JP2000236673A - Power supply - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply in which reliability can be enhanced and the size can be reduced, while suppressing the increase in the number of elements of a chopper circuit. SOLUTION: This power supply supplies a capacitor C0 with power by switching a switching element Q2, also serving as a chopper, at a high frequency during an interval when an input current Iin flows in the positive direction using an AC power supply and at the same time, supplies a load discharge lamp FL with high frequency power by switching switching elements Q1-Q4 at a high frequencies. When the input current Iin flows in the negative direction, a switching element Q4, also serving as a chopper, is switched at high frequency to supply the capacitor C0 with power, and at the same time, supplies the load discharge lamp FL with high frequency power by switching the switching elements Q1-Q4 at high frequencies.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply.

[0002]

2. Description of the Related Art A conventional power supply device of this type is an inverter device disclosed in U.S. Pat. No. 4,948,897.

FIG. 12 shows the basic configuration. In this conventional example, a series circuit including a pair of switching elements Q1 and Q2 and a series circuit including a pair of switching elements Q3 and Q4 are connected between both ends of a capacitor C0 serving as a DC power supply. Between the connection point of the series circuit composed of the switching elements Q1 and Q2 and the connection point of the series circuit composed of the switching elements Q3 and Q4, there is a load circuit composed of the resonance inctor L, the resonance capacitor C and the discharge lamp FL as a load. Chopper choke L01 connected in series in parallel with switching element Q2, diode bridge DB composed of diodes D1 to D4, and full-wave rectifier circuit composed of AC power supply AC. The driving of each of the switching elements Q1 to Q4 is controlled by driving signals S1 to S4 from the control circuit CTR.

Each of the switching elements Q1 to Q4 is a MOSF
ET, and a parasitic diode (not shown) is connected in anti-parallel.

The connection point between the chopper choke L01 and the diode bridge DB and the switching element Q3
Chopper choke L02 is connected between the connection points of Q4.

The operation of this conventional example will be described with reference to FIGS. FIG. 13 shows a circuit operation in one cycle of the AC power supply AC. FIG. 13A shows the AC voltage Vac of the AC power supply AC.
(B) shows the current IL01 flowing through the chopper choke L01, and (c) shows the waveform of the chopper choke L02.
Current IL02 flowing through (D)-(g) show currents IQ1-IQ4 flowing through the switching elements Q1-Q4, respectively.
Is shown. FIG. 2H shows the current If flowing through the resonance capacitor C, and FIG. 1I shows the current Ila flowing through the discharge lamp FL.
Is shown.

Here, the circuit operation during the valley period T1 of the voltage Vac of the AC power supply AC shown in FIG.
Performed by

At time t1, as shown in FIGS. 14 (a) and 14 (d), the drive signals S1 and S4 become low level, and the switching elements Q1 and Q4 are turned off.
As shown in (c), when the drive signals S2 and S3 become high level and the switching elements Q2 and Q3 are turned on, thereby, the diode bridge DB, the chopper choke L01, the switching element Q2, A chopper current IL01 flows through the path of the diode bridge DB as shown in FIG. Further, the AC energy, the diode bridge DB, the chopper choke L02, and the switching element Q are generated by the magnetic energy stored in the chopper choke L02 and the AC power AC.
As shown in FIG. 14F, the chopper current IL02 flows through the path of the parasitic diode 3, the capacitor C0, and the diode bridge DB, and supplies energy to the capacitor C0. Thereafter, when the magnetic energy of the chopper choke L02 is released, the chopper current IL02 becomes zero. Also, the magnetic energy stored in the resonance choke L causes the resonance choke L to pass through the parasitic diode of the switching element Q3, the capacitor C0, the parasitic diode of the switching element Q2, the resonance capacitor C, or the discharge lamp FL. The current If shown in FIG. 14 (l) is applied to the resonance capacitor C, and the load (lamp) current Ila shown in FIG. 14 (m) is applied to the discharge lamp FL.
At the time when the magnetic energy of the resonance choke L is released, the capacitor C0 is used as a DC power supply, and a load is applied through the path of the switching element Q3, the resonance choke L, the discharge lamp FL or the resonance capacitor C, and the switching element Q2. Power is supplied to a certain discharge lamp FL, and a current If shown in FIG. 14 (l) and a load current Ila shown in FIG. 14 (m) flow.

At time t2, the drive signals S1 and S4 become high from FIGS. 14A and 14D, and the switching elements Q1 and Q4 are turned on, as shown in FIGS. 14B and 14C. When the drive signals S2 and S3 become low level and the switching elements Q2 and Q3 are turned off, the AC power AC, the diode bridge DB, and the magnetic energy stored in the chopper choke L01 are used as power sources. A chopper current IL01 flows through the path of the chopper choke L01, the parasitic diode of the switching element Q1, the capacitor C0, and the diode bridge DB as shown in FIG. And chopper chalk L
When the magnetic energy of 01 is released, the chopper circuit operation stops, and the chopper current IL01 becomes zero.

Further, using the AC power supply AC as a power supply, an AC power supply AC, a diode bridge DB, a chopper choke L
02, switching element Q4, diode bridge DB
14C, the chopper current IL02 flows through the chopper choke L02 as shown in FIG. Further, the parasitic diode of the switching element Q1, the capacitor C0, the switching element Q4 from the resonance choke L via the discharge lamp FL or the resonance capacitor C or the discharge lamp FL by the magnetic energy accumulated in the resonance choke L. When the current If shown in FIG. 14 (l) and the load current Ila shown in FIG. 14 (m) flow through the path of the parasitic diode and the magnetic energy of the resonance choke L is released, the capacitor C0 is connected to the DC power supply. The switching element Q1, the resonance capacitor C or the discharge lamp F
Power is supplied to the discharge lamp FL as a load through the path of L, the resonance choke L, and the switching element Q4, and a current If shown in FIG. 14 (l) and a load current Ila shown in FIG.

At time t3, the same operation as at time t1 is performed.

Next, a description will be given of the circuit operation during the period T2 when the AC power supply AC is in the positive direction and the power supply voltage Vac is in the peak portion.
The circuit operation from time t4 to time t6 is basically the same as that of time t1 to time t1.
Since the circuit operation at t3 is almost the same and the voltage value of the AC power supply AC is higher than that at the valley, the current IQ handled by the switching elements Q1 and Q2 as shown in FIGS.
1, the value of IQ2 is higher than in the case of times t1 to t3. Thus, in the conventional circuit configuration, the switching element Q
2 serves as a chopper combined element.

By repeating the operation from time t1 to time t6, it is possible to realize a power supply device capable of stably lighting the discharge lamp FL and simultaneously suppressing input current distortion.

FIGS. 14I and 14J show currents IQ3 and IQ4 flowing through the switching elements Q3 and Q4, and FIG. 14K shows the voltage V _BA between B and A in FIG.

Next, as another conventional example, US Pat.
There is a power supply device described in Japanese Patent No. 63,490. FIG. 15 shows the basic configuration. In this circuit, a series circuit including a pair of switching elements Q1 and Q2, a series circuit including a pair of switching elements Q3 and Q4,
A plurality of series circuits each including a pair of diodes D1 and D2 are connected in parallel to the capacitor C0. Between the connection point of the series circuit of the switching elements Q1 and Q2 and the connection point of the series circuit of the switching elements Q3 and Q4, at least the discharge lamp FL and the resonance inductor L which are connected in series, and the discharge lamp FL (of the fluorescent lamp) In this case, a load circuit including a resonance capacitor C connected in parallel to the non-power supply side is connected. Then, a series circuit of the AC power supply AC and the chopper choke L0 is connected between a connection point of the series circuit of the diodes D1 and D2 and a connection point of the series circuit of the switching elements Q1 and Q2.

In this power supply device of the prior art, the switching element Q2 is also used as a chopper while the current direction of the input current Iin is the direction of the arrow in FIG. The high frequency power is supplied to the discharge lamp FL by performing the switching operation at a high frequency as the switching element and supplying the power to the capacitor C0, and simultaneously performing the switching operation at the high frequency with the switching elements Q1 to Q4. The direction of the input current Iin is opposite to the direction of the arrow in FIG. 15 (hereinafter, referred to as a negative direction).
During this period, the switching element Q1 operates as a chopper and operates at high frequency to supply power to the capacitor C0, and at the same time, performs high-frequency switching operation of the switching elements Q1 to Q4 to supply high frequency power to the discharge lamp FL.

The switching elements Q1 to Q4 are controlled and driven by drive signals S1 to S4 of the control circuit CTR.

First, the operation of the conventional example at the time of rated lighting will be described with reference to FIGS. FIG. 16 shows one cycle of the circuit operation of the AC power supply AC, and FIG.
The waveform of the AC voltage Vac of C is shown in FIG.
(c) to (f) show switching elements Q1 to
Currents IQ1 to IQ4 flowing through Q4 are shown. FIG. 3G shows the current If flowing through the resonance capacitor C, and FIG. 3I shows the current Ila flowing through the discharge lamp FL.

First, the direction of the input current Iin is positive,
The circuit operation in the period T1 of the trough of the voltage Vac of the AC power supply AC will be described with reference to FIG.

At time t1, as shown in FIGS. 17 (a) and (d), the drive signals S1 and S4 become low level, and the switching elements Q1 and Q4 are turned off.
As shown in (c), when the drive signals S2 and S3 become high level and the switching elements Q2 and Q3 are turned on, the path of the switching element Q2, the diode D2, and the chopper choke L0 using the AC power supply AC as a power source. As a result, the input current Iin shown in FIG. Also,
Due to the magnetic energy stored in the resonance choke L, the parasitic diode of the switching element Q3, the capacitor C0, the switching element Q2
The load (lamp) current Ila shown in FIG. 17 (l) and the current If shown in FIG. 17 (k) flow through the parasitic diode, the discharge lamp FL or the resonance capacitor C, and the magnetic energy of the resonance choke L At the point of discharge, power is supplied to the discharge lamp FL as a load through the path of the switching element Q3, the resonance capacitor L, the discharge lamp FL or the resonance capacitor C, and the switching element Q2 using the capacitor C0 as a DC power supply. The load current Il shown in FIG.
a, The current If shown in FIG.

At time t2, as shown in FIGS. 17A and 17D, the drive signals S1 and S4 become high level, and the switching elements Q1 and Q4 are turned on.
As shown in (c), when the drive signals S2 and S3 become low level and the switching elements Q2 and Q3 are turned off, thereby, the magnetic energy stored in the chopper choke L0 and the AC power supply AC are used as power supplies, AC, parasitic diode of switching element Q1, capacitor C
The input current Iin shown in FIG. 17E flows through the path of 0, the diode D2, and the chopper choke L0. Then, when the magnetic energy of the chopper choke L0 is released,
The operation of the chopper circuit stops, and the input current Iin becomes zero.

Also, the magnetic energy stored in the resonance choke L causes the discharge lamp F
L or resonance capacitor C, switching element Q1
The load current Ila shown in FIG. 17 (l) and the current If shown in FIG. 17 (k) flow through the parasitic diode, the capacitor C0, and the parasitic diode of the switching element Q4.
When the magnetic energy of the resonance choke L is released, the switching element Q
1. Power is supplied to the discharge lamp FL, which is a load, through the path of the discharge lamp FL or the resonance capacitor C, the resonance choke L, and the switching element Q4, and the load current Ila shown in FIG. The current If shown in FIG.

At time t3, the same operation as at time t1 is performed.

Next, the circuit operation during the peak period T2 of the power supply voltage Vac in the positive direction of the AC power supply AC will be described with reference to FIG. 17. The circuit operation from time t4 to t6 is basically from time t1 to time t1. It is almost the same as the circuit operation at t3.
Since the value of the voltage Vac of C is higher than that of the valley, the values of the currents IQ1 and IQ2 handled by the switching elements Q1 and Q2 are lower than those at times t1 to t3 as shown in FIGS. Get higher.

Thus, in the circuit configuration of the conventional example, the switching element Q2 functions as a chopper element while the direction of the input current Iin is positive.

Next, a description will be given of the circuit operation during the period T3 of the AC valley with the direction of the input current being negative, with reference to FIG.

At time t7, as shown in FIGS. 17 (a) and 17 (d), the drive signals S1 and S4 become high level, and the switching elements Q1 and Q4 are turned on.
As shown in (c), when the drive signals S2 and S3 become low level and the switching elements Q2 and Q3 are turned off, the AC power supply AC is used as the power
The input current Iin shown in FIG. 17E flows through the path of the chopper choke L0, the diode D1, and the switching element Q1.

Also, the discharge light FL or the resonance capacitor C and the switching element Q are output from the resonance choke L by the magnetic energy stored in the resonance choke L.
The load current Ila shown in FIG. 17 (l) and the current If shown in FIG. 17 (k) flow through the parasitic diode 1, the capacitor C0, and the parasitic diode of the switching element Q4, respectively, and the magnetic energy of the resonance choke L is reduced. At the point of discharge, power is supplied to the discharge lamp FL as a load through the path of the switching element Q1, the discharge lamp FL or the resonance capacitor C, the resonance choke L, and the switching element Q4 using the capacitor C0 as a DC power supply. A load current Ila shown in FIG. 17 (l) and a current If shown in FIG.

At time t8, S is calculated from FIGS. 17 (a) and (d).
1 and S4 go low, Q1 and Q4 turn off, S2 and S3 go high, and Q2 and Q3 turn on from FIGS. 17 (b) and (c). Thus, using the magnetic energy stored in the chopper choke L0 and the AC power supply AC as power sources, the AC power supply AC, the chopper choke L0, the diode D1, the capacitor C0, and the switching element Q2
17 (e) flows through the path of the parasitic diode of FIG. Then, when the magnetic energy of the chopper choke L0 is released, the chopper circuit operation stops, and the input current Iin becomes zero.

Also, due to the magnetic energy stored in the resonance choke L, the resonance choke L passes through the parasitic diode of the switching element Q3, the capacitor C0, the parasitic diode of the switching element Q2, the discharge lamp FL or the resonance capacitor C. Thus, the load current Ila shown in FIG. 17 (l) and the current If shown in FIG. 17 (k) flow. When the magnetic energy of the resonance choke L is released, power is supplied to the load through the path of the switching element Q3, the resonance choke L, the discharge lamp FL or the resonance capacitor C, and the switching element Q2 using the capacitor C0 as a power supply. , The load current Ila shown in FIG.
The current If shown in FIG.

At time t9, the same operation as at time t7 is performed.

Next, the circuit operation during the peak period T4 of the power supply voltage Vac in the negative direction of the AC power supply AC will be described with reference to FIG. 17. The circuit operation from time t10 to t12 is basically from time t7 to time t7. Since the circuit operation at time t9 is almost the same and the voltage value of the AC power supply is higher than that at the trough, the values of currents IQ1 and IQ2 handled by switching elements Q1 and Q2 are as shown in FIG.
(F), as shown in (g).

By repeating the operation from time t1 to time t12, a power supply device constituting a discharge lamp lighting device capable of stably lighting the discharge lamp FL and suppressing input current distortion can be realized. In FIG. 17, (h) and (i) indicate currents IQ3 and IQ flowing through the switching elements Q3 and Q4.
4 and FIG. 14 (j) shows the voltage V _BA between B and A in FIG.

In FIG. 15, ID1 and ID2 denote currents flowing through the diodes D1 and D2, respectively, and Vdc denotes a capacitor C
0 indicates a voltage between both ends.

[0035]

By the way, in the conventional example shown in FIG. 12, during one period of the AC power supply AC, an input current flows through each of the switching elements Q1 to Q4, and the stress applied to the chopper dual element is reduced by four. Switch elements Q1 to Q
4 can be allocated, but two chopper chokes L1 and L2 are required, which causes a problem that the number of parts is large and the cost is high.

In the conventional example shown in FIG. 15, in one period of the AC power supply AC, the two switching elements Q1 and Q2 driven by the driving signals S1 and S2 are the two switching elements Q1 and Q2. Stress concentrates on the switching elements Q1 and Q2, and there are problems related to reliability such as the life of the elements and temperature rise.

The present invention has been made in view of the above points,
An object of the present invention is to provide a power supply device capable of improving reliability and miniaturizing while suppressing an increase in the number of elements of a chopper circuit.

[0038]

To achieve the above object, according to the present invention, two series circuits each comprising a pair of switching elements connected in series between both ends of a capacitor serving as a power supply are connected in parallel. In addition, in a full bridge circuit configuration in which a load circuit is connected between a connection point of one pair of switching elements and a connection point of the other pair of switching elements, and diodes are connected to each switching element in anti-parallel, Another pair of diodes connected in series to both ends of an arbitrary switching element among the switching elements is connected in parallel in the same direction as the diode connected in antiparallel to the switching element, and the switching element and the load are connected. Another pair of diodes connected in series to both ends of an adjacent switching element via a circuit Connected in parallel in the same direction as the diode connected in anti-parallel to the switching element, between the midpoint of another pair of diodes connected in series, and the midpoint of another pair of diodes connected in series. A series circuit of an AC power supply and a chopper choke is connected to form a chopper circuit, and the pair of switching elements connected in series are alternately turned on and off so as not to be simultaneously turned on, and a diagonal of a full bridge circuit configuration. By synchronizing the on / off operation of the switching element corresponding to the side, the input current whose input distortion is suppressed by the chopper circuit is drawn, and at the same time, the energy is supplied to the load circuit.

According to a second aspect of the present invention, in the first aspect of the present invention, the frequency and duty of all the switching elements are modulated.

According to a third aspect of the present invention, in the first aspect of the present invention, at least the frequency or duty of each of the switching elements serving also as the chopper is modulated.

According to a fourth aspect of the present invention, in the first aspect, a discharge lamp is provided in the load circuit, and the frequency and the duty of the switching element are modulated.

According to a fifth aspect of the present invention, in the first aspect of the present invention, a discharge lamp is provided in the load circuit, and the duty of each switching element that does not double as the chopper operation is modulated during dimming.

According to a sixth aspect of the present invention, in the first aspect of the present invention, the duty ratio of one of the switching elements connected in series is unbalanced, and the direct current is superimposed on the load circuit.

According to a seventh aspect of the present invention, in any one of the third to sixth aspects, the frequencies of all the switching elements are modulated.

According to the present invention, the circuit configuration as described above allows the amount of current flowing through each switching element to be distributed during one AC power supply cycle without greatly increasing the number of parts. It is possible to improve reliability. In addition, input current distortion is suppressed,
Stable power can be supplied to the load.

Further, by modulating the frequency and duty of the switching element, it is possible to adjust the load output in accordance with the input current, to keep the input power and the output power substantially constant at all times, and to reduce the DC power supply voltage rise. Suppress.

Further, in the power supply device, at least the frequency or duty of each switching element that also serves as a chopper on the power supply side is modulated,
The load output can be adjusted according to the input current, and the input power and the output power can always be kept substantially constant.

Further, by providing a discharge lamp in the load and modulating the frequency and duty of the switching element, it is possible to adjust the output of the discharge lamp in accordance with the input current. A discharge lamp lighting device including an inverter device that is always kept substantially constant can be configured.

Further, by providing a load with a discharge lamp and modulating the duty of the switching element on the non-power supply side which does not also serve as the chopper operation, the DC power supply voltage is increased during the dimming of the discharge lamp, thereby achieving stable lighting.

Further, by making the duty ratio of each of the one or more switching elements connected in series unbalanced, it is possible to superimpose DC on a load.

[0051]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments. (Embodiment 1) FIG. 1 shows a basic configuration of the present embodiment. In the present embodiment, the DC power capacitor C0 is connected in parallel with each series circuit including the switching elements Q1 and Q2 and the switching elements Q3 and Q4, which are connected in series. A resonance load circuit including at least a resonance choke L connected in series, a discharge lamp FL serving as a load, and a resonance capacitor C connected in parallel to the discharge lamp FL is connected between the connection points of the switching elements Q3 and Q4. , A series circuit of diodes D3 and D4 is connected to the switching element Q2, and a series circuit of diodes D1 and D3 is connected in parallel to the switching element Q4, respectively, between the connection point of the diodes D1 and D2 and the connection point of the diodes D3 and D4. A main circuit is formed by connecting a series circuit of a chopper choke L0 and an AC power supply AC, and a switching element Driven controlled by a drive signal S1~S4 control circuit CTR the 1～Q4.

The switching elements Q1 to Q4 are MOSFE
T, each with a parasitic diode (not shown)
Are connected in anti-parallel.

In the power supply device of the present embodiment, the switching element Q2 is also used as a chopper while the current direction of the input current Iin is in the direction of the arrow in FIG. At the same time as switching elements are switched at high frequency to supply power to the capacitor C0, the switching elements Q1 to Q4 switch at high frequency to supply high-frequency power to the discharge lamp FL as a load.

Also, during a period when the current direction of the input current Iin is opposite to the direction of the arrow in FIG. 1 (hereinafter referred to as a negative direction), the switching element Q4 is switched at a high frequency as a chopper switching element to the capacitor C0. At the same time as supplying power, the switching elements Q1 to Q4 switch at a high frequency, so that
L is supplied with high frequency power.

Next, the operation of this embodiment will be described with reference to FIGS. FIG. 2 shows a circuit operation in one cycle of the AC power supply AC, and FIG. 2A shows the AC voltage Va of the AC power supply AC.
3B shows the input current Iin, and FIGS. 3C to 3F show the currents IQ1 to IQ4 flowing through the switching elements Q1 to Q4, respectively. FIG. 3G shows the current If flowing through the resonance capacitor C, and FIG. 3H shows the current Ila flowing through the discharge lamp FL.

Next, the direction of the input current Iin is a positive direction,
The circuit operation during the period T1 of the valley of the AC power supply voltage Vac will be described with reference to FIG.

At time t1, as shown in FIGS. 3 (a) and 3 (d), the drive signals S1 and S4 become low level, the switching elements Q1 and Q4 are turned off, and FIGS. 3 (b) and 3 (c). When the drive signals S2 and S3 go high and the switching elements Q2 and Q3 turn on as shown in FIG.
Using an AC power supply AC as a power supply, a diode D3, a switching element Q2, a diode D2, a chopper choke L0
The input current Iin shown in FIG. Also, the parasitic choke L of the switching element Q3, the capacitor C0, the switching element Q
The load current (lamp current) Ila shown in FIG. 3 (k) and the current If shown in FIG. 3 (j) flow through the parasitic diode 2, the discharge lamp FL or the resonance capacitor C, and the magnetism of the resonance choke L When the energy is released, the switching element Q3,
Power is supplied to the discharge lamp FL as a load through the path of the resonance choke L, the discharge lamp FL or the resonance capacitor C, and the switching element Q2, and the load current Il shown in FIG.
a, a current If shown in FIG.

At time t2, as shown in FIGS. 3A and 3D, the drive signals S1 and S4 go high, turning on the switching elements Q1 and Q4, and FIGS. As shown in the figure, the drive signals S2 and S3 become low level,
When the switching element Q2 and the switching element Q3 are turned off, the AC power supply AC, the diode D3, the parasitic diode of the switching element Q1, the capacitor C0, and the diode D2 are supplied with the magnetic energy accumulated in the chopper choke L0 and the AC power supply AC as power supplies. , The input current Iin shown in FIG.
Flows. Then, when the magnetic energy of the chopper choke L0 is released, the chopper circuit operation stops, and the input current Iin becomes zero.

Also, the discharge energy of the discharge lamp F from the resonance choke L is increased by the magnetic energy stored in the resonance choke L.
L or resonance capacitor C, switching element Q1
The load current Ila shown in FIG. 3K and the current If shown in FIG. 3J respectively flow through the parasitic diode, the capacitor C0, and the parasitic diode of the switching element Q4.

When the magnetic energy of the resonance choke L is released, the load is provided on the path of the switching element Q1, the discharge lamp FL or the resonance capacitor C, the resonance choke L, and the switching element Q4 using the capacitor C0 as a power supply. Power is supplied to the discharge lamp FL, and a load current Ila shown in FIG. 3 (k) and a current If shown in FIG. 3 (j) are output.

At the next time t3, the same operation as at the time t1 is performed.

Next, a description will be given of the circuit operation during the period T2 of the peak portion of the AC power supply voltage Vac when the AC power supply AC is in the positive direction.
Performed by

First, the circuit operation from time t4 to t6 is basically the same as the circuit operation from time t1 to t3, and since the value of the voltage Vac of the AC power supply AC is higher than the valley, the switching element Q1 Current I handled by switching element Q2
Q1 and IQ2 become higher as shown in FIGS. 3 (g) and 3 (f). Thus, in the circuit configuration of the present embodiment, the input current Iin
Is positive, the switching element Q2 serves as a chopper element.

Next, a description will be given of the circuit operation during the period T3 of the valley of the voltage Vac of the AC power supply AC with the direction of the input current Iin being negative, with reference to FIG.

At time t7, as shown in FIGS. 3 (a) and 3 (d), the drive signals S1 and S4 become high level, the switching elements Q1 and Q4 are turned on, and FIGS. 3 (b) and 3 (c). As shown in the figure, the drive signals S2 and S3 become low level,
When the switching elements Q2 and Q3 are turned off, the AC power supply AC, the chopper choke L0, the diode D1, the switching element Q
4. The input current Iin shown in FIG. 3E flows through the path of the diode D4.

Further, the magnetic energy stored in the resonance choke L causes the discharge lamp FL or the resonance capacitor C, the switching element Q
The load current Ila shown in FIG. 3 (k) and the current If shown in FIG. 3 (j) flow through the parasitic diode 1, the capacitor C0, and the parasitic diode of the switching element Q4, and the magnetic energy of the resonance choke L is released. At this time, the switching element Q
1. Power is supplied to the discharge lamp FL as a load through the path of the discharge lamp FL or the resonance capacitor C, the resonance choke L, and the switching element Q4, and the load current I shown in FIG.
la and the current If shown in FIG.

At time t8, as shown in FIGS. 3 (a) and 3 (d), the drive signals S1 and S4 become low level, the switching elements Q1 and Q4 are turned off, and FIGS. 3 (b) and 3 (c). As shown in the figure, the drive signals S2 and S3 become high level,
When the switching elements Q2 and Q3 are turned on, the AC power supply AC, the chopper choke L0, the diode D1, the switching element Q3, and the magnetic energy stored in the chopper choke L0 and the AC power supply AC are used as power supplies.
3 (e) flows through the path of the parasitic diode, the capacitor C0, and the diode D4. Then, when the magnetic energy of the chopper choke L0 is released, the chopper circuit operation stops, and the input current Iin becomes zero.

Also, due to the magnetic energy accumulated in the resonance choke L, the resonance choke L passes through the parasitic diode of the switching element Q3, the capacitor C0, the parasitic diode of the switching element Q2, the discharge lamp FL or the resonance capacitor C. The load current Ila shown in FIG. 3K and the current If shown in FIG. When the magnetic energy of the resonance choke L is released, the switching element Q
3. Power is supplied to the discharge lamp FL as a load through the path of the resonance choke L, the discharge lamp FL or the resonance capacitor C, and the switching element Q2, and the load current I shown in FIG.
la, and a current If shown in FIG.

At the next time t9, the same operation as at time t7 is performed.

Next, a description will be given of the circuit operation during the period T4 in which the AC power supply AC is in the negative direction and the AC power supply voltage Vac is at the peak of FIG.
Performed by

The circuit operation from time t10 to t12 is basically the same as the circuit operation from time t7 to t9 described above. Since the value of the voltage Vac of the AC power supply AC is higher than that of the valley, the switching element Q3 , Q4 handle currents IQ3, I
The value of Q4 increases as shown in FIGS. 3 (i) and 3 (h).

By repeating the operation from time t1 to time t12, power can be supplied to the discharge lamp FL as a load, and at the same time, input current distortion can be suppressed.

In the present embodiment, by changing the diode bridge and adopting the above-described connection method, a period in which the chopper current flows within one cycle of the AC power supply AC is formed in a full bridge without increasing the number of chopper chokes. By distributing the switching elements to the four switching elements Q1 to Q4, a power supply device capable of improving reliability by lowering the temperature of the switching elements Q1 to Q4, reducing the size of the chopper circuit by reducing the number of elements, and reducing cost is realized. Things.

In FIG. 1, ID1 and ID3 are diodes D.
1, I3 indicates a current flowing in the load circuit, and Iz indicates a current flowing in the load circuit. (Embodiment 2) A circuit diagram of this embodiment is shown in FIG. In this embodiment, a transformer T, capacitors C3 and C4, chokes L1 and C2 are provided at both ends of an AC power supply AC in the circuit diagram of the first embodiment.
An input filter F including L2 and L2 is provided.

Since other configurations and circuit operations of the present embodiment are the same as those of the first embodiment, FIG.
The same symbols and numbers as those of the circuit components of No. are attached, and the description is omitted.

According to the present embodiment, the provision of the input filter F makes it possible to make the current Iac of the AC power supply AC substantially sinusoidal.

(Embodiment 3) FIG. 5 shows a circuit configuration of this embodiment. In the present embodiment, a series connection of switching elements Q1 and Q2 and a series connection of switching elements Q3 and Q4 are connected in parallel to a DC power supply capacitor C0, and a connection point of the switching elements Q1 and Q2 is provided. It comprises at least a resonance ingector L connected in series, a preheated discharge lamp FL as a load, and a resonance capacitor C connected between the non-power supply terminals of the discharge lamp FL between the connection point of the switching elements Q3 and Q4. Connected to a resonant load circuit, and diodes D1 and D1 are connected to the switching element Q1.
Is connected to the switching element Q3 by the diode D
3, the series circuit of D4 is connected in parallel, and the main circuit is connected by connecting the AC power supply AC to the chopper choke L0 connected in series between the connection point of the diodes D1 and D2 and the connection point of the diodes D3 and D4. And the switching elements Q1 to Q4 are connected to drive signals S1 to S4 of the control circuit CTR.
4 drives and drives. Switching elements Q1 to Q
Reference numeral 4 denotes a MOSFET, and a parasitic diode (not shown) is connected in anti-parallel.

The power supply of this embodiment uses the AC power supply AC as a power supply, and uses the switching element Q1 as a chopper while the current direction of the input current Iin is the direction of the arrow in FIG. 5 (hereinafter referred to as the positive direction). The high-frequency power is supplied to the discharge lamp FL as a load by switching the switching elements Q1 to Q4 at a high frequency at the same time as switching the switching elements Q1 to Q4 at a high frequency. Also, during a period when the current direction of the input current Iin is opposite to the direction of the arrow in FIG. 5 (hereinafter referred to as a negative direction), the switching element Q3 is switched as a chopper switching element at a high frequency to supply power to the capacitor C0. At the same time as switching element Q1
-Switching element Q4 is switched at high frequency to supply high-frequency power to discharge lamp FL as a load.

Next, the operation of this embodiment will be described with reference to FIGS. FIG. 6 shows a circuit operation in one cycle of the AC power supply AC, and FIG. 6A shows the AC voltage Va of the AC power supply AC.
FIG. 3B shows the input current Iin, FIG. 3C shows the current IQ2 flowing through the switching element Q2, and FIG.
FIG. 4D shows a current IQ1 flowing through the switching element Q1.
(E) shows the current I flowing through the switching element Q4.
FIG. 4F shows the current IQ3 flowing through the switching element Q3, FIG. 4G shows the current If flowing through the resonance capacitor C, and FIG. 4H shows the load current flowing through the discharge lamp FL. Ila is shown.

Next, the direction of the input current Iin is a positive direction,
The circuit operation in the period T1 of the trough of the AC power supply voltage Vac will be described with reference to FIG.

At time t1, the drive signals S1 and S4 go high as shown in FIGS. 7B and 7C, and the switching elements Q1 and Q4 are turned on. As shown in the figure, the drive signals S2 and S3 become low level,
When the switching elements Q2 and Q3 are turned off, the input current Iin shown in FIG. 7E flows through the path of the diode D3, the switching element Q1, the diode D2, and the chopper choke L0 using the AC power supply AC as a power supply. Also, the magnetic energy stored in the resonance choke L causes the resonance choke L to pass through the discharge lamp FL or the resonance capacitor C, the parasitic diode of the switching element Q1, the capacitor C0, and the parasitic diode of the switching element Q4. The load current I shown in FIG.
la, when the current If shown in FIG. 7 (j) flows and the magnetic energy of the resonance choke L is released, the switching element Q1, the discharge lamp FL or the resonance capacitor C, the switching element Q
Power is supplied to the discharge lamp FL, which is a load, through the path of FIG.
The load current Ila shown in (k) and the current I shown in FIG.
Flow f.

At time t2, as shown in FIGS. 7A and 7D, the drive signals S2 and S3 go high, turning on the switching elements Q2 and Q3, and FIGS. 7B and 7C. As shown in the figure, the drive signals S1 and S4 become low level,
When the switching elements Q1 and Q4 are turned off, the AC power source AC, the diode D3, the capacitor C0, the parasitic diode of the switching element Q2, the diode D2, the chopper The input current Iin shown in FIG. 7E flows through the path of the choke L0. Then, when the magnetic energy of the chopper choke L0 is released, the chopper circuit operation stops, and the input current Iin becomes zero.

Also, due to the magnetic energy stored in the resonance choke L, the resonance choke L passes through the parasitic diode of the switching element Q3, the capacitor C0, the parasitic diode of the switching element Q2, the discharge lamp FL or the resonance capacitor C. Thus, a load current Ila shown in FIG. 7 (k) and a current If shown in FIG. 7 (j) flow. When the magnetic energy of the resonance choke L is released, the switching element Q
3. Power is supplied to the discharge lamp FL which is a load through the path of the resonance choke L, the discharge lamp FL or the resonance capacitor C, and the switching element Q2, and the load current I shown in FIG.
la, and outputs the current If to FIG. 7 (j).

At time t3, the same operation as at time t1 is performed.

Next, a description will be given of the circuit operation during the period T2 in which the AC power supply AC is in the positive direction and the AC power supply voltage Vac is at the peak of FIG.
Performed by

The circuit operation from time t4 to t6 is basically the same as the circuit operation from time t1 to t3, and since the voltage value of the AC power supply is higher than the valley, the switching element Q
1 and Q2, the values of the currents IQ1 and IQ2 are as shown in FIG.
As shown in FIG.

Thus, in the circuit configuration of the present embodiment, the switching element Q1 serves as a chopper element while the direction of the input current Iin is positive.

Next, a description will be given of the circuit operation during the period T3 of the valley of the AC power supply voltage Vac with the direction of the input current Iin being negative, with reference to FIG.

First, at time t7, as shown in FIGS. 7 (a) and 7 (d), the drive signals S2 and S3 become high level, and the switching elements Q2 and Q3 are turned on.
As shown in (c), when the drive signals S1 and S4 become low level and the switching elements Q1 and Q4 are turned off, the AC power supply AC
The input current Iin shown in FIG. 7E flows through the path of the chopper choke L0, the diode D1, the switching element Q3, and the diode D4.

The parasitic choke L causes the parasitic diode of the switching element Q3, the capacitor C0, the parasitic diode of the switching element Q2, the discharge lamp FL or the resonant capacitor C to be generated from the resonant choke L by the magnetic energy stored in the resonant choke L. 7 (k) and the current If flows in FIG. 7 (j), respectively.
When the magnetic energy of the resonance choke L is released, the capacitor C0 is used as a DC power source, and the switching element Q3, the resonance choke L, the discharge lamp FL or the discharge lamp which is a load on the path of the resonance capacitor C and the switching element Q2. The power is supplied to the FL, and a load current Ila shown in FIG. 7 (k) and a current If shown in FIG. 7 (j) are output.

At time t8, as shown in FIGS. 7 (a) and 7 (d), the drive signals S2 and S3 go low, turning off the switching elements Q2 and Q3, and FIGS. 7 (b) and 7 (c). As shown in the figure, the drive signals S1 and S4 become high level,
When the switching elements Q1 and Q4 are turned on, the AC power source AC, the chopper choke L0, the diode D1, the capacitor C0, the parasitic diode of the switching element Q4, Diode D4
The input current Iin shown in FIG. Then, when the magnetic energy of the chopper choke L0 is released, the chopper circuit operation stops, and the input current Iin becomes zero.

[0092] Also, the discharge energy of the discharge lamp F from the resonance choke L is increased by the magnetic energy stored in the resonance choke L.
L or resonance capacitor C, switching element Q1
The load current Ila shown in FIG. 7K and the current If shown in FIG. 7J flow through the parasitic diode, the capacitor C0, and the parasitic diode of the switching element Q4. When the magnetic energy of the resonance choke L is released, the switching element Q
1. Power is supplied to the discharge lamp FL as a load through the path of the discharge lamp FL or the resonance capacitor C, the resonance choke L, and the switching element Q4, and the load current I shown in FIG.
la, and a current If shown in FIG.

At the next time t9, the same operation as at the time t7 is performed.

Next, a description will be given of the circuit operation during the period T4 in which the AC power supply AC is in the negative direction and the AC power supply voltage Vac is at the peak of FIG.
Performed by The circuit operation from time t10 to t12 is basically the same as the circuit operation from time t7 to t9, and since the value of the voltage Vac of the AC power supply AC is higher than the valley, the current handled by the switching elements Q3 and Q4 The values of IQ3 and IQ4 increase as shown in FIGS. 7 (h) and 7 (i).

By repeating the operation from time t1 to time t12, it is possible to supply power to the discharge lamp FL as a load and to suppress input current distortion at the same time.

Also in this embodiment, by modifying the diode bridge and adopting the above-described connection method, the period in which the chopper current flows within one cycle of the AC power supply AC is increased without increasing the number of chopper chokes. The switching elements Q1 to Q4 can be distributed, the reliability of the switching elements Q1 to Q4 can be improved due to a temperature drop, and the chopper section can be reduced in size and cost can be reduced by reducing the number of elements. (Embodiment 4) The circuit configuration of the present embodiment is the same as the circuit configuration of Embodiment 1 shown in FIG. 1, and therefore the description of the configuration will be omitted with reference to FIG.

The present embodiment is characterized in that the on-duty of the switching elements Q2 and Q4, which also serves as a chopper operation, controls the input power and simultaneously controls the output of the load circuit. In the present embodiment, the input / output power is controlled by controlling a period in which only the switching element Q1 or Q3 is turned on among the four switching elements Q1 to Q4.

Next, the circuit operation of this embodiment is shown in FIG.
The circuit operation will be described.

In the circuit operation of the present embodiment, the time t in FIG. 8 during which only the switching element Q1 or Q3 of the four switching elements Q1 to Q4 is turned on.
1 to t2, time t3 to t4, time t6 to t7, time t8
The circuit operations other than the periods from t1 to t9, times t11 to t12, times t13 to t14, times t16 to t17, and times t18 to t19 are the same as those in the first embodiment, and thus the description of the circuit operations here is omitted. .

First, a description will be given of the circuit operation during the period Tl of the valley of the AC power supply voltage Vac when the AC power supply AC is in the positive direction.
Performed by

In the period from time t1 to t2, FIG.
As shown in (a) and (d), the drive signals S1 and S4 become low level, and the switching elements Q1 and Q4 are turned off. Also, as shown in FIG. 8B, the driving signal S2 remains at the low level, the switching element Q2 remains off, and as shown in FIG. The element Q3 turns on. Therefore, the switching element Q3 is output from the resonance choke L by the magnetic energy stored in the resonance choke L.
The load current Ila shown in FIG. 8 (l) is supplied via the parasitic diode, the capacitor C0, the parasitic diode of the switching element Q2, the discharge lamp FL or the resonance capacitor C.
The current If shown in FIG. 8K flows.

At time t2, the circuit operation is the same as at time t1 in the description of the circuit operation of the first embodiment.

Next, during the period from time t3 to time t4, the drive signal S1 goes high as shown in FIG. 8A, and the switching element Q1 is turned on.
As shown in (c), the drive signals S2 and S3 go low, and the switching elements Q2 and Q3 are turned off. Further, as shown in FIG. 8D, the switching element Q4 is kept off while the drive signal S4 remains at the low level. As a result, the magnetic energy accumulated in the chopper choke L0 and the AC power supply AC are used as power supplies, and the AC power supply AC, the diode D3, the parasitic diode of the switching element Q1, the capacitor C0, the diode D2, and the chopper choke L0 are used as a path in FIG. ) Flows through the input current Iin. The magnetic energy stored in the resonance choke L causes the discharge from the resonance choke L via the discharge lamp FL or the resonance capacitor C, the parasitic diode of the switching element Q1, the capacitor C0, and the parasitic diode of the switching element Q4. The load current Ila shown in FIG. 8 (1) and the current If shown in FIG. 8 (k) flow.

At time t4, the circuit operation is the same as at time t2 in the description of the circuit operation of the first embodiment.

Next, a description will be given of the circuit operation during the period T2 in which the AC power supply AC is in the positive direction and the AC power supply voltage Vac is at the peak of FIG.
Performed by The circuit operation from time t6 to t10 is basically the same as the circuit operation from time t1 to t5, and since the value of the voltage Vac of the AC power supply AC is higher than the valley, the current handled by the switching elements Q1 and Q2 The values of IQ1 and IQ2 increase as shown in FIGS. 8 (f) and 8 (g).

Thus, in the circuit configuration used in this embodiment,
While the direction of the input current Iin is positive, the switching element Q2
Is a chopper dual-purpose element.

Next, a description will be given of the circuit operation during the period T3 of the valley portion of the AC power supply voltage Vac with the direction of the input current Iin being negative, with reference to FIG.

In the period from time t11 to time t12, FIG.
As shown in FIG. 8A, the drive signal S1 goes high, turning on the switching element Q1.
As shown in FIG. 8C, the drive signals S2 and S3 go low, the switching elements Q2 and Q3 are turned off, and as shown in FIG. Q4 keeps off.

At this time, due to the magnetic energy stored in the resonance choke L, the discharge choke L causes the discharge lamp FL or the resonance capacitor C, the parasitic diode of the switching element Q1, the capacitor C0, and the parasitic diode of the switching element Q4. , A load current Ila shown in FIG. 8 (l) and a current If shown in FIG. 8 (k) flow.

At the next time t12, the circuit operation is the same as at time t7 in the circuit operation explanatory diagram of the first embodiment.

In the period from time t13 to time t14, FIG.
As shown in FIGS. 8A and 8D, the drive signals S1 and S4 go low, the switching elements Q1 and Q4 turn off, and the drive signal S3 goes high as shown in FIG. 8C. , The switching element Q3 is turned on. FIG.
As shown in (b), the switching element Q2 continues to be turned off while the drive signal S2 remains at the low level. Thus, using the magnetic energy stored in the chopper choke L0 and the AC power supply AC as power supplies, the AC power supply AC, the chopper choke L0, the diode D1, the switching element Q3
The input current Iin shown in FIG. 8E flows through the path of the parasitic diode, the capacitor C0, and the diode D4.

Also, due to the magnetic energy stored in the resonance choke L, the resonance choke L passes through the parasitic diode of the switching element Q3, the capacitor C0, the parasitic diode of the switching element Q2, the discharge lamp FL or the resonance capacitor C. Thus, the load current Ila shown in FIG. 8 (l) and the current If shown in FIG. 8 (k) flow.

At time t14, the circuit operation is the same as at time t8 in the description of the circuit operation of the first embodiment.

Next, a description will be given of the circuit operation during the period T4 in which the AC power supply AC is in the negative direction and the AC power supply voltage Vac is at the peak of FIG.
Performed by

The circuit operation during the period from time t16 to t20 is basically the same as the circuit operation during the period from time t11 to t15, and the value of the voltage Vac of the AC power supply AC is higher than that at the valley. The values of the currents IQ3 and IQ4 handled by the element switching elements Q3 and Q4 increase as shown in FIGS. 8 (h) and 8 (i).

Thus, by repeating the operation in the period from time t1 to time t20, it is possible to supply power to the discharge lamp FL as a load and at the same time suppress input current distortion. In the present embodiment, as shown in FIG. 8, by controlling the on-duty of the switching elements Q2 and Q4, which are also used as choppers, the output of the discharge lamp FL connected to the full bridge circuit is controlled, and at the same time, the input power is controlled. For example, by reducing the duty, it is possible to reduce the input power and the load output, and by reducing the input power, it is possible to suppress an increase in the DC power supply voltage.

FIG. 8 (j) shows the voltage V between B and A in FIG.
Indicates _BA . (Embodiment 5) The circuit configuration of the present embodiment is the same as that of the embodiment 1 shown in FIG. 1, and therefore the description of the configuration will be omitted with reference to FIG. FIG. 9 illustrates a circuit operation explanatory diagram of the present embodiment.

This embodiment is characterized in that the output of the load circuit can be controlled by controlling the on-duty of the switching elements Q1 and Q3 which also serve as chopper diode operation. ~
The output power is controlled by controlling such that there is a period during which only the switching element Q2 or the switching element Q4 is turned on in Q4, and controlling the period.

The circuit operation of this embodiment will be described with reference to FIG.

In the circuit operation of this embodiment, of the four switching elements Q1 to Q4, only the switching element Q2 or the switching element Q4 is turned on, and the time t1 to t2, the time t3 to t4, and the time t6 in FIG.
To t7, time t8 to t9, time t11 to t12, time t
13 to t14, time t16 to t17, time t18 to t1
Since the circuit operation other than the period of 9 is the same as that of the first embodiment, the description of the circuit operation here is omitted.

First, the circuit operation during the period T1 of the AC valley with the AC power supply AC in the positive direction will be described with reference to FIG.

In the period between times t1 and t2, FIG.
As shown in (d), the drive signals S1 and S4 become low level, and the switching elements Q1 and Q4 are turned off. Further, as shown in FIG. 9C, the drive signal S3 remains at the low level, and the switching element Q3 remains off. Further, as shown in FIG. 9B, the drive signal S2 goes high, and the switching element Q2 turns on.

Thus, the parasitic energy of the switching element Q3, the capacitor C0, the parasitic diode of the switching element Q2, the discharge lamp FL or the resonance capacitor C is output from the resonance choke L by the magnetic energy stored in the resonance choke L. 9 through FIG.
The load current Ila shown in (l) and the current I shown in FIG.
f flows. Further, using the AC power supply AC as a power supply, an input current Iin shown in FIG. 9E flows through a path of the diode D3, the switching element Q2, the diode D2, and the chopper choke L0.

At time t2, the circuit operation is the same as at time t1 in the description of the circuit operation of the first embodiment.

During the period from time t3 to time t4, the driving signal S4 goes high as shown in FIG. 9D, turning on the switching element Q4, and driving as shown in FIGS. 9B and 9C. The signals S2 and S3 become low level, and the switching element Q2 and the switching element Q3 are turned off. In addition, as shown in FIG.
Remains at the low level, and the switching element Q1 continues to be turned off. Thereby, the resonance choke L and the discharge lamp FL are generated by the magnetic energy stored in the resonance choke L.
Alternatively, a resonance capacitor, a parasitic diode of the switching element Q1, a capacitor C0, a switching element Q4
A load current Ila shown in FIG. 9 (l) and a current If shown in FIG. 9 (k) flow through the parasitic diode path. Further, from the magnetic energy of the chopper choke L0 and the AC power supply AC, the AC power supply AC, the diode D3, the parasitic diode of the switching element Q1, the capacitor C0, the diode D
2. The input current Iin shown in FIG. 9E flows through the path of the chopper choke L0.

At time t4, the circuit operation is the same as at time t2 in the circuit operation explanatory diagram of the first embodiment.

At time t5, the same operation as at time t1 is performed.

Next, a description will be given of the circuit operation in the period T2 in which the AC power supply AC is in the positive direction and the AC power supply voltage Vac is at the peak of FIG.
Performed by

The circuit operation during the period from time t6 to t10 is basically the same as the circuit operation from time t1 to t5, and the value of the voltage Vac of the AC power supply AC is higher than that of the valley.
Currents IQ1, IQ2 handled by switching elements Q1, Q2
Becomes higher as shown in FIGS. 9 (f) and 9 (g). Thus, in the circuit configuration used in the present embodiment, the switching element Q2 functions as a chopper element while the direction of the input current Iin is positive.

Next, a description will be given of the circuit operation during the period T3 of the valley portion of the AC power supply voltage Vac when the direction of the input current Iin is negative, with reference to FIG.

In the period from time t11 to time t12, FIG.
As shown in FIG. 9D, the drive signal S4 goes high, turning on the switching element Q4, and FIG.
As shown in (c), the drive signals S2 and S3 go low, and the switching elements Q2 and Q3 are turned off. Further, as shown in FIG. 9A, the drive signal S1 remains at the low level, and the switching element Q1 is kept off.

At this time, due to the magnetic energy accumulated in the resonance choke L, the discharge choke L causes the discharge lamp FL or the resonance capacitor C, the parasitic diode of the switching element Q1, the capacitor C0, and the parasitic diode of the switching element Q4. , A load current Ila shown in FIG. 9 (l) and a current If shown in FIG. 9 (k) flow.

Using the AC power supply AC as a power supply, an input current Iin shown in FIG. 9E flows through the path of the AC power supply AC, the resonance choke L0, the diode D1, the switching element Q4, and the diode D4.

At time t12, the circuit operation is the same as at time t7 in the description of the circuit operation of the first embodiment.

In the period from time t13 to t14, FIG.
As shown in FIGS. 9A and 9D, the drive signals S1 and S4 go low, the switching elements Q1 and Q4 turn off, and the drive signal S2 goes high as shown in FIG. 9B. , The switching element Q2 is turned on. FIG.
As shown in (c), the drive signal S3 remains at the low level, and the switching element Q3 continues to be turned off. Thus, using the magnetic energy stored in the chopper choke L0 and the AC power supply AC as power sources, the AC power supply AC, the chopper choke L0, the diode D1, the switching element Q
3 parasitic diode, capacitor C0, diode D4
The input current Iin shown in FIG.

The resonance choke L causes the magnetic energy stored in the resonance choke L to pass through the parasitic diode of the switching element Q3, the capacitor C0, the parasitic diode of the switching element Q2, the discharge lamp FL or the resonance capacitor C. Thus, the load current Ila shown in FIG. 9 (l) and the current If shown in FIG. 9 (k) flow.

At time t14, the circuit operation is the same as at time t8 in the description of the circuit operation of the first embodiment.

At time t15, the same operation as at time t10 described above is performed.

Next, a description will be given of the circuit operation during the period T4 in which the AC power supply AC is in the negative direction and the AC power supply voltage Vac is at the peak of FIG.
Performed by

The circuit operation during the period from time t16 to t20 is basically the same as the circuit operation during the period from time t11 to t15, and the voltage value of the AC power supply is higher than the valley portion.
Currents IQ3, IQ4 handled by switching elements Q3, Q4
Becomes higher as shown in FIGS. 9 (h) and 9 (i).

By repeating the operation from time t1 to time t20, power can be supplied to the discharge lamp FL, and at the same time, input current distortion can be suppressed.

In the present embodiment, as shown in FIG. 9, the output of the discharge lamp FL connected to the full bridge circuit is controlled by controlling the on-duty of the switching elements Q1 and Q3 also serving as a chopper diode. Control.

From these operations, the duty of the switching elements Q1 and Q3 is reduced, for example, to reduce the output. At this time, the duty of the chopper switching device Q2, Q4 does not change, so that the amount of input electric power does not change, and as a result, the DC power supply voltage can be increased.

Here, as in the present embodiment, the load is changed to the discharge lamp F.
When L is set, the DC power supply voltage at the time of dimming can be increased when the discharge lamp is dimmed by the above control method. As a result, stable lighting can be performed at the time of dimming.

FIG. 9 (j) shows the voltage V between B and A in FIG.
Indicates _BA . (Embodiment 6) The circuit configuration of the present embodiment is the same as the circuit diagram of Embodiment 1 shown in FIG. 1, and therefore the description of the configuration will be omitted with reference to FIG. FIG. 10 is a circuit operation explanatory diagram of the present embodiment.

In the present embodiment, the output of the discharge lamp FL, which is a load connected to the full bridge circuit, is reduced by reducing the on-duty of any one of the switching elements Q1 to Q4 formed of the full bridge circuit. The DC voltage is superimposed on the output of the load circuit by controlling the on-duty of the switching element Q2 which also serves as a chopper operation.

The circuit operation of this embodiment will be described with reference to FIG.

In the circuit operation of the present embodiment, of the four switching elements Q1 to Q4, only the switching element Q3 is turned on during the period from time t2 to time t2 in FIG.
3, time t6 to t7, time t11 to t12, time t15
The circuit operation other than the period from t16 to t16 is the same as that of the first embodiment, and thus the circuit operation is omitted here.

First, during the period from time t2 to t3, FIG.
While the drive signals S1 and S4 remain at the low level as shown in FIGS. 0 (a) and (d), the switching elements Q1 and Q4 continue to be turned off, and the drive signal S3 becomes the high level as shown in FIG. The switching element Q3 continues to be turned on.
Further, as shown in FIG. 10B, the drive signal S2 becomes low level, and the switching element Q2 is turned off.

As a result, the magnetic energy stored in the chopper choke L0 and the AC power supply AC are used as power supplies, and the AC power supply AC, the diode D3, the parasitic diode of the switching element Q1, the capacitor C0, the diode D2, and the chopper choke L0 are used as a diagram. An input current Iin shown in FIG. In addition, the magnetic energy stored in the resonance choke L causes the resonance choke L to
10 (l) via the discharge lamp FL or the resonance capacitor C, the parasitic diode of the switching element Q1, the capacitor C0, and the parasitic diode of the switching element Q4.
And the current If shown in FIG. 10 (k) flows.

At time t3, the circuit operation is the same as at time t2 in the first embodiment, and at time t4, the circuit operation is the same as at time t1.

Next, a description will be given of the circuit operation during the period T2 in which the AC power supply AC is in the positive direction and the AC power supply voltage Vac is at the peak of FIG.
Perform with 0. The circuit operation during the period from time t5 to t8 is
Basically, the operation is substantially the same as the circuit operation during the period from time t1 to t4, and since the value of the voltage Vac of the AC power supply AC is higher than the trough, the current IQ handled by the switching elements Q1 and Q2 is
The values of IQ1 and IQ2 become higher as shown in FIGS.

Next, a description will be given of the circuit operation during the period T3 of the valley portion of the AC power supply voltage Vac when the direction of the input current Iin is negative, with reference to FIG.

In the period from time t11 to time t12, FIG.
As shown in FIGS. 10A and 10D, while the drive signals S1 and S4 remain at the low level, the switching elements Q1 and Q4 continue to be turned off, and the drive signal S3 remains at the high level as shown in FIG. , The switching element Q3 keeps on. Further, as shown in FIG. 10B, the drive signal S2 becomes low level, and the switching element Q2 is turned off. Thereby, the magnetic energy stored in the resonance choke L passes through the resonance choke L, the discharge lamp FL or the resonance capacitor C, the parasitic diode of the switching element Q1, the capacitor C0, and the parasitic diode of the switching element Q4. The load current Ila shown in FIG.
A current If shown in FIG. 10K flows.

At time t12, the same operation as at time t9 described above is performed.

Next, a description will be given of the circuit operation in the period T4 in which the AC power supply AC is in the negative direction and the AC power supply voltage Vac is at the peak of FIG.
Perform with 0.

The circuit operation during the period from time t13 to t16 is basically the same as the circuit operation during the period from time t9 to t12, and since the value of the voltage Vac of the AC power supply AC is higher than that of the valley, the switching operation is performed. Current IQ handled by elements Q3 and Q4
3 and IQ4 become higher as shown in FIGS. 10 (i) and 10 (j).

By repeating the operation in the period from time t1 to time t16, it is possible to supply power to the discharge lamp FL as a load and to suppress input current distortion.

In this embodiment, as shown in FIG. 10, by reducing the on-duty of any one switching element, it is possible to superimpose a DC voltage on the output of the discharge lamp FL connected to the full bridge circuit. I do. Accordingly, when the discharge lamp FL is connected to the load, it is possible to superimpose a DC voltage on the discharge lamp FL at the time of dimming, thereby enabling stable lighting.

FIG. 10 (j) shows the voltage V between B and A in FIG.
Indicates _BA . (Embodiment 7) The circuit configuration of the present embodiment is the same as that of the embodiment 1 shown in FIG. 1, and therefore the description of the configuration will be omitted with reference to FIG. FIG. 11 is a circuit operation explanatory diagram of the present embodiment.

In the present embodiment, the load is controlled by controlling the on-duty of the chopper dual-purpose element only during the period in which the chopper dual-purpose switching element of the full-bridge circuit switching elements Q1 to Q4 operates. When the output of the discharge lamp FL is reduced, a DC voltage is superimposed on the output of the discharge lamp FL connected to the full bridge circuit, and at the same time, an increase in the DC power supply voltage can be suppressed.

Next, the circuit operation of this embodiment will be described with reference to FIG.
A description will be given starting with 1.

In the circuit operation of the present embodiment, the duty of the chopper-operated element is modulated only when the chopper-operated switching elements Q2 and Q4 are performing the chopper operation. Time t2 to t3, time t6 to t7, and time t6 in FIG. t1
The circuit operation other than the period from 0 to t11 and the time from t14 to t15 is the same as that of the first embodiment, and the circuit operation from the time t1 to t8 is the same as that of the sixth embodiment. According to the circuit operation explanatory diagram of FIG.
0 to t11 and time t14 to t15.

In the period from time t10 to time t11, FIG.
As shown in FIGS. 11B and 11C, while the drive signals S2 and S3 remain at the low level, the switching elements Q2 and Q3 continue to be turned off, and the drive signal S1 remains at the high level as shown in FIG. the switching element Q1 is kept oN in and drive signal S4 as shown in FIG. 11 (d) is a low level <br/> Tsu name, the switching element Q4 is turned off.

Thus, using the magnetic energy stored in the chopper choke L0 and the AC power supply AC as power sources, the AC power supply AC, the chopper choke L0, the diode D1,
Parasitic diode of switching element Q3, capacitor C
0, the input current Iin shown in FIG. 11E flows through the path of the diode D4. In addition, the magnetic energy stored in the resonance choke L causes the resonance choke L to
Parasitic diode of switching element Q3, capacitor C
0, parasitic diode of switching element Q2, discharge lamp F
A load current Ila shown in FIG. 11 (l) and a current If shown in FIG. 11 (k) flow through L or the resonance capacitor C.

At time t11, the same operation as at time t9 is performed.

Next, when the AC power supply AC is in the negative direction, the circuit operation during the period from time t13 to t16 in the peak period T4 of the AC power supply voltage Vac is basically the same as the circuit operation during the period from time t9 to t12. Since the value of the voltage Vac of the AC power supply AC is higher than that of the valley, the switching element Q3
The values of the currents IQ3 and IQ4 handled by Q4 are as shown in FIG.
It becomes higher as shown in (j).

By repeating the operation from time t1 to time t16, the power supply apparatus can supply power to the load and simultaneously suppress input current distortion.

In the present embodiment, as shown in FIG. 11, the on-duty of the switching element, which is also used as a chopper, is reduced only during the period in which the chopper also operates, so that the switching element is connected to a full bridge circuit. DC voltage is superimposed on the output of the load discharge lamp FL, and an increase in the DC power supply voltage can be suppressed. Thereby, when the discharge lamp FL is connected to the load, it is possible to suppress a rise in the DC power supply voltage at the time of dimming and to superimpose a DC voltage on the discharge lamp FL to thereby enable stable lighting.

FIGS. 11F and 11G show currents IQ1 and IQ2 of switching elements Q1 and Q2, respectively.
(K) shows the voltage V _BA between points B and A in FIG.

(Embodiment 8) In this embodiment, the output of the load can be controlled by modulating the frequency and duty of all the switching elements Q1 and Q4 in the circuit configuration of Embodiment 1 shown in FIG. It is what it was.

At this time, assuming that the load is the discharge lamp FL, lighting during dimming is enabled by the above control method.

(Embodiment 9) In the ninth embodiment, when the discharge lamp FL is used as the load in the circuit configuration of the first embodiment shown in FIG.
1 and Q4 are modulated with respect to the frequency and on-duty to supply a sufficient preheating current to the discharge lamp FL. Thereafter, at the time of starting, the frequency and the on-duty of the switching elements Q1 and Q4 are modulated and the discharge lamp FL is modulated. It is designed to start lighting.

[0174]

According to the first aspect of the present invention, two series circuits each including a pair of switching elements connected in series between both ends of a capacitor serving as a power supply are connected in parallel, and a connection point of one of the pair of switching elements is connected. In a full bridge circuit configuration in which a load circuit is connected between the switching element and a connection point of the other pair of switching elements, and a diode is connected to each switching element in anti-parallel, both ends of an arbitrary switching element of the switching elements Another pair of diodes connected in series to the switching element is connected in parallel in the same direction as the diode connected in antiparallel to the switching element, and both ends of the switching element adjacent to the switching element via the load circuit. The other pair of diodes connected in series is connected in anti-parallel to the switching element. A series circuit of an AC power supply and a chopper choke is connected between the midpoint of another pair of diodes connected in series in the same direction as the diode, and the other pair of diodes connected in series. A chopper circuit to alternately turn on and off the pair of switching elements connected in series so as not to be turned on at the same time, and synchronize on / off operations of switching elements corresponding to diagonal sides of a full bridge circuit configuration. Thus, the input current, which suppresses input distortion suppression by the chopper circuit, is drawn, and at the same time, energy is supplied to the load circuit. Therefore, it is possible to distribute the chopper current to each switching element while suppressing an increase in the number of chopper circuit elements. Therefore, the stress of each switching element can be reduced, and the reliability and size can be improved. Next, also there is an effect that it is possible to supply stable power to the load circuit.

According to a second aspect of the present invention, in the first aspect of the present invention, since the frequencies and the duties of all the switching elements are modulated, the load output can be adjusted in accordance with the input current. There is an effect that the output power can always be kept substantially constant.

According to the third aspect of the present invention, at least the frequency or duty of each switching element also serving as the chopper is modulated in the first aspect of the invention, so that the load output can be adjusted according to the input current. Thus, there is an effect that the input power and the output power can always be kept substantially constant.

According to a fourth aspect of the present invention, in the first aspect of the present invention, a discharge lamp is provided in the load circuit, and the frequency and duty of the switching element are modulated, so that the output of the discharge lamp is adjusted according to the input current. This is advantageous in that a discharge lamp lighting device including an inverter device that always keeps input power and output power substantially constant can be configured.

According to a fifth aspect of the present invention, in the first aspect of the present invention, a discharge lamp is provided in the load circuit, and the duty of each switching element that does not double as the chopper operation at the time of dimming is modulated to increase the DC power supply voltage. Therefore, there is an effect that a discharge lamp lighting device capable of stably lighting the discharge lamp even at the time of dimming can be realized.

According to the invention of claim 6, in the invention of claim 1, since the duty ratio of each of the switching elements connected in series is unbalanced, there is an effect that DC can be superimposed on the load circuit.

In the invention of claim 7, since the frequencies of all the switching elements are modulated in the invention of claims 3 to 6, there is an effect that finer control is possible.

[Brief description of the drawings]

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

FIG. 2 is a waveform chart for explaining a circuit operation according to the first embodiment of the present invention.

FIG. 3 is a waveform diagram for explaining a circuit operation of the above.

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

FIG. 5 is a circuit diagram according to a third embodiment of the present invention.

FIG. 6 is a waveform diagram for explaining a circuit operation of the above.

FIG. 7 is a waveform diagram for explaining a circuit operation of the above.

FIG. 8 is a waveform chart for explaining a circuit operation according to a fourth embodiment of the present invention.

FIG. 9 is a waveform chart for explaining a circuit operation according to the fifth embodiment of the present invention.

FIG. 10 is a waveform chart for explaining a circuit operation according to the sixth embodiment of the present invention.

FIG. 11 is a waveform chart for explaining a circuit operation according to a seventh embodiment of the present invention.

FIG. 12 is a circuit diagram of one conventional example.

FIG. 13 is a waveform diagram for explaining a circuit operation of the above.

FIG. 14 is a waveform diagram for explaining a circuit operation of the above.

FIG. 15 is a circuit diagram of another conventional example.

FIG. 16 is a waveform chart for explaining the circuit operation of the above.

FIG. 17 is a waveform chart for explaining the circuit operation of the above.

[Explanation of symbols]

 FL Discharge lamp D1 to D4 Diode Q1 to Q4 Switching element AC AC power supply L0 Chopper choke C Resonant capacitor L Resonant choke C0 Capacitor CTR Control circuit S1 to S4 Drive signal Iin Input current Ila Load current If current

Claims (7)

[Claims] 1. A series connection circuit comprising a pair of switching elements connected in series between both ends of a capacitor serving as a power supply, and a connection point between one pair of switching elements and another pair of switching elements. In a full-bridge circuit configuration in which a load circuit is connected between the switching elements and a diode is connected in anti-parallel to each switching element, another pair connected in series to both ends of an arbitrary switching element among the switching elements. Is connected in parallel in the same direction as the diode connected in anti-parallel to the switching element, and another pair connected in series to both ends of an adjacent switching element via the switching element and the load circuit. In the same direction as the diode connected in anti-parallel to the switching element. A series circuit of an AC power supply and a chopper choke is connected between a midpoint of another pair of diodes connected in series and the other pair of diodes connected in series to form a chopper circuit. The pair of switching elements connected in series with each other are alternately turned on and off so as not to be simultaneously turned on, and the on / off operations of the switching elements corresponding to the diagonal sides of the full bridge circuit configuration are synchronized, whereby the chopper circuit is turned on. A power supply device for drawing in an input current in which input distortion is suppressed and simultaneously supplying energy to a load circuit. 2. The power supply device according to claim 1, wherein frequencies and duties of all the switching elements are modulated. 3. The power supply device according to claim 1, wherein at least the frequency or duty of each of the switching elements serving also as the chopper is modulated. 4. The power supply device according to claim 1, wherein a discharge lamp is provided in the load circuit, and a frequency and a duty of the switching element are modulated. 5. The power supply device according to claim 1, wherein a discharge lamp is provided in the load circuit, and the duty of each switching element that does not double as the chopper operation is modulated at the time of dimming. 6. The power supply device according to claim 1, wherein the duty ratio of one of the switching elements connected in series is unbalanced, and the direct current is superimposed on the load circuit. 7. The power supply device according to claim 3, wherein the frequencies of all the switching elements are modulated.