JP4989688B2 - Discharge lamp lighting device and lighting apparatus equipped with the same - Google Patents

Description

  The present invention relates to a discharge lamp lighting device having a control circuit for controlling lighting of a discharge lamp, and a lighting fixture including the discharge lamp lighting device.

  A conventional discharge lamp lighting device includes a control voltage response element that controls a charge amount to a charge / discharge capacitor in order to apply a high pulse voltage immediately after the polarity of a rectangular wave applied to the discharge lamp is switched. Yes. As such an example, “the charging operation to the charging / discharging capacitor C2 is rectangular-wave-inverted by inserting a control voltage response element S3 such as SSS in series with the charging resistor R1 and the charging / discharging capacitor C2. "Restricted to be performed only at the time" (for example, see Patent Document 1) has been proposed.

JP-A-7-94289 (page 4, FIGS. 1 and 2)

  A discharge lamp has a characteristic that it tends to light up when a longer period (hereinafter referred to as “applied homopolar period”) from when a high pulse voltage is applied to when the polarity of a rectangular wave applied to the discharge lamp is switched. is doing. However, in a starting circuit using a two-terminal thyristor such as Sidac, the voltage at which the two-terminal thyristor conducts varies, so that the generation period of high-voltage pulses is irregular. In the conventional technology, in order to suppress irregularity of the generation cycle, the charging operation to the charge / discharge capacitor is regulated using the control voltage response element, but there is a problem that the manufacturing cost becomes expensive. .

  The present invention has been made in order to solve the above-described problems. The discharge lamp has a longer application homopolar period and a shorter time until the discharge lamp is lit without increasing the manufacturing cost. A lighting device is obtained.

  The discharge lamp lighting device of the present invention receives a power supply from a DC power circuit that converts AC power of an AC power source into a DC voltage, an inverter circuit that converts an output of the DC power circuit into an AC voltage, A load circuit that outputs to the discharge lamp; a start circuit that generates a high voltage pulse in the discharge lamp; a voltage detection circuit; and a control circuit, wherein the start circuit is provided between outputs of the DC power supply circuit. A charging resistor and a charging / discharging capacitor connected in series, a step-up transformer having a secondary winding inserted in the load circuit, and a two-terminal thyristor connected in series with the primary winding of the step-up transformer, The step-up transformer and the two-terminal thyristor are connected in parallel to the charge / discharge capacitor, and the voltage detection circuit detects the voltage of the charge / discharge capacitor, and the control Road, the when the voltage value of the charging and discharging capacitor detected by the voltage detection circuit reaches a predetermined voltage, and controls the inverter circuit, for inverting the polarity of the output AC voltage.

The discharge lamp lighting device according to the present invention reverses the polarity of the AC voltage of the discharge lamp when the voltage of the charge / discharge capacitor reaches a predetermined voltage so as not to be affected by variations in the voltage at which the two-terminal thyristor is conducted. Then, the applied homopolar period from the high-voltage pulse generated thereafter to the next reversal of polarity is lengthened, and the time until the discharge lamp is turned on is shortened.
Further, since a resistor can be used for the voltage detection circuit, it can be formed at a low cost, and the discharge lamp lighting device of the present invention itself has an effect of reducing the manufacturing cost.

1 is a circuit diagram showing a configuration of a discharge lamp lighting device according to Embodiment 1. FIG. It is a wave form diagram when the 2 terminal thyristor of Embodiment 1 is conducted at the lower limit value of the variation range of the conduction voltage and a high voltage pulse is generated. It is a wave form diagram when the 2 terminal thyristor of Embodiment 1 is conducted at the upper limit value of the variation range of the conduction voltage and a high voltage pulse is generated. It is a wave form diagram when the 2 terminal thyristor of Embodiment 2 is conducted at the lower limit value of the variation range of the conduction voltage and a high voltage pulse is generated. It is a wave form diagram when the 2 terminal thyristor of Embodiment 2 is conducted at the upper limit value of the variation range of the conduction voltage and a high voltage pulse is generated. FIG. 12 is a waveform diagram when a high-pressure pulse starts to be generated with a pulse generation interval shorter than a certain period in the third embodiment. FIG. 10 is a waveform diagram when a high-pressure pulse starts to be generated for a longer period of time than a certain period in the third embodiment. It is a block diagram of the lighting fixture which concerns on Embodiment 4. 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, a discharge lamp lighting device 100 includes a DC power supply circuit 1, a half-bridge inverter circuit 2, a load circuit 3, a start circuit 4, a detection circuit 8, and a control circuit 5. .

The DC power supply circuit 1 includes a rectifier circuit 12 that rectifies AC power of an AC power supply 11 such as a commercial power supply into DC power, a capacitor 13 connected between both output terminals of the rectifier circuit 12, and a capacitor 13 connected in parallel. And a step-up chopper circuit 14 of the voltage adjustment circuit.
The step-up chopper circuit 14 has a circuit in which an inductor 15 and a switching element 16 are connected in series to the output terminal of the rectifier circuit 12, and the inverter circuit 2 passes through a diode 17 from the connection point of the inductor 15 and the switching element 16 with forward polarity. Connected.

The inverter circuit 2 includes a series circuit of a first electrolytic capacitor 21 and a second electrolytic capacitor 22 connected between outputs of the step-up chopper circuit 14 and a series of the first electrolytic capacitor 21 and the second electrolytic capacitor 22. And a series circuit of a first switching element 23 and a second switching element 24 connected in parallel with the circuit.
The inverter circuit 2 converts the DC voltage from the boost chopper circuit 14 into an AC voltage and supplies it to the load circuit 3.

  The load circuit 3 includes a capacitor 32, a capacitor 33, and an inductor 31. The capacitor 32 and the inductor 31 are connected in series between the connection point of the first electrolytic capacitor 21 and the second electrolytic capacitor 22 and the connection point of the first switching element 23 and the second switching element 24. The capacitor 33 is connected between the connection point of the capacitor 32 and the inductor 31 and the ground.

  A high pressure discharge lamp 7 is attached to the load circuit 3, and a series circuit of the high pressure discharge lamp 7 and the secondary winding 41 a of the step-up transformer 41 is connected in parallel with the capacitor 32. As the high-pressure discharge lamp 7, an HID lamp (high-pressure mercury lamp), a high-pressure sodium lamp, a metal halide lamp, or the like can be used. The high-pressure discharge lamp 7 corresponds to a “discharge lamp” that is a lighting target of the present invention.

  The starting circuit 4 includes a series circuit of a charging resistor 42 and a charging / discharging capacitor 43 connected between outputs of the boosting chopper circuit 14, and primary windings 41 b and 2 of a boosting transformer 41 connected in parallel with the charging / discharging capacitor 43. A series circuit of terminal thyristors 44, and serves as an igniter (lamp means) for applying a high-pressure pulse to the high-pressure discharge lamp 7. In the present embodiment, a Cydac or the like is used for the two-terminal thyristor 44.

The control circuit 5 is connected to the switching element 16 of the step-up chopper circuit 14 and the switching elements 23 and 24 of the inverter circuit 2, and performs output control of the DC power supply circuit 1 and operation control of the inverter circuit 2, respectively. . Note that the voltage storage means 51 and the period measurement means 52 are not used in the present embodiment, but are used in the embodiments described later.
In the control of the boost chopper circuit 14, the control circuit 5 has means (not shown) for detecting the output voltage of the boost chopper circuit 14, and the switching element 16 of the boost chopper circuit 14 according to the detected output voltage. The output voltage is feedback controlled by controlling on / off at a high frequency.

  In the control of the switching element of the inverter circuit 2, the control circuit 5 alternately switches the operation of turning off one of the switching elements 23 and 24 and turning on and off the other switching element between them. The AC voltage by the inverter circuit 2 is obtained. The alternating timing is set to a low frequency that is sufficiently slower than the cycle in which the other one is switched on and off at a high frequency. This single polarity switching at low frequency that creates alternating current of the inverter circuit 2 is hereinafter referred to as “low frequency switching”.

  The detection circuit 8 is arranged in parallel with the charge / discharge capacitor 43 of the starting circuit 4 and detects a voltage applied to the charge / discharge capacitor 43.

  The control circuit 5 performs low-frequency switching of the switching elements 23 and 24 if the detected voltage reaches a predetermined voltage when the high-pressure discharge lamp 7 is started and lit. The control circuit 5 has means (not shown) for detecting the voltage and current of the high-pressure discharge lamp 7, and when the high-pressure discharge lamp 7 is lit, the control circuit 5 switches the inverter circuit 2 according to the detected voltage and current. The power of the high-pressure discharge lamp 7 is adjusted by performing chopper control with the elements 23 and 24. The control circuit 5 is an arithmetic unit provided with a microcomputer (microcomputer), a DSP (Digital Signal Processor) and the like.

Next, the operation of the present embodiment will be described.
In general, the two-terminal thyristor 44 has variations in conducting voltage. If there is a variation in the conducting voltage, the timing at which the high-pressure pulse is generated varies, the applied homopolar period also varies, and the lighting of the high-pressure discharge lamp 7 becomes unstable. Therefore, the control circuit 5 according to the present embodiment switches the low frequency of the switching elements 23 and 24 when the voltage of the charge / discharge capacitor 43 becomes smaller than the lower limit of the variation range of the voltage at which the two-terminal thyristor is conducted. I do. By reversing the polarity at the lowest limit of the variation range, the applied homopolar period is provided in a stable state. Here, the “value smaller than the lower limit value” means that it is substantially equal to or slightly lower than the lower limit value.

  FIG. 2 is a waveform diagram when the two-terminal thyristor of the first embodiment is turned on at the lower limit value of the variation range of the conduction voltage and a high voltage pulse is generated. FIG. 3 is a waveform diagram when the two-terminal thyristor of the first embodiment is conducted at the upper limit value of the variation range of the conduction voltage and a high voltage pulse is generated. 2 and 3, (a) shows the charging voltage of the charge / discharge capacitor 43, (b) shows the gate signal waveform of the switching element 23, (c) shows the gate signal waveform of the switching element 24, ( d) shows a voltage waveform of the high-pressure discharge lamp 7.

  As shown in FIGS. 2A, 2B, and 2C, the control circuit 5 determines that the charging voltage of the charging / discharging capacitor 43 is smaller than the lower limit value of the power variation range in which the two-terminal thyristor is conducted. The low frequency switching of the switching elements 23 and 24 is performed. FIGS. 2 (a) and 2 (d) show that the high voltage pulse is generated in the high pressure discharge lamp because the voltage at which the two-terminal thyristor 44 becomes conductive after the low frequency switching is performed is reached.

  3, similarly to FIG. 2, in FIGS. 3A, 3 </ b> B, and 3 </ b> C, the control circuit 5 determines that the charging voltage of the charging / discharging capacitor 43 is lower than the lower limit value of the power variation range in which the two-terminal thyristor is conducted. When the value becomes small, the control circuit 5 performs low-frequency switching of the switching elements 23 and 24. 3A and 3D, the low-frequency switching is performed, and then the charge / discharge capacitor 43 is charged until the upper limit of the variation range of the two-terminal thyristor 44 is reached, and then a high-pressure pulse is generated in the high-pressure discharge lamp. It shows that you are doing.

As shown in FIG. 3, when the conducting power of the two-terminal thyristor 44 is the upper limit value of the variation range, the applied same electrode period is shortened, but still a sufficient time for lighting the high-pressure discharge lamp is secured. Further, the detection circuit 8 used in the present embodiment is formed using a resistor, and the device can be realized at low cost.
The discharge lamp lighting device according to the present embodiment measures the voltage of the charge / discharge capacitor 43 while using the inexpensive detection circuit 8, and the measured voltage is low with a value smaller than the lower limit value of the variation range of the two-terminal thyristor. By performing the frequency switching, it is possible to obtain an effect of extending the applied same electrode period and facilitating lighting of the high-pressure discharge lamp 7.

Embodiment 2. FIG.
In the first embodiment, the predetermined voltage of the charge / discharge capacitor 43 is set to be smaller than the lower limit value of the variation range of the voltage at which the two-terminal thyristor 44 is conducted. However, in the present embodiment, the predetermined voltage is set to the charge / discharge capacitor. The value is smaller than the maximum voltage value of 43. Here, the “value smaller than the maximum voltage value” means that it is substantially equal to or slightly lower than the maximum voltage value accumulated in the charge / discharge capacitor 43.

  In the discharge lamp lighting device 100 according to the present embodiment, the control circuit 5 includes voltage storage means 51 (see FIG. 1) that holds the maximum voltage value of the charge / discharge capacitor 43. Other configurations are the same as those of the first embodiment (FIG. 1), and the same portions are denoted by the same reference numerals.

  FIG. 4 is a waveform diagram when the two-terminal thyristor of the second embodiment is turned on at the lower limit of the variation range of the conduction voltage and a high voltage pulse is generated. FIG. 5 is a waveform diagram when the two-terminal thyristor of the second embodiment is turned on at the upper limit of the conduction voltage variation range and a high voltage pulse is generated. 4 and 5, (a) shows the charging voltage of the charging / discharging capacitor 43, (b) shows the gate signal waveform of the switching element 23, (c) shows the gate signal waveform of the switching element 24, ( d) shows a voltage waveform of the high-pressure discharge lamp 7.

  4 (a), 5 (b), and 5 (c), the control circuit 5 determines that the voltage of the charge / discharge capacitor 43 detected by the detection circuit 8 is smaller than the maximum voltage value that is a predetermined voltage. When switching, the switching elements 23 and 24 are switched at a low frequency. 4 and 5 (a) and 5 (d) show that the two-terminal thyristor 44 reaches a voltage at which the two-terminal thyristor 44 becomes conductive immediately after the low-frequency switching is performed, and a high-pressure pulse is generated in the high-pressure discharge lamp. Show. That is, FIG. 4 and FIG. 5 show that even if there is a variation in the conducting voltage of the two-terminal thyristor 44, the control circuit 5 performs control so that a high-voltage pulse is generated immediately after switching the low frequency. ing.

  The discharge lamp lighting device according to the present embodiment maintains the maximum value of the voltage applied to the charge / discharge capacitor 43 and uses it to switch the low frequency even if there is a variation in the voltage that the two-terminal thyristor 44 communicates with. By performing this and lengthening the applied same electrode period, an effect of facilitating lighting of the high-pressure discharge lamp 7 can be obtained.

Embodiment 3 FIG.
In the first and second embodiments, the polarity of the AC voltage supplied to the load circuit 3 when the charge / discharge capacitor 43 reaches a predetermined voltage is reversed. In the present embodiment, however, Even when the constants such as the charge / discharge capacitor 43 and the charge resistor 42 vary, the generation interval of the high voltage pulse is controlled to be constant.

  In the discharge lamp lighting device 100 according to the present embodiment, the control circuit 5 measures a period from the maximum voltage value (or minimum voltage value) to the maximum voltage value (or minimum voltage value) of the charge / discharge capacitor 43. Period measuring means 52 (see FIG. 1) is provided. This period is the same as the generation period of the high voltage pulse. Other configurations are the same as those of the first embodiment (FIG. 1), and the same portions are denoted by the same reference numerals.

  FIG. 6 is a waveform diagram when the pulse generation interval of the third embodiment starts to generate a high voltage pulse shorter than a certain period. FIG. 7 is a waveform diagram when the pulse generation interval of the third embodiment starts to generate a high-pressure pulse longer than a certain period. 6 and 7, (a) shows the output voltage of the boost chopper circuit 14, (b) shows the charging voltage of the charge / discharge capacitor 43, and (c) shows the voltage waveform applied to the high-pressure discharge lamp 7. Indicates.

  As shown in FIG. 6, when the generation period of the high voltage pulse is shorter than a certain period, the control circuit 5 controls the switching element 16 of the step-up chopper circuit 14 to be turned on / off at a high frequency to lengthen the off period. As a result, the output voltage of the step-up chopper circuit 14 is lowered, and the charging time of the charge / discharge capacitor 43 is delayed.

  Further, as shown in FIG. 7, when the generation period of the high voltage pulse is longer than a certain period, the control circuit 5 controls the switching element 16 of the step-up chopper circuit 14 to be turned on / off at a high frequency, thereby extending the on period. As a result, the output voltage of the step-up chopper circuit 14 is increased, and the charging time of the charge / discharge capacitor 43 is shortened.

As described above, the control circuit 5 controls the switching element 16 of the step-up chopper circuit 14 to adjust the output power even when there are individual variations in constants such as the charge / discharge capacitor 43 and the charging resistor 42, and the charging / discharging capacitor 43 and the charging resistor 42. The interval until the discharge capacitor 43 reaches a predetermined voltage can be made constant.
The discharge lamp lighting device according to the present embodiment has a control circuit 5 that makes low-frequency switching constant in addition to the characteristics according to the first and second embodiments, and is stable and resistant to variations in individual components. Lighting function can be obtained.

Embodiment 4 FIG.
FIG. 8 is a configuration diagram of a lighting fixture according to the fourth embodiment.
In FIG. 8, the luminaire 300 includes the discharge lamp lighting device 100 according to any one of the first to third embodiments, the high-pressure discharge lamp 7 attached to the load circuit of the discharge lamp lighting device 100, and the reflector 200. I have.

  The lighting fixture 300 according to the present embodiment includes the discharge lamp lighting device 100 according to any one of the first to third embodiments, thereby shortening the time until the high-pressure discharge lamp 7 is lit and having an inexpensive component configuration. The effect that it can manufacture can be acquired.

  1 DC power supply circuit, 2 inverter circuit, 3 load circuit, 4 start circuit, 5 control circuit, 7 high pressure discharge lamp, 8 detection circuit, 11 AC power supply, 12 rectifier circuit, 13 capacitor, 14 boost chopper circuit, 15 inductor, 16 Switching element, 17 diode, 21 electrolytic capacitor, 22 electrolytic capacitor, 23 switching element, 24 switching element, 31 inductor, 32 capacitor, 33 capacitor, 41 step-up transformer, 41a secondary winding, 41b primary winding, 42 charging resistance 43 Charging / discharging capacitor, 44 2-terminal thyristor, 51 voltage storage means, 52 period measuring means, 100 discharge lamp lighting device, 200 reflector, 300 lighting fixture.

Claims (7)

A DC power supply circuit that converts AC power of the AC power supply into DC voltage;
An inverter circuit for converting the output of the DC power supply circuit into an AC voltage;
A load circuit that receives power supply from the inverter circuit and outputs it to a discharge lamp;
A starting circuit for generating a high voltage pulse in the discharge lamp;
A voltage detection circuit and a control circuit;
The starting circuit is provided between the outputs of the DC power supply circuit, and is connected in series to a charging resistor and a charging / discharging capacitor; a step-up transformer in which a secondary winding is inserted into the load circuit; A two-terminal thyristor connected in series with the wire,
The step-up transformer and the two-terminal thyristor are connected in parallel to the charge / discharge capacitor,
The voltage detection circuit detects the voltage of the charge / discharge capacitor,
The control circuit controls the inverter circuit to invert the polarity of the output AC voltage when the voltage value of the charge / discharge capacitor detected by the voltage detection circuit reaches a predetermined voltage. Discharge lamp lighting device. The predetermined voltage is
The discharge lamp lighting device according to claim 1, wherein the discharge lamp lighting device is smaller than a lower limit value of a variation range of a voltage at which the two-terminal thyristor is conducted. Voltage storage means for storing the maximum voltage value of the charge / discharge capacitor;
The predetermined voltage is
The discharge lamp lighting device according to claim 1, wherein the discharge lamp lighting device is smaller than a maximum voltage value held in the voltage storage unit .
The DC power supply circuit is
Voltage adjustment means for adjusting the output voltage,
The control circuit includes:
Measure the period from charge to discharge of the charge / discharge capacitor,
The discharge lamp lighting according to any one of claims 1 to 3, wherein the voltage adjusting unit is controlled to adjust the output voltage of the DC power supply circuit so that the measured period becomes a certain period. apparatus. The control circuit includes:
If the measured period is shorter than a certain period,
The discharge lamp lighting device according to claim 4, wherein an output voltage of the DC power supply circuit is lowered. The control circuit includes:
If the measured period is longer than a certain period,
The discharge lamp lighting device according to claim 4, wherein an output voltage of the DC power supply circuit is increased.   The lighting fixture provided with the discharge lamp lighting device as described in any one of Claims 1-6.

Images