 20 of the igniter starting circuit is the two-terminal thyristor. When the breakover voltage of 21 is reached, the two-terminal thyristor 21 becomes conductive and a high voltage pulse is generated on the secondary winding side of the step-up transformer 16.
When the generation interval of the high voltage pulse becomes too wide, the startability is deteriorated, and therefore the maximum value (maximum specified interval) of the generation interval is normally specified.

FIG. 2B shows a waveform when the capacity of the charge / discharge capacitor 20 is increased.
In a discharge lamp lighting device, it is desired to reduce the attenuation of a high-pressure pulse. The attenuation of the high-voltage pulse can be reduced as the capacity of the charge / discharge capacitor 20 of the igniter starting circuit increases.
However, as shown in FIG. 2B, when the capacity of the charge / discharge capacitor 20 is increased, the time for charging the charge / discharge capacitor 20 also becomes longer, and the generation interval of the high-voltage pulse exceeds the specified value.

FIG. 2C shows a waveform when the resistance value of the charging resistor 18 is reduced.
Even when the capacity of the charging / discharging capacitor 20 is increased, the generation interval of the high-voltage pulse can be shortened by reducing the resistance value of the charging resistor 18.
However, as shown in FIG. 2 (c), if the resistance value of the charging resistor 18 is decreased, the current flowing through the charging resistor 18 immediately after the high voltage pulse is generated increases, so that it is necessary to use a resistor having a large rated power. .

  Even when the capacity of the charge / discharge capacitor 20 is increased to reduce the attenuation of the high voltage pulse, the generation interval of the high voltage pulse can be shortened (less than the maximum specified interval) by using the charging resistor 18 having a small rated power. The operation will be described next.

FIG. 3 is a diagram showing the high-voltage pulse and the waveform of the igniter starting circuit according to the first embodiment.
As shown in FIG. 3, when starting the high pressure discharge lamp 17, when the voltage value of the charge / discharge capacitor 20 rises to the vicinity of the breakover voltage of the two-terminal thyristor 21, the control circuit 22 The output voltage is lowered to a voltage value close to the breakover voltage of the two-terminal thyristor 21. When the high voltage pulse is generated and the voltage of the charge / discharge capacitor 20 is decreased, the output voltage of the step-up chopper circuit 5 is controlled to return to the voltage value before the decrease.
A detailed operation for controlling the output voltage of the boost chopper circuit 5 will be described next.

FIG. 4 is a flowchart showing the operation of the control circuit according to the first embodiment.
Hereinafter, description will be given based on each step of FIG.

(S101)
In the storage device included in the control circuit 22, information on “a voltage value sufficient to make the two-terminal thyristor 21 conductive”, information on “a minimum voltage value necessary for making the two-terminal thyristor 21 conductive”, and Information of “a predetermined voltage value in the vicinity of a voltage for conducting the two-terminal thyristor 21” is stored.

Note that “a voltage value sufficient to make the two-terminal thyristor 21 conductive” can be set to an arbitrary voltage value as long as the voltage value is larger than the minimum voltage value (breakover voltage) at which the two-terminal thyristor 21 is conductive. .
The “voltage value sufficient to make the two-terminal thyristor 21 conductive” corresponds to the first output voltage in the present invention.

The “minimum voltage value necessary for conducting the two-terminal thyristor 21” is equal to or higher than the minimum voltage value (breakover voltage) for conducting the two-terminal thyristor 21 and the “two-terminal thyristor 21 is rendered conductive. Any voltage value can be set as long as the voltage value is smaller than “sufficient voltage value”.
The “minimum voltage value necessary for conducting the two-terminal thyristor 21” corresponds to the second output voltage in the present invention.

The “predetermined voltage value near the voltage for conducting the two-terminal thyristor 21” can be set to an arbitrary voltage value as long as the voltage value is smaller than the voltage value (breakover voltage) for conducting the two-terminal thyristor 21.
The “predetermined voltage value near the voltage that causes the two-terminal thyristor 21 to conduct” corresponds to the predetermined voltage in the present invention.

(S102)
The control circuit 22 reads “a voltage value sufficient to make the two-terminal thyristor 21 conductive” stored in the storage device.

(S103)
The control circuit 22 performs on / off control of the switching element 7 at a high frequency so that the output voltage of the boost chopper circuit 5 becomes the read “voltage value sufficient to make the two-terminal thyristor 21 conductive”.

(S104)
The voltage detection means detects the charging voltage charged in the charge / discharge capacitor 20.
The control circuit 22 acquires the voltage value of the charge / discharge capacitor 20 detected by the voltage detection means.

(S105)
The control circuit 22 determines whether or not the detected charging voltage of the charging / discharging capacitor 20 has reached a “predetermined voltage value near the voltage at which the two-terminal thyristor 21 is conducted”.
If the charging voltage has not reached the “predetermined voltage value near the voltage at which the two-terminal thyristor 21 is conducted”, steps S104 to S105 are repeated.

(S106)
When the charging voltage reaches “a predetermined voltage value in the vicinity of a voltage for conducting the two-terminal thyristor 21”, the control circuit 22 stores “a minimum voltage value necessary for conducting the two-terminal thyristor 21” stored in the storage device. "Is read out.

(S107)
The control circuit 22 performs on / off control of the switching element 7 at a high frequency so that the output voltage of the boost chopper circuit 5 becomes the read “minimum voltage value necessary to make the two-terminal thyristor 21 conductive”.

(S108)
The voltage detection means detects the charging voltage charged in the charge / discharge capacitor 20.
The control circuit 22 acquires the voltage value of the charge / discharge capacitor 20 detected by the voltage detection means.

(S109)
The control circuit 22 determines that the two-terminal thyristor 21 is turned on when the detected charging voltage of the charge / discharge capacitor 20 becomes lower than “a predetermined voltage value near the voltage that makes the two-terminal thyristor 21 conductive”. . That is, the occurrence of a high voltage pulse is detected based on the charging voltage.
Steps S108 to S109 are repeated until the charging voltage of the charging / discharging capacitor 20 becomes lower than “a predetermined voltage value in the vicinity of the voltage that makes the two-terminal thyristor 21 conductive”.

(S110)
When it is determined that the two-terminal thyristor 21 is turned on, that is, when the generation of a high-pressure pulse is detected, the control circuit 22 detects at least one of the voltage and current of the high-pressure discharge lamp 17.

(S111)
The control circuit 22 determines whether or not the high pressure discharge lamp 17 has been lit.
This determination is made when the voltage value of the high pressure discharge lamp 17 becomes lower than a predetermined value or when the current value of the high pressure discharge lamp 17 becomes higher than a predetermined value. Is determined.
When the high pressure discharge lamp 17 is lit, the starting operation of the high pressure discharge lamp 17 is finished.

(S112)
When the high-pressure discharge lamp 17 is not lit, the control circuit 22 waits until a predetermined time has elapsed from the generation of the high-pressure pulse, returns to step S102, and repeats steps S102 to S112.
As this predetermined time, for example, a time during which the charging current sufficiently decreases is set.

As described above, in the present embodiment, when the high-pressure discharge lamp 17 is started, when the charging voltage does not reach the “predetermined voltage value near the voltage for conducting the two-terminal thyristor 21”, the boost chopper circuit 5 The output voltage is set to “a voltage value sufficient to make the two-terminal thyristor 21 conductive”.
Therefore, before the high voltage pulse is generated, the output voltage of the boost chopper circuit 5 can be increased, and the charging time to the charge / discharge capacitor 20 can be shortened.
Further, when the charging voltage reaches “a predetermined voltage value in the vicinity of the voltage for conducting the two-terminal thyristor 21”, the output voltage of the boost chopper circuit 5 is set to “the minimum voltage value necessary for conducting the two-terminal thyristor 21”. Set to.
Therefore, the output voltage of the boost chopper circuit 5 can be lowered immediately before the high voltage pulse is generated, and the current flowing through the charging resistor 18 can be reduced immediately after the high voltage pulse is generated.
Therefore, even when the capacity of the charge / discharge capacitor 20 is increased to reduce the attenuation of the high voltage pulse, the generation interval of the high voltage pulse can be shortened by using the charging resistor 18 having a small rated power.

Further, after a predetermined time has elapsed from the generation of the high voltage pulse, the output voltage of the boost chopper circuit 5 is set to “a voltage value sufficient to make the two-terminal thyristor 21 conductive”.
For this reason, the output voltage of the step-up chopper circuit 5 can be raised after the charging current flowing through the charging resistor 18 is lowered.
Therefore, the current flowing through the charging resistor 18 can be reduced, and the charging resistor 18 having a small rated power can be used.

  Further, by using the charging resistor 18 having a small rated power, the igniter starting circuit can be reduced in size.

  In the first embodiment, the output voltage of the boost chopper circuit 5 is increased after a predetermined time has elapsed from the generation of the high voltage pulse in step S112. However, the present invention is not limited to this, and the elapse of the predetermined time has elapsed. The output voltage of the step-up chopper circuit 5 may be gradually increased without waiting. A similar effect can be obtained by such an operation.

Embodiment 2. FIG.
In the first embodiment, the high voltage pulse generation interval is shortened by using the charging resistor 18 having a small rated power by changing the output voltage of the boost chopper circuit 5.
In the second embodiment, another embodiment will be described in which, even if the capacity of the charge / discharge capacitor 20 is increased, the generation interval of the high-voltage pulse is shortened by using a charging resistor having a small rated power.

FIG. 5 is a circuit diagram of a discharge lamp lighting device according to the second embodiment.
As shown in FIG. 5, the charging / discharging circuit of the discharge lamp lighting device according to the present embodiment includes a first charging resistor 18a, a diode 19, and a charging / discharging capacitor 20 connected in series between the outputs of the step-up chopper circuit 5. Are connected in parallel with the first charging resistor 18a, the second charging resistor 24 having a resistance value smaller than that of the first charging resistor 18a, and controlled by the control circuit 22 to turn on the connection of the second charging resistor 24. -It has the switch 23 to turn off.
The switch 23 can be realized by an arbitrary configuration as long as the connection is turned on / off, such as a semiconductor such as a contact relay or FET.

Furthermore, the discharge lamp lighting device according to the present embodiment includes voltage detection means (not shown) for detecting a charging voltage charged in the charge / discharge circuit.
Other configurations are the same as those of the first embodiment (FIG. 1), and the same portions are denoted by the same reference numerals.

Also in the second embodiment, as in the first embodiment, the storage device of the control circuit 22 stores in advance a “predetermined voltage value near the voltage that makes the two-terminal thyristor 21 conductive”. .
The “predetermined voltage value near the voltage for conducting the two-terminal thyristor 21” can be set to an arbitrary voltage value as long as the voltage value is smaller than the voltage value (breakover voltage) for conducting the two-terminal thyristor 21.
The “predetermined voltage value near the voltage that causes the two-terminal thyristor 21 to conduct” corresponds to the predetermined voltage in the present invention.

FIG. 6 is a diagram showing the high-voltage pulse and the waveform of the igniter starting circuit according to the second embodiment.
As shown in FIG. 6, when starting the high pressure discharge lamp 17, the control circuit 22 turns off the switch 23 when the voltage value of the charge / discharge capacitor 20 rises to near the breakover voltage of the two-terminal thyristor 21. To do. When a high voltage pulse occurs and the voltage value of the charge / discharge capacitor 20 decreases, the switch 23 is turned on.
The detailed operation for controlling the switch 23 will be described next.

FIG. 7 is a flowchart showing the operation of the control circuit according to the second embodiment.
Hereinafter, description will be given based on each step of FIG.
In the following description, it is assumed that the charge / discharge capacitor 20 is not charged and the switch 23 is on.

(S201)
The control circuit 22 outputs a signal for turning on the switch 23.
The switch 23 turns on the switch 23 based on a signal from the control circuit 22. Thereby, the 2nd charge resistance 24 will be in the state connected in parallel with the 1st charge resistance 18a.

(S202)
The voltage detection means detects the charging voltage charged in the charge / discharge capacitor 20.
The control circuit 22 acquires the voltage value of the charge / discharge capacitor 20 detected by the voltage detection means.

(S203)
The control circuit 22 determines whether or not the detected charging voltage of the charging / discharging capacitor 20 has reached a “predetermined voltage value near the voltage at which the two-terminal thyristor 21 is conducted”.
If the charging voltage has not reached the “predetermined voltage value near the voltage at which the two-terminal thyristor 21 is conducted”, the process returns to step S202.

(S204)
When the charging voltage reaches “a predetermined voltage value in the vicinity of a voltage for conducting the two-terminal thyristor 21”, the control circuit 22 outputs a signal for turning off the switch 23.
The switch 23 turns off the switch 23 based on a signal from the control circuit 22. As a result, the second charging resistor 24 is not connected in parallel with the first charging resistor 18a.

(S205)
The voltage detection means detects the charging voltage charged in the charge / discharge capacitor 20.
The control circuit 22 acquires the voltage value of the charge / discharge capacitor 20 detected by the voltage detection means.

(S206)
The control circuit 22 determines that the two-terminal thyristor 21 is turned on when the detected charging voltage of the charge / discharge capacitor 20 becomes lower than “a predetermined voltage value near the voltage that makes the two-terminal thyristor 21 conductive”. . That is, the occurrence of a high voltage pulse is detected based on the charging voltage.
When the charging voltage of the charging / discharging capacitor 20 is not lower than “a predetermined voltage value in the vicinity of the voltage for conducting the two-terminal thyristor 21”, the process returns to step S205.

(S207)
When it is determined that the two-terminal thyristor 21 is turned on, that is, when the generation of a high-pressure pulse is detected, the control circuit 22 detects at least one of the voltage and current of the high-pressure discharge lamp 17.

(S208)
The control circuit 22 determines whether or not the high pressure discharge lamp 17 has been lit.
This determination is made when the voltage value of the high pressure discharge lamp 17 becomes lower than a predetermined value or when the current value of the high pressure discharge lamp 17 becomes higher than a predetermined value. Is determined.
When the high pressure discharge lamp 17 is lit, the starting operation of the high pressure discharge lamp 17 is finished.

(S209)
When the high-pressure discharge lamp 17 is not lit, the control circuit 22 waits until a predetermined time elapses from the generation of the high-pressure pulse, returns to step S201, and repeats steps S201 to S209.
As this predetermined time, for example, a time during which the charging current sufficiently decreases is set.

As described above, in the present embodiment, when starting the high-pressure discharge lamp 17, the switch 23 is turned on when the charging voltage has not reached “a predetermined voltage value in the vicinity of the voltage for conducting the two-terminal thyristor 21”. To do.
Therefore, before the high voltage pulse is generated, the second charging resistor 24 is connected in parallel with the first charging resistor 18a, and the charging time to the charging / discharging capacitor 20 is reduced by the second charging resistor 24 having a small resistance value. Can be shortened.
In addition, when the charging voltage reaches “a predetermined voltage value in the vicinity of the voltage for conducting the two-terminal thyristor 21”, the switch 23 is turned off.
For this reason, the second charging resistor 24 can be disconnected from the first charging resistor 18a in parallel with the first charging resistor 18a immediately before the high voltage pulse is generated, and the first charging having a large resistance value immediately after the high voltage pulse is generated. The current is limited by the resistor 18a, and the current flowing through the first charging resistor 18a can be reduced.
Therefore, even when the capacity of the charge / discharge capacitor 20 is increased to reduce the attenuation of the high voltage pulse, the generation interval of the high voltage pulse is shortened using the first charging resistor 18a and the second charging resistor 24 having a small rated power. be able to.

Further, the switch 23 is turned on after a predetermined time has elapsed since the generation of the high voltage pulse.
For this reason, the second charging resistor 24 can be connected in parallel with the first charging resistor 18a after the charging current flowing through the first charging resistor 18a is reduced.
Therefore, the current flowing through the first charging resistor 18a and the second charging resistor 24 can be reduced, and the charging resistor 18 having a small rated power can be used.

  Further, by using the charging resistor 18 having a small rated power, the igniter starting circuit can be reduced in size.

Embodiment 3 FIG.
FIG. 8 is a diagram illustrating a configuration of a lighting fixture according to Embodiment 3. In FIG.
As shown in FIG. 8, the lighting fixture of the present embodiment includes the discharge lamp lighting device 100 according to any of the first or second embodiment, and the high-pressure discharge lamp 17 attached to the load circuit of the discharge lamp lighting device 100. And a reflector 200.

  With such a configuration, when the discharge lamp lighting device 100 starts the high-pressure discharge lamp 17, the lighting fixture in the present embodiment performs the operation of either the first or second embodiment.

  As described above, in the present embodiment, the lighting fixture includes the discharge lamp lighting device according to any of the first or second embodiment. Thereby, even when the capacity of the charge / discharge capacitor 20 is increased to reduce the attenuation of the high voltage pulse, the charging resistor 18 having a small rated power can be used to shorten the generation interval of the high voltage pulse, and the igniter starting circuit can be reduced in size. It is possible to obtain a lighting apparatus that can

  1 DC power supply circuit, 2 AC power supply, 3 rectifier circuit, 4 capacitor, 5 step-up chopper circuit, 6 inductor, 7 switching element, 8 diode, 9 first electrolytic capacitor, 10 second electrolytic capacitor, 11 first switching Element, 12 second switching element, 13 inductor, 14 capacitor, 15 capacitor, 16 step-up transformer, 17 high pressure discharge lamp, 18 charging resistor, 18a first charging resistor, 19 diode, 20 charge / discharge capacitor, 21 2-terminal thyristor , 22 control circuit, 23 switch, 24 second charging resistor, 100 discharge lamp lighting device, 200 reflector.

Claims (6)

A load circuit to which the discharge lamp is attached;
A rectifier circuit for rectifying commercial power;
A step-up chopper circuit that converts the output voltage of the rectifier circuit into a desired DC voltage;
An inverter circuit that converts a DC voltage from the boost chopper circuit into an AC voltage and supplies the AC voltage to the load circuit;
A step-up transformer having a secondary winding inserted into the load circuit, a two-terminal thyristor connected to the primary winding side of the step-up transformer, and a charge / discharge circuit provided between outputs of the step-up chopper circuit A starting circuit for generating a high voltage pulse in the secondary winding of the step-up transformer when the charging voltage of the charging / discharging circuit rises and the two-terminal thyristor becomes conductive;
Control means for controlling at least the step-up chopper circuit, and voltage detection means for detecting a charging voltage charged in the charge / discharge circuit,
The control means includes
When starting the discharge lamp of the load circuit,
When the detected charging voltage does not reach a predetermined voltage smaller than the voltage value for conducting the two-terminal thyristor, the output voltage of the boost chopper circuit is set to a minimum voltage value for conducting the two-terminal thyristor. Set to a large first output voltage,
When the detected charging voltage reaches a predetermined voltage smaller than a voltage value for conducting the two-terminal thyristor, an output voltage of the boost chopper circuit is equal to or higher than a minimum voltage value for conducting the two-terminal thyristor, The discharge lamp lighting device is set to a second output voltage smaller than the first output voltage. The control means includes
Detecting the occurrence of the high voltage pulse based on the charging voltage;
2. The discharge lamp lighting device according to claim 1, wherein an output voltage of the step-up chopper circuit is set to the first output voltage after a predetermined time has elapsed since the generation of the high voltage pulse. A load circuit to which the discharge lamp is attached;
A rectifier circuit for rectifying commercial power;
A step-up chopper circuit that converts the output voltage of the rectifier circuit into a desired DC voltage;
An inverter circuit that converts a DC voltage from the boost chopper circuit into an AC voltage and supplies the AC voltage to the load circuit;
A step-up transformer having a secondary winding inserted into the load circuit, a two-terminal thyristor connected to the primary winding side of the step-up transformer, and a charge / discharge circuit provided between outputs of the step-up chopper circuit A starting circuit for generating a high voltage pulse in the secondary winding of the step-up transformer when the charging voltage of the charging / discharging circuit rises and the two-terminal thyristor becomes conductive;
Control means for controlling at least the step-up chopper circuit, and voltage detection means for detecting a charging voltage charged in the charge / discharge circuit,
The charge / discharge circuit is
A first charging resistor, a diode, and a charging / discharging capacitor connected in series between outputs of the boost chopper circuit;
A second charging resistor connected in parallel with the first charging resistor;
A switch controlled by the control means to turn on and off the connection of the second charging resistor;
The discharge lamp lighting device, wherein the second charging resistor has a resistance value smaller than that of the first charging resistor. The control means includes
When starting the discharge lamp of the load circuit,
When the detected charging voltage has not reached a predetermined voltage smaller than a voltage value for conducting the two-terminal thyristor, the switch is turned on,
4. The discharge lamp lighting device according to claim 3, wherein when the detected charging voltage reaches a predetermined voltage smaller than a voltage value for conducting the two-terminal thyristor, the switch is turned off. The control means includes
Detecting the occurrence of the high voltage pulse based on the charging voltage;
5. The discharge lamp lighting device according to claim 3, wherein the switch is turned on after a predetermined time has elapsed since the generation of the high-pressure pulse.   A lighting fixture comprising the discharge lamp lighting device according to any one of claims 1 to 5.

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