JPH01252175A - Inverter device - Google Patents

Abstract

PURPOSE:To obtain a high input power factor by providing a rectifier circuit, a voltage resonance type inverter circuit and a coupling capacitor circuit. CONSTITUTION:An inverter circuit is composed of a rectifier circuit 1, a smoothing capacitor 2, a resonance circuit consisting of a switching transistor(Tr) Q4, a capacitor C4 and an inductor L2 and an inverter circuit having an inductor L3. One output from the rectifier circuit 1 is connected at one end of the smoothing capacitor 2 through the series circuit of an inductor L1 and a diode D4, and the other output is connected to the other end of, the smoothing capacitor 2. A capacitor C3 is connected between a collector for the Tr Q4 and the inductor L1. Consequently, the inverter circuit is turned ON-OFF at a high frequency, and high-frequency voltage is generated in the resonance circuit. Accordingly, the high-frequency voltage is applied to a node between the inductor L1 and the diode D4 through the coupling capacitor C3, thus turning the diode D4 ON-OFF at a high frequency.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an inverter device, which is used, for example, to light a discharge lamp, and which has a simple circuit configuration, a high input power factor, and a high frequency inverter device with little low frequency ripple. The present invention relates to an inverter device capable of outputting voltage.

[Prior Art] Conventionally, as an inverter device used, for example, in a discharge lamp lighting device, one shown in FIG. 11, for example, is known. The device shown in the figure includes a rectifier circuit 1 consisting of a diode bridge DB that rectifies commercial power AC, a smoothing capacitor 2, and a choke coil CH1, a diode D3, a transistor connected between the rectifier circuit 1 and the smoothing capacitor 2, Q3, a chopper circuit 3 consisting of a switching control circuit CT1, and an inverter circuit 4.

The discharge lamp 5 is connected to the output of the inverter circuit 4 via a choke coil CH2. That is, in the device shown in FIG. 11, the input power factor can be improved by connecting the output of the rectifier circuit 1 to the smoothing capacitor 2 via the chopper circuit 3 with a good power factor and supplying power to the inverter circuit 4. Was.

However, in such a conventional example, there is a problem that the circuit configuration becomes complicated and the device becomes expensive. For this reason, an inverter device shown in FIG. 12 has been proposed as an inverter device that improves the input power factor with a simple configuration. That is, in the circuit shown in FIG. 12, the positive output end of the rectifier circuit 1 is connected to one end a of the inverter circuit 4 via the choke coil CH1, and the inverter circuit 4 is turned on and off alternately. A transistor Q1. It is formed as a half-bridge circuit consisting of a series circuit of Q2, diodes Di and D2 connected in parallel to each transistor Ql and Q2, and a series circuit of capacitors C1 and C2.

Also, the transistor Q1. A series circuit of a choke coil CH2 as a stabilizing element and a discharge lamp 5 is connected between the connection point (point b) of Q2 and the connection point of capacitors C1 and C2, and the negative output end of the rectifier circuit 1 is connected to the transistor Q1.
It is connected to the connection point (point b) of Q2.

Note that the transistor Q1 of the inverter circuit 4. The switching control circuit CT2 which turns Q2 on and off alternately is constituted by, for example, an oscillator such as an astable multivibrator.

In the circuit of FIG. 12, the switching control circuit CT2
When the transistor Q1 is turned on by The voltage of the capacitor CI is divided by C2 and applied to the series circuit of the choke coil CH2, which is a stabilizing element, and the discharge lamp 5. At this time, the current flowing through the discharge lamp 5 flows through the transistor Q1. Therefore, a combined current of the current for storing electromagnetic energy in the choke coil CHI from the commercial power supply AC and the current flowing through the discharge lamp 5 flows through the transistor Q1. Next, transistor Q1
turns off and transistor Q2 turns on, the electromagnetic energy accumulated in choke coil CHI is transferred to commercial power supply AC1 diode bridge DB and choke coil CH1.
, the smoothing capacitor 2, and the diode D2 to charge the smoothing capacitor 2. On the other hand, the voltage of the smoothing capacitor 2 is divided by the capacitors C1 and C2, the voltage of the capacitor C2 is applied to the choke coil CH2 and the discharge lamp 5, and the voltage is supplied to the discharge lamp 5. In this case, transistors Ql, Q2, diodes Di, D2,
Chiyoke coil CH2, discharge lamp 5 and capacitor C1
A half-bridge inverter circuit is formed by C2, and a step-up chopper circuit is formed by choke coil CH1, transistor Q1, smoothing capacitor 2, and diode D2. Therefore, by sharing transistor Q1 and diode D2 in both circuits, the circuit is Configuration becomes easier. That is, according to the circuit shown in FIG. 12, the input power factor can be improved with a relatively simple circuit configuration.

[The problem that the invention attempts to solve, li! However, in the inverter device shown in Fig. 12, the voltage across the smoothing capacitor is approximately twice the peak value of the AC input voltage, which inconveniently necessitates extremely high voltage resistance switching elements for the inverter circuit. there were. In particular, when the AC input voltage is 100V, but when the AC input voltage is 200V, an element with a higher withstand voltage is required, but there is also the disadvantage that such a switching element is difficult to obtain.

SUMMARY OF THE INVENTION In view of the above-mentioned problems with conventional devices, an object of the present invention is to provide an inverter device with a high input power factor through a simple circuit configuration, and to use relatively low breakdown voltage switching elements. The purpose is to do so.

A further object of the present invention is to apply a DC voltage that is almost completely smoothed and has little low frequency ripple to an inverter circuit.

[Means for Solving the Problems] An inverter device according to a first aspect of the present invention includes a rectifier circuit that rectifies an AC power supply, a smoothing capacitor, and at least one
a voltage resonant inverter circuit having two switching elements and a resonant circuit connected to the switching element; a series circuit of an inductance element and a diode connected between the output of the rectifier circuit and the smoothing capacitor;
and a coupling capacitor circuit that supplies the output of the resonant circuit to a connection point between the inductance element and the diode of the series circuit. This coupling capacitor circuit may be a capacitor only, or may be a series circuit of a capacitor and an impedance element.

Further, an inverter device according to a second aspect includes an inverter circuit including a rectifier circuit that rectifies an AC power supply, a smoothing capacitor, and a switching element, an inductance element connected between the output of the rectifier circuit and the smoothing capacitor, and A series circuit of diodes, an inductance element through which a high-frequency current of the inverter circuit flows, and a coupling capacitor that supplies the output of a secondary winding or intermediate tap provided in the inductance element to a connection point between the inductance element and the diode of the series circuit. Equipped with a circuit.

Furthermore, an inverter device according to a third aspect includes an inverter circuit having a rectifier circuit that rectifies a human-powered AC power source, a smoothing capacitor, and a switching element, and an inductance element through which a high-frequency current of the inverter circuit flows, A high frequency voltage generated in the element is applied between the rectifier circuit and the smoothing capacitor.

Furthermore, an inverter device according to a fourth aspect includes an inverter circuit including a rectifier circuit for rectifying input AC power, a smoothing capacitor, and a switching element, an inductance element connected between the output of the rectifier circuit and the smoothing capacitor. and a series circuit of a plurality of capacitors connected in parallel with a load to which the output of the inverter circuit is supplied, and one connection point between the plurality of capacitors, an inductance element of the series circuit, and a diode. a coupling capacitor circuit that connects the connection point of
It is characterized by comprising the following.

[Function] In the inverter device according to the first aspect described above, the switching elements constituting the inverter circuit are
It is turned on and off at a high frequency of 0KHz. A high frequency voltage is generated in the resonant circuit by this on/off. This high frequency voltage is applied to the connection point of the pixel element in the series circuit of the inductance element and the diode via the coupling capacitor circuit. As a result, the diodes in this series circuit turn on and off at high frequency, and as a result, the AC input current flows even when the instantaneous value of the AC voltage is low or other than near the peak value, and the effective current decreases with respect to the average current. This makes it possible to increase the input power factor.

Further, in the second aspect, the inverter device generates a high frequency voltage by turning on and off the switching element, and a high frequency current flows through the inductance element. The high frequency voltage generated in the secondary coil or intermediate tap of this inductance element is supplied via the coupling capacitor circuit to the connection point between the inductance element and the diode connected to the output of the rectifier circuit. As a result, the diode connected to the inductance element is turned on and off at high frequency, and the input power factor is improved as described above.

Furthermore, in the third aspect, a high frequency voltage generated in response to on/off of the switching element is applied between the rectifier circuit and the smoothing capacitor. This results in
The diodes of the rectifier circuit are switched at high frequency. Therefore, the AC input current flows even when the instantaneous value of the AC voltage is low or near the peak value, and the effective current decreases with respect to the average current, making it possible to increase the input power factor.

Further, in the fourth aspect, the inverter device generates a high frequency voltage by turning on and off the switching element, and this high frequency voltage is supplied to the load. Then, the high frequency voltage applied to this load is divided by the plurality of capacitors and supplied to the connection point between the inductance element and the diode connected to the output of the rectifier circuit, and the input power factor is improved in the same way as described above. Ru.

[Example code] Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 shows the configuration of an inverter device according to an embodiment of the present invention. The device in the figure includes a rectifier circuit 1 composed of a diode bridge etc. for rectifying commercial power AC, a smoothing capacitor 2, a switching transistor Q4, a resonant circuit composed of a capacitor C4 and an inductor L2, and an inductor L3. It is equipped with an inverter circuit.

Further, one output of the rectifier circuit 1, for example, the positive output, is connected to one end of the smoothing capacitor 2 via a series circuit of an inductor L1 and a diode D4, and the other output of the rectifier circuit 1 is connected to the other end of the smoothing capacitor 2. It is connected. Further, a capacitor C3 is connected between the collector of the transistor Q4 constituting the inverter circuit and the connection point between the inductor L1 and the diode D4. Note that a preheating capacitor C5 is connected between both terminals of the discharge lamp 5.

In the inverter device shown in FIG. 1, commercial power AC is rectified by a rectifier circuit 1 and applied to a smoothing capacitor 2 via a series circuit of an inductor L1 and a diode D4. On the other hand, the base of the switch notching transistor Q4 is connected to a switch notching control circuit (not shown) using, for example, several tens of
A switching signal with a frequency of KHz is applied. Incidentally, the switching control circuit can be constituted by, for example, an astable multivibrator. In this way, when the switching transistor Q4 is turned on and off, a high frequency AC voltage is generated across the resonant circuit connected to the collector of the transistor, and this voltage is applied to the discharge lamp 5 via the current limiting inductor L3. discharge lamp 5
is lit. Note that, as in the conventional case, the discharge lamp 5 is preheated by the capacitor C5 prior to lighting the discharge lamp 5.

In the above operation, the high frequency voltage generated at the collector of the transistor Q4 passes through the capacitor C3 to the connection point between the choke coil L1 and the diode D4, that is, the diode D4.
is applied to the anode of

As a result, the diode D4 is repeatedly turned on and off at a frequency higher than the frequency of the input AC power supply AC.

Therefore, the AC input current has a conduction period even when the instantaneous value of the input AC voltage is low.

That is, the input terminal allows AC voltage to flow even outside the vicinity of the peak value, and the effective current decreases with respect to the average current, making it possible to increase the input power factor.

Next, the operation of the circuit shown in FIG. 1 will be explained in more detail with reference to FIG. In addition, in FIG. 2, the transistor Q
The switching frequency of No. 4 is sufficiently higher than the frequency of the input AC power supply, and therefore the instantaneous value AC of the voltage of the input AC power supply is a constant positive voltage, as shown by the dashed line in FIG. 2(f). Assume that you have When the transistor Q4 is turned on and off at high frequency, its collector-emitter voltage is approximately 0 during the period when the transistor is on, and the voltage between the capacitor C when the transistor is off, as shown in FIG. 2(a).
The waveform is a sinusoidal waveform determined by the characteristics of the resonant circuit between L4 and the inductor L2.

During the period when transistor Q4 is on, diode D4 initially
is cut off, therefore, as shown in the same figure (b), the capacitor C passes from the rectifier circuit 1 through the inductor L1.
Current flows through C3 and charges this capacitor C3. When the capacitor C3 is gradually charged and the anode voltage of the diode D4 rises to a predetermined value or higher, the diode D4 is turned on. Note that the cathode voltage of the diode D4 is a constant DC voltage due to the presence of the smoothing capacitor 2, as shown in FIG. This causes the diode D
4, a current flows from the rectifier circuit 1 through the inductor L1, and this current flows to the smoothing capacitor 2, etc. Further, while the transistor Q4 is on, a current as shown in FIG. 2(b) flows from the smoothing capacitor 2 etc. to the collector of the transistor Q4 via the resonant circuit of the capacitor C4 and the inductor L2.

Next, when transistor Q4 turns off from this state,
The collector current of the transistor Q4 is cut off, and the charge charged in the capacitor C3 flows into the smoothing capacitor 2 via the diode D4.

That is, as shown in FIG. 2(C), the diode D4
A current flows from capacitor C3. Then, when the collector voltage of transistor Q4 passes through the peak value and drops to a predetermined value, current no longer flows through diode D4, and thereafter, the anode voltage of diode D4 also decreases in accordance with the decrease in the collector voltage of transistor Q4. As described above, in the circuit of FIG. 1, when the switching transistor Q4 is on, the capacitor C3 is charged by the output of the rectifier circuit 1, and the transistor Q4
When the capacitor C3 is turned off, the charge stored in the capacitor C3 flows into the smoothing capacitor via the diode D4. In this way, by switching the transistor Q4 at high frequency, even if the instantaneous value of the input AC power source is low, it is possible to flow the input current according to the on/off operation of the transistor Q4, and as described above, the input power factor can be reduced. It becomes possible to increase the

FIG. 3 shows the configuration of an inverter device according to another embodiment of the present invention. The device shown in the figure uses a voltage resonance type inverter circuit like the device shown in FIG. 1, but unlike the inverter circuit shown in FIG. 1, it uses two transistors Q5 and C6. Q6 is turned on alternately to generate a high frequency voltage for lighting the discharge lamp.

In this circuit as well, capacitor C7 of the inverter circuit
A high frequency signal is applied to the anode electrode of the diode D4 from one end of the resonant circuit constituted by the transformer T1 and the transformer T1 via the capacitor c6. Note that the inductor Ll
, L4 are for blocking high frequency current, and inductor L5 is a current limiting choke coil for limiting the current flowing through the discharge lamp 5. In this circuit as well, the diode D
It is clear that 4 is turned on and off by a high frequency signal and operates to have a conduction period even when the instantaneous value of the input AC power source is low, thus improving the input power factor.

FIG. 4 shows the configuration of an inverter device according to still another embodiment of the present invention. In the device shown in the figure, the capacitor C4 of the resonant circuit in the inverter device shown in FIG. 1 is replaced with a series circuit of two capacitors C8 and C9. A high frequency voltage is taken out from the connection point of these capacitors C8 and C9 via capacitor C3 and is applied to the anode of diode D4. The other parts are the same as the apparatus shown in FIG.

In the device shown in FIG. 4, a high frequency voltage similar to that at the collector of transistor Q4 is generated at the connection point between capacitors C8 and C9. Therefore, by feeding back this high frequency voltage to the anode of the diode p4 via the capacitor C3, the diode D4 is turned on and off at high frequency. As a result, the input current becomes continuous and flows even when the instantaneous value of the input power source is low, improving the input power factor. In the circuit of Figure 4, the diode D can be adjusted by adjusting the values of capacitors C8 and C9.
It is possible to change the level of the high frequency voltage applied to the anode of No. 4, and therefore, accurate circuit operating conditions can be easily set.

FIG. 5 shows the configuration of an inverter device according to still another embodiment of the present invention. In the device shown in the figure, a capacitor C10 is inserted between one end of a parallel resonant circuit constituted by a capacitor C4 and an inductor L2 similar to the device shown in FIG. 1 and one electrode of the discharge lamp 5. The other end of the resonant circuit, ie, the collector of the transistor Q4, is connected to the other electrode of the discharge lamp 5 via a choke coil L3, similar to the circuit shown in FIG. And capacitor CIO
A high frequency voltage is applied to the anode of the diode D4 from the electrode side of the discharge lamp 5 connected to the diode D4 via the capacitor C11. The other parts are the same as the apparatus shown in FIG.

In the device shown in FIG. 5, the high frequency voltage generated by turning on and off the transistor Q4 is applied to the discharge lamp 5 via the capacitor C10 and the inductor L3.
is lit. Then, the capacitor C1 of the discharge lamp 5
A high frequency voltage is applied to the anode of the diode D4 from the electrode side connected to 0 through the capacitor C11, and this diode D4 is turned on and off at high frequency. This results in
As described above, it is possible to improve the input power factor. In this circuit, the level of the high frequency signal applied to diode D4 can be adjusted by adjusting the value of capacitor C10, for example. Further, the capacitor CIO can be used together with the inductor L3 or in place of the inductor L3 to limit the current flowing through the discharge lamp 5.

FIG. 6 shows the configuration of an inverter device according to still another embodiment of the present invention. In the device shown in the figure, a transformer T is used instead of the current limiting inductor L3 in the device shown in FIG.
2, and connect the primary coil of this transformer T2 to the discharge lamp 5.
A high frequency voltage is applied from the secondary coil to the anode of the diode D4 via the capacitor C12.

That is, the transformer T2 can be considered to be the inductor L3 in FIG. 1 provided with a secondary coil.

The other parts are the same as the apparatus shown in FIG.

In the device shown in FIG. 6, a high frequency voltage generated by turning on and off the transistor Q4 is applied to the discharge lamp 5 via the primary coil of the transformer T2, and the discharge lamp 5 is turned on. A high frequency voltage is induced in the secondary coil of the transformer T2 by the high frequency current flowing through the primary coil of the transformer T2, and this high frequency voltage is applied to the anode of the diode D4 via the capacitor C12. This results in
Diode D4 is turned on and off at high frequency, making it possible to increase the input power factor in the same manner as described above.

FIG. 7 shows the configuration of an inverter device according to still another embodiment of the present invention. In the device shown in the figure, an inductor L6 in which a center tap is provided in place of the current-limiting inductor L3 in the device shown in FIG.
returns to the anode. The other parts are the same as the apparatus shown in FIG.

In the device shown in FIG. 7, the high frequency signal flowing through the inductor L6 due to the operation of the inverter circuit is extracted from the intermediate tap point and applied to the anode of the diode D4 via the capacitor C13. As a result, the diode D4 is turned on and off at high frequency, and the input power factor is improved in the same manner as described above. Note that the level of the high frequency signal applied to the diode D4 can be appropriately selected by adjusting the position of the center tap of the inductor L6.

FIG. 8 shows the configuration of an inverter device according to still another embodiment of the present invention. The device shown in the figure uses a transformer T3 having a secondary coil in place of the current-limiting inductor L3 in the device shown in FIG. capacitor 2
It is connected between one end of the Further, the series circuit of inductor L1 and diode D4 and capacitor C3 in the circuit of FIG. 1 are not used. That is, the eighth
The illustrated device is configured so that current flows from the positive output terminal of the rectifier circuit 1 to one end of the smoothing capacitor 2 via the secondary coil of the transformer T3. The other parts are the same as those of the apparatus shown in FIG.

In the device shown in FIG. 8, transistor Q4 is turned on and off at high frequency by a switching pulse applied from a control circuit (not shown), and capacitor C4 and inductor L2
A high-frequency voltage is generated across the resonant circuit.

This high frequency voltage is applied to the discharge lamp 5 via the primary coil of the transformer T3, and the discharge lamp 5 is turned on. At this time, the high frequency current flowing from the collector of the transistor Q4 to the primary coil of the transformer T3 causes the
A high frequency current is induced in the next coil, and this high frequency voltage is applied between the positive output terminal of the rectifier circuit 1 and one end of the smoothing capacitor. As a result, the diodes constituting the diode bridge of the rectifier circuit 1 are turned on and off at high frequency.

Therefore, the input current flows continuously even when the instantaneous value of the input AC voltage is low, improving the input power factor. Further, the voltage across the smoothing capacitor 2 becomes a nearly perfect DC voltage, and a sufficiently smoothed voltage is supplied as a power source for the inverter circuit. In addition, as mentioned above, the rectifier circuit 1
Since the diode is turned on and off by the high frequency voltage induced in the secondary coil of the transformer T3, it is desirable to use a high speed diode as the diode. In this way, according to the circuit shown in FIG. 8, it is possible to improve the input power factor with an extremely simple circuit.

FIG. 9 shows the configuration of an inverter device according to still another embodiment of the present invention. The inverter device shown in the figure includes a rectifier circuit 1 for rectifying input AC power, a smoothing capacitor 2, an inductor L7 having an intermediate tap, a switching transistor Q7. The inverter circuit includes diodes D5 and p6 connected in parallel to switching transistors Q8 and switching transistors Q7 and Q8. Switching transistors Q7 and Q8 are connected in series between both terminals of smoothing capacitor 2, and a connection point between these transistors Q7 and Q8, that is, the emitter of transistor Q7 or the collector of transistor Q8, is connected to one end of inductor L7 via capacitor C18. A discharge lamp 5 is connected. The other end of the inductor L7 is connected to one end of the smoothing capacitor 2, such as a positive terminal, and the intermediate tap point of the inductor L7 is connected to the positive output terminal of the rectifier circuit 1. In addition, in FIG. 9, the positive output terminal of the rectifier circuit 1 can also be connected to one end of the inductor L7 that is not connected to the smoothing capacitor 2. Further, it is advantageous if the diode bridge of the rectifier circuit 1 is composed of high-speed diodes.

In the device of FIG. 9, transistors Q7 and Q8
are alternately turned on and off at a high frequency of several tens of KHz, for example, by switching pulses input from a control circuit (not shown). As a result, a high frequency voltage is generated at the connection point between the transistors Q7 and Q8, and this high frequency voltage is applied to the discharge lamp 5 via the capacitor C18, so that the discharge lamp 5 is lit. In this case, since the high frequency current flowing through the discharge lamp 5 also flows through the inductor L7, a high frequency voltage is output from the intermediate tap point of the inductor L7 and applied to the positive output terminal of the rectifier circuit 1. Therefore, the diodes of the rectifier circuit 1 are turned on and off at high frequencies, and the input power factor increases similarly to the device shown in FIG. Further, the DC voltage applied to the inverter circuit is almost completely smoothed, and switching elements constituting the inverter circuit do not require particularly high voltage resistance, and the circuit becomes simple.

FIG. 10 shows the configuration of an inverter device according to still another embodiment of the present invention. The inverter device in the same figure is
In the device shown in the figure, the capacitor C5 for preheating the filament of the discharge lamp 5 is replaced with a series circuit of two capacitors C14 and C15, and a high frequency signal is transmitted from the connection point of these capacitors C14 and C15 to the anode of the diode D4 via the capacitor C16. It is configured to feed back voltage.

The other parts are the same as the apparatus shown in FIG.

In the device shown in FIG. 10, transistor Q4 is turned on and off at high frequency, and a high frequency voltage is generated at the output of the parallel resonant circuit constituted by capacitor C4 and inductor L2. This high frequency voltage is applied to the discharge lamp 5 via the current limiting inductor L3, and the discharge lamp is turned on. In this case, the series circuit of capacitors C14 and C15 functions to flow a preheating current to the filament of the discharge lamp 5 immediately after the power is turned on, but also divides the high frequency voltage applied between the two electrodes of the discharge lamp 5 to Diode D4 through C16
It also serves to apply voltage to the anode of the

As a result, the diode D4 is switched at high frequency, and the human power factor is improved in the same manner as described above. In this manner, the circuit shown in FIG. 10 can increase the input power factor with a simple circuit configuration in which the filament preheating capacitor of the discharge lamp 5 is divided into two capacitors. Also,
Since no extra circuit elements are connected to the current path of the discharge lamp 5, extremely accurate circuit operation can be performed without causing inconveniences such as the lamp going out.

[Effects of the Invention] As described above, according to the present invention, the input power factor of the inverter device can be increased with a simple circuit configuration. Furthermore, since the DC voltage supplied to the inverter circuit is almost completely smoothed, a high frequency voltage with less low frequency ripple is supplied to the discharge lamp.

Furthermore, it is not necessary to use a switching element with a particularly high breakdown voltage, thereby preventing an increase in the price of the device.

[Brief explanation of the drawing]

1 and 3 to 10 are block circuit diagrams each showing a schematic configuration of an inverter device according to an embodiment of the present invention, and FIG. 2 explains the operation of the inverter device of FIG. 1. FIGS. 11 and 12 are block circuit diagrams showing the configuration of a conventional inverter device, respectively. 1: rectifier circuit, 2: smoothing capacitor, 3: chopper circuit, 4: inverter circuit, 5 two discharge lamps, Ql. Q2. ..., Q4:) transistor, DI, D2.・・・
・. D6: Diode, Ll, L2. ..., Ll: inductor, Tl, T2. T3: ) Lance, CI, C2,・
..., C18: Capacitor.

Claims (1)

[Claims] 1. A voltage resonant inverter circuit comprising a rectifier circuit for rectifying input AC power, a smoothing capacitor, at least one switching element, and a resonant circuit connected to the switching element, the output of the rectifier circuit and A series circuit of an inductance element and a diode connected between the smoothing capacitor and a coupling capacitor circuit that supplies the output of the resonant circuit to a connection point of the inductance element and the diode of the series circuit. inverter device. 2. An inverter circuit having a rectifier circuit for rectifying input AC power, a smoothing capacitor, and a switching element; a series circuit of an inductance element and a diode connected between the output of the rectifier circuit and the smoothing capacitor; It is characterized by comprising an inductance element through which a high-frequency current flows, and a coupling capacitor circuit that supplies the output of a secondary winding or intermediate tap provided in the inductance element to a connection point between the inductance element and the diode of the series circuit. inverter device. 3. An inverter circuit having a rectifier circuit for rectifying input AC power, a smoothing capacitor, and a switching element, and an inductance element through which a high-frequency current of the inverter circuit flows, and the high-frequency voltage generated in the inductance element is connected to the rectifier circuit. An inverter device characterized in that a voltage is applied between the smoothing capacitor and the smoothing capacitor. 4. An inverter circuit including a rectifier circuit for rectifying input AC power, a smoothing capacitor, and a switching element; a series circuit of an inductance element and a diode connected between the output of the rectifier circuit and the smoothing capacitor; A series circuit of a plurality of capacitors connected in parallel with a load to which an output is supplied, and a coupling capacitor circuit that connects one connection point between the plurality of capacitors and a connection point of an inductance element and a diode of the series circuit. An inverter device comprising: