JP2003086386A - Discharge lamp lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out steady illumination control by improving the power factor in the circuit of a voltage doubler rectifier. SOLUTION: The lighting device comprises a power supply circuit for carrying out the voltage doubler rectification of the AC power, a phase angle detection circuit for detecting the phase angle by the output of the AC power supply, a switching circuit for converting the DC output of the power supply circuit into high frequency by the drive frequency from a driver, a control circuit for controlling the drive frequency of the driver, a discharge lamp that is impressed with the high frequency output of the switching circuit, a choke circuit for restricting the current to the discharge lamp, and a lamp current detection circuit for detecting the current to the discharge lamp. The voltage generated in the choke circuit is returned to the power supply circuit and the control circuit controls the driver based on the output of the lamp current detection circuit and the phase angle detection circuit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge lamp lighting device for lighting a discharge lamp at a high frequency.

[0002]

2. Description of the Related Art FIG. 21 shows a conventional discharge lamp lighting device,
In the figure, 1 is an AC power supply, 2 is a noise filter, 4, 5
Is a diode, and 7 and 8 are smoothing capacitors. The series circuit of the diodes 4 and 5 and the series circuit of the smoothing capacitors 7 and 8 are connected in parallel, and one end of the AC input 1 is the diode 4,
The other end is connected to the connection point of the smoothing capacitors 7 and 8 at the connection point of 5 to form a so-called voltage doubler rectifier circuit. 1
0 is a switching element 1 driven by a driver 9
It is a switching circuit composed of 1 and 12 and constitutes a half bridge. Here, the switching elements 11 and 12
Is a MOSFET with a built-in regenerative diode. Thirteen
Is a discharge lamp (hereinafter referred to as a lamp), 14 is a resonance capacitor, 15 is a choke coil, the lamp 13 and the resonance capacitor 14 are connected in parallel, the lamp 13 and the choke coil 15 are connected in series, and one end of the switching circuit 10 is connected.
The other end of the smoothing capacitor 8 is connected to the positive electrode of the smoothing capacitor 8.

Next, the operation will be described. The AC input input via the noise filter 2 is the diode 4,
5. Double voltage rectification is performed by the smoothing capacitors 7 and 8.
The DC output that has been subjected to the voltage doubler rectification is applied to the switching circuit 10, and the driver 9 alternately turns ON and OFF the switching element 11 and the switching element 12, whereby the high frequency power is converted. Switching circuit 10
The high frequency power output by the choke coil 15
The lamp 13 is turned on while receiving the current limitation by the. Further, the resonance capacitor 14 is one of the factors that secure the lamp voltage at the time of starting the lamp and also determine the resonance point of the circuit during lighting.

Here, when the lamp 13 is lit by the voltage doubled and rectified, the voltage input to the switching circuit 10 is higher than the voltage of the capacitor input type circuit in which the AC voltage is full-wave rectified and smoothed. Since there is a margin for, just changing the switching frequency,
A wide range of lamp output can be obtained. That is, the lamp voltage can be secured even when the output of the lamp 13 is reduced, and the lamp 13 can be prevented from flickering and extinguishing.
Even if the output of the lamp 13 is increased, there is an advantage that the switching phase does not advance and the driving can be performed safely.
Therefore, the configuration is particularly effective for a lighting device for an AC100V power source.

[0005]

However, as shown in FIG.
The conventional circuit configuration shown in 1 has the following problems. First, the smoothing capacitors 7 and 8 are charged for a very short time, and the charges necessary for the circuit are charged within that period, so that the peak of the input current becomes extremely large, which may shorten the life of the smoothing capacitors. It was FIG. 22C shows the state of this input current. In FIGS. 22A and 22B, the input voltage of the AC power supply 1 and the positive electrode voltage of the smoothing capacitor 7 are shown on the same time axis as the input current. It is a thing.
Since the power factor is low as described above, there is a fear that equipment on the AC power supply side may be destroyed.

Second, the dimmer 20 whose input voltage is a phase control type
When the thyristor in the dimmer is turned on near the phase angle of 90 degrees when the phase is controlled by, the inrush current flows further and the life of the smoothing capacitors 7 and 8 is further shortened. There is a risk that the components located between the capacitor 20 and the smoothing capacitor 7 or 8 and the diodes 4 and 5 may be damaged. FIG. 23 (c) shows the state of this inrush current, and (a) and (b) respectively show the input voltage of the AC power supply 1 and the positive electrode voltage of the smoothing capacitor 7 on the same time axis as the input current. It is a thing. At this time, not only the lighting device but also the dimmer 20 itself may cause malfunction or failure.

To solve such a problem, for example, Japanese Patent Laid-Open No. 10-271831 proposes a circuit configuration as shown in FIG. Description of the same points as in FIG. 21 will be omitted, and different points will be described. In the figure, diodes 3 and 6 are provided between the diode 4 and the smoothing capacitor 7 and between the diode 5 and the smoothing capacitor 8, respectively.
Is inserted. Also, the choke coil is 2 of 31 and 32.
The capacitor 1 is divided into a connection point, a connection point of the diodes 3 and 4, and a connection point of the diodes 5 and 6, respectively.
8 and 19 are connected.

As a result, the voltage generated between the choke coils 31 and 32 is used to make use of the choke coils 31 and 3.
2 connection point → capacitor 18 → diode 3 → smoothing capacitor 7 path (hereinafter referred to as “path Lb1-1”), A
C power supply 1 → diode 4 → capacitor 18 → path of connection point of choke coils 31 and 32 (hereinafter, “path Lb1-
2 ”), the connection point between the choke coils 31 and 32 → the capacitor 19 → the diode 5 → the path of the AC power supply 1 (hereinafter referred to as“ path Lb2-1 ”), and the AC power supply 1 → the smoothing capacitor 8 → the diode. 6 → capacitor 19 → path of connection point of choke coils 31 and 32 (hereinafter, “path L
b2-2 ”). Figure 2
Compared with the circuit shown by 1, the period during which the smoothing capacitors 7 and 8 are charged is extended, and as a result, the power factor is improved.

Further, in FIG. 24, the currents flowing through the capacitor 18, the capacitor 19 and the choke coil 32 are designated as Ib1, Ib2 and Im, respectively, and the current Ib1 and the current Ib2 are shown.
Is the current Ib (= Ib1 + Ib2). Current Ib
1 is represented by the sum of the electric currents passing through the paths Lb1-1 and Lb1-2, respectively (the two paths are collectively referred to as "path Lb1").
And). Similarly, the current Ib2 is generated by the path Lb2−
It is represented by the sum of 1 and the current passing through the path Lb2-2 (both paths are collectively referred to as "path Lb2"). Further, the path of the connection point between the choke coils 31 and 32 → the choke coil 32 → the connection point between the smoothing capacitors 7 and 8 and the smoothing capacitor 7
Connection point of and 8 → choke coil 32 → choke coil 3
The path of the connection point of 1 and 32 is collectively referred to as a path Lm.

FIG. 25 shows the frequency characteristics of the currents Ib and Im and the current (Im + Ib) obtained by adding them. Current I
Both b and Im have maximum points, and the frequencies giving the respective maximum points are f3 and f5. In addition, current (Im
+ Ib) has maximum points at frequencies f3 and f5, and has a minimum point between frequencies f3 and f5. The frequency giving this minimum point is f4.

Here, in Japanese Patent Laid-Open No. 10-271831, in the case of dimming, the switching frequency is set to the current (Im +
Ib) is proposed to be controlled in a range in which it monotonically decreases, that is, in a range where the frequency is f5 or higher. The AC voltage and the currents Im and Ib corresponding to the AC voltage when the phase is controlled in this way
The waveforms of 1, Ib2 and the lamp current are shown in (a), (b), (c), (d) and (e) of FIG. 26, respectively. Comparing FIG. 22E with FIG. 22 or FIG. 23C, it can be seen that the lamp current is leveled and the peak is reduced. In the figure, the waveform modulated at high frequency is shown by filling the inside of the envelope with black, and the same notation is used for the figures in the following text.

However, the circuit configuration shown in FIG. 24 has the following problems. First, in designing the main circuit, the switching circuit 10 to the smoothing capacitor 8
It was necessary to connect two choke coils to the path through which the largest amount of current flows to the positive electrode, and it was difficult to miniaturize the circuit. Secondly, with the three elements of the two choke coils 31, 32 and the capacitor 18 (or 19),
The conditions for setting power condition and stable lighting had to be set, and the degree of freedom in design was low.

Thirdly, for control purposes, if the frequency range in which the current (Ib + Im) monotonically decreases is used, f3 to f4 or f5 or more is selected as the frequency range from FIG. However, when f3 to f4 is selected as the frequency range, there is a problem that the dimming function cannot be sufficiently exhibited because the dimming range cannot be wide. Further, when f5 or more is selected as the frequency range, the current flowing through the path Lb becomes considerably smaller than the current flowing through the path Lm, so that there is a problem that the power factor improving effect cannot be exhibited. Furthermore, if f4 to f5 are included in the frequency range, there may be two frequencies f that give one current value.
There is a problem that the current (Ib + Im) cannot be fed back. And these subjects were the same also about the discharge current in a lamp.

Furthermore, in the low dimming degree, the dimmer 2
When the load on the circuit side viewed from 0 became light, the dimmer 20 malfunctioned and sometimes flickers. FIG. 27B shows an AC voltage when the dimmer 20 makes such a malfunction, and FIG. 27A shows an AC voltage when the dimmer 20 makes a normal operation for comparison. It is a representation.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a discharge lamp lighting device that is small in size and capable of dimming control while improving the power factor.

[0016]

DISCLOSURE OF THE INVENTION A discharge lamp lighting device according to the present invention comprises a power supply circuit for rectifying a voltage of an AC power supply and an AC power supply.
A phase angle detection circuit that detects the phase angle from the output of the power supply, a switching circuit that converts the DC output of the power supply circuit into a high frequency by the drive frequency from the driver, a control circuit that controls the drive frequency of the driver, and a high frequency of the switching circuit. A discharge lamp to which an output is applied, a choke circuit that limits the current flowing in the discharge lamp, and a lamp current detection circuit that detects the current flowing in the discharge lamp are provided, and the voltage generated in the choke circuit is fed back to the power supply circuit. The control circuit controls the driver based on the outputs of the lamp current detection circuit and the phase angle detection circuit.

Further, the present invention is configured to include a shutdown circuit for stopping the driver when the phase angle detected by the phase angle detection circuit is a predetermined value or more.

The power supply circuit is composed of first and second capacitors connected in series and first, second, third and fourth diodes connected in series in forward polarity. The negative electrode and the first capacitor of the first capacitor are connected to each other. The positive electrode of the second capacitor is connected, the connection point between the cathode of the first diode and the positive electrode of the first capacitor is used as the output point of the power supply circuit, and the anode of the fourth diode and the negative electrode of the second capacitor are connected. The connection point is grounded, one end of the AC power source is connected to the positive electrode of the second capacitor, the other end is connected to the cathode of the third diode, and the discharge lamp and the choke circuit are connected to the output point of the switching circuit. Connected in series, and the voltage generated in the choke circuit is applied to the connection point between the first and second diodes and the third and fourth diodes.
It is configured such that feedback is made to each of the connection points of the diodes through the impedance elements.

Further, the impedance elements connected to the connection points of the first and second diodes and the connection points of the third and fourth diodes are third and fourth capacitors, respectively, and the choke circuit has an intermediate tap. The choke coil is provided so that the connection point between the third and fourth capacitors and the intermediate tap are connected directly or via an inductor.

In addition, the fluctuation range of the driving frequency of the driver is such that the second current flowing between the first current flowing through the third capacitor or the fourth capacitor and the positive electrode of the second capacitor flows between the intermediate tap and the positive electrode of the second capacitor. It is configured to include a point where the added value of the electric current has a minimum value with respect to the frequency.

Further, the variation range of the driving frequency of the driver is configured to include the range in which the first current flowing through the third capacitor or the fourth capacitor monotonically decreases with respect to the frequency.

Further, the variation range of the driving frequency of the driver is the third current flowing as the discharge current of the discharge lamp in the second current flowing between the intermediate tap and the positive electrode of the second capacitor.
It is configured to include a point at which the current of (1) becomes minimum with respect to the frequency.

Further, in the first period in which the first current is dominant over the second current and in the second period in which the second current is dominant over the first current, the first period and the second period It is configured such that different drive control is performed during the period.

The drive frequency of the drive is feedback-controlled based on the output of the lamp current detection circuit in the first period, and the drive frequency is fixed at the second period.

Further, in at least two or more dimming ranges,
It is configured such that the settings for determining the feedback value are different.

Further, in the first dimming range, the settings for determining the feedback value are the same in both the first period and the second period, and in the second dimming range, the first period and the second period are the same. The setting for determining the feedback value is configured to be different during the period.

Further, the dimming control circuit has a setting for determining at least two or more feedback values, and is configured to change the feedback value in synchronization with the voltage change by the AC power source.

Further, the feedback value is configured to be changed in a half cycle of the AC power supply.

Further, the feedback value is changed between the ON period and the OFF period of the thyristor in the phase control dimmer connected to the AC power source.

Further, the object of feedback is constructed so as to be within the range of the driving frequency.

Further, the object of feedback is configured to be the upper limit of the driving frequency.

In addition, the upper limit of the drive frequency which is the feedback target in the first period is set to be higher than the upper limit of the drive frequency which is the feedback target in the second period.

Further, the upper limit of the drive frequency which is the feedback target in the second period is set to be lower than the frequency which gives the minimum point of the third current.

Further, the change of the setting for determining the feedback value is configured to be continuous.

Further, the phase angle detection circuit has first and second comparators, the divided voltage value at the connection point of the second and third diodes is set as the detection value, and the first and second capacitors are connected. The first and second partial pressure values at the points are respectively set as the first and second threshold values, and the average value of the first threshold value is higher than the average value of the detected value, and the second threshold value The average value is set to be lower than the average value of the detected values, and the first comparator outputs a high output when the detected value exceeds the first threshold value. Then, when the detected value falls below the second threshold value, the high output is set, and the first and second
The output of the comparator is used as the output of the phase angle detection circuit.

Furthermore, the lighting apparatus is constructed using a bent fluorescent lamp having the discharge lamp lighting device according to any one of claims 1 to 20.

[0037]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. 1 is a schematic circuit diagram according to Embodiment 1 of the present invention. In the figure, 1 to 13 and 18 to 20 are the same as those shown in FIG. 15 is an intermediate tap 1
6 is a choke coil, 17 is an inductor, 21 is a phase angle detection circuit, 22 is a lamp current detection circuit, 23 is a control circuit, and 24 is a shutdown circuit. Also, AC
Of the input lines, the voltage on the side connected to the diode 4 is Vac, and the voltage on the side connected to the smoothing capacitor 8 is Vac.
It is called dc.

The outline of the operation will be described. The phase angle detection circuit 21 detects the phase of the dimmer 20, and the control circuit 23 sets a dimming target value based on the detected phase angle. Then, the lamp current detection circuit 22 detects the lamp current, and this is fed back to control the oscillation frequency of the driver 9. Further, the output of the phase angle detection circuit 21 is input to the shutdown circuit 24, and the driver 9 is stopped and turned off at a predetermined phase angle or more.

FIG. 2 is a detailed circuit diagram showing the circuit configuration of the phase angle detection circuit 21, the lamp current detection circuit 22, the control circuit 23 and the like. The same or corresponding portions as those of the conventional example or FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted. Only different points will be described. In the figure, 140 is an auxiliary resonance capacitor connected to reduce the current flowing through the filament of the lamp 13 and to reduce the power consumption, and may be omitted if necessary. CT is a current transformer that detects the lamp current, and the resonance capacitor 14 is calculated from the current (Ib + Im).
Also, the amount of current obtained by subtracting the current flowing through the auxiliary resonance capacitor 140 is detected.

FIG. 3 is an explanatory diagram of the driver 9.
The driver 9 is an IC having terminals 91, 92, 93 and 94, 91 is a power supply terminal, 92 and 93 are gate signal generating terminals, and 94 is an oscillation frequency determining terminal. Terminal 94
Has a reference voltage 95 and a current / frequency conversion circuit 96 inside, and oscillates at a frequency output proportional to the current flowing from the reference voltage 95 to a resistor or the like connected to the outside. As a result, the driver 9 alternately turns ON / OFF the gate signal generation terminals 92 and 93 at an oscillation frequency proportional to the resistance value of the resistor connected to the terminal 94. Hereinafter, based on FIGS. 2 and 3, the phase angle detection circuit 21, the lamp current detection circuit 22, the control circuit 23,
The configurations and functions of the driver 9 and the shutdown circuit 24 will be described.

In the phase angle detection circuit 21, the resistors R1 and R2 are
Vac is resistance-divided by a capacitor C1, a resistor R
3, a diode D1, D2 and a resistor R4 constitute a differentiating circuit to detect an AC voltage input for each AC cycle (50/60 Hz). This AC voltage input is converted into a DC signal by the integrating circuit composed of the resistor R5 and the capacitor C2, and is input to the control circuit 23. Here, this DC signal is the time width in which the phase is turned on (hereinafter, “phase ON width”).
And) and decreases as the phase angle increases.

In the lamp current detection circuit 22, the lamp current detected by the current transformer CT is full-wave rectified by the diode bridge DB1 and the current is passed through the resistor R6 to detect the lamp current as a voltage output. The detected lamp current is input to the control circuit 23 via the filter including the resistors R7 and R8 and the capacitor C3.

In the control circuit 23, the signal from the phase angle detection circuit 21 is amplified by the operational amplifier AMP1 and used as the positive input of the error amplifier AMP2 which constitutes the error amplifier. Further, the signal from the lamp current detection circuit 22 is used as the negative input of the error amplifier AMP2.

The driver 9 is started by the voltage input by the starting resistor 25, and receives power from the snubber capacitor 26 after starting. A resistor R9 and a diode D3 are connected to the oscillation frequency determining terminal 94 of the driver 9, and a current always flows from the reference voltage 95 inside the driver to the resistor R9. Therefore, regardless of the state of the cathode side of the diode D3, the resistor R9 The minimum value of the oscillation frequency is determined. A resistor R1 is provided on the cathode side of the diode D3.
0 and R11 are connected, resistor R10 is error amplifier AM
It is connected to the output of P2 and contributes to the feedback of the lamp current. The resistor R11 is switched by the transistor Tr1, and the transistor Tr1 receives the output of the lamp current output point A as a base input via the resistors R12, R13 and the constant voltage diode ZD1 and is switched at high frequency. The transistor Tr1 switched at high frequency is turned on
It is almost equivalent to the state. The capacitor C4 is connected for stabilizing the switching operation of the transistor Tr1 and may be omitted if necessary.

In the shutdown circuit 24, the output of the phase angle detection circuit 21 is input to the base of the transistor Tr2 via the constant voltage diode ZD2. The collector of the transistor Tr2 is connected to the base of the transistor Tr3, and the collector of the transistor Tr3 has a resistance R1.
4 is connected to the power supply terminal 91 of the driver 9. When the phase angle is small (when the phase ON width is large), the output of the phase angle detection circuit 21 turns on the transistor Tr2.
Then, the transistor Tr3 is turned off.
When the phase ON width falls below a predetermined value, the transistor Tr2 is turned off and the transistor Tr3 is turned on, so that the resistance R14 having a relatively smaller resistance value than the resistance 25.
Thereby lowering the voltage of the driver 9 and stopping the oscillation. Even after the transistor Tr2 is turned off and oscillation is stopped, the smoothing capacitor 8 is turned off unless the AC power source 1 is turned off.
Will continue to be charged and Vdc will have a certain level of potential, so that the transistor Tr3 will remain ON and oscillation stop will be maintained.

Next, the dimming control will be described. Figure 4
(A), (b), (c), (d), and (e) are the input voltage whose phase ON width is controlled to about 75%, and the corresponding current Im, current Ib1, current Ib2, and lamp. The current waveform is represented on the same time axis. Since the lamp current is fed back, the period in which the current Ib1 or the current Ib2 is dominant and the period in which the current Im is dominant are clearly separated. As shown in FIG. 7E, the period in which the current Ib1 or the current Ib2 is dominant is the period b, and the period in which the current Im is dominant is the period m. Also, the current I flowing through the lamp
b and the component of the current Im are the current ILb and the current ILm, respectively.
And Here, the difference between the current Ib and the current ILb or the difference between the current Im and the current ILm corresponds to the current flowing through the resonance capacitor 14 and the auxiliary resonance capacitor 140.

FIGS. 5A, 5B, and 5C show current Im and current Ib, current ILb and current ILm, and current (I
(m + Ib) and current (ILb + ILm). As shown in the figure, the frequency is slightly higher than the frequency at which the maximum point of the current Ib is given, the frequency at which the monotonous decrease of the current Ib starts is f1 and slightly lower than the frequency at which the minimum point of the current Im is given, and the frequency at which the monotonous increase of the current Im ends. F2
And

FIG. 6 is an enlarged view of the currents ILb and ILm in the frequency range f1 to f2. Frequency fb based on the figure
The definitions of 1, fb2, and fm will be described. First, the current value of the current Im at the frequency f1 is set to If1m, and the current I
The frequency when the current value becomes If1m on b is set to fb1. Further, the frequency before the minimum point where the monotone decrease of the current ILm ends is fm, and the current value of the current ILm at this frequency is Ifmm. Further, the frequency when the current value becomes Ifmm on the current ILb is fb2.

Based on the above definition, the frequency range f1 to f2
The dimming control in will be described. FIG. 7 is an explanatory diagram showing the relationship between the dimming degree and the driving frequency in the periods b and m. As shown in the figure, the dimming range is divided into three ranges of dimming ranges 1, 2, and 3 according to the lightness, darkness, and lightness of the dimming degree.

Since the driving frequency changes depending on the operation (ON / OFF) of the transistor Tr1, the period b in each dimming range is based on the operation of the transistor Tr1.
The operating state of m will be described. In the dimming range 1 or 2, the transistor Tr1 is always ON and the periods b and m
However, since it is ON, the upper limit of the frequency of the returned lamp current is the frequency f2 in both the periods b and m. FIG. 8 (h) shows this state, and the upper limit of the lighting frequency in the dimming range 1 or 2 is the frequency f2 in both the periods b and m.
Is. (A), (b), (c), (d),
(E), (f), and (g) have the same time axis, respectively, and the phase-controlled input voltage, the corresponding current Im, current Ib1, current Ib2, lamp current, and transistor Tr.
The base voltage and the collector voltage of No. 1 are shown.

In the dimming range 3, the transistor Tr
Since 1 is ON during the period b and OFF during the period m, the period b
The upper limit of the frequency in is the frequency f2, and the upper limit of the frequency in the period m is the frequency fm. FIG. 9H shows this state, and the upper limit of the lighting frequency in the dimming range 3 is the frequency f2 in the period b and the frequency fm in the period m.
Is. (A), (b), (c), (d),
(E), (f), and (g) have the same time axis, respectively, and the phase-controlled input voltage, the corresponding current Im, current Ib1, current Ib2, lamp current, and transistor Tr.
The base voltage and the collector voltage of No. 1 are shown.

Although the upper limit value of the frequency has been described here, the range in which the frequency actually fluctuates is, as shown in FIG. 7, in the dimming range 1, the frequencies f1 to fb1 in the period b.
The frequency is f1 in the period m, the frequencies fb1 to fb2 are in the period b in the dimming range 2, the frequencies f1 to fm are in the period m, and the frequencies fb2 to f2 are in the period b in the dimming range 3 and the frequency fm is in the period m. is there.

When the dimming range 3 is the deepest,
Driven at the frequency f2 in the period b and at the frequency fm in the period m, the current ILb in the period b keeps a constant peak, and thus the transistor Tr1 is not turned off. Further, when the drive is performed at the upper limit frequency in both the periods b and m as described above, the peak waveform of the current ILb becomes a waveform substantially proportional to the phase-controlled AC voltage waveform,
Although the width and the peak thereof are reduced, the resistors R12 and R13 are set in advance by the phase angle detection circuit 21 and the shutdown circuit 24 so that the transistor Tr1 is turned on at a predetermined phase angle or more to stop the drive. The voltage diode ZD1 is set.

Further, the dimming becomes deeper, the load on the circuit side seen from the dimmer 20 becomes lighter, and even when the dimmer 20 does not operate normally, the shutdown circuit 23 detects that the phase width becomes narrow, The driver 9 is shut down. Figure 1
0 and 11 are comparisons of the phase widths when the dimmer 20 normally operates and when the dimmer 20 abnormally operates with a light load on the circuit side. In the figure, (a), (b),
(C) shows the AC input voltage, the D2 cathode voltage, and the positive input voltage (phase ON width) of the operational amplifier AMP1, respectively. It can be seen from the comparison between FIGS. 10C and 11C that a state in which the phase width is narrowed due to an abnormal operation is detected.

As described above, the frequency band used in the dimming control is the current peak and the current Im with respect to the frequency of the current Ib.
The frequency band used in the period in which the current Ib is dominant and the period in which the current Im is dominant is divided according to the dimming degree. It is possible to perform smooth dimming while exhibiting the power factor improving effect.

Moreover, since the switching of the transistor Tr1 is performed at a high frequency, it is possible to realize a structure in which the boundary between the ON period and the OFF period is not clearly shown.
Therefore, even if the control system is switched according to the dimming degree as described above, there is no difference in the light output at the boundary of the dimming degree.
Further, even if the dimmer 20 malfunctions at a low dimming degree, the oscillation of the driver 9 can be surely stopped and turned off.

FIG. 12 shows an equivalent circuit of the choke coil 15 and the inductor 17. In the figure, (a) shows a main part of the choke coil 15 and the inductor 17, and the winding direction of the choke coil 15 is opposite when viewed from the intermediate tap 16. Therefore, the equivalent circuit is as shown in (b). The inductance-M (0 <M) is separated. As a result, when the inductance L3 of the inductor 17 and the mutual inductance -M are combined, (c)
At the connection point of the two choke coils as shown in (L3-
It is equivalent to a circuit to which an inductor having an inductance of M) is connected.

Thus, one choke coil 15 and one choke coil 1
Since the inductor 17 constitutes the main circuit, the choke coil 15 is the only large-sized coil, and the circuit is small, and the choke coil 15 is provided with the intermediate tap 16 to magnetically couple the paths Lb and Lm. Therefore, by combining the mutual inductor component −M (0 <M) and the inductance L3 of the inductor 17, the degree of freedom in design can be increased.

Embodiment 2. In the first embodiment, a differentiating circuit is used for the phase angle detection circuit 21 and the frequency range between the period b and the period m is switched by the output of the current detection circuit 22, but in the present embodiment, the phase angle detection circuit is used. 21
Two comparators (hereinafter referred to as "comparators")
Is used to detect the phase width, and the frequency range in the period b and the period m is switched based on this output.

The schematic circuit diagram is the same as FIG. Compared with the first embodiment, the circuit configurations of the phase angle detection circuit 21 and the control circuit 22 are different. The configurations and functions of the phase angle detection circuit 21 and the control circuit 22 will be described with reference to FIG.

In the control circuit 21, Vdc is changed to the resistance R1.
5, R16 and R17 divide the resistor R15, R1
Comparator CMP1 with the divided voltage value between 6 as the threshold value 1.
Of the resistors R16 and R17 as the threshold value 2 and the positive input of the comparator CMP2. Also,
Vac is divided by resistors R18 and R19, and the positive input of comparator CMP1 and comparator C
Negative input of MP2. In this way, the average value of the detected values is sandwiched between the threshold values 1 and 2, and a high output is output when the detected value exceeds the threshold value of the comparator CMP1, and a high output is output when the detected value falls below the threshold value of the comparator CMP2. Get the output. As a result, the phase ON width is half the AC cycle (1
(00/120 Hz) and converted into a rectangular wave. Then, the phase ON width converted into the rectangular wave by the two comparators is additively output by the diodes D4 and D5, converted into a direct current by the integrating circuit composed of the resistor R5 and the capacitor C2, and the operational amplifier AMP1 of the control circuit 23.
Is input.

14, 15 and 16 show inputs to the operational amplifier AMP1 when the phase ON width is about 75%, about 50%, and when the dimmer malfunctions at low dimming and light load, respectively. 7 shows a comparison of voltages. In the figure, (a), (b), and (c) show the threshold values of the comparators CMP1 and 2, the cathode voltages of the diodes D4 and D5, and the operational amplifier AMP1 on the same time axis, respectively.
3 shows a waveform of an input voltage to the. From the comparison of these figures, the input voltage to the operational amplifier AMP1 is the phase ON width 7
It becomes smaller in order of 5%, 50%, when the dimmer malfunctions at low dimming and light load.

The voltage additionally output by the diodes D6 and D7 is applied to the transistor Tr of the control circuit 23.
It becomes a base signal of 1. As a result, Tr1 is turned on only during the phase ON period, and the resistor R11 becomes effective. As a result, the transistor Tr1 is turned on in the period b and turned off in the period m, and the upper limit of the lighting frequency is the period b.
And f2 in the period m. FIG. 17 (f) shows this state, and FIG. 17 (a), (b), (c),
(D) and (e) respectively have the same time axis, and the phase-controlled input voltage and the corresponding current Im, current Ib1,
The current Ib2, the lamp current, and the upper limit of the lighting frequency are shown.

Although the upper limit of the frequency has been described here, the range in which the frequency actually fluctuates is the frequencies f1 to f2 in the period b and the frequencies f1 to fm in the period m.
Is. Further, current Im and current Ib, current ILb and current ILm, current (Im + Ib) and current (ILb + ILm)
The frequency characteristics of are the same as those shown in FIGS.

As described above, since the phase width is detected by the two comparators, half of the AC cycle (1
(00/120 Hz), the phase width can be reliably detected. Moreover, since the upper limit frequency for feeding back the lamp current is switched between the period b and the period m, the control of the period m can be facilitated while utilizing the power factor improving effect of the period b. Further, similarly to the first embodiment, even if the dimmer 20 malfunctions at a low dimming degree, the oscillation of the driver 9 can be surely stopped and turned off.

Third Embodiment In the above-described embodiments, the upper limit frequency for returning the lamp current is set to the period b and the period m.
However, in the present embodiment, the period b
The frequency range of f1 to f2, and the frequency of the period m is f
It is fixed at m.

The schematic circuit diagram is the same as that of FIG. 1, and only the internal configuration of the control circuit 23 is different from that of the second embodiment. This point will be described with reference to the detailed circuit diagram of FIG. In the figure, the control circuit 23 includes diodes D6 and D7.
Is used as the base signal of the transistor Tr4, and the output of the transistor Tr4 is used as the base signals of the transistors Tr5 and Tr6. When the transistor Tr5 is ON, the positive input terminal of the error amplifier AMP2 becomes 0, and the output of the error amplifier AMP2 becomes 0.

When the transistor Tr6 is turned on, the resistor R20 becomes effective. Transistor Tr
5, when Tr6 is turned on, the resistors R9, R10 and R2
The drive is at a fixed frequency determined by 0. As a result, in the period b, the transistors Tr5 and Tr6 are turned off.
As the FF, the feedback of the lamp current is enabled, the feedback of the lamp current is disabled in the period m, and the resistors R9, R10, and R20 are used.
It is configured to drive at a fixed frequency determined by.

FIG. 19 (f) shows the validity / invalidity of the feedback of the lamp current with respect to the periods b and m, and FIGS. 19 (a), (b), (c), (d) and (e). Shows the phase-controlled input voltage and the corresponding current Im, current Ib1, current Ib2, and lamp current on the same time axis.

From the above operation, the frequencies f1 to
The frequency f2 is set as the fluctuation range, and the frequency is fixed at fm in the period m. In addition, the current Im and the current Ib, the current ILb and the current IL
The frequency characteristics of m, the current (Im + Ib) and the current (ILb + ILm) are the same as those in FIGS.

As described above, since the lamp current is fed back in the period b and is driven at the fixed frequency in the period m, the power factor improving effect in the period b can be utilized with a simple structure.
Moreover, the control of the period m can be simplified.

In the first to third embodiments, the switching of the setting for determining the feedback value is the switching of the frequency range, but the present invention is not limited to this. For example, the same effect can be obtained by switching the feedback gain or the like between the period m and the period b.

Fourth Embodiment FIG. 20 is a schematic front view showing a state in which the discharge lamp lighting device according to the present invention is incorporated in a light bulb type fluorescent lamp device. Conventional example or Embodiment 1
The description of the points that are the same as those of the circuit configuration of No. 3 will be omitted, and the points of difference will be described. In the figure, 27 is a base, 28 is a cover, 29 is a globe, and 30 is a circuit board on which the discharge lamp lighting device corresponding to any one of the first to third embodiments is mounted. The lamp 13 is a bent fluorescent lamp, and the lamp 13, the base 27, the cover 28, the globe 29, and the circuit board 30 are integrated to form a compact fluorescent lamp device. Since the circuit board 30 can be configured with a small number of parts, it can be incorporated in a light bulb type fluorescent lamp as shown in the drawing, and a light bulb type fluorescent lamp device compatible with a phase control dimmer can be obtained.

[0074]

Since the present invention is constructed as described above, it has the following effects.

As described above, according to the first aspect of the invention, the phase angle detection circuit for detecting the phase angle when the AC power source is phase-controlled, and the switching circuit according to the output of the phase angle detection circuit. It has a control circuit that changes the drive frequency, detects the current flowing through the lamp, and feeds it back to the drive frequency in the dimming control circuit. Light control can be performed.

According to the second aspect of the invention, in the discharge lamp lighting device according to the first aspect, the driving of the switching circuit by the driver is stopped when the phase angle is a predetermined value or more, so that the circuit operates reliably. It is possible to maintain the lighting state only within the range that is possible and to surely turn off the light even if the dimmer malfunctions.

According to the invention described in claim 3, in the discharge lamp lighting device according to claim 1 or 2, the power supply circuit includes first and second capacitors connected in series, and first and second capacitors connected in series in forward polarity. It is composed of a second, a third and a fourth diode, the negative electrode of the first capacitor is connected to the positive electrode of the second capacitor, and the connection point between the cathode of the first diode and the positive electrode of the first capacitor is a power circuit. The output point of
The connection point between the anode of the diode and the negative electrode of the second capacitor is grounded, and one end of the AC power supply is
Connect the positive electrode of the second capacitor to the cathode of the third diode, connect the other end to the cathode of the third diode, and connect the series circuit of the discharge lamp and the choke circuit to the output point of the switching circuit. Since it is configured to feed back to the connection point of the 1st and 2nd diodes and the connection point of the 3rd and 4th diodes via impedance elements, respectively,
It is possible to improve the power factor with a simple configuration without using a choke coil other than the choke coil for reducing the lamp current, and to greatly reduce the inrush current when using a phase control dimmer. The degree of freedom can be expanded.

According to the invention described in claim 4, in the discharge lamp lighting device according to claim 3, the high frequency output generated at the intermediate tap of the choke coil is coupled to the AC power source and the smoothing capacitor through the inductor and the capacitor. As the configuration, the current flowing from the AC power supply to the smoothing capacitor is dispersed in high frequency, so the power factor is improved and the phase control is performed without using a choke coil other than the choke coil for reducing the lamp current. It is possible to significantly reduce the inrush current when the type dimmer is used and to increase the degree of freedom in design.

According to the fifth aspect of the present invention, in the discharge lamp lighting device according to the fourth aspect, by adequately selecting the driving frequency of the driver, it is possible to obtain sufficient current in the path shunted from the intermediate tap. , The power factor can be greatly improved.

According to the invention described in claim 6, in the discharge lamp lighting device according to claim 4 or 5, by adequately selecting the driving frequency of the driver, sufficient current can be obtained in the path shunted from the intermediate tap. The power factor can be significantly improved, and the frequency band can be easily selected.

According to the invention described in claim 7, in the discharge lamp lighting device according to any one of claims 4 to 6, the variation range of the driving frequency of the driver is within the second current, and the discharge current of the lamp is The third current flowing as
Since the minimum point is included, the power factor can be significantly improved and the frequency band can be easily selected.

According to the invention described in claim 8, in the discharge lamp lighting device according to any one of claims 4 to 7,
Drive control that is different between the first period and the second period in the first period in which the current is more dominant than the second current and in the second period in which the second current is more dominant than the first current. Since it is configured to perform, the dimming control can be easily performed while maximizing the power factor improving effect.

According to the invention described in claim 9, in the discharge lamp lighting device according to claim 8, the current flowing through the lamp is detected, and the dimming control circuit feeds back the driving frequency.
Since it is configured to drive at a fixed frequency in the second period,
It is possible to perform dimming control with a simple configuration while exhibiting the power factor improving effect.

According to the invention of claim 10, claim 9 is provided.
In the discharge lamp lighting device described above, the current flowing through the lamp is detected, the dimming control circuit feeds back the driving frequency, and the second period is driven at a fixed frequency, so that the power factor improving effect is exhibited. In addition, dimming control can be performed with a simple configuration.

According to the invention of claim 11, claim 9 is provided.
In the discharge lamp lighting device described above, the setting for determining the feedback value is made different in at least two or more dimming ranges, and the power factor improving effect is maximized according to each dimming degree. You can

According to the invention of claim 12, claim 9 is provided.
In the discharge lamp lighting device described, in the first dimming range, the setting for determining the feedback value is the same in both the first period and the second period, and in the second dimming range, the first setting is performed.
Since the setting for determining the feedback value is made different between the period and the second period, it is possible to surely perform the dimming control while maximizing the power factor improving effect.

According to the invention described in claim 13, claim 9 is provided.
In the discharge lamp lighting device described above, the dimming control circuit has at least two settings for determining feedback values, and changes the settings for determining feedback values in synchronization with changes in the AC power supply voltage. Since the configuration is adopted, reliable dimming control can be performed with a simple configuration.

According to the invention of claim 14, claim 1
In the discharge lamp lighting device according to 2 or 13, since the setting for determining the feedback value is changed in a half cycle of the AC power source, the lamp current ripple is made positive and negative symmetrical, and a simple configuration is ensured. Dimming control can be performed.

According to the invention of claim 15, claim 1
In the discharge lamp lighting device according to 3 or 14, since the setting for determining the feedback value is changed between the ON period and the OFF period of the thyristor in the phase control dimmer connected to the AC power source, Phase angle detection can be detected with a simple circuit, and reliable dimming control can be performed.

According to the invention of claim 16, claim 1
In the discharge lamp lighting device according to any one of 0 to 15, since the feedback target is set to the range of the frequency to be fed back, the dimming control can be reliably performed with a simple configuration.

According to the invention of claim 17, claim 1
In the discharge lamp lighting device according to any one of 0 to 15, since the feedback target is set to the upper limit of the feedback frequency, the dimming control can be reliably performed with a simpler configuration.

According to the invention of claim 18, claim 1
In the discharge lamp lighting device according to item 7, since the upper limit of the frequency in the feedback coefficient in the first period is set to be higher than the upper limit of the frequency in the feedback coefficient in the second period, reliable dimming control can be performed. .

According to the invention of claim 19, claim 1
In the discharge lamp lighting device according to 8, the upper limit of the drive frequency that is the feedback target in the second period is set to be lower than the frequency that gives the minimum point of the third current. It is possible to perform reliable dimming control while maximizing the effect.

According to the invention of claim 20, claim 1
In the discharge lamp lighting device according to any one of 0 to 19, since the setting for determining the feedback value is continuously changed, the lamp can maintain stable lighting without flicker.

According to the invention of claim 21, claim 9
20. In the discharge lamp lighting device according to any one of 20 to 20,
The phase angle detection circuit has first and second comparators, and the divided voltage value at the connection point of the second and third diodes is set as the detection value.
The first and second divided voltage values at the connection point of the second capacitor are set as the first and second threshold values, respectively, and the average value of the first threshold value is higher than the average value of the detected values. The average value of the threshold values of 2 is set to be lower than the average value of the detected values.
In the comparator of 1, the output is high when the detected value exceeds the first threshold, and in the second comparator, when the detected value is below the second threshold, the high output is output. Since the output of the first and second comparators is set as the output of the phase angle detection circuit, the phase angle can be reliably detected even when the load changes such as the lighting state of the lamp.

According to the invention of claim 22, claim 1
Since the lighting fixture uses the bent fluorescent lamp having the discharge lamp lighting device according to any one of 1 to 21, a compact bulb-shaped fluorescent lamp can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic circuit diagram showing a schematic circuit of a discharge lamp lighting device according to a first embodiment of the present invention.

FIG. 2 is a detailed circuit diagram showing a detailed circuit of the discharge lamp lighting device according to the first embodiment of the present invention.

FIG. 3 is an explanatory diagram illustrating a function of a driver 9 of the discharge lamp lighting device according to the first embodiment of the present invention.

FIG. 4 is a waveform diagram showing the relationship between phase-controlled input voltage, lamp current, etc. of the discharge lamp lighting device according to the first embodiment of the present invention.

FIG. 5 is an explanatory diagram showing the relationship between the frequency and the lamp current of the discharge lamp lighting device according to the first embodiment of the present invention.

FIG. 6 is an explanatory diagram showing a relationship between a frequency and a lamp current in a frequency range f1 to f2 of the discharge lamp lighting device according to the first embodiment of the present invention.

FIG. 7 is an explanatory diagram showing a relationship between a phase ON width and a frequency in dimming ranges 1, 2, and 3 of the discharge lamp lighting device according to the first embodiment of the present invention.

FIG. 8 is a waveform diagram showing the relationship between each voltage and each current in the dimming range 1 or 2 of the discharge lamp lighting device according to the first embodiment of the present invention.

FIG. 9 is a waveform diagram showing the relationship between each voltage and each current in the dimming range 3 of the discharge lamp lighting device according to the first embodiment of the present invention.

FIG. 10 is a waveform diagram showing the relationship between each voltage and each current when the dimmer normally operates during low light control and light load in the discharge lamp lighting device according to the first embodiment of the present invention.

FIG. 11 is a waveform diagram showing the relationship between each voltage and each current when the dimmer abnormally operates during low dimming and light load in the discharge lamp lighting device according to the first embodiment of the present invention.

FIG. 12 shows an equivalent circuit of the choke coil 15 and the inductor 17 of the discharge lamp lighting device according to the first embodiment of the present invention.

FIG. 13 is a detailed circuit diagram showing a detailed circuit of the discharge lamp lighting device according to the second embodiment of the invention.

FIG. 14 is a waveform diagram showing a relationship between each voltage and each current when the discharge lamp lighting device according to the second embodiment of the present invention is driven by an input voltage having a phase ON width of 75%.

FIG. 15 is a waveform diagram showing a relationship between each voltage and each current when the discharge lamp lighting device according to the second embodiment of the present invention is driven by an input voltage having a phase ON width of 50%.

FIG. 16 is a waveform diagram showing a relationship between each voltage and each current when the discharge lamp lighting device according to the second embodiment of the present invention is driven by an input voltage of low dimming and a light load to perform an abnormal operation.

FIG. 17 is a waveform diagram showing the relationship between the phase-controlled input voltage, lamp current, etc. of the discharge lamp lighting device according to the second embodiment of the present invention.

FIG. 18 is a detailed circuit diagram showing detailed circuits of a phase angle detection circuit and a control circuit of the discharge lamp lighting device according to the third embodiment of the present invention.

FIG. 19 is a waveform diagram showing the relationship between phase-controlled input voltage, lamp current, etc. of the discharge lamp lighting device according to the third embodiment of the present invention.

FIG. 20 is a schematic front view showing a schematic front surface of a compact fluorescent lamp according to Embodiment 4 of the present invention.

FIG. 21 is a circuit diagram of a first conventional discharge lamp lighting device.

FIG. 22: A input to the first conventional discharge lamp lighting device
It is a waveform diagram explaining the relationship between the C voltage and the input current.

FIG. 23 is a waveform diagram illustrating the relationship between the AC voltage and the input current, which are phase-controlled and input to the first conventional discharge lamp lighting device.

FIG. 24 is a circuit diagram of a second conventional discharge lamp lighting device.

FIG. 25 is an explanatory diagram illustrating frequency characteristics of each current in the second conventional discharge lamp lighting device.

FIG. 26 is a waveform diagram showing the relationship between each voltage and each current according to the second conventional discharge lamp lighting device.

FIG. 27 is a waveform diagram showing the relationship between each voltage and each current when the second conventional discharge lamp lighting device has abnormally operated the dimmer at the time of low light control and light load.

[Explanation of symbols]

1 AC power supply 3-6 diode 7, 8 Smoothing capacitor 9 drivers 10 Switching circuit 11, 12 Switching element 13 lamps 14 Resonant capacitor 140 Auxiliary resonance capacitor 15 choke coil 16 middle tap 17 Inductor 18, 19 capacitors 21 Phase angle detection circuit 22 Lamp current detection circuit 23 Control circuit 24 Shutdown circuit 25 Starting resistance 26 snubber capacitors 27 base 28 cover 29 gloves 30 circuit board CT current transformer

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05B 41/392 H05B 41/29 CF term (reference) 3K072 AA02 AA05 AA06 AC02 AC11 BA03 BB01 BB04 BB05 BB06 BB09 BC01 BC05 CA03 CA11 CA16 DA02 DB01 DB03 DB09 DC01 DC07 DC08 DD04 DE02 DE03 EA06 EA07 EB08 FA05 GA03 GB12 GC04 HA05 HA06 HA10 HB03 3K082 AA16 AA19 AA33 AA39 AA54 AA66 BA05 BA12 BD16 BD05 BD32 BD58 BD32 BD28 BD31 BD23 CA37 3K098 CC12 CC14 CC24 CC41 CC44 CC56 CC57 DD22 DD35 DD37 DD43 DD44 EE03 EE28 EE32 FF01 FF04 FF16

Claims (22)

[Claims] 1. A power supply circuit that double-rectifies an AC power supply, a phase angle detection circuit that detects a phase angle from an output of the AC power supply, and a DC output of the power supply circuit is converted into a high frequency by a drive frequency from a driver. A switching circuit, a control circuit for controlling the driving frequency of the driver, a discharge lamp to which the high frequency output of the switching circuit is applied, a choke circuit for limiting a current flowing through the discharge lamp, and a current flowing through the discharge lamp. A lamp current detection circuit for detecting the voltage, the voltage generated in the choke circuit is fed back to the power supply circuit, and the control circuit controls the driver based on the outputs of the lamp current detection circuit and the phase angle detection circuit. A discharge lamp lighting device characterized by being controlled. 2. The discharge lamp lighting device according to claim 1, further comprising a shutdown circuit that stops the driver when the phase angle detected by the phase angle detection circuit is a predetermined value or more. . 3. The power supply circuit includes first and second capacitors connected in series and first, second, third and fourth diodes connected in series in forward polarity, and a negative electrode of the first capacitor. The positive electrode of the second capacitor is connected, the connection point between the cathode of the first diode and the positive electrode of the first capacitor is set as the output point of the power supply circuit, and the anode of the fourth diode and the negative electrode of the second capacitor are connected. Is connected to the positive electrode of the second capacitor, the other end is connected to the cathode of the third diode, and the discharge point is connected to the output point of the switching circuit. A series circuit of a light and a choke circuit is connected, and an impedance element is connected to a connection point between the first and second diodes and a connection point between the third and fourth diodes to generate a voltage in the choke circuit. The discharge lamp lighting device according to claim 1 or 2, wherein the discharge lamp lighting device is configured to return via the device. 4. Impedance elements connected to the connection points of the first and second diodes and the connection points of the third and fourth diodes are third and fourth capacitors, respectively, and the choke circuit is an intermediate circuit. The discharge lamp lighting device according to claim 3, wherein the choke coil is provided with a tap, and a connection point between the third and fourth capacitors and the intermediate tap are connected directly or via an inductor. . 5. A variation range of a driving frequency of the driver flows between a first current flowing through the third capacitor or the fourth capacitor and a positive current between the intermediate tap and the second capacitor. The discharge lamp lighting device according to claim 4, further comprising a point where the added value of the second current has a minimum value with respect to the frequency. 6. The driving frequency variation range of the driver includes a range in which the first current flowing through the third capacitor or the fourth capacitor monotonically decreases with respect to the frequency. Item 4. The discharge lamp lighting device according to Item 4 or 5. 7. A third current flowing as a discharge current of the discharge lamp among the second currents flowing between the intermediate tap and the positive electrode of the second capacitor, in a variation range of the driving frequency of the driver. Is a minimum with respect to frequency,
The discharge lamp lighting device according to any one of claims 4 to 6, further comprising: 8. The first period during which the first current is dominant over the second current and the second period during which the second current is dominant over the first current. The discharge lamp lighting device according to any one of claims 4 to 7, wherein different drive control is performed in the period of 2 and the second period. 9. The drive frequency of the drive is feedback-controlled on the basis of the output of the lamp current detection circuit in the first period, and the drive frequency is driven at a fixed frequency in the second period. The discharge lamp lighting device according to claim 8. 10. The discharge lamp lighting device according to claim 9, wherein a setting for determining a feedback value is different between the first period and the second period. 11. The discharge lamp lighting device according to claim 9, wherein the setting for determining the feedback value is different in at least two or more dimming ranges. 12. In the first dimming range, the setting for determining the feedback value is the same in both the first period and the second period, and the first period is in the second dimming range. 10. The discharge lamp lighting device according to claim 9, wherein the setting for determining the feedback value is different in the second period. 13. The dimming control circuit has a setting for determining at least two feedback values, and AC.
The discharge lamp lighting device according to claim 9, wherein the feedback value is changed in synchronization with a voltage change caused by a power supply. 14. The feedback value is changed at a half cycle of the AC power supply.
The discharge lamp lighting device described. 15. The feedback value is used as an ON period and an OF of a thyristor in a phase control dimmer connected to the AC power source.
14. Changing between the F period and the period.
Or the discharge lamp lighting device according to 14. 16. The discharge lamp lighting device according to claim 10, wherein the feedback target is in the range of the drive frequency. 17. The discharge lamp lighting device according to claim 10, wherein the feedback target is an upper limit of the drive frequency. 18. The discharge lamp according to claim 17, wherein the upper limit of the drive frequency that is the feedback target in the first period is higher than the upper limit of the drive frequency that is the feedback target in the second period. Lighting device. 19. The upper limit of the drive frequency that is the feedback target in the second period is lower than the frequency that gives the minimum point of the third current.
The discharge lamp lighting device described. 20. The setting change for determining the feedback value is continuously changed.
The discharge lamp lighting device according to any one of 1. 21. The phase angle detection circuit has first and second comparators, and a divided voltage value at a connection point of the second and third diodes is set as a detection value, and the first and second comparators are set. The first and second divided voltage values at the connection point of the capacitors are respectively set as first and second threshold values, and the average value of the first threshold values is higher than the average value of the detected values, Is set to be lower than the average value of the detected values, and the first comparator outputs a high output when the detected value exceeds the first threshold value. In the second comparator, a high output is set when a detected value falls below the second threshold, and outputs of the first and second comparators are set to the phase angle. The discharge lamp lighting device according to any one of claims 9 to 20, characterized in that the output is a detection circuit. 22. A lighting fixture using a bent fluorescent lamp having the discharge lamp lighting device according to claim 1.