JP4776645B2 - Discharge lamp lighting device and lighting apparatus equipped with the same - Google Patents

Description

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

  Conventionally, “a low-voltage switching element can be used in a lighting device for an HID lamp, and miniaturization is possible. As a technology for the purpose of the above, “DC power supply E, down converter 1 for controlling the power of the discharge lamp La, smoothing capacitor Cf for smoothing the output of the down converter 1, and the output of the down converter 1 as a rectangular wave A full-bridge inverter 2 for converting to current, an igniter IG for generating a high voltage pulse for starting, and a discharge lamp La connected to the output of the full-bridge inverter 2 via the igniter IG for smoothing before lighting The voltage Vc of the capacitor Cf is controlled so that the voltage up to the discharge lamp system including the smoothing capacitor Cf is limited to a predetermined value or less except for the high voltage pulse for starting. Is proposed (Patent Document 1).

  In addition, there is a configuration in which a step-down chopper (chopper circuit 10) and a full bridge inverter circuit are configured so that the detection voltage of the lamp voltage and the lamp current can be detected by a DC voltage (Patent Document 2).

  In addition, the present invention provides a discharge lamp lighting device that can easily correct both at least the variation in the detected voltage value and the variation in the detected current value, and can perform power adjustment efficiently. As a technology for the purpose, “power control means 11 and 18 for constant power control of power supplied to the discharge lamp in a steady state according to the lamp current and lamp voltage of the discharge lamp 14, and an analog circuit of the power control means” Power supply means 19 for supplying a constant DC voltage to the unit. This power supply means has the above-mentioned DC constant voltage variable means R7 for adjusting the output power in the steady state of the lighting device "(Patent Document 3).

JP 2003-187996 A (summary) JP2003-178896A (FIG. 1) Japanese Patent Laid-Open No. 7-135086 (summary)

  The down converter 1 described in Patent Document 1 and the step-down chopper described in Patent Document 2 adjust lamp power. When these configurations are not used, the lamp voltage and current may fluctuate greatly in synchronization with the AC power supply frequency. In this case, it becomes difficult to perform the constant power control so that the lamp has a rated output in a steady state.

For example, in a circuit composed of a step-down chopper and a full bridge inverter circuit described in Patent Document 2, both the lamp voltage and the detected voltage of the lamp current are the same DC voltage as the output voltage of the step-down chopper circuit. By further smoothing the DC voltage, the control circuit can detect these with a substantially flat DC voltage and perform power control without being influenced by the AC power supply frequency.
However, if these configurations are not used, the detection by the DC voltage as described above cannot be performed, so that the detection voltage of the lamp voltage and the lamp current is a rectangular wave, and even if this is smoothed, it is affected by the AC power supply frequency. As a result, the detection voltage of the lamp voltage and the lamp current fluctuates.

  Further, in the technique described in Patent Document 3, a variable resistor for performing power adjustment is provided, but it takes time for adjustment.

  The present invention has been made to solve the above-described problems, and is capable of easily performing constant power control even when the lamp current and voltage fluctuate in synchronization with the frequency of the AC power supply. An object is to provide a lighting device.

A discharge lamp lighting device according to the present invention is a discharge lamp lighting device that is connected to a commercial power source having a different frequency depending on an installation environment, and a rectifier circuit that rectifies the commercial power source, and an output voltage of the rectifier circuit is a predetermined DC voltage. A step-up chopper circuit that converts the voltage from the step-up chopper circuit into an alternating current; a terminal that connects a load; a control unit that controls the operation of the inverter; and a voltage applied to the load is detected. Voltage detecting means for controlling the frequency of the AC voltage applied to the load to be a common multiple of each frequency of the commercial power supply , and determining the AC power supplied to the load. When performing power control, a common multiple of a time corresponding to one cycle at each different frequency of the commercial power supply is taken, and the negative power is reduced within a half of the time corresponding to the common multiple. The voltage value applied to the acquired by the voltage detecting means obtains an average value within the time, and performs constant power control of AC power supplied to the load by using the average value.

  According to the discharge lamp lighting device according to the present invention, stable constant power control of the power supplied to the discharge lamp can be performed.

Embodiment 1 FIG.
FIG. 1 is a diagram showing a discharge lamp lighting device and its peripheral configuration according to Embodiment 1 of the present invention.
In FIG. 1, an alternating current supplied from an alternating current power source 1 is rectified into a direct current by a rectifier circuit 2 and smoothed by a smoothing capacitor 3.
The DC voltage output from the rectifier circuit 2 is converted into a voltage value by a step-up chopper circuit including a coil 4, a diode 5, and an FET (Field Effect Transistor) 6 and then output.
The FETs 7 and 8 and the capacitors 9 and 10 constitute a half-bridge inverter circuit, converts a DC voltage output from the chopper circuit into an AC voltage, and supplies AC power to a load such as the discharge lamp 14.

  The coil 13 and the starting circuit 15 serve as an igniter that instantaneously applies a high voltage to the discharge lamp 14. The discharge lamp 14 is connected to a load terminal (not shown) and can be removed.

The current detection circuit 16 detects a current flowing through the discharge lamp 14 and outputs a detection value to the control circuit. The voltage detection circuit 17 detects a voltage applied to the discharge lamp 14 and outputs a detection value to the control circuit.
The control circuit 18 controls the operation of the FETs 7 and 8 and performs constant power control of the discharge lamp 14. The control circuit 18 includes a storage device such as a memory (not shown).

  The “DC power supply circuit” in the first embodiment corresponds to the AC power supply 1, the rectifier circuit 2, and the smoothing capacitor 3. The configuration of the “DC power supply circuit” is not limited to this configuration.

  The control circuit 18 is composed of an arithmetic device such as a microcomputer or a DSP (Digital Signal Processor). Further, a storage device storing a program for instructing the operation is appropriately provided.

Next, constant power control of the discharge lamp 14 will be described.
The discharge lamp lighting device is shipped after adjusting variations in output power caused by variations in characteristics of components such as coils so that the output power in a steady state becomes a rated value. Thereby, during the steady operation of the discharge lamp 14, the operation of the FETs 7 and 8 is controlled by the control circuit 18 so that the output power becomes the rated value.

However, in the case of the configuration as shown in FIG. 1, the current flowing through the discharge lamp 14 and the applied voltage vary in synchronization with the frequency of the AC power supply 1. Therefore, the constant power control is performed so that the average value of the voltage and current in a certain period becomes the rated value. The certain period is a time corresponding to a constant multiple of one cycle of the AC power source 1.
However, commercial AC power supplies have different frequencies depending on the geographical location. For example, in Japan, there are two types of frequencies, 50 Hz and 60 Hz. If the frequency is different, the time corresponding to one cycle is naturally different.
Therefore, when the average value is obtained based on one period of either 50 Hz or 60 Hz, there is a disadvantage that a value different from the average value obtained by the operation at the other frequency is calculated.

  A technique for avoiding such inconvenience due to the difference in frequency of the AC power supply 1 will be described with reference to FIG.

FIG. 2 shows waveforms such as voltage in each case where the frequency of the AC power supply 1 is different. FIG. 2A shows the case where the frequency = 50 Hz, and FIG. 2B shows the case where the frequency = 60 Hz.
The constant power control of the discharge lamp 14 is performed such that an average of voltage and current in a certain period is obtained and the average value is set as a rated value. Here, the following description will be given assuming that the average value of the period of 0.00 s to 0.05 s in FIG. 2 is obtained.

  The output power of the discharge lamp 14 in the period of 0.00 s to 0.05 s in FIG. 2 is determined depending on the frequency of the AC voltage applied to the discharge lamp 14 during this period. In FIG. 2, the frequency of the AC voltage applied to the discharge lamp 14 is 300 Hz, taking the common multiple of the frequency of the AC power source 1 in each of the cases (a) and (b).

In the case of FIG. 2A, the period of 0.00 s to 0.05 s corresponds to 2.5 cycles of the AC power source 1 and corresponds to 15 cycles of the AC voltage applied to the discharge lamp 14.
In the case of FIG. 2B, the period of 0.00 s to 0.05 s corresponds to three cycles of the AC power source 1 and corresponds to 15 cycles of the AC voltage applied to the discharge lamp 14.
That is, at the time of 0.05 s, the AC voltage applied to the discharge lamp 14 corresponds to 15 cycles in both cases of FIGS. If the average value of the current and voltage of the discharge lamp 14 is obtained at this time, they coincide with each other.
Therefore, by obtaining the average value of the current and voltage of the discharge lamp 14 in units of 0.05 s and performing the constant power control, the constant power control can be performed based on the same reference even if the frequency of the AC power supply 1 is different. Therefore, it is not necessary to implement different processing according to the frequency of the AC power supply 1.

  As described above, the constant power control can be performed based on the same reference regardless of the frequency of the AC power source 1 because the frequency of the AC voltage applied to the discharge lamp 14 is a common multiple of the frequency of the AC power source 1. .

  That is, under the configuration of FIG. 1, the control circuit 18 drives and controls the FETs 7 and 8 so that the frequency of the AC voltage applied to the discharge lamp 14 is a common multiple of the frequency of the AC power source 1. Even if the frequency of 1 differs depending on the installation environment, constant power control can be easily performed.

  In the first embodiment, the use of the FET has been described with reference to FIG. 1, but the present invention is not limited to this, and any switching element can be used. The same applies to the following embodiments.

In addition, regarding how to obtain the frequency (50 Hz, 60 Hz) of the AC power supply 1, if these numerical values are known, the numerical values are stored in a storage device such as a memory provided in the control circuit 18. Just keep it. Further, a frequency detection circuit may be provided before the rectifier circuit 2.
A storage device such as a memory may be provided in the control circuit 18 itself, or may be provided separately and connected to the control circuit 18.

Embodiment 2. FIG.
In the first embodiment, it has been described that the frequency of the AC voltage applied to the discharge lamp 14 is a common multiple of the frequency of the AC power source 1. In the second embodiment, based on the premise, it will be described on which time point the average value of the current and voltage of the discharge lamp 14 is obtained.

In the first embodiment, at 0.05 s in FIG. 2, the AC voltage applied to the discharge lamp 14 is 15 cycles in both FIGS. 2A and 2B, and at this time the current of the discharge lamp 14 and When the average value of voltage was calculated | required, it demonstrated that both corresponded.
The procedure for obtaining the time when (a) and (b) coincide, that is, the time of 0.05 s in the case of FIG. 2, will be described with reference to FIG.

  FIG. 3 illustrates a procedure for obtaining a point in time when the average values of the current and voltage of the discharge lamp 14 match when the frequency of the AC power supply 1 is different. Each waveform is the same as in FIG.

(1) First, in both FIGS. 3A and 3B, a time corresponding to one cycle of the AC power source 1 is obtained.
In the case of FIG. 3A, since the frequency is 50 Hz, one cycle = 1/50 s = 6/300 s.
In the case of FIG. 3B, since the frequency is 60 Hz, one cycle = 1/60 s = 5/300 s.

(2) Next, a common multiple of the time corresponding to one period obtained in step (1) is obtained. Here, it is 30/300 s.
(3) Next, the common multiple obtained in step (2) is halved. Here, it is 15/300 s.

(4) The time of 15/300 s obtained in step (3) corresponds to the time of 0.05 s in the first embodiment.

  The time point at which the average values of the currents and voltages of the discharge lamps 14 can be obtained by the procedures as described in steps (1) to (4) above. It should be noted that even if the average value is obtained at the time of 30/300 s, 45/300 s, 60/300 s due to the periodicity of alternating current, it is natural that the same values are obtained.

  As described above, the common multiple of the time corresponding to one cycle of the AC power supply 1 is obtained, and the average value of the current and voltage of the discharge lamp 14 is obtained in a period corresponding to one half of the time, and the average value is used. By performing the constant power control, the constant power control can be easily performed even if the frequency of the AC power supply 1 varies depending on the installation environment.

In addition, when performing constant power control, when acquiring the electric current and applied voltage which flow into the discharge lamp 14, each value should just be acquired using the current detection circuit 16 or the voltage detection circuit 17. FIG.
That is, within the period obtained in the above steps (1) to (4), the control circuit 18 obtains each value using the current detection circuit 16 and the voltage detection circuit 17, and calculates the average value during the same period. Can be sought.

Embodiment 3 FIG.
In the first and second embodiments, it has been described that an average value of the current and voltage of the discharge lamp 14 in a certain period is obtained and constant power control is performed using the average value.
On the other hand, when detecting an abnormality in the discharge lamp 14, an instantaneous value is used instead of an average value. This is because when the abnormality detection is performed using the average value, the abnormality is not detected unless the current and voltage of the discharge lamp 14 are constantly in an abnormal state.
Therefore, the control circuit 18 uses an average value of current and voltage for constant power control of the discharge lamp 14 and uses an instantaneous value for abnormality detection.

Embodiment 4 FIG.
In the first to third embodiments, it has been described that constant power control is performed using an average value of the current and voltage of the discharge lamp 14 in a certain period.
In the fourth embodiment, a method that can easily correct variations in output power caused by variations in characteristics of components such as coils will be described. The discharge lamp lighting device and its peripheral configuration are the same as in FIG.

  In the fourth embodiment, the output power of the discharge lamp 14 is adjusted by the following steps (1) to (4). Hereinafter, each step will be described.

(1) At the stage before the discharge lamp lighting device is shipped, the discharge lamp 14 is removed from the terminal, and a constant current load is connected instead to make the load current constant. For example, in the case of a 70 W inverter, a rated current of 0.8 A when the discharge lamp 14 is lit is used as a load current.
The rated current value of the constant current load is given to the control circuit 18 in advance by a method such as inputting from a predetermined input terminal or storing in a storage device such as a memory.

(2) A predetermined electrical signal is given to the control circuit 18 to notify the control circuit 18 that power adjustment is to be performed from now. Upon receiving the electrical signal, the control circuit 18 shifts to a mode for performing power adjustment as described below.
Here, the electric signal refers to, for example, applying a predetermined DC voltage to a terminal provided in the control circuit 18.

(3) The control circuit 18 controls the driving of the FETs 7 and 8 and causes a current to flow through the constant current load. Next, the control circuit 18 acquires a load current value from the current detection circuit 16.
At this time, there is a difference between the rated current value of the constant current load and the current value detected by the current detection circuit 16 due to variations in component characteristics. Here, it is assumed that the detected current value is 0.9 A while the rated current value is 0.8 A.

(4) The control circuit 18 obtains a ratio between the detected value detected in step (3) and the rated current value. Here, 0.8A ÷ 0.9A≈0.889.
The control circuit 18 stores the obtained value as a correction coefficient in a storage device such as a memory.

The power adjustment is completed by the method as described above in steps (1) to (4). When shipping the discharge lamp lighting device, remove the constant current load.
When the discharge lamp 14 is turned on and constant power control is performed, the following operation (5) is performed using the correction coefficient obtained in step (4).

(5) When performing the constant power control of the discharge lamp 14, the control circuit 18 obtains the current value of the discharge lamp 14 from the current detection circuit 16, and obtains the output power of the discharge lamp 14. At this time, the detection value acquired from the current detection circuit 16 is displaced due to variations in component characteristics.
Therefore, the control circuit 18 reads the correction coefficient stored in the storage device in the previous step (4), multiplies the value by the detected value, and obtains the output power using the multiplied value.
For example, when the detection value is 0.9 A, the current value used for power calculation is 0.9 A × 0.889 = 0.8 A.
As a result, accurate power calculation is possible regardless of variations in component characteristics, and the accuracy of constant power control is improved.

As described above, according to the fourth embodiment, the correction coefficient is obtained using the load current value obtained by connecting the constant current load, and the constant power control is performed using the correction coefficient. Accurate power calculation is possible regardless of variations.
Further, as described in Patent Document 1, it is not necessary to adjust the power by adjusting the variable resistance, and the adjustment can be performed with a simple procedure.

Embodiment 5 FIG.
In the fourth embodiment, power adjustment is performed before the discharge lamp lighting device is shipped, and the correction coefficient is stored in the storage device. When the constant power control of the discharge lamp 14 is performed, the correction coefficient is used. A method for performing accurate power calculation has been described.
In the fifth embodiment, a configuration capable of performing power adjustment at an arbitrary time after shipment of the discharge lamp lighting device will be described.

FIG. 4 is a diagram showing a discharge lamp lighting device and its peripheral configuration according to the fifth embodiment.
In FIG. 4, a constant current load 20 is connected in parallel with a terminal to which the discharge lamp 14 is connected, and a switch 19 is newly provided for switching which of the discharge lamp 14 and the constant current load 20 power is supplied to. The switch 19 performs a switching operation according to an instruction from the control circuit 18.
Other configurations are the same as those in FIG.

  Next, the operation of the configuration of FIG. 4 will be described. Note that it may be either whether or not the power adjustment is performed before the discharge lamp lighting device is shipped.

(1) A predetermined electrical signal is given to the control circuit 18 to notify the control circuit 18 that power adjustment is to be performed from now. Upon receiving the electrical signal, the control circuit 18 shifts to a mode for performing power adjustment as described below.
At this time, the control circuit 18 switches the switch 19 to the constant current load 20 side.

(2) The correction coefficient is obtained by the method as in steps (3) to (4) described in the fourth embodiment and stored in the storage device. If there is a correction coefficient already stored, it is overwritten with the latest value.
When the discharge lamp 14 is turned on and constant power control is performed, the following operation (3) is performed using the correction coefficient obtained in step (4).

(3) When performing the constant power control of the discharge lamp 14, the control circuit 18 switches the switch 19 to the discharge lamp 14 side, and uses the technique described in step (5) of the fourth embodiment. Constant power control using a correction coefficient is performed.

As described above, according to the configuration and method described in the fifth embodiment, the power adjustment of the discharge lamp 14 can be performed at any time after the discharge lamp lighting device is shipped.
For example, even when the output power characteristics change due to aging of parts, changes in usage environment, etc., the power can be adjusted immediately and with an easy procedure, so that accurate constant power control can always be performed.

Embodiment 6 FIG.
In the first to fifth embodiments described above, a half-wave discharge phenomenon (a phenomenon in which the current flowing through the discharge lamp becomes asymmetrical between positive and negative) occurs due to the life of the discharge lamp 14, and the upper capacitor 9 and the lower capacitor 10. The voltage may become unbalanced, and a voltage exceeding the allowable voltage of each element may be applied to destroy the element.
In the sixth embodiment of the present invention, a configuration and control operation capable of protecting the FETs 7 to 8 and the capacitors 9 to 10 of the half bridge inverter circuit when such a voltage imbalance occurs will be described.

FIG. 5 is a diagram showing a discharge lamp lighting device and its peripheral configuration according to the sixth embodiment.
The discharge lamp lighting device according to the sixth embodiment includes a DC output voltage detection circuit 21 that detects the output voltage of the boost chopper circuit, and a capacitor voltage detection circuit 22 that detects the voltage of the lower capacitor 10. . The DC output voltage detection circuit 21 and the capacitor voltage detection circuit 22 each output a detection value to the control circuit 18.
Other configurations are the same as those in FIG. 1 described in the first embodiment, and thus description thereof is omitted.
In the configuration of FIG. 1, when a DC output voltage detection circuit is already provided to control the output voltage of the boost chopper circuit, this may be used as the DC output voltage detection circuit 21.

The configuration of the discharge lamp lighting device according to Embodiment 6 has been described above.
Next, the operation of the discharge lamp lighting device according to Embodiment 6 will be described.
When starting the lighting of the discharge lamp, the control circuit 18 performs operations such as the following steps (1) to (3), for example.

(1) The control circuit 18 turns on / off the FET 7 that is the upper switching element at a high frequency during a predetermined period (hereinafter referred to as the first period) at the start of the lighting operation, and the FET 8 that is the lower switching element. Leave off.
(2) Next, the control circuit 18 performs an on / off operation of the lower switching element FET 8 at a high frequency for a predetermined period (hereinafter referred to as a second period) after the first period ends, The FET 7 that is a switching element is turned off.
(3) The control circuit 18 thereafter switches the operations (1) to (2) alternately at a low frequency. Further, a high voltage start pulse is generated at least once every half cycle of the low frequency by using the start circuit 15.

When a current flows to the discharge lamp 14 only during the first period of step (1), the voltage applied to the upper capacitor 9 is reduced and the voltage applied to the lower capacitor 10 is increased.
Under this state, when a current flows to the discharge lamp 14 in the second period of the step (2), a further current flows in a state where the voltage of the lower capacitor 10 is high, and the lower switching element 8 May be destroyed by overcurrent or overvoltage.
For example, when the state where the current flows to the discharge lamp 14 continues only in the first period of the step (1), the voltage applied to the lower capacitor 10 exceeds the allowable voltage of the capacitor 10, and the capacitor 10 May be destroyed.

  In order to prevent the destruction of the capacitor and FET as described above, the discharge lamp lighting device according to the sixth embodiment includes the DC output voltage detection circuit 21 and the capacitor voltage detection circuit 22, and the control circuit 18 detects the detected value. And each element was protected from overcurrent or overvoltage. Hereinafter, the protection operation will be described.

(1) Protection of the capacitor 10 The control circuit 18 monitors the detection value of the capacitor voltage detection circuit 22, and stops the lighting operation of the discharge lamp 14 when the detection result exceeds the allowable voltage of the lower capacitor 10. To do.

(2) Protection of Capacitor 9 The configuration of FIG. 5 does not include a circuit or the like that directly detects the voltage applied to the capacitor 9, but the detection result of the capacitor voltage detection circuit 22 from the detection result of the DC output voltage detection circuit 21. By subtracting, an operation equivalent to detecting the voltage applied to the capacitor 9 can be performed.
The control circuit 18 monitors the detection values of the DC output voltage detection circuit 21 and the capacitor voltage detection circuit 22, and when the above subtraction result exceeds the allowable voltage of the upper capacitor 9, the lighting operation of the discharge lamp 14 is performed. Stop.

  The above (1) and (2) are for directly protecting the capacitors 9 to 10 from overvoltage, but as a result, the voltage and current state of the circuit is stabilized, so that the switching element is overcurrent. The effect which protects from can also be exhibited.

  If the voltage imbalance between the upper capacitor 9 and the lower capacitor 10 is improved after the control circuit 18 performs the protective operation as described in (1) to (2) above, the control circuit 18 causes the discharge lamp 14 to The lighting operation may be resumed.

  Further, the lighting operation of the discharge lamp 14 is stopped as a result of the protection operation as described in the above (1) to (2), and the voltage imbalance between the upper capacitor 9 and the lower capacitor 10 is improved thereafter. When the resumption of the lighting operation is repeated a predetermined number of times, it is assumed that the circuit state is unstable and the control circuit 18 may not resume the lighting operation thereafter.

  In the discharge lamp lighting device according to the sixth embodiment, it has been described that the DC output voltage detection circuit 21 and the capacitor voltage detection circuit 22 are provided and the detected values are monitored. However, in the configuration of FIG. A DC output voltage detection circuit 21 and a capacitor voltage detection circuit 22 may be provided, and the operation may be similarly performed to monitor each detected value and protect each element.

The “capacitor voltage detection means” in the sixth embodiment corresponds to a circuit for detecting a voltage applied to the capacitors 9 to 10.
That is, the capacitor voltage detection circuit 22 corresponds to the detection of the voltage applied to the capacitor 10, and the DC output voltage detection circuit 21 and the capacitor voltage detection circuit 22 correspond to the detection of the voltage applied to the capacitor 9. It corresponds to this.
These are established under the circuit configuration of FIG. 5. If the circuit configuration is different, the configuration of the capacitor voltage detecting means is appropriately changed as necessary.

  As described above, according to the configuration and method described in the sixth embodiment, when the voltages of the upper capacitor 9 and the lower capacitor 10 are imbalanced, the FET 7 of the half-bridge inverter circuit, 8 and capacitors 9 and 10 can be protected from overcurrent and overvoltage.

  In addition, when the voltage imbalance of the capacitors 9 and 10 occurs, the voltage imbalance of the capacitors 9 and 10 is changed by changing the high frequency on / off period (including the low frequency period) of the switching elements 7 and 8. You may improve. Furthermore, it may be used in combination with the method of stopping the lighting operation described above.

  The method described in the sixth embodiment is effective even when a voltage imbalance of the capacitors 9 and 10 occurs due to the lighting of the discharge lamp 14 and the lifetime of the capacitors 9 and 10.

It is added that Embodiments 1 to 6 described above can be used in any combination.
Further, the drive control of the FETs 7 and 8 when performing the constant power control can be appropriately performed using a well-known method or the like.

Embodiment 7 FIG.
By incorporating the discharge lamp lighting device described in the first to sixth embodiments into a lighting fixture, a lighting fixture capable of effectively performing constant power control or the like of the lighting fixture is obtained.

It is a figure which shows the discharge lamp lighting device which concerns on Embodiment 1, and its periphery structure. The waveform of voltage etc. in each case where the frequencies of the AC power supply 1 are different is shown. A procedure for obtaining a point in time when the average values of the currents and voltages of the discharge lamps 14 match when the frequency of the AC power supply 1 is different will be described. It is a figure which shows the discharge lamp lighting device which concerns on Embodiment 5, and its periphery structure. It is a figure which shows the discharge lamp lighting device which concerns on Embodiment 6, and its periphery structure.

Explanation of symbols

  1 AC power supply, 2 rectifier circuit, 3 smoothing capacitor, 4 coil, 5 diode, 6 to 8 FET, 9 to 10 capacitor, 13 coil, 14 discharge lamp, 15 starting circuit, 16 current detection circuit, 17 voltage detection circuit, 18 Control circuit, 19 switch, 20 constant current load, 21 DC output voltage detection circuit, 22 capacitor voltage detection circuit.

Claims (5)

A discharge lamp lighting device connected to a commercial power source having a different frequency depending on the installation environment,
A rectifier circuit for rectifying the commercial power supply;
A step-up chopper circuit that converts the output voltage of the rectifier circuit into a predetermined DC voltage;
An inverter that converts the voltage from the boost chopper circuit into alternating current;
A terminal for connecting a load;
Control means for controlling the operation of the inverter;
Voltage detecting means for detecting a voltage applied to the load;
With
The control means includes
The frequency of the AC voltage applied to the load is
Control to be a common multiple of each frequency of the commercial power supply ,
When performing constant power control of AC power supplied to the load,
Take a common multiple of time corresponding to one period at each different frequency of the commercial power supply,
Obtaining a voltage value applied to the load within a half of the time corresponding to the common multiple by the voltage detection means to obtain an average value within the same time;
A discharge lamp lighting device that performs constant power control of AC power supplied to the load using the average value . Comprising current detection means for detecting the current flowing through the load;
The control means includes
When performing constant power control of AC power supplied to the load,
Take a common multiple of time corresponding to one period at each different frequency of the commercial power supply,
The current value flowing through the load within a half of the time corresponding to the common multiple is obtained by the current detection means to obtain an average value within the same time,
The discharge lamp lighting device according to claim 1 , wherein constant power control of AC power supplied to the load is performed using the average value. The control means includes
When performing constant power control of AC power supplied to the load, use the average value of the voltage value,
The discharge lamp lighting device according to claim 1 or 2 , wherein an instantaneous value of the voltage value is used when detecting an abnormality of the load. The control means includes
When performing constant power control of AC power supplied to the load, use the average value of the current value,
The discharge lamp lighting device according to claim 2 , wherein an instantaneous value of the current value is used when detecting an abnormality of the load. A lighting fixture comprising the discharge lamp lighting device according to any one of claims 1 to 4 .

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