JP2002051548A - Power supply and discharge lamp lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress abnormal increase in the output of a DC-DC converter and cause a boosting circuit to smoothly operate. SOLUTION: The discharge lamp lighting device is provided with a DC-DC converter 1 that converts the level of the voltage of direct-current power supply E and thereafter rectifies and smoothes it to obtain a first direct-current voltage; a boosting circuit 2 that increases, rectifies, and smoothes the voltage the level of which is converted by the converter, to obtain a second direct-current voltage; an start-assisting circuit 3 consisting of a resistor, a capacitor, and the like; a low-frequency inverter 4 comprising a switching element; an igniter 5 comprising a capacitor, a switching element, and the like; a load insertion circuit 7 consisting of a resistor R71 and a switching element SW71; and a control circuit 6 that exercises switching control on the DC-DC converter 1 and the low-frequency inverter 4, and further operates the switching element SW71 under specified conditions to reduce the gradient of change in voltage due to smoothing by the DC-DC converter 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DC-DC converter that steps up and down (converts a voltage of a DC power supply to an arbitrary level) and outputs the converted voltage.
The present invention relates to a power supply device having a converter and a discharge lamp lighting device using the same.

[0002]

2. Description of the Related Art In a discharge lamp lighting device, when a discharge lamp is a high-intensity discharge lamp (HID lamp), a ballast circuit for stably lighting the discharge lamp and a starting circuit for generating a high voltage necessary for starting discharge are provided. Starting circuit is required.

FIG. 31 shows a circuit diagram of a conventional discharge lamp lighting device. The discharge lamp lighting device shown in FIG.
12, a DC-DC converter 1 including a transformer T1, a lighting switch SW1, and a DC-DC converter
A DC power supply E connected to the input of the DC converter 1,
Boost circuit 2 whose input is connected to winding (secondary winding) n12
A starting auxiliary circuit 3 connected to the output of the DC-DC converter 1, a low-frequency inverter 4 having an input connected to the output of the DC-DC converter 1, and a discharge circuit connected to the output of the low-frequency inverter 4. Electric lamp (high-intensity discharge lamp) La;
An igniter 5 provided between the booster circuit 2 and the low-frequency inverter 4 and the discharge lamp La, and a control circuit 6pa for controlling the DC-DC converter 1 and the low-frequency inverter 4
And

However, the DC power supply E and the switch SW1
And a DC-DC converter 1, a connection terminal T
Controller input connection TN having N11 and TN12
1 is provided between the booster circuit 2 and the low-frequency inverter 4 and the igniter 5 for connection terminals TN21 and TN
Controller output connection TN2 having TN23 and TN23
Is provided. An igniter output connection portion TN3 having connection terminals TN31 and TN32 is provided between the igniter 5 and the discharge lamp La.

More specifically, the DC-DC converter 1 includes a switch SW1, a controller input connection TN1, and a winding (primary winding) n1.
1 and a diode D11 connected in series between both ends of a winding n12.
And a capacitor (smoothing capacitor) C11, and a resistor R11 for detecting load current and connected between one end of the winding n12 and the negative output terminal of the DC power supply E, and is configured as a flyback type. The voltage of the DC power supply E is stepped up / down (level converted) by the switching of the FET Q11 and the operation of the transformer T1, and the stepped up / down voltage is rectified and smoothed by the diode D11 and the capacitor C11 to obtain an output voltage across the capacitor C11. Things. Here, when the FET Q11 is turned on, the winding n
Although a current flows through 11, the current does not flow through the winding n12, and energy is stored in the transformer T1 during this time.
On the other hand, when the FET Q11 is turned off, the energy stored in the transformer T1 flows to the capacitor C1 via the diode D1.

The booster circuit 2 includes resistors R21 and R22, capacitors C21 to C24, and diodes D21 to D24.
Are formed in a Cockcroft-Walton circuit, and the capacitors C21 to C24 are charged stepwise by the electromotive voltage of the winding n12 to obtain a boosted voltage.

The starting assist circuit 3 comprises a capacitor C31 and resistors R31 and R32 connected in series between both ends of the capacitor C11 via a resistor R11, and a diode D31 connected in parallel with the resistor R31. When the electric lamp La is started, a current is supplied to the electric discharge lamp La by the charged capacitor C31 to assist the electric discharge lamp La in starting easily.

The low frequency inverter 4 is a series-connected FET
A full-bridge type inverter formed by connecting Q41, Q42 and FETs Q43, Q44 connected in series to both ends of a capacitor C11 via a resistor R11.
The DC power from the DC converter 1 is converted into AC power and supplied to the discharge lamp La.

The igniter 5 includes a switching element SG1 such as a GAP, and a winding (primary) connected between a high-voltage output terminal of the booster circuit 2 and one output terminal of the low-frequency inverter 4 via the switching element SG1. Winding n)
A pulse transformer T5 having a winding (secondary winding) n52 interposed at the output of the low-frequency inverter 4 and connected in series with the discharge lamp La; a capacitor C51 connected to the output of the low-frequency inverter 4; A discharge resistor R51 and a pulse generating capacitor C52 are connected in parallel between the output terminal on the high voltage side of the circuit 2 and one output terminal of the low frequency inverter 4, and when the discharge lamp La is started. A high-voltage pulse voltage is applied to the discharge lamp La.

The control circuit 6pa detects the lamp current Ila from the resistor R11, detects the lamp voltage Vla from the output of the DC-DC converter 1, and controls on / off of the FET Q11 based on the lamp current Ila and the lamp voltage Vla. , And on / off control of the FETs Q41 to Q44. The details of the on / off control will be described together with the following circuit operation.

FIG. 32 is an operation waveform diagram of the discharge lamp lighting device. The operation of the discharge lamp lighting device will be described with reference to FIG. When the power is turned on by turning on the switch SW1, the control circuit 6pa is activated, and switching control for repeatedly turning on / off the FET Q11 is performed. Thereby, the capacitor C11 of the DC-DC converter 1
Voltage V _C11 and the capacitor C 31 of the starting auxiliary circuit 3
With the voltage V _C31 increases, the capacitor connected to the output terminal of the high voltage side of the step-up circuit 2 for boosting the winding n12 of the DC-DC converter 1 receives an electromotive voltage C52
Voltage V _C52 rises.

Further, in parallel with the switching control, the voltage V _{C52 of the} capacitor C52 becomes sufficiently high.
With the polarity to increase the voltage difference between the terminals TN22 and TN23, the FETs Q41 and
Control for turning on 43 is performed. Thereby, the voltage V
_C11 and V _C31 are applied to the discharge lamp La as no-load voltages. At this time, it goes without saying that the discharge lamp La is in a non-lighting, no-load state.

Thereafter, the detected lamp voltage Vla (≒) is set so that the value of the voltage V _C11 is maintained at a predetermined value (for example, 400 V).
Control for intermittently oscillating the FET Q11 is performed according to V _C11 ). Thereby, the “intermittent oscillation section” shown in FIG.
As described above, a time period during which the FET Q11 maintains the off state occurs.

Thereafter, when the charging voltage of the capacitor C52 reaches a predetermined voltage, the switching element SG1 turns on,
The charged voltage (several hundred V to several kV) is applied to the winding n51 of the pulse transformer T5, and a high voltage (about several tens kV) Vp for starting is applied to the discharge lamp La from the secondary winding n52. I do. As a result, the discharge lamp La starts discharging and reaches lighting.

When the discharge lamp La is turned on, the FET Q4
1, Q44 and the FETs Q42, Q43 are alternately turned on / off. Thereby, appropriate AC power is supplied from the low frequency inverter 4 to the discharge lamp La, and the discharge lamp La maintains stable lighting.

Japanese Patent Application Laid-Open No. H11-329780 discloses a discharge lamp that raises the output voltage of a chopper and then lowers the oscillation frequency of an inverter when the discharge lamp is switched from a dimming lighting state to an all-light lighting state. A lighting device is disclosed.

[0017]

However, FIG.
When the discharge lamp La is started, the discharge lamp lighting device of DC
-Although the FET Q11 of the DC converter 1 is temporarily fixed to the OFF state and enters an intermittent oscillation state in which the switching is stopped, there is a problem that it takes time to turn on the discharge lamp due to the intermittent oscillation.

That is, in the case of the DC-DC converter 1, in the case of the intermittent oscillation, the FET Q11 is kept off unless the lamp voltage Vla becomes lower than the predetermined threshold voltage. Line n1
The operation of the booster circuit 2 for boosting the electromotive voltage of the second circuit also stops. For this reason, comparing the case where the intermittent oscillation shown in FIG. 33A is not performed and the case where the intermittent oscillation shown in FIG. 33B is performed, the latter is better than the former in the capacitor C52.
The time required for the voltage V _C52 to reach the predetermined voltage TH _BO for turning on the switching element SG1 becomes long, and it takes time to light the discharge lamp.

Further, in order to solve such a problem, DC
-If the DC converter 1 is in a state of constant oscillation without a stop time, the output voltage of the DC-DC converter 1 continues to rise because the DC-DC converter 1 is in a no-load state in which no load is connected to the output side. And the breakdown voltage of each element is exceeded.

The present invention has been made in view of the above circumstances, and provides a power supply device and a discharge lamp lighting device capable of suppressing an abnormal increase in the output of a DC-DC converter and smoothly operating a booster circuit. The purpose is to do.

[0021]

According to the first aspect of the present invention, there is provided a DC power supply, and a voltage of the DC power supply is level-converted, and then rectified and smoothed.
A DC-DC converter for obtaining a DC voltage;
A booster circuit for boosting, rectifying and smoothing the voltage level-converted by the C converter to obtain a second DC voltage;
A power supply device for supplying power to a load from an output of a DC converter, applying a voltage to the load from the DC-DC converter for a predetermined time, and superimposing a voltage from a booster circuit on the voltage; A power consumption circuit having at least a consuming element is provided between a DC-DC converter and a load, and a switching unit is operated under a predetermined condition to reduce a slope of a voltage change due to smoothing of the DC-DC converter. It is characterized by.

According to a second aspect of the present invention, in the power supply device according to the first aspect, a control circuit for operating the power consuming circuit when the first DC voltage reaches a predetermined value is provided.

According to a third aspect of the present invention, in the power supply device according to the first aspect, a control circuit for operating the power consuming circuit until the second DC voltage rises to a predetermined value is provided.

According to a fourth aspect of the present invention, there is provided the power supply device according to the first aspect, further comprising a control circuit for operating the power consumption circuit for a predetermined period within a period during which the second DC voltage rises.

According to a fifth aspect of the present invention, there is provided the power supply device according to the first aspect, further comprising a control circuit, wherein the power consuming circuit has a charging element, and the control circuit is configured to control the output voltage of the DC-DC converter with respect to time. , And power is supplied from the DC-DC converter to the power consumption circuit.

The invention according to claim 6 is the invention according to claim 1 or 5
The power supply device described above is characterized in that a plurality of charge / discharge circuits having different time constants of the charging circuit are provided at the output of the DC-DC converter.

According to a seventh aspect of the present invention, there is provided a DC power supply, a DC-DC converter for converting the voltage of the DC power supply, and then rectifying and smoothing to obtain a first DC voltage, and the DC-DC converter. And a booster circuit for boosting, rectifying and smoothing the level-converted voltage to obtain a second DC voltage, supplying power to the load from the output of the DC-DC converter, and supplying the power from the DC-DC converter for a predetermined time. A power supply device for applying a voltage to a load and superimposing a voltage from a booster circuit on the voltage, comprising a control unit for changing a ratio between output power of the DC-DC converter and power supply to the booster circuit. And

According to an eighth aspect of the present invention, in the power supply device of the seventh aspect, a circuit for rectifying and smoothing in the DC-DC converter forms a closed circuit.
A circuit having at least a switching element is connected in series, and the control means controls the switching element to control the DC-D
It is characterized in that the ratio between the output power of the C converter and the power supply to the booster circuit is changed.

The ninth aspect of the present invention is the first or seventh aspect.
In the power supply device described above, the DC-DC converter is capable of bidirectional conversion.

According to a tenth aspect of the present invention, in the power supply device according to the ninth aspect, the DC-DC converter supplies power from the DC power supply to the load side until the output voltage reaches the first predetermined value. And the output voltage is the first
After reaching the second predetermined value, power conversion is performed in the reverse direction of regenerating power from the load side to the DC power supply side until reaching the second predetermined value lower than that, and the output voltage reaches the second predetermined value. Thereafter, the forward power conversion is performed again until the first predetermined value is reached.

The eleventh aspect of the present invention relates to the first to the first aspects.
0, the booster circuit includes:
Stepwise charge using capacitor and diode
It is characterized by obtaining a DC voltage.

The twelfth aspect of the present invention is the first aspect of the present invention.
0, wherein the DC-DC converter has a transformer for voltage conversion, and the booster circuit is constituted by another winding provided on the transformer.

According to the thirteenth aspect of the present invention, there is provided the method according to any one of the first to first aspects.
0, wherein the DC-DC converter has a flyback type circuit configuration.

[0034] The invention according to claim 14 is the invention according to claims 1 to 1
0, wherein a charging / discharging circuit comprising at least a capacitor and a resistor and a low-frequency inverter having a full bridge configuration are connected to the output of the DC-DC converter, and the output of the boosting circuit is charged. A capacitor is connected, a series circuit of the primary side of the pulse transformer and a switching element is connected to the capacitor, and a series circuit of the secondary side of the pulse transformer and a load is connected to the output of the low frequency inverter. .

According to the fifteenth aspect of the present invention, there is provided the method as set forth in the first to the first aspects.
0 and a discharge lamp as a load.

According to a sixteenth aspect of the present invention, in the power supply device according to the tenth aspect, the load is a discharge lamp, and the first and second predetermined values are a no-load secondary voltage required for starting the discharge lamp. , And is set so that the no-load secondary voltage falls between the first and second predetermined values.

According to a seventeenth aspect of the present invention, in the discharge lamp lighting device according to the fifteenth aspect, the on-time of the switching element connected to the primary side of the pulse transformer is adjusted to provide a high-voltage pulse for starting the discharge lamp. Is characterized by controlling the time until the occurrence of.

[0038]

FIG. 1 is a block diagram of a first embodiment according to the present invention, and FIG. 2 is an operation waveform diagram under the control of the control circuit of FIG. 1. FIG. The form will be described. However, FIG. 1 shows a schematic configuration.

That is, the discharge lamp lighting device shown in FIG.
31 is different from the discharge lamp lighting device of FIG. 31 in that a load insertion circuit 7 including a resistor (power consumption resistor) R71 and a switching element SW71 connected in series and connected in parallel to the output of the DC-DC converter 1 is provided. A control circuit 6 having the same configuration as the control circuit 6pa of FIG. 31 except that it has a control function of turning on / off the switching element SW71 of the load insertion circuit 7 is provided.

Here, FIG. 3 shows an operation waveform diagram under the control of the control circuit of FIG. As shown in FIG.
When the detected lamp voltage Vla (≒ V _C11 ) exceeds the voltage Vt after the power is turned on in order to maintain the voltage V _{C11 of the} capacitor C11 at a predetermined voltage (for example, 400 V) Vt, the control circuit 6pa of FIG. When the voltage reaches a threshold voltage slightly higher than the voltage Vt (hereinafter referred to as threshold voltage Vth1), the switching control for the FET Q11 is stopped to temporarily fix the FET Q11 to the OFF state, and the detected lamp voltage Vla Reaches a threshold voltage slightly lower than voltage Vt (hereinafter referred to as threshold voltage Vth2), FE
Switching control for repeatedly turning on / off the TQ 11 is sequentially repeated until the discharge lamp La is turned on.

The control circuit 6 of the first embodiment also performs the same control as described above, except that, as shown in FIG. 2, after the power is turned on, the detected lamp voltage Vla changes to the voltage Vt.
When the threshold voltage Vth11 is slightly lower than the threshold voltage Vth11, control is performed to fix the switching element SW71 to ON, for example, until the discharge lamp La is turned on. In the example of FIG. 2, the threshold voltage Vth11 is set to a level slightly lower than the threshold voltage Vth1. Also, the threshold voltage Vth11 is
The voltage is higher than the maximum value of the lighting voltage of the discharge lamp La.

Next, the control operation of the control circuit 6, which is a feature of the first embodiment, will be described. However, it is assumed that the switching element SW71 is off when the power is off.

When the power is turned on, the control circuit 6 is activated, and as shown in FIG.
Control to turn off is performed. As a result, the voltage V _C11 of the capacitor C11 of the DC-DC converter 1 increases.

Thereafter, when the detected lamp voltage Vla reaches the threshold voltage Vth11, control for fixing the switching element SW71 to ON is performed. Thereby, the resistance R7
1 is a capacitor C1 via a switching element SW71.
1 in parallel with each other, and the power of the capacitor C11 is
As a result, the voltage V _C11 is restrained from rising. As a result, the lamp voltage Vla becomes equal to the threshold voltage Vth1.
Time until the level of the FET Q11 is increased.
The start time of the control for temporarily fixing OFF is delayed.

Thereafter, when the detected lamp voltage Vla reaches the level of the threshold voltage Vth1, the control for stopping the switching control of the FET Q11 and temporarily fixing the FET Q11 to OFF is performed. Thereafter, when the detected lamp voltage Vla reaches the threshold voltage Vth2, the FET Q
Switching control for repeatedly turning on / off 11 is performed. Such control is sequentially and repeatedly executed, and when the lighting of the discharge lamp La is confirmed, the switching element SW7
Control for turning off 1 is performed.

As described above, according to the first embodiment, the power of the capacitor C11 is forcibly consumed by the resistor R71 by connecting the resistor R71 in parallel with the capacitor C11 in the no-load state, so that the DC-DC Since the frequency of the operation stop of the converter 1 is reduced, the operation frequency of the booster circuit 2 becomes higher than that of the conventional discharge lamp lighting device, so that the booster circuit 2 can be operated smoothly and the output of the DC-DC converter 1 Abnormal rise can be suppressed.

In the first embodiment, the booster circuit 2 having the Cockcroft-Walton circuit configuration is used.
The booster circuit of the present invention is not limited to the Cockcroft-Walton circuit, and may be, for example, a winding separately provided on the secondary side of the transformer T1, or a configuration using both this winding and the Cockcroft-Walton circuit.

FIG. 4 is a configuration diagram of a second embodiment according to the present invention, and FIG. 5 is an operation waveform diagram under the control of the control circuit of FIG. 4. The description of the second embodiment will be made below using these diagrams. Do.

The discharge lamp lighting device shown in FIG. 4 has the same configuration as that of the first embodiment except that a control circuit 6a is provided instead of the control circuit 6 shown in FIG. And the control circuit 6a
The difference from the control circuit 6 is that the FET Q1
When the detected lamp voltage Vla reaches the threshold voltage Vth11, control is performed to fix the switching element SW71 to ON, and when the detected lamp voltage Vla is higher than the threshold voltage Vth11. When the discharge voltage reaches the low threshold voltage Vth12, the switching element SW71 is fixed to off, and the control is sequentially repeated until the discharge lamp La is turned on. However,
The threshold voltage Vth12 is lower than Vt, the threshold voltage Vth12 is lower than the threshold voltage Vth11, and the threshold voltages Vth11, Vth12
Is a capacitor C1 required for starting the discharge lamp La.
1 or more. Further, the threshold voltage Vth12 is set higher than the voltage of the capacitor C11 which is reduced by the resistor R71 when the switching element SW71 is turned on.

Next, the characteristic operation of the discharge lamp lighting device having the above-described configuration will be described. When the DC-DC converter 1 operates after the power is turned on, the voltage V _{C11 of the} capacitor C11 increases since the discharge lamp La is in a no-light no-load state. Thereafter, when the voltage V _C11 reaches the threshold voltage Vth11, the switching element SW71 is turned on. here,
In the no-load state, when the power supplied from the primary side to the secondary side of the DC-DC converter 1 is WNL, if the following equation is satisfied, the voltage V _C11 is reduced by turning on the switching element SW71.

WNL ≦ Vt ² / R71 When the switching element SW71 is turned on, the voltage V
_{When C11} decreases to reach the threshold voltage Vth12, the switching element SW71 is turned off. As a result, the voltage V _C11 of the capacitor C11 increases again.

Such control is sequentially and repeatedly executed.
When the lighting of the discharge lamp La is confirmed, for example, the discharge lamp La
During the lighting of, the switching element SW71 is fixed off so that the power of the capacitor C11 is not consumed by the resistor R71.

As described above, according to the second embodiment, in the no-load state, the output power of the DC-DC
Since it is adaptively consumed at 71, an abnormal increase in the output of the DC-DC converter 1 can be suppressed. Also, D
Since the C-DC converter 1 does not operate due to intermittent oscillation and the booster circuit 2 always operates, the booster circuit 2 can be operated more smoothly.

FIG. 6 is a block diagram of a third embodiment according to the present invention, and FIG. 7 is an operation waveform diagram under the control of the control circuit of FIG. 6. The third embodiment will be described below with reference to these drawings. Do. FIG. 6 shows a partial configuration of the discharge lamp lighting device.

That is, the discharge lamp lighting device shown in FIG.
The difference from the first embodiment is that the output voltage of the load insertion circuit 7a, which is composed of the impedance element Z connected in series and the switching element SW71 and is connected in parallel to the output of the DC-DC converter 1, and the output voltage of the booster circuit 2 are predetermined. It is determined whether or not the threshold voltage Vth21 has been reached. When the threshold voltage Vth21 has been reached, the monitoring circuit 8 includes a comparator 81 that sets the output level to high.
Is turned on, and when the output level of the monitoring circuit 8 becomes high,
The control circuit 6b has the same configuration as the control circuit 6 except that the control circuit 6b has a function of performing control to turn off the switching element SW71.

Next, the characteristic operation of the discharge lamp lighting device having the above configuration will be described. After turning on the power, as shown in FIG.
The switching element SW71 is turned on, and thereafter, when the output voltage of the booster circuit 2 reaches the threshold voltage Vth21, the switching element SW71 is turned off. Here, when the switching element SW71 is turned on, the start time of the control for temporarily fixing the FET Q11 to the off state is delayed, the DC-DC converter 1 continuously operates until the start time, and the booster circuit 2 operates the DC-DC converter 1 8, the time required for the output voltage of the booster circuit 2 to reach the threshold voltage Vth21 is shorter than in the conventional operation waveform in which the start time is earlier as shown in FIG. Become. That is, the time until the first high-voltage pulse is obtained is shortened.

As described above, according to the third embodiment, the DC-DC
Since the booster circuit 2 can be operated smoothly and the rise of the output voltage of the booster circuit 2 can be accelerated while suppressing an abnormal increase in the output of the converter 1, the first high-voltage pulse is generated by the igniter 5. Voltage can be generated quickly.

FIG. 9 is a block diagram of the fourth embodiment according to the present invention, and FIG. 10 is an operation waveform diagram under the control of the control circuit of FIG. 9. The description of the fourth embodiment will be made below with reference to these drawings. Do. However, FIG. 9 shows a partial configuration of the discharge lamp lighting device.

That is, the discharge lamp lighting device shown in FIG.
The difference from the third embodiment is that the monitoring circuit 8 is not provided, and the function of performing control to turn on the switching element SW71 after turning on the power and to turn off the switching element SW71 after a lapse of a predetermined time from the time of turning on the power is provided. A control circuit 6c having the same configuration as that of the control circuit 6b except that the control circuit 6b is provided.

Next, the characteristic operation of the discharge lamp lighting device having the above configuration will be described. After the power is turned on, the switching element SW71 is turned on as shown in FIG.
Turns off. Therefore, also in the fourth embodiment, as in the third embodiment, the time required to obtain the first high-voltage pulse is shortened.

As described above, according to the fourth embodiment, the DC-DC
Since the booster circuit 2 can be operated smoothly and the rise of the output voltage of the booster circuit 2 can be accelerated while suppressing an abnormal increase in the output of the converter 1, the first high-voltage pulse is generated by the igniter 5. Voltage can be generated quickly.

FIG. 11 is a configuration diagram of a fifth embodiment according to the present invention, and FIG. 12 is an operation waveform diagram under the control of the control circuit of FIG. 11. The fifth embodiment will be described below with reference to these drawings. Do. However, FIG. 11 shows a partial configuration of the discharge lamp lighting device.

That is, the discharge lamp lighting apparatus shown in FIG. 11 is different from the third embodiment in that when the output level of the monitoring circuit 8 becomes high after the switching element SW71 is turned on after the power is turned on, the switching element is switched. A control circuit configured similarly to the control circuit 6b except that the control circuit 6b has a function of sequentially and repeatedly performing a control of turning off the SW 71 and a control of turning on the switching element SW 71 when the discharge lamp La is not turned on. 6d.

Next, the characteristic operation of the discharge lamp lighting device having the above configuration will be described. After power-on, as shown in FIG. 12, the switching element SW71 is turned on.
When the output voltage of the booster circuit 2 reaches the threshold voltage Vth21,
The switching element SW71 is turned off. This allows
The first high-voltage pulse is immediately applied to the discharge lamp La. However, when the discharge lamp La does not reach the starting lighting, the switching element SW71 is immediately turned on, and thereafter, the booster circuit 2 is the threshold voltage Vth21
, The switching element SW71 is turned off.
Such control is repeated until the discharge lamp La reaches the start lighting.

As described above, according to the fifth embodiment, the discharge lamp La
The high voltage pulse voltage can be quickly generated by the igniter 5 until the start lighting. That is, not only the first high voltage pulse voltage but also the second and subsequent high voltage pulses can be quickly generated.

In the third and fifth embodiments, the output voltage of the booster circuit 2 is compared with the threshold voltage Vth21. However, the output side of the booster circuit 2, for example, the diode D24 shown in FIG. And the capacitor C24 and the resistor R2
A configuration may be adopted in which the voltage at the connection point with the second and the predetermined threshold voltage are compared. With this configuration, the same effect as described above can be obtained.

In the example of FIG. 12, the threshold voltage Vth21
Is set lower than the output voltage of the booster circuit 2 when the igniter 5 generates the high-voltage pulse voltage, but may be set higher than the normal output voltage of the booster circuit 2 at that time. In this case, the switching element S
W71 is always on until the discharge lamp La is turned on unless the threshold voltage set higher than the normal output voltage is reached.

FIG. 13 is a block diagram of a sixth embodiment according to the present invention, and FIG. 14 is an operation waveform diagram under the control of the control circuit of FIG. 13. The sixth embodiment will be described below with reference to these drawings. Do. However, FIG. 13 does not show some of the switches SW1 and the like shown in FIG.

That is, the discharge lamp lighting device shown in FIG. 13 is different from the discharge lamp lighting device of FIG. 31 in that the starting auxiliary circuit 3a and the control circuit 6e are respectively provided with the starting auxiliary circuit 3 and the control circuit 6pa in FIG. Is provided in place of

The starting auxiliary circuit 3a includes a capacitor C31,
In addition to the circuit of the resistors R31 and R32 and the diode D31, a high-impedance resistor R33 provided in series with this circuit, and an FE connected in parallel with the resistor R33.
TQ31 is further provided.

After the power is turned on, the control circuit 6e
1 is performed in the same manner as the control circuit 6pa of FIG. 31 except that the switching control for repeatedly turning ON / OFF of the switch 1 is performed, and when the detected lamp voltage Vla reaches a predetermined voltage Vth31, the FET Q31 is turned on. Be composed. Said voltage Vth31, in the example of FIG. 14 is set to a voltage immediately before the voltage V _C11 of the capacitor C11 reaches a predetermined voltage (400V).

FIG. 15 shows an operation waveform diagram under the control of the control circuit of FIG. In the discharge lamp lighting device of FIG. 31, as shown in FIG. 15, when the switch SW1 is turned on (time t0), the DC-DC converter 1 starts operation from time t1 which is slightly delayed, and thereafter, the detection is performed. In order to keep the lamp voltage Vla at a predetermined voltage, an intermittent oscillation state is set (after time t3).

On the other hand, in the sixth embodiment, as shown in FIG. 14, after the power is turned on, the DC-DC converter 1
The operation is started by the switching control of the FET Q11 from a time point t1 which is slightly delayed. On the other hand, after this, when the detected lamp voltage Vla reaches the voltage Vth31 (time t2),
The FET Q31 turns on. As a result, the resistor R33 is short-circuited, and the charging current for the capacitor C31 increases, so that the DC-DC converter 1 can be continuously operated.

Next, the characteristic operation of the discharge lamp lighting device having the above configuration will be described. After the power is turned on, the capacitor C11 and the resistors R11, R32, and R3 are between the time t1 and the time t2.
1. Capacitor C31, resistor R33 and capacitor C
The capacitor C31 is charged through the path of No. 11. In this case, since the high impedance resistor R33 is interposed in the path, the capacitor C31 is charged relatively slowly.

Thereafter, when the FET Q31 is turned on at time t2, the capacitor C11 and the resistors R11, R32, R3
1. The capacitor C31 is charged through the path of the capacitor C31 and the capacitor C11. In this case, since the high-impedance resistor R33 does not intervene and the charging current to the capacitor C31 increases, the capacitor C31 functions in the same manner as the resistor R71 and the impedance element Z described above. It becomes possible. As a result, the booster circuit 2 can also perform continuous boosting, and the time required for the voltage of the capacitor C52 to reach the voltage for turning on the switching element SG1 is shortened.

As described above, according to the sixth embodiment, the DC-DC
Starting auxiliary circuit 3 for continuously operating converter 1
By controlling the charging operation a, an abnormal increase in the output of the DC-DC converter 1 can be suppressed, the booster circuit 2 can be operated smoothly, and the rise of the output voltage of the booster circuit 2 can be accelerated. .

The starting auxiliary circuit 3 shown in the example of FIG.
Instead of the circuit configuration a, for example, as shown in FIG. 16, a capacitor C31 and resistors R32 and R33 connected in series between both ends of the capacitor C11 via a resistor R11.
And an FET Q31 connected in parallel with the resistor R33. That is, the diode D31
Is replaced by the body diode of the FET Q31, and the resistance R
A configuration may also be used in which the resistor 31 and the resistor R33 are shared.

FIG. 17 is a block diagram of a seventh embodiment according to the present invention, FIG. 18 is a block diagram of a monitoring function of the control circuit of FIG. 17, and FIGS. 19, 20, and 21 are control diagrams of the control circuit of FIG. FIG. 7 is an operation waveform diagram, and the seventh embodiment will be described below with reference to these diagrams. However, FIG.
A part of the switch SW1 shown in FIG.

That is, the discharge lamp lighting device shown in FIG. 17 is different from the discharge lamp lighting device of FIG.
A second starting auxiliary circuit 30 connected in parallel to the output of the DC converter 1 is further provided, and a control circuit 6f is provided instead of the control circuit 6pa in FIG.

The start-up assist circuit 30 is connected to a series-connected F
ETQ301, capacitor C301 and resistor R30
1 and R302, and a diode D301 connected in parallel with the resistor R301.

The difference between the control circuit 6f and the control circuit 6pa of FIG. 31 is that the control circuit 6f includes a resistor R61, a diode D61, a capacitor C61 and a comparator 61, as shown in FIG. The terminal voltage V _D11 is detected, and it is determined (monitored) whether the terminal voltage V _C61 of the capacitor C61 corresponding to the voltage V _D11 exceeds a predetermined threshold voltage Vth41, and if it exceeds, the output level of the comparator 61 becomes high. And a comparator 6 for the monitoring function.
It has a control function of turning on the FET Q301 when it receives a high signal from 1.

Next, the features and characteristics of the discharge lamp lighting device having the above configuration will be described.
The operation will be described. After power on, DC-DC converter
When the data 1 starts operating, “V” shown in FIG._D11Like
And the voltage V_C11And a rectangular wave that alternately switches to approximately 0V
Voltage V_D11Is generated at both ends of the diode D11, and FIG.
8 is applied to the input of the circuit. In this case, the voltage V_D11Is
Pressure V_C11, The voltage of the capacitor C61
Charged via the resistor R61, the voltage of the capacitor C61
V_C61Rises. Thereafter, the voltage V_D11Cut to about 0V
In other words, the capacitor C61 is connected via the diode D61.
And discharge, voltage V_C61Descends. Here, the seventh embodiment
In the state, the threshold voltage Vth41 is_{D1 1}Cut to approximately 0V
Voltage V at the time of switching_C61Is set lower than
You. Therefore, the DC-DC converter 1 starts operating.
And "V" shown in FIG._C61”, The threshold voltage Vth
Voltage V below 41_C61Occurs at both ends of capacitor C61
And the output level of the comparator 61 becomes low.
(Low).

Thereafter, when the DC-DC converter 1 stops operating due to the intermittent oscillation, the voltage V _{C11 of the} capacitor _C11
Is applied to both ends of the diode D11, and the voltage V _C11 is applied to the input of the circuit of FIG. 18, and the voltage V _{C61 of the} capacitor C61 is applied like “V _C61 ” shown in FIG.
There therefore exceed the threshold voltage Vth41 rises, becomes a high output level of the comparator 61 as "V _61" shown in FIG. 20, FE by the control of the control circuit 6f according to this
TQ301 turns on. Thereby, the capacitor C1
1 causes a charge current to flow through the start-up assist circuit 30, and the power of the capacitor C11 is consumed by the start-up assist circuit 30.
The C-DC converter 1 can be operated almost continuously, and the booster circuit 2 can be operated almost continuously. In the example of FIG. 21, the output level of the comparator 61 becomes high at time t2 '.

As described above, according to the seventh embodiment, the DC-DC
Abnormal rise of output of converter 1 is suppressed and booster circuit 2
Can be operated smoothly, and the rise of the output voltage of the booster circuit 2 can be accelerated.

Also, for example, the capacitance of the capacitor C301
Is larger than that of the capacitor C31.
If the constant is also increased, as shown in FIG.
A high-voltage pulse Vp is generated and the capacitors C31 and C3
01 to discharge current I_C31, I _C301Flows. And release
After the breakdown of the lamp La occurs, the capacitor
Relatively high voltage from C31, ratio from capacitor C301
It is possible to supply the current for starting
It is possible to provide a discharge lamp lighting device with good startability.
It works.

FIG. 22 is a block diagram of an eighth embodiment according to the present invention, and FIG. 23 is an operation waveform diagram under the control of the control circuit of FIG. 22. The eighth embodiment will be described below with reference to these drawings. Do. However, FIG. 22 shows a schematic configuration.

That is, the discharge lamp lighting device shown in FIG. 22 is different from the discharge lamp lighting device of FIG.
The DC converter 1a and the control circuit 6g are shown in FIG.
In place of the DC-DC converter 1 and the control circuit 6pa.

The DC-DC converter 1a is a D-DC converter shown in FIG.
The difference from the C-DC converter 1 is that the diode D
It further includes a resistor R12 provided in series between the capacitor R11 and the capacitor C11, and a switching element SW11 connected in parallel with the resistor R12.

The control circuit 6g is different from the control circuit 6pa of FIG. 31 in that the switching element SW11 is turned on every time the detected lamp voltage Vla starts to rise after the power is turned on until the discharge lamp La is turned on. Each time the detected lamp voltage Vla rises and reaches the threshold voltage Vth52, the switching element SW11 is turned off, and after the discharge lamp La is started and lit, the switching element SW11 is fixed to be turned on. I have. In the example of FIG. 23, when the lamp voltage Vla reaches the voltage Vth51, the DC-DC converter 1a intermittently oscillates and the voltage V _{C11 of the} capacitor C11 is controlled to be substantially constant at the voltage Vth51. It is.

Here, in the discharge lamp lighting device of FIG. 31, the reason why the output voltage of the booster circuit 2 is less likely to rise than the output voltage of the DC-DC converter 1 is that rectification of the output stage of the DC-DC converter 1 and This is because the impedance of the booster circuit 2 is higher than the impedance of the smoothing section.
Therefore, more power is supplied from the DC-DC converter 1 to the rectifying and smoothing unit than to the booster circuit 2.

In the eighth embodiment, attention is paid to this point, and the DC-
An impedance element (the resistor R12 in the example of FIG. 22) is added to the rectifying unit of the DC converter 1a to increase the impedance of the rectifying and smoothing unit. This allows
The amount of power supplied to the booster circuit 2 is forcibly increased, and the speed of boosting the output voltage of the booster circuit 2 can be increased.

[0092] In the discharge lamp lighting device constituted as described above, the capacitor C52 of the igniter 5 is charged by the output voltage V ₂ of the booster circuit 2, the voltage of the capacitor C52 V _C52
Rises. Then, the voltage V _C52 becomes the switching element S
When the breakdown voltage of G1 is reached, the switching element SG1 is turned on to rapidly discharge the capacitor C52, and a high-voltage pulse voltage is applied to the discharge lamp La.

At this time, the output voltage V _C11 of the DC-DC converter 1a is applied to the discharge lamp La. However, in the eighth embodiment, the voltage V _C11 is low due to the provision of the resistor R12 in the rectifying and smoothing section. There is a possibility that the possibility that the lighting of the discharge lamp La fails will increase. However, since the control is performed as shown in FIG. 23, the possibility that the lighting of the discharge lamp La fails will not increase. That is, the switching element SW11 is turned on until the detected lamp voltage Vla reaches the threshold voltage Vth52, so that the output voltage of the DC-DC converter 1a rises quickly as in the prior art, and the discharge lamp L
The voltage required for lighting a. Thereby, the discharge lamp La
Is less likely to fail as in the prior art.

[0094] Further, when the detected lamp voltage Vla reaches the threshold voltage Vth52, the switching element SW11 is turned off, raise the equivalent impedance of the rectifier unit of the DC-DC converter 1a, shown in FIG. 23, "V _2" As described above, the speed of boosting the output voltage of the booster circuit 2 increases. Thereafter, as described above, when the switching element SG1 is turned on, a high-voltage pulse voltage is applied to the discharge lamp La. Thereafter, the switching element SW11 is turned on.
It goes without saying that such control is repeated until the discharge lamp La is turned on.

As described above, according to the eighth embodiment, it is possible to suppress an abnormal increase in the output of the DC-DC converter 1a and to operate the booster circuit 2 smoothly while ensuring good startability. 2, the rising of the output voltage can be accelerated.

FIG. 24 is a block diagram of a ninth embodiment according to the present invention, and FIG. 25 is an operation waveform diagram under the control of the control circuit of FIG. 24. The ninth embodiment will be described below with reference to these drawings. Then, the discharge lamp lighting device shown in FIG. 24 is different from the eighth embodiment in that the DC-D
The C converter 1b is provided.

In the discharge lamp lighting device configured as described above, when the switching element SW11 is turned on, the output voltage of the DC-DC converter 1b rises quickly to turn on the discharge lamp La, as in the eighth embodiment. The required voltage is reduced, and the possibility that the lighting of the discharge lamp La fails will be reduced as in the related art.

On the other hand, when the detected lamp voltage Vla reaches the threshold voltage Vth52 and the switching element SW11 is turned off, the equivalent impedance of the rectifier of the DC-DC converter 1b becomes infinite, and the secondary All of the electromotive force on the side is supplied to the booster circuit 2. As a result, the voltage V _{C11 of the} capacitor C11 does not increase as in “Vla (V _C11 )” shown in FIG. 25, but the boosting speed of the output voltage of the booster circuit 2 as in “V ₂ ” in FIG. Rises.

As described above, according to the ninth embodiment, it is possible to suppress an abnormal increase in the output of the DC-DC converter 1b and to operate the booster circuit 2 smoothly while ensuring good startability. 2, the rising of the output voltage can be accelerated.

In a no-load state, when the switching element SW11 is off, a leakage current flows from the capacitor C11 to the discharge lamp La, and the voltage V
_{If C11} is lower than the threshold voltage Vth52, and more desirable to the voltage V _C11 turns on the switching element SW11 again configured to increase the threshold voltage Vth52.

Further, control having hysteresis may be performed in the determination of the threshold voltage Vth52. Vth52 is Vth
It must be at least a predetermined value lower than 51.

FIG. 26 is a block diagram of a tenth embodiment according to the present invention. The tenth embodiment will be described below with reference to FIG. 26. The discharge lamp lighting device shown in FIG. As a difference from the embodiment, a DC-DC converter 1c is provided.

This DC-DC converter 1c has the structure shown in FIG.
A resistor R13 provided in series between both ends of a winding n12 of a transformer T1 and an FET Q12 connected in parallel with the resistor R13 in place of the resistor R12 and the switching element SW11. That is, the tenth
In the embodiment, the resistor R13 is provided as an impedance element in the smoothing portion of the DC-DC converter 1c.

In the discharge lamp lighting device configured as described above, the current is supplied from the transformer T1 of the DC-DC converter 1c to the diode D through the FET Q12 or the resistor R13.
11, and the capacitor C11 is charged. When power is supplied from the capacitor C11 to the discharge lamp La, the FET Q12 is turned on when the FET Q12 is turned on.
Current flows via the body diode of the FET Q12 even when the FET Q12 is off, so that the output impedance to the discharge lamp La decreases. Therefore, the FET Q
Even if the discharge lamp La is turned on when the lamp 12 is off, the electric charge stored in the capacitor C11 is quickly supplied to the discharge lamp La at the moment of lighting, so that good startability can be obtained.

Further, when the impedance element is always connected to the smoothing portion, when the discharge lamp La is turned on, the DC-
Since this causes a loss of power supplied from the DC converter 1c to the discharge lamp La via the low-frequency inverter 4, the FET Q12 is fixed to be on to create a path for passing a current by bypassing the impedance element.

As described above, according to the tenth embodiment, it is possible to suppress an abnormal increase in the output of the DC-DC converter 1c and to operate the booster circuit 2 smoothly while ensuring good startability. 2, the rising of the output voltage can be accelerated.

FIG. 27 is a block diagram of an eleventh embodiment according to the present invention, and FIG. 28 is an operation waveform diagram under the control of the control circuit of FIG. 27. The eleventh embodiment will be described below with reference to these drawings. Do. However, FIG. 27 shows a partial configuration of the discharge lamp lighting device.

That is, the discharge lamp lighting device shown in FIG. 27 is different from the discharge lamp lighting device of FIG.
Instead of the DC-DC converter 1 and the control circuit 6pa
In addition to the C-DC converter 1d and the control circuit 6h, a mode switching circuit 9 is further provided.

The DC-DC converter 1d is a DC-DC converter 1d shown in FIG.
A difference from the C-DC converter 1 is that an FET (MOSFET) Q13 is used instead of the diode D11 in FIG.
And a driver 13 for driving the FET Q13. In addition, the windings n11 and F
Large-capacity capacitor C1 connected in parallel with ETQ11
0 is further provided. Q13 is not limited to an FET, but may be a diode D11 and a switching element connected in parallel with the diode D11 and capable of conducting in the opposite polarity. If there is no means such as a diode between the DC power supply E and the DC-DC converter 1d, which has a function of blocking a current having a polarity opposite to that during normal operation, the capacitor C10
Is not particularly necessary, but since the capacitor C10 is generally used for stabilizing the circuit and reducing noise, the eleventh embodiment employs a configuration including the capacitor C10.

The control circuit 6h is different from the control circuit 6pa in FIG. 31 in that the F
The configuration is such that a high-frequency control signal for the ETQ 11 is always output. That is, the control circuit 6h does not need to have an intermittent oscillation control function for stabilizing the voltage of the capacitor C11 to a substantially constant voltage in a no-load state after the power is turned on.

The mode switching circuit 9 is interposed between the output port of the high frequency control signal for the DC-DC converter 1d in the control circuit 6h and the FET Q11 and the driver 13, and outputs the control signal to the FET Q11 and the driver 13. When the detected lamp voltage Vla rises and reaches the threshold voltage Vth61, the contact M on the driver 13 side is switched to the switch SW91 for switching to either one.
When the detected lamp voltage Vla decreases and reaches a threshold voltage Vth62 lower than the threshold voltage Vth61, the comparator 91 has a hysteresis function that switches the switch SW91 to the contact M0 on the FET Q11 side. ing. However, the values of the threshold voltages Vth61 and Vth62 are, as described above,
It is set near the secondary voltage value in the no-load state.

Next, the characteristic operation of the discharge lamp lighting device having the above configuration will be described. As shown in the example of FIG. 28, after the power is turned on, the FET Q11 is repeatedly turned on / off, and the lamp voltage Vla increases. At this time, the booster circuit 2 performs a boosting operation by receiving the electromotive force of the winding n12 of the transformer T1.

Thereafter, when the detected lamp voltage Vla rises and reaches the threshold voltage Vth61, the switch SW91 is switched to the contact M1 on the driver 13 side, the switching operation of the FET Q11 is stopped, and the FET Q13 is repeatedly turned on / off. . Thereby, the FET Q13, the transformer T
1 and the body diode of the FET Q11 form a flyback circuit in the opposite direction to the normal, the flow of power supply is switched from the winding n12 to the winding n11 of the transformer T1, and the charge of the capacitor C11 is
Go to 10. As a result, the charge of the capacitor C11 decreases, and the voltage of the capacitor C11 starts to decrease. At this time, since the booster circuit 2 receives the high-frequency voltage generated in the transformer T1, it can continue the boosting operation.

Thereafter, when the detected lamp voltage Vla falls and reaches the threshold voltage Vth62, the switch SW91 is switched to the contact M0 on the FET Q11 side, the switching operation of the FET Q13 is stopped, and the FET Q11 is repeatedly turned on / off. As a result, the flow of power supply switches from the winding n11 to the winding n12 of the transformer T1, and the voltage of the capacitor C11 starts to increase. Such control is repeated until the discharge lamp La reaches the start lighting.

As described above, according to the eleventh embodiment, the switch M is switched to the contact M0 or the contact M1 according to the lamp voltage Vla.
Since W91 is switched, the lamp voltage Vla is changed to the threshold voltage V
The voltage boosting operation can be continued without stopping the voltage boosting circuit 2 while stabilizing the voltage to a substantially constant voltage between th61 and the threshold voltage Vth62. As a result, it is possible to quickly generate a high voltage. Further, capacitors C10 and C11
There is also an advantage that useless power loss does not occur because charges only flow between the spaces.

FIG. 29 is a block diagram of a twelfth embodiment according to the present invention, and FIG. 30 is an operation waveform diagram under the control of the control circuit of FIG. 29. The twelfth embodiment will be described below with reference to these drawings. Do. However, FIG. 29 shows a schematic configuration.

That is, the discharge lamp lighting device shown in FIG. 29 is different from the discharge lamp lighting device of FIG.
In place of the igniter 5 and the control circuit 6pa, an igniter 5a and a control circuit 6i are provided.

The igniter 5a corresponds to the igniter 5 shown in FIG.
31 is different from the switching element SG1 in FIG. 31 in that the switching element SW51 is turned on in accordance with a control signal from the control circuit 6i.

The control circuit 6i is different from the control circuit 6pa of FIG. 31 in that a control function of turning on the switching element SW51 so that the generation interval of the high-voltage pulse voltage becomes longer each time the start of the discharge lamp La fails. Have.

Here, the capacitors C11 and C31 are DC
-Is charged by the DC converter 1, and the charging speed of one of the capacitors C31 is determined by resistances R31 and R31.
Since 32 exists in the charging path, the time constant is large, and it is slower than the charging speed for the other capacitor C11.

If the boosting speed is increased by continuously operating the boosting circuit 2 in the no-load state as in each of the above embodiments, the igniter 5 is activated before the charging of the capacitor C31 of the starting auxiliary circuit 3 is completed. It operates and generates a high-voltage pulse.

As described above, when the charging speed of the capacitor C31 is low, the starting assisting effect of the starting assisting circuit 3, that is, the capacitor C3 is started when the discharge lamp La starts discharging.
The effect of pushing the current into the discharge lamp La by the charging voltage of 1 to make the discharge lamp La easier to light is reduced.

Therefore, in the twelfth embodiment, the discharge lamp La
Each time the start of the lamp fails, the generation interval of the high-voltage pulse voltage is lengthened to increase the charge voltage of the start-up assist circuit 3, thereby reliably lighting the discharge lamp La.

Next, the characteristic operation of the discharge lamp lighting device having the above configuration will be described. When the power is turned on, the discharge lamp La
Is turned off, the DC-DC converter 1 operates, the capacitor C11 is charged, and the capacitor C31 is charged at a slower charging rate.
On the other hand, the booster circuit 2 also operates in response to the operation of the DC-DC converter 1, and the capacitor C52 is charged to a voltage required for discharging the discharge lamp La.

Thereafter, when the voltage across the capacitor C52 reaches a voltage necessary for discharging the discharge lamp La, the switching element SW51 is turned on by a control signal from the control circuit 6i. Then, the high-voltage pulse voltage of the capacitor C52 via the pulse transformer T5 is superimposed on the no-load voltage of the discharge lamp La by the capacitor C11. Further, the pushing current _Ic31 from the capacitor C31 flows to the discharge lamp La. Thereby, the discharge lamp L
a leads to start-up lighting, but if the pushing current I _c31 from the start-up assist circuit 3 to the discharge lamp La is small, the discharge lamp La
May not light up.

As described above, when the start of the discharge lamp La fails, the switching element SW51 is turned on so that the generation interval of the high-voltage pulse voltage becomes longer each time the start of the discharge lamp La fails. _As shown in " _c31 ", the pushing current _Ic31 increases. Thereby, the discharge lamp La is easily turned on. Note that Ip in FIG. 30 is a pulse current.

As described above, in the first to eleventh embodiments, when the charging of the capacitor C52 is constant and the start of the discharge lamp La fails, the same energy as the previous time is supplied to the capacitor C52.
According to the twelfth embodiment, when the start of the discharge lamp La fails, greater energy is supplied from the capacitor C52 to the discharge lamp La than in the previous case. In addition to being easy to light,
Since a (minimum) pushing current required for starting the discharge lamp La can be supplied adaptively, stress on each element and the discharge lamp La can be reduced. If the configuration of the twelfth embodiment is applied to any of the first to eleventh embodiments, the booster circuit 2 can be operated smoothly, and an abnormal increase in the output of the DC-DC converter 1 is suppressed. be able to.

[0128]

As is apparent from the above description, according to the first aspect of the present invention, the DC power supply and the voltage of this DC power supply are level-converted, and then rectified and smoothed to obtain the first DC voltage. And a DC-DC converter for obtaining
A booster circuit for boosting, rectifying and smoothing the voltage level-converted by the converter to obtain a second DC voltage;
A power supply device that supplies power to a load from an output of a DC converter, applies a voltage to the load from a DC-DC converter for a predetermined time, and superimposes a voltage from a booster circuit on the voltage. Since a power consumption circuit having at least an element is provided between the DC-DC converter and the load, and the switching means is operated under a predetermined condition, the slope of the voltage change due to the smoothing of the DC-DC converter is reduced. The output power of the DC-DC converter is forcibly consumed by the power consuming element, and the frequency of stopping the operation of the DC-DC converter required to obtain the first DC voltage is reduced. The frequency of operation of the circuit increases, the booster circuit can operate smoothly, and the output of the DC-DC converter is abnormal. It is possible to suppress the temperature.

According to a second aspect of the present invention, in the power supply device of the first aspect, a control circuit for operating a power consuming circuit when the first DC voltage reaches a predetermined value is provided. The booster circuit can be operated smoothly, and an abnormal increase in the output of the DC-DC converter can be suppressed.

According to a third aspect of the present invention, in the power supply device of the first aspect, a control circuit for operating the power consumption circuit until the second DC voltage rises to a predetermined value is provided. In addition, the booster circuit can be operated smoothly, and an abnormal increase in the output of the DC-DC converter can be suppressed.

According to the fourth aspect of the present invention, the power supply device according to the first aspect includes a control circuit for operating the power consumption circuit for a predetermined period within a period during which the second DC voltage rises. With this configuration, the booster circuit can be operated smoothly, and an abnormal increase in the output of the DC-DC converter can be suppressed.

According to a fifth aspect of the present invention, in the power supply device according to the first aspect, a control circuit is provided, the power consumption circuit has a charging element, and the control circuit controls the output voltage of the DC-DC converter. On the other hand, the power is supplied from the DC-DC converter to the power consumption circuit with a delay in time. In this configuration as well, the booster circuit can be operated smoothly, and an abnormal increase in the output of the DC-DC converter is suppressed. be able to.

According to the invention of claim 6, in the power supply device of claim 1 or 5, the output of the DC-DC converter is provided with a plurality of charging / discharging circuits having different time constants of the charging circuit. With this configuration, the booster circuit can be operated smoothly, and an abnormal increase in the output of the DC-DC converter can be suppressed.

According to the seventh aspect of the present invention, the DC power supply, the DC-DC converter for converting the voltage of the DC power supply, and then rectifying and smoothing to obtain the first DC voltage, and the DC-DC converter A booster circuit for boosting, rectifying and smoothing the voltage converted by the DC converter to obtain a second DC voltage, supplying power to the load from the output of the DC-DC converter, and
A power supply device for applying a voltage from a converter to a load and superimposing a voltage from a booster circuit on this voltage,
Since the control means for changing the ratio between the output power of the converter and the power supply to the booster circuit is provided, the booster circuit can be operated smoothly if the ratio is increased so that the power supply to the booster circuit is increased. At this time, DC-DC
The amount of output power of the converter is reduced, and an abnormal increase in the output of the DC-DC converter can be suppressed.

According to the invention of claim 8, in the power supply device of claim 7, the circuit for rectifying and smoothing in the DC-DC converter forms a closed circuit, and the switching element is provided in the closed circuit. At least the circuits are connected in series, and the control means controls the switching element to control D
The ratio between the output power of the C-DC converter and the power supply to the booster circuit is changed. This configuration also allows the booster circuit to operate smoothly and suppresses an abnormal increase in the output of the DC-DC converter. be able to.

According to the ninth aspect of the present invention, in the power supply device according to the first or seventh aspect, since the DC-DC converter can perform bidirectional conversion, the DC-DC converter does not generate useless power loss and can be used as a booster. To operate smoothly, DC-DC
An abnormal rise in the output of the converter can be suppressed.

According to the tenth aspect, the ninth aspect is provided.
In the power supply device described above, the DC-DC converter performs forward power conversion for supplying power from the DC power supply to the load side until the output voltage reaches a first predetermined value, and the output voltage becomes the first predetermined value. After that, power conversion is performed in the reverse direction of regenerating power from the load side to the DC power supply side until reaching a second lower predetermined value, and after the output voltage reaches the second predetermined value, Since the forward power conversion is performed again until the first predetermined value is reached, the booster circuit operates smoothly without causing unnecessary power loss, and an abnormal increase in the output of the DC-DC converter is suppressed. be able to.

According to the eleventh aspect of the present invention, the first aspect is provided.
11. In the power supply device according to any one of the above items, the booster circuit obtains the second DC voltage by stepwise charging using a capacitor and a diode. Even in this configuration, the booster circuit can operate smoothly. Besides DC-D
An abnormal increase in the output of the C converter can be suppressed.

According to the twelfth aspect of the present invention, the first aspect is provided.
11. The power supply device according to any one of
The DC converter has a transformer for voltage conversion, and the booster circuit is constituted by a separate winding provided on the transformer. Even with this configuration, the booster circuit can be operated smoothly and the DC-DC converter An abnormal increase in output can be suppressed.

According to the thirteenth aspect, according to the first aspect,
11. The power supply device according to any one of
Since the DC converter has a flyback type circuit configuration, even with this configuration, the booster circuit can be operated smoothly, and an abnormal increase in the output of the DC-DC converter can be suppressed.

According to the fourteenth aspect of the present invention, the first aspect
11. The power supply device according to any one of claims 1 to 10, wherein a charging / discharging circuit including at least a capacitor and a resistor and a low-frequency inverter having a full bridge configuration are connected to a DC-D
Connect to the output of the C converter, connect the charging capacitor to the output of the booster circuit, connect the primary side of the pulse transformer and the series circuit of the switching element, and connect the secondary side of the pulse transformer to the output of the low frequency inverter. In this configuration, the booster circuit can be operated smoothly, and an abnormal increase in the output of the DC-DC converter can be suppressed.

According to the fifteenth aspect, the first aspect is provided.
To 10 and a discharge lamp as a load, so that the booster circuit can be operated smoothly and an abnormal rise in the output of the DC-DC converter can be suppressed. it can.

According to the sixteenth aspect, according to the first aspect,
0, the load is a discharge lamp, and the first and second predetermined values are substantially close to a no-load secondary voltage required for starting the discharge lamp, and the first and second predetermined values are the same. Since the no-load secondary voltage is set to fall between the values,
The no-load secondary voltage can be maintained at a voltage required for starting the discharge lamp.

According to the seventeenth aspect, the first aspect is provided.
5. The discharge lamp lighting device according to item 5, wherein
Since the on-time of the switching element connected to the next side is adjusted to control the time until the high voltage pulse for starting the discharge lamp is generated, for example, a charge / discharge circuit including at least a capacitor and a resistor is provided. If so, it is possible to control the current flowing from the charge / discharge circuit to the discharge lamp.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a first embodiment according to the present invention.

FIG. 2 is an operation waveform diagram under the control of the control circuit of FIG. 1;

FIG. 3 is an operation waveform diagram under the control of the control circuit of FIG. 31;

FIG. 4 is a configuration diagram of a second embodiment according to the present invention.

FIG. 5 is an operation waveform diagram under the control of the control circuit of FIG. 4;

FIG. 6 is a configuration diagram of a third embodiment according to the present invention.

FIG. 7 is an operation waveform diagram under the control of the control circuit of FIG. 6;

8 is an operation waveform diagram under the control of the control circuit of FIG. 31.

FIG. 9 is a configuration diagram of a fourth embodiment according to the present invention.

FIG. 10 is an operation waveform diagram under the control of the control circuit of FIG. 9;

FIG. 11 is a configuration diagram of a fifth embodiment according to the present invention.

FIG. 12 is an operation waveform diagram under the control of the control circuit of FIG. 11;

FIG. 13 is a configuration diagram of a sixth embodiment according to the present invention.

FIG. 14 is an operation waveform diagram under the control of the control circuit of FIG. 13;

FIG. 15 is an operation waveform diagram under the control of the control circuit of FIG. 31;

FIG. 16 is a diagram showing another configuration example of the starting auxiliary circuit.

FIG. 17 is a configuration diagram of a seventh embodiment according to the present invention.

18 is a configuration diagram of a monitoring function of the control circuit of FIG.

FIG. 19 is an operation waveform diagram under the control of the control circuit of FIG. 17;

20 is an operation waveform diagram under the control of the control circuit of FIG. 17;

FIG. 21 is an operation waveform diagram under the control of the control circuit of FIG. 17;

FIG. 22 is a configuration diagram of an eighth embodiment according to the present invention.

FIG. 23 is an operation waveform diagram under the control of the control circuit of FIG. 22;

FIG. 24 is a configuration diagram of a ninth embodiment according to the present invention.

FIG. 25 is an operation waveform diagram under the control of the control circuit of FIG. 24;

FIG. 26 is a configuration diagram of a tenth embodiment according to the present invention.

FIG. 27 is a configuration diagram of an eleventh embodiment according to the present invention.

FIG. 28 is an operation waveform diagram under the control of the control circuit of FIG. 27;

FIG. 29 is a configuration diagram of a twelfth embodiment according to the present invention.

FIG. 30 is an operation waveform diagram under the control of the control circuit of FIG. 29;

FIG. 31 is a circuit diagram of a conventional discharge lamp lighting device.

FIG. 32 is an operation waveform diagram of the discharge lamp lighting device of FIG. 31.

FIG. 33 is an explanatory diagram of a problem that the discharge lamp lighting device of FIG. 31 has.

[Explanation of symbols]

1, 1a, 1b, 1c, 1d DC-DC converter 2 Booster circuit 3, 3a Start auxiliary circuit 30 Start auxiliary circuit 4 Low frequency inverter 5, 5a Igniter 6, 6a, 6b, 6c, 6d, 6e, 6f, 6g, 6
h, 6i control circuit 7 load insertion circuit 8 monitoring circuit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tomoyuki Nakano 1048 Kazumasa Kadoma, Osaka Prefecture Matsushita Electric Works, Ltd. 72) Inventor Takashi Kanbara 1048 Kadoma, Kazuma, Osaka Prefecture F-term in Matsushita Electric Works, Ltd. AA03 BB03 CA02 CB04 CB05 CC05 CC12 CC34 DA06 DB01 DC05 5H730 AS04 AS11 BB23 BB57 BB86 DD04 EE02 EE06 EE60 EE65 FD21 FG01

Claims (17)

[Claims] 1. A DC power supply, a DC-DC converter for level-converting a voltage of the DC power supply, and then rectifying and smoothing to obtain a first DC voltage, and a voltage level-converted by the DC-DC converter. And a boost circuit for obtaining a second DC voltage by boosting, rectifying and smoothing, supplying power from the output of the DC-DC converter to the load, and applying a voltage from the DC-DC converter to the load for a predetermined time. A power supply device for superimposing a voltage from a booster circuit on this voltage, wherein a power consumption circuit having at least a switching means and a power consumption element is provided between the DC-DC converter and the load, and switching is performed under a predetermined condition. Activating the means, D
A power supply device for reducing a slope of a voltage change due to smoothing of a C-DC converter. 2. The power supply device according to claim 1, further comprising a control circuit that operates the power consumption circuit when the first DC voltage reaches a predetermined value. 3. Until the second DC voltage rises to a predetermined value.
The power supply device according to claim 1, further comprising a control circuit that operates the power consumption circuit. 4. The power supply device according to claim 1, further comprising a control circuit that operates the power consumption circuit for a predetermined period within a period during which the second DC voltage rises. 5. A control circuit, wherein the power consumption circuit has a charging element, and the control circuit delays a time with respect to an output voltage of the DC-DC converter to supply power from the DC-DC converter to the power consumption circuit. The power supply device according to claim 1, wherein 6. The power supply device according to claim 1, wherein a plurality of charge / discharge circuits having different time constants of a charging circuit are provided at an output of the DC-DC converter. 7. A DC power supply, a DC-DC converter for level-converting the voltage of the DC power supply, and then rectifying and smoothing to obtain a first DC voltage, and a voltage level-converted by the DC-DC converter. And a boost circuit for obtaining a second DC voltage by boosting, rectifying and smoothing, supplying power from the output of the DC-DC converter to the load, and applying a voltage from the DC-DC converter to the load for a predetermined time. A power supply device for superimposing a voltage from a booster circuit on this voltage, comprising a control unit for changing a ratio between output power of the DC-DC converter and power supply to the booster circuit. 8. A circuit for rectifying and smoothing in a DC-DC converter forms a closed circuit, and a circuit having at least a switching element is connected in series to the closed circuit, and the control means controls the switching element. DC-D
8. The power supply device according to claim 7, wherein the ratio between the output power of the C converter and the power supply to the booster circuit is changed. 9. The power supply device according to claim 1, wherein the DC-DC converter is capable of bidirectional conversion. 10. The DC-DC converter performs forward power conversion for supplying power from the DC power supply to the load side until the output voltage reaches a first predetermined value, and the output voltage reaches a first predetermined value. After that, power conversion is performed in the reverse direction of regenerating power from the load side to the DC power supply side until a second predetermined value lower than the second predetermined value is reached. 10. The power supply device according to claim 9, wherein the power conversion in the forward direction is performed again until the predetermined value of 1 is reached. 11. The power supply device according to claim 1, wherein the step-up circuit obtains the second DC voltage by stepwise charging using a capacitor and a diode. 12. The DC-DC converter has a transformer for voltage conversion, and the booster circuit is constituted by another winding provided on the transformer.
The power supply device according to any one of the above. 13. The power supply device according to claim 1, wherein the DC-DC converter has a flyback type circuit configuration. 14. A charge / discharge circuit comprising at least a capacitor and a resistor, and a low-frequency inverter having a full bridge configuration are connected to an output of a DC-DC converter,
A charging capacitor is connected to the output of the booster circuit, a primary circuit of the pulse transformer and a series circuit of the switching element are connected to this, and a pulse transformer 2 is connected to the output of the low-frequency inverter.
11. The power supply device according to claim 1, wherein a series circuit of a secondary side and a load is connected. 15. A discharge lamp lighting device comprising: the power supply device according to claim 1; and a discharge lamp as a load. 16. The load is a discharge lamp, and the first and second predetermined values are substantially close to a no-load secondary voltage required for starting the discharge lamp, and the first and second predetermined values are not equal to each other. No load in between 2
The power supply device according to claim 10, wherein the power supply device is set so that the next voltage falls. 17. The method according to claim 15, wherein an on-timing of a switching element connected to a primary side of the pulse transformer is adjusted to control a time until a high-voltage pulse for starting a discharge lamp is generated. The discharge lamp lighting device as described in the above.