JPH10257765A - High power factor ac/dc converter and lighting unit for high power factor high luminance discharge lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a high power factor AC/DC converter and a lighting unit for a high luminance discharge lamp in which a high power factor can be sustained over a wide fluctuation range of AC commercial input power supply. SOLUTION: AC power is received from an AC commercial power supply 1 at input terminals 3, 5 and converted through a rectifier circuit 7, a diode 11 and a filter circuit 14 into DC power which is supplied to a DC-DC converter section 24. The DC-DC converter section 24 comprises a coupling capacitor 13 connected with an FET 27, a transformer 25, a diode 31 and a capacitor 33. The FET 27 works as a switching element for both a step-up chopper circuit turning energy from the coupling capacitor 13 on/off at high frequency, and the DC-DC converter section 24 for turning the current from the primary winding of the transformer 25 on/off thus enhancing the power factor over a wide fluctuation range of input.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an AC / DC converter for converting a commercial AC input power supply voltage into a stable DC output voltage, and more particularly to a high power factor AC / DC converter. The present invention also relates to a high power factor and high brightness discharge lamp lighting device configured by providing an inverter at an output terminal of the AC / DC converter.

[0002]

2. Description of the Related Art As for an AC / DC converter having a high power factor, the present applicant has already proposed Japanese Patent Application No. 3-280454 (Japanese Patent Application Laid-Open No. 5-95681). Although this circuit has a simple configuration, it achieves both high power factor and economy. However, the conditions of the circuit constants make it difficult to make the input voltage correspond to a wide range of fluctuation, which is practically impossible.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to enable an AC / DC converter having a high power factor to operate in correspondence with a wide range of input voltage. Another object is to obtain a lighting device for a high power factor and high brightness discharge lamp using the high power factor AC / DC converter.

[0004]

Means for Solving the Problems The present invention proposes the following means to solve this problem. That is, a full-wave rectifier circuit including a pair of input terminals to be connected to a commercial AC power supply; a pair of AC input terminals and a pair of DC output terminals, wherein the AC input terminals of the rectifier circuit are the pair of input terminals. A full-wave rectifier circuit connected to the input terminal; an inductor, a diode, and a smoothing circuit connected to the DC output terminal of the full-wave rectifier circuit and connected in series with each other; A series circuit including two capacitors is connected to one end of the diode, and a charging diode for charging each of the capacitors in series is connected between the two capacitors. A smoothing circuit in which energy discharging diodes for discharging energy in parallel from the two capacitors are connected to the two capacitors, respectively; A control circuit for generating an on / off drive signal having a frequency sufficiently higher than the wave number; a switching element including a pair of main electrodes and a control terminal, the control terminal of which is turned on / off by the control circuit; One end of the main electrode is connected to a connection point between the inductor and the diode via a coupling capacitor, and the other end of the main electrode is connected to a switching element connected to one end of the smoothing circuit; and at least a primary winding; A transformer having a secondary winding, the primary winding of which is connected between a connection point between the smoothing circuit and the diode and a main electrode of the switching element; A high power factor AC / DC converter comprising a rectifier connected to a secondary winding of a vessel and an output terminal connected to the rectifier is proposed.

[0005] As a second means, a high power factor AC / DC converter is characterized in that rectifying means connected to a secondary winding of the transformer transfers energy in response to turning on of the switching element. suggest.

As a third means, a high power factor AC / DC converter is characterized in that rectifying means connected to a secondary winding of the transformer transmits energy corresponding to the time when the switching element is turned off. suggest.

As a fourth means, a current detecting means is connected in series to a main current terminal of the switching element, and a control is performed so that a peak current of the switching element is made constant by a signal of the current detecting means. A high power factor AC / DC converter is proposed.

As a fifth means, a voltage detecting means for obtaining a substantially average value is connected to the AC input terminal, and the output power is corrected by controlling the frequency of the switching element by a signal of the voltage detecting means. A featured high power factor AC / DC converter is proposed.

As a sixth means, a voltage detecting means is connected in parallel with the output terminal, and the output voltage is made constant by controlling the frequency of the switching element by a signal from the voltage detecting means. Power factor AC / DC
Suggest converter.

As a seventh means, a current detecting means is connected in series with the output terminal, and the output current is made constant by controlling the pulse width of the switching element by a signal of the current detecting means. High power factor AC / D
A C converter is proposed.

As an eighth means, the high power factor AC /
A high power factor high intensity discharge lamp lighting device characterized by being connected to an output terminal of a DC converter via an inverter circuit to a high intensity discharge lamp.

[0012]

FIG. 1 shows that the high power factor AC /
The DC converter and the high power factor high-intensity discharge lamp lighting device will be described. This device is roughly divided into a high power factor AC / DC converter 2, an inverter circuit 35 receiving the DC output thereof and converting it into a rectangular wave of about 100 Hz, an igniter 37, a high-intensity discharge lamp 39, and a current detector 45. And a high power factor and high brightness discharge lamp lighting device.

First, the high power factor AC / DC converter 2 will be described in detail. As shown in FIG. 1, the commercial AC power supply 1 is connected to a bridge type rectifier circuit 7 via input terminals 3 and 5, as shown in FIG. The DC output terminal of the rectifier circuit 7 is supplied to the smoothing circuit 14 via the inductor 9 and the diode 11. The connection point between the inductor 9 and the diode 11 is connected to the drain electrode of the FET 27 via the capacitor 13, and its source electrode is connected to the minus side of the smoothing circuit 14. The gate electrode of the FET 27 is turned on and off by the control circuit 29 at a high frequency of about 100 kHz. These parts are rectifier chopper circuits. That is, the input commercial AC power supply 1 (100 V to 200 V, 50 Hz) is connected to the rectifier circuit 7.
And rectified through the inductor 9 and the capacitor 13
The FET 27 repeats on and off at a high frequency of 100 kHz.

First, when the FET 27 is on, a current for charging the capacitor 13 flows from the inductor 9. This current flows until the voltage of the capacitor 13 reaches the positive voltage of the smoothing circuit 14, and energy is accumulated in the inductor 9 and the capacitor 13. Next, when the FET 27 is turned off, the inductor 9
The current energy stored in the charging circuit 14 charges the smoothing circuit 14 through the diode 11. Since the capacitance in the smoothing circuit 14 is a sufficiently large value, the DC voltage Eb is kept substantially constant in a steady state. Since the input AC current always passes through the inductor 9, the current is continuous.

Next, the positive side of the smoothing circuit 14 is connected to the drain of the FET 27 via the primary winding n 1 of the transformer 25. The secondary winding n2 of the transformer 25 is connected to a diode 31 for rectification and a capacitor 33 for smoothing, and also to a DC output terminal. Further, a voltage detector 43 is connected to the smoothing capacitor 33, and a detection output thereof is connected to a detection input terminal of the control circuit 29. The control circuit 29 is a general circuit configured by adding a widely used switching power supply integrated circuit and some auxiliary components.

As for the transformer 25, the above D
In addition to the function as a component of the C-DC converter 24, there is a function of resetting the capacitor 13 due to natural vibration between the capacitor 13 and the primary winding n1 of the transformer 25. F
When the ET 27 is on, the electric charge stored in the capacitor in the smoothing circuit 14 supplies power to the output terminal through the primary winding n1 of the transformer 25 and the subsequent circuits, and
Is off, the energy of the current flowing through the primary winding n1 of the transformer 25 is reduced by the capacitor 13 and the diode 1
The current flows through the path 1 to invert the voltage of the capacitor 13.

Next, the operation will be described in detail. It is assumed that the switching frequency of the FET 27 is sufficiently higher than the frequency of the commercial AC power supply 1. Therefore, the input voltage is regarded as constant during one cycle of switching, and the inductance L1 of the inductor 9 is sufficiently large with respect to the switching frequency, so that it can be regarded as substantially constant current. The excitation inductance L0 of the primary winding of the transformer 25 is considerably smaller than the inductance L1 of the inductor 9, the turns ratio is 1: 1, and the capacitance of the capacitor 33 is sufficiently large to be described as a voltage source. . Hereinafter, the description will be given by dividing into time sections T0, T1,..., T5 shown in FIG.

[Section T0-T1] When the FET 27 is turned on at time T0,
Until then, commercial AC power supply 1 → inductor 9 → diode 1
1 → smoothing circuit 14 → The current flowing in the closed loop of the commercial AC power supply 1 flows into the FET 27 while charging the capacitor 13. At the same time, the voltage Eb of the smoothing circuit 14 is applied to the primary winding n1 of the transformer 25, but the voltage polarity of the secondary winding n2 is negative with respect to the output voltage E0. No current flows to the secondary side because it is cut off. Therefore, at time T0, the exciting current starts flowing through the closed loop of the smoothing circuit 14 → n1 → FET27 → smoothing circuit 14 in the primary winding n1 of the transformer 25 at time T0, and Eb / L0 (L0: Vessel 2
(Excitation inductance of 5).

[Section T1-T2] At time T1, when the voltage of the capacitor 13 becomes the voltage Eb of the smoothing circuit 14, the voltage is clamped, and the current of the inductor 9 flows into the smoothing circuit 14 via the diode 11. Therefore, the current flowing through the FET 27 disappears from the current flowing through the smoothing circuit 14, but continues to rise with the slope of Eb / L0. 2 (b) and 2 (c) show the waveforms. This operation mode continues until the FET 27 is turned off. FET27
Is substantially constant unless the effective values of the load and the input voltage change, so that this period is longer when the phase of the input voltage is higher, and is approximately 0 to 3.0 μs.

[Section T2-T3] When the FET 27 is turned off at the time T2, 1
The exciting current flowing to the next winding n1 is n1 → capacitor 13 →
The current flows through the closed loop of the diode 11 → n1. The voltage of the FET 27 increases from zero according to the voltage of the capacitor 13. On the other hand, the current of the secondary winding n2 of the transformer 25 is FET
27, the capacitor 1 of the primary winding n1 of the transformer 25
Since the voltage of 3 is applied, the current still does not flow. Then, the current of the inductor 9 as the input current continues to flow to the smoothing circuit 14 while decreasing.

[Section T3-T4] At time T3, the voltage of the capacitor 13 becomes -Vo.
, The voltage of the primary winding n1 of the transformer 25 also becomes -Vo and 2
Current starts to flow to the next winding n2. Then, the secondary winding voltage is clamped at the output voltage Eo, and the primary winding is also fixed at Eo. When the primary winding voltage becomes constant at Eo, the capacitor 13 is no longer charged, and therefore the primary current In1 of the transformer 25 is reduced.
Becomes zero at time T3 as shown in FIG. 2 (a), and the stored energy is commutated to the secondary winding n2. The secondary winding current In2 decreases with the slope of Eo / Lo as shown in FIG. FET2
The voltage 7 is the sum of the voltage of the capacitor 13, the voltage of the primary winding n1 of the transformer 25, and the output voltage Eo. At time T4, the current in the secondary winding n2 becomes zero, and all the energy stored in the exciting inductance of the transformer 25 is released. The current of the inductor 9 continues to flow to the smoothing circuit 14.
The time from time T3 to T4 is determined by the value of the output current Io,
It is about 4 μs at the maximum output current.

[Section T4-T5] This section is a period from when the secondary current becomes zero to when the FET 27 is turned on next time. Times of Day
At T5, the FET 27 is turned on again, and the operation from time T0 is repeated. FIG. 2G shows the waveform of the current Ii flowing through the inductor 9.

Hereinafter, when a simulation is performed for one cycle of the AC frequency, the commercial AC input current Ii has a waveform in which a DC component is superimposed on a sine wave, and its power factor is a value very close to 1.

[0019]

[Operation of Smoothing Circuit] Next, the operation of the smoothing circuit 14 will be described with reference to the waveform diagram shown in FIG. In this operation description, it is assumed that the inductor 9 and the diode 11 are short-circuited. Also, it is assumed that the current to the DC-DC converter section 24 supplies a constant current within a range that does not reduce the smoothing action.

As shown in FIG. 3, a full-wave rectified voltage is applied to an output terminal of a rectifier circuit 7 formed by bridge-connecting diodes.
(e1) appears. This full-wave rectified voltage (e1) is applied to the DC-DC converter unit 24 and is also applied to the capacitors 15 and 17 connected in series for charging. In this case, since the capacitors 15 and 17 are in series and each capacitance is almost equal, a rectified voltage (e2) obtained by dividing the full-wave rectified voltage (e1).
Is applied to the individual capacitors 15 and 17 on a half-by-half basis. Here, the full-wave rectified voltage (e1) and the rectified voltage (e2) are virtual voltages independent of the circuit, and therefore,
They are shown in parentheses or shown by broken lines in FIG.

Next, when the full-wave rectified voltage (e1) rises, the capacitors 15 and 17 are connected to the commercial AC power supply 1 from time t2 when the capacitor voltage e3 becomes lower than the rectified voltage (e2) to peak time t3. , The capacitor voltage e3 rises to the peak voltage of the rectified voltage (e2) at time t3. Peak time t3
Since the rectified voltage (e2) falls from
17 is no longer charged, and each capacitor voltage e3 maintains its value. After the time t4, the capacitor voltage e3 becomes higher than the full-wave rectified voltage (e1), so that the diodes 19 and 23 that have been in the off state are turned on. , 17 to the DC-DC converter 24. During this energy supply, the rectifier circuit 7 becomes non-conductive, and no current flows from the commercial AC power supply 1 to the DC-DC converter unit 24 via the rectifier circuit 7. At time t1, the capacitor voltage e3
Is lower than the full-wave rectified voltage (e1).
When the capacitors 9 and 23 are turned off, the capacitors 15 and 17 no longer discharge. Thereafter, the capacitor voltage e3 maintains the value at that time, and the full-wave rectifier circuit 7 conducts. At time t2, the capacitor voltage e3 becomes lower than the rectified voltage (e2), and charging of the capacitors 15, 17 is started. Thereafter, the same operation is repeated. Accordingly, the output voltage of the entire smoothing circuit 14, that is, the input voltage to the DC-DC converter section 24 becomes a smoothed DC voltage as shown by the waveform e4, and the output voltage e4 does not decrease to 0V. DC-
The DC converter 24 can be operated stably.

The input current of the rectifier circuit 7 has a waveform (i
1), and the input current to the circuit of the capacitors 15 and 17 connected in series becomes the current as shown by the waveform i2. Therefore, the current input from the commercial AC power supply 1 to the entire circuit has the waveform i3. As shown, compared to a simple capacitor-based smoothing circuit, the pause period is short, and the peak value is low, resulting in a very good power factor.

In the operation of the smoothing circuit 14, the element that determines the timing at which the diodes 19 and 23 are turned on is automatically determined and operated according to the voltage relationship of the commercial AC power supply 1. Therefore, the commercial AC power supply 1
Is varied, for example, in a wide range of 100 V / 200 V, the voltage and current values are only approximately proportional, and the device operates without any trouble.

By the respective operations of the AC / DC converter 2 and the smoothing circuit 14 described above, the power factor is improved, and the commercial AC power supply 1 operates satisfactorily even in a wide range. In order to cope with 100V / 200V, the capacitance of the coupling capacitor 13 is reduced and the charging energy at the time of 200V input is selected to be small. On the other hand, at the time of input of 100 V, the energy becomes insufficient, but this shortage can be compensated by designing the constant of the inductor 9.

Next, the high-intensity discharge lamp lighting device will be described. In FIG. 1, an inverter 3 receives a DC output generated at output terminals 30 and 32 of an AC / DC converter 2.
5 to a rectangular wave of about 100 Hz.
Necessary electric power is supplied to the high-intensity discharge lamp 39 via. The electric power required for the high-intensity discharge lamp 39 is as follows. First, a sufficiently high voltage is applied at the time of ignition, and secondly, a holding current required to maintain the ignition state immediately after the ignition is constant. Third, it is necessary to supply predetermined substantially constant power during steady lighting.

FIG. 4 illustrates the relationship between the voltage and the current of the high-intensity discharge lamp. Before lighting, it is a region α of a relatively high voltage with almost zero current, immediately after lighting is a region β of a relatively large current, and at the time of steady lighting, it is represented by a region γ on a hyperbola showing constant power.

In order to realize control of these three types of areas, as shown in FIG.
3 is connected to the capacitor 33, that is, the output terminals 30 and 32 of the AC / DC converter 2, and the detection signal is sent to the control circuit 29 to control the frequency of the operation of the DC-DC converter 24 and to control the peak current ( The method will be described in the following region γ) to suppress the output voltage. For the region β, the current detector 45 is set to AC / D
The detection signal is sent to the control circuit 29 in series with the output terminal 32 of the C converter 2, and the operation of the DC-DC converter 24 is pulse width modulated to suppress the output current. Further, for the region γ, the current detector 41 is connected to the drain circuit of the FET 27, the detection signal is sent to the control circuit 29, and the peak value of the drain current of the FET 27 is controlled so as to be constant.
The operation of the DC-DC converter unit 24 is constant power control.

FIG. 5 illustrates the voltage and current of each part of the lighting of the high-intensity discharge lamp 39 over time. In the area α before lighting, the discharge lamp current (m) is almost zero and the discharge lamp voltage (k) indicates a high voltage. When the igniter 37 operates to generate a pulse voltage of several kilovolts, the lamp is fired and the discharge lamp current (m) flows. In the area β immediately after the ignition, the value of the discharge lamp current (m) is slightly large, and the value of the discharge lamp voltage (k) is slightly small. In addition, the current (j) of the inductor 9 at this time is a series of high-frequency rectangular waves whose contour is similar to the commercial AC voltage (h). After a short period of time, the power (n) supplied to the discharge lamp increases, and the region becomes a region γ at the time of steady lighting.
At this time, the waveforms of the respective parts continue to be constant. The waveform shown in FIG. 5 is a conceptual waveform for explanation, and neither the vertical axis nor the horizontal axis indicates an actual value.

FIGS. 6 and 7 show an embodiment of a high power factor and high brightness discharge lamp lighting apparatus according to the present invention, respectively.
The waveform of each part at the time of 200V input and the waveform of each part at the time of 100V input are also obtained by simulation. In these figures, e14 is a smoothed output voltage of the smoothing circuit 14, which is a waveform in which a switching waveform is superimposed on a DC voltage. IQ is a switching element F
This is the current waveform of ET27, and VQ is its voltage waveform. Ii is a waveform corresponding to the input current from the commercial AC power supply 1. In comparison with the input voltage waveform e1 of the commercial AC power supply 1, the input current Ii has a waveform whose contour is substantially proportional to e1. Further, the input current Ii
Is compared between when AC100V is input and when AC200V is input, similarly, the contour becomes a waveform substantially proportional to e1. The waveform of the input current Ii is averaged into a continuous sine wave by inserting a filter effective for a high frequency of switching.

FIG. 8 shows an embodiment of the high power factor and high intensity discharge lamp lighting device according to the present invention, in which 200 V input and 1
5 shows an actually measured waveform of an AC input current at the time of 00V input. As the actual measurement conditions, a filter effective for the high frequency of the above-described switching is inserted in the input circuit, and each of them has a substantially continuous sinusoidal waveform, which indicates that the input circuit has a high power factor.

FIG. 9 shows a high power factor AC / D according to the present invention.
Another embodiment of the C converter and the high power factor high intensity discharge lamp lighting device is shown. This embodiment is different from the embodiment shown in FIG. 1 in that a voltage detector 18 is connected in parallel to a capacitor at the lower stage of the smoothing circuit 14.
And the signal of the voltage detector 18 causes the FET 27
The output power is corrected by controlling the frequency. In this embodiment, the connection position of the voltage detector 18 has the same effect at other connection positions as long as a detection signal proportional to the average value of the voltage value of the commercial AC power supply 1 can be obtained. is there.

When the current detecting means 41 controls the peak current of the FET 27 to be constant, the transformer 25
Is constant regardless of the fluctuation of the commercial AC power supply 1. However, in practice, due to the delay of the control system and the response delay of the switching element, AC100V / 2
At the time of large voltage fluctuation such as at the time of 00V switching, an error occurs in energy transmission.

To correct this error, the voltage of the lower capacitor of the smoothing circuit 14 is detected by the voltage detector 18, and the amount of voltage change is realized by changing the switching frequency of the switching element. As an example, when the switching frequency is 100 KHz at AC 100 V, AC 200
Energy transfer to the secondary side at 65 KHz at V coincided.

In this embodiment, the connection position of the voltage detector 18 is the same as that of the other connection positions as long as a detection signal proportional to the average value of the voltage of the commercial AC power supply 1 can be obtained. It is.

[0035]

Since the present invention has the above-described features, it has a simple configuration, and is compact, lightweight, has a high power factor,
It has a high efficiency effect. Especially 100V / 20
It is very economical to share 0V.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a high power factor AC / DC converter and a high power factor high brightness discharge lamp lighting device according to the present invention.

FIG. 2 is a waveform diagram for explaining the operation of the converter circuit.

FIG. 3 is a waveform chart for explaining the operation of the smoothing circuit.

FIG. 4 shows a characteristic diagram of the high power factor high intensity discharge lamp lighting device according to the present invention.

FIG. 5 shows the voltage and current of each part over time in the high power factor and high brightness discharge lamp lighting device according to the present invention.

FIG. 6 shows a waveform of each part at the time of 200 V input in one embodiment of the high power factor high luminance discharge lamp lighting device according to the present invention.

FIG. 7 shows waveforms at various points when 100 V is input in one embodiment of the high power factor high luminance discharge lamp lighting device according to the present invention.

FIG. 8 shows a waveform of an AC input current at the time of 200V input and at the time of 100V input in one embodiment of the high power factor and high brightness discharge lamp lighting device according to the present invention.

FIG. 9 shows another embodiment of the high power factor AC / DC converter and the high power factor high luminance discharge lamp lighting device according to the present invention.

[Explanation of symbols]

1: Commercial AC power supply 24: DC-DC converter 3,
5 Input terminal 7 Rectifier circuit 9 Inductor 11 Diode 14 Smoothing circuit 15, 17 Capacitor 18 Voltage detector 19, 2
1, 23: diode 24: DC-DC converter section 25: transformer 2
7 FET 29 Control circuit 31 Diode 33 Capacitor 35 Inverter circuit 37 Igniter 39
... High-intensity discharge lamp 41 ... Current detector 43 ... Voltage detector 45 ... Current detector

Claims (8)

[Claims] 1. A full-wave rectifier circuit comprising: a pair of input terminals to be connected to a commercial AC power supply; and a pair of AC input terminals and a pair of DC output terminals, wherein the rectifier circuit has an AC input terminal. A full-wave rectifier circuit connected to the pair of input terminals; an inductor, a diode, and a smoothing circuit connected to the DC output terminal of the full-wave rectifier circuit and connected in series with each other; A series circuit including two capacitors having a capacitance is connected to one end of the diode, and a charging diode for charging these capacitors in a series relationship is connected between the two capacitors. A smoothing circuit in which energy discharging diodes for discharging energy in parallel from the respective capacitors are connected to the two capacitors, respectively; A switching device having a pair of main electrodes and a control terminal; and a control circuit for generating a sufficiently high frequency on-off driving signal by comparing the frequency
The control terminal is turned on and off by the control circuit, one end of the main electrode is connected to a connection point between the inductor and the diode via a coupling capacitor, and the other end of the main electrode is connected to one end of the smoothing circuit. A switching element connected to the switching element; and a transformer having at least a primary winding and a secondary winding, wherein the primary winding is connected to a connection point between the smoothing circuit and the diode and a main element of the switching element. A transformer connected between the electrodes; 2 of this transformer
A high power factor AC / DC converter comprising: a rectifier connected to the next winding; and an output terminal connected to the rectifier. 2. The high power factor A according to claim 1, wherein the rectifier connected to the secondary winding of the transformer transmits energy corresponding to when the switching element is turned on.
C / DC converter. 3. The high power factor A according to claim 1, wherein the rectifier connected to the secondary winding of the transformer transmits energy corresponding to a time when the switching element is turned off.
C / DC converter. 4. A current detecting means is connected in series to a main current terminal of the switching element, and a signal from the current detecting means is controlled to keep a peak current of the switching element constant. The high power factor AC / DC converter according to claim 3. 5. A voltage detecting means for obtaining a substantially average value is connected to the pair of AC input terminals, and a frequency of the switching element is controlled by a signal from the voltage detecting means.
The high power factor AC / DC converter according to claim 3 or 4, wherein the output power is corrected. 6. A voltage detecting means is connected in parallel with said output terminal, and a frequency of said switching element is controlled by a signal of said voltage detecting means to make an output voltage constant. The high power factor AC / DC converter according to claim 4 or 5. 7. The output current is connected to the output terminal in series, and the output current is made constant by controlling the pulse width of the switching element by the signal of the current detection means. The high power factor AC / DC converter according to claim 4. 8. An output terminal of the high power factor AC / DC converter according to claim 3 which is connected to a high-intensity discharge lamp via an inverter circuit. Power factor high intensity discharge lamp lighting device.