JPH0265673A - Inverter apparatus - Google Patents

Abstract

PURPOSE:To match a voltage applied to a drive and control circuit with an input voltage to a control power supply circuit and to make a voltage-matching transformer, etc., unnecessary by providing a rectifier and smoothing circuit obtaining a control power from the oscillating current of an LC series resonance circuit for control power and by setting the circuit constant of said LC series resonance circuit appropriately. CONSTITUTION:In a control power supply circuit A4, when switching elements Q1 and Q2 are respectively ON and OFF after starting, a sine waved oscillating current I1 flows through an LC series resonance circuit KY1 for control power according to the path of DC power E-inductance element L1-capacitor C3. Thus, said control power supply circuit is provided with the LC series resonance circuit KY1 for control power and with a rectifier and smoothing circuit SH1 obtaining said control power from the oscillating current I1 of said LC series resonance circuit KY1 after starting. In this manner, the circuit constant of said LC series resonance circuit KY1 is set appropriately so that it is possible to contrive to match a voltage applied to a drive and control circuit DR with an input voltage to the control power supply circuit A4. Therefore, a voltage- matching transformer and a current limiting resistor can be made unnecessary.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to an impark device that supplies power to a load such as a discharge lamp, and particularly to a drive/control circuit that controls the on/off of a switching element. A. Concerning the supply of power.

[Traditional techniques]

FIG. 9 shows a basic circuit diagram of a conventional first series type impark device. In FIG. 9, a DC power source E is obtained by rectifying and smoothing a commercial power source as it is, or by boosting or stepping down the voltage using a transformer.

Direct current? tiE (A series circuit of switching elements Q,, Q! is connected to E. Switching element Q +
, Q z and the negative side of the DC power source E, a series circuit of an inductance element L+ and capacitors C, , CI is connected. The capacitor C1 is a resonance capacitor, and a load LD is connected in parallel to both ends of the capacitor C1.

Capacitor C! is a capacitor for cutting a DC component to prevent a DC component from being supplied to the load LD+, and two switching elements Q, , Q.

When the on and off duties of the battery are equal, a DC voltage that is half of the power supply voltage E is charged at the rate shown in the figure.

The capacitance value of the DC component cutting capacitor C2 is usually set to be sufficiently larger than the capacitance value of the resonance capacitor C1. Two switching elements Q + , Q
t is its drive/control '4. [g circuit DR alternately turns on and applies a high frequency voltage to the LC series resonant circuit for load consisting of inductance element L1 and capacitor C3.

As a result, an oscillating current flows through the LC series resonant circuit for the load, and the oscillating voltage generated in the resonant capacitor C5 energizes the load LDI.

The inverter device shown in FIG. 9 has a high input voltage (in this case, DC voltage), and this voltage cannot be directly applied to the drive/control circuit DR.
A control power source 4B for operating the drive/control circuit DR is supplied from a DC power source E via a control power supply circuit A. In this control power supply circuit A1, a series circuit including a diode DI, a current limiting resistor R, and an electrolytic capacitor C0 is connected in parallel to a DC power supply. and,
A Zener diode ZD and a drive/control circuit DR are connected in parallel to the capacitor C0. As a result, a voltage ■o and a current ■ are applied to the drive/control circuit DR via the current limiting resistor R1 and the diode D. control power is supplied.

Capacitor C0 is the control power supply voltage ■. It is for smoothing of
Zener diode ZD is for overvoltage protection and voltage ■. It is for stabilizing current limiting resistor R1, and E-V. By providing a voltage of V0. to operate the drive/control circuit DR, the voltage V0. A control power source of current I0 is obtained.

FIG. 10 is a time chart for explaining the operation of the inverter device of FIG. 9. In the same figure (al is the voltage across the switching element Q2, in the same figure (bl is the current flowing in the switching element Q2, in the same figure fcl is the oscillating current flowing in the LC series resonant circuit for load (current flowing in the inductance element)) In the same figure, fdl is the load current, and in the same figure (al
1 and 2 respectively indicate the voltage of the capacitor C2 for cutting the DC component. In the figure, E indicates the voltage of the DC power supply E.

FIG. 11 shows a conventional second inverter device.

In this inverter device, the control power supply circuit A shown in FIG.
In this example, a control power supply circuit A2 is used in place of the power supply circuit I. This control T:IB supply circuit A2 uses a transformer T for commercial power supply, takes the voltage of the commercial power supply AC as the primary input, and converts the secondary output voltage obtained by stepping down the voltage by the transformer T1 to the diode D1. And the voltage ■ is rectified and smoothed by capacitor C0. , current■. A Zener diode Z is connected in parallel with the capacitor C0.
D and the drive/control circuit DR are connected in the same manner as in FIG. The rest of the configuration is similar to that of FIG. 9.

FIG. 12 shows a third conventional inverter device.

This inverter device uses a controlled power supply circuit A in place of the controlled power supply circuit AI in FIG. In other words, the capacitor C2 for cutting the DC component in FIG. 9 is connected in series with the load LD between the negative side (ground side) of the DC power supply E and one end of the load LD. A capacitor C0 is charged from a capacitor C2 for cutting DC components via a diode D1 and a current limiting resistor R8, and used as a control power source (voltage 2., current to) of the drive/control circuit DR. The rest of the configuration is the same as that in FIG. 9.

[Problem to be solved by the invention]

According to the inverter device of FIG. 9 described above, the voltage v0. for operating the drive/control circuit DR is relatively simple. Although a controlled power source of current I0 can be obtained, the following power loss P always occurs in the current limiting resistor R.

(E Vo)” PI = (w)...
(11) In order to obtain sufficient control power regardless of fluctuations in DC current -aE, etc., it is necessary to use a certain amount of current limiting resistor R
, it is necessary to set the resistance value of . therefore,
When the voltage of DC power supply E is high, current limiting resistor R,
The efficiency of the inverter device decreases because the power loss P increases rapidly. Furthermore, the heat generation of the current limiting resistor R5 is also a big problem, and it is necessary to connect a resistor with a high power value in parallel as the current limiting resistor R1, which is disadvantageous in terms of implementation and cost.

Therefore, the above configuration cannot be said to be practical.

Further, according to the inverter device shown in FIG. 11, sufficient control power can be obtained without increasing the power loss tU, and although it is practical, a transformer T is required, so the control power supply circuit There were problems in that A2 was expensive and the transformer T was large and heavy.

Furthermore, according to the inverter device shown in FIG. 12, control power is obtained from the DC component cutting capacitor C2 via the control power supply circuit A, so that the DC component of the capacitor C2 is approximately equal to the power supply voltage E. Since it is half, the power loss of the current limiting resistor R1 can be reduced by almost half compared to the conventional example shown in FIG.

However, in the inverter device shown in FIG. 12, the current supplied to the drive/control circuit DR is . There was a problem that it was not possible to make the value very large.

An object of the present invention is to eliminate the need for a transformer or current limiting resistor for matching the voltage applied to the drive/control circuit and the input voltage to the control power supply circuit, and to provide a control power supply circuit that is lightweight and inexpensive. It is efficient and controllable because it does not cause the temperature of parts to rise. An object of the present invention is to provide an impark device that can sufficiently supply current from an ITi source supply circuit to a drive/control circuit.

[Means to solve the problem]

The inverter device of the present invention includes a switching element that converts the voltage of a DC power supply into an AC voltage by switching and applies it to a load, a drive/control circuit that turns on and off the switching element, and an LC series circuit to which an AC voltage is applied. and a control power supply circuit consisting of a rectifier/smoothing circuit that rectifies and smoothes the oscillating current of this LC series resonant circuit and supplies it to the drive/control circuit as control power, and a drive/control circuit that changes the voltage of the DC power supply at startup. and a starting circuit that supplies the power to the engine.

[For production]

According to the configuration of the present invention, after startup, the alternating current voltage obtained by the switching element is applied to the LC series resonant circuit, and an oscillating current flows through the LC series resonant circuit. Then, the rectifier/smoothing circuit rectifies and smoothes the oscillating current of the LC series resonant circuit and supplies it to the drive/control circuit as a control power source.

In this case, the oscillating current of the LC series resonant circuit is rectified and smoothed, so by appropriately setting the circuit constants of the LC series resonant circuit, the voltage applied to the drive/control circuit and the input terminal to the control power supply circuit can be adjusted. Matching can be achieved, thus eliminating the need for voltage matching transformers and current limiting resistors. As a result, it is lightweight, inexpensive, and consumes less power per unit. 1
1. It does not cause a temperature rise in the components of the power supply circuit, and is highly efficient.

Moreover, since the control power supply circuit is configured to take in oscillating current from an LC series resonant circuit provided separately from the power supply path to the load and supply it to the drive/control circuit, a sufficient amount of current is supplied to the drive/control circuit. can do.

[Example ■]

A first embodiment of this invention will be described based on FIGS. 1 and 2. As shown in FIG.
+, Q By turning on and off z, the voltage of the DC power supply E is changed to the switching elements Q, , Q.

In the inverter device, which converts the AC voltage into an AC voltage and applies it to the load LD, the LC series resonant circuit KY to which the AC voltage is applied rectifies and smoothes the oscillating current of this LC series resonant circuit KY to drive and control. The control power supply circuit A4 includes a rectifier/smoothing circuit SH that supplies the circuit DR as a control power supply, and a startup circuit ST that supplies the voltage of the DC power supply E to the drive/control circuit DR at startup.

According to the configuration of this embodiment, after startup, the switching elements Q1. The alternating current voltage obtained by Qz is applied to the LC series resonant circuit KY, and an oscillating current i flows through the LC series resonant circuit KY. And rectification/smoothing circuit S
H, rectifies and smoothes the oscillating current of the LC series resonant circuit KY and supplies it to the drive/control circuit DR as a control power source.

This first embodiment will be explained in detail below.

The inverter bag surface of the first embodiment is a direct 2It electric wire #E,
A series circuit of switching elements QQ2 connected to a DC power source, a drive/control f111 circuit DR that turns on each switching element Q + and Qz alternately, and switching elements Q1. An inductance element 1-1 connected between the connection point of Q2 and the negative side of DC current [E, a capacitor C for resonance, and a capacitor C for cutting DC components.
2, a load LD+ connected in parallel to the resonance capacitor C1, a starting circuit ST, a control power supply circuit A4, and a drive/control circuit DR.

The control jTj power supply circuit A4 includes a switching element Q.

A series circuit of a 2° capacitor C1 and a diode D2 on an inductance element connected in parallel to and a diode D connected in parallel to the diode D2.

It consists of a series circuit of a capacitor C0 and a constant voltage diode ZD connected in parallel to the capacitor C0.

In this case, a rectifier/smoothing circuit SH includes a diode Dt, a diode D connected in parallel to this diode D2, and a series circuit of a capacitor C0.

The control power source is obtained from the oscillating current of an LC series resonant circuit KY for control power source consisting of an inductance element L2 and a capacitor C3.

The starting circuit ST has a configuration as shown in FIG. 1, for example. That is, a series circuit including a resistor R3 and a voltage regulating diode ZD is connected in parallel to the DC power supply E. And P
The base of the NP-type transistor Q is connected to the connection point between the resistor R3 and the constant voltage diode ZDt, and the resistor R is connected between the collector of the transistor Q and the positive side of the DC power supply E.
2 are connected, and the emitter of transistor Q is connected to diode D through diode D3, and capacitor C0.
connected to the connection point.

The operation of the startup circuit ST is controlled by the drive/control circuit DR through the resistor R1, the transistor Q, and the diode D, since the transistor Q3 becomes conductive when an AC input for generating the DC power source E, such as a commercial power source, is turned on. Power is supplied, and the drive/control circuit DR switches between switching elements Q, ,Q
, are driven on alternately. This reduces the inductance element.

A high frequency voltage is applied to the I-C series resonant circuit for the load consisting of the capacitor CL and the LC series resonant circuit for the load, and an oscillating current flows through the LC series resonant circuit for the load. is energized.

Next, the operation of the controlled power supply circuit A, which is a feature of the present invention, will be explained in detail. After startup, switching elements Q + and Q z are turned on alternately. Then, when the switching element Q1 is on, the switching element Q
2 is off, the LC series resonant circuit K is connected via the path of DC power supply E - inductance element 2 - capacitor C
A sinusoidal oscillating current ■1 flows through Y. Further, when the switching element Q1 is off and the switching element Q is on, the charge stored in the capacitor C1 is discharged through the inductance element Lt, and an oscillating current 2 similarly flows through the LC series resonant circuit KY.

As described above, when switching element Q, is on and switching element Q! In any case when the is on, there is vibration in the LC series resonant circuit KY. Stream 1 will flow.

As shown in FIG. 1, by connecting the diode DD2, when the oscillating current 1 flows in the direction of the arrow, the diode DI becomes conductive, and the oscillating current 1 flows through the diode D1 to the capacitor C0. It is charged and also consumed by the drive and control circuit DR. In this way,
Voltage ■. , the source can control the current r0.

Also, oscillating current! , flows in the opposite direction to the direction of the arrow, the diode D2 becomes conductive and the inductance element L
2 and capacitor C3 continues, and at this time, control power is supplied to drive/control circuit DR from capacitor C0.

In this case, although the charge charged in the capacitor C0 is consumed, the amount of charge charged in the capacitor C0 is sufficient, so that power can be supplied without any problem. At this time, L
The control power source is obtained from the oscillating current It flowing through the C series resonant circuit KY, and the LC series resonant circuit KY,
By appropriately setting the circuit constants of the control power supply circuit A4, it is possible to match the voltage applied to the drive/control circuit DR, and there is no need to provide a current limiting resistor.
There is no power loss at all.

Note that the oscillating current I and the current flowing in the LC series resonant circuit for load (current flowing in the inductance element L1) ILI
Since the combined current of flows through the switching element QQ2, the switching elements Q + , Q ! ■ To reduce power loss in the oscillating current.

It is desirable that it be as small as possible. Therefore, the control fi
The resonant frequency f0 of the LC series resonant circuit Y + for the l power supply is set considerably higher than the switching frequency rsw of the switching element Q1°Q□, as shown in equation (2).

Further, since the drive/control circuit DR is a load that consumes power, that is, a resistance bone, the oscillating current (1) actually attenuates while freely oscillating.

As described above, after starting up, the LC series resonant circuit Y
The control power source is obtained from the + oscillating current 11.

Since the voltage V0 of the control power source obtained from the oscillating current I of the LC series resonant circuit KY is set higher than the Zener voltage of the constant voltage diode ZDz, a reverse voltage is applied to the diode D after startup. In addition, transistor Q
3 is cut off, and the power supply from the starting circuit ST to the drive/control circuit DR is cut off. Therefore, power loss occurs in the transistor Q and resistor R7 only at the moment of startup, but no power loss occurs in the startup circuit ST after startup.

The startup circuit ST may have any circuit configuration as long as it can supply the necessary control power to the drive/control circuit DR only during startup, and can stop supplying the control power after startup. Good too.

FIG. 2 shows a time chart for explaining the operation of the inverter device shown in FIG. 1 described above.

The figure (δ) is the voltage across the switching element Q2, and the figure (δ) is the voltage across the switching element Q2.
bl is the current lot flowing through the switching element Q2, and tel in the figure is the oscillating current flowing through the LC series resonant circuit for the load (
A current I (Ll) flowing through the inductance element L1, +d+ in the figure is an oscillating current II flowing in the LC series resonant circuit KY for control power supply, and tel in the figure is a load current flowing in a sinusoidal manner.

As described above, in this embodiment, the control power supply L
A C series resonant circuit KY is provided, and a rectifier/smoothing circuit SH, which obtains control power from the oscillating current It of the LC series resonant circuit KY after startup, is provided, so the LC series resonant circuit Y
By appropriately setting the + circuit constants, driving and
It is possible to match the voltage applied to the control circuit DR and the input voltage to the control power supply circuit A4, thereby eliminating the need for a voltage matching transformer or current limiting resistor. As a result, the control power supply circuit A is lightweight, inexpensive, and has low power loss.
It is efficient because it does not cause the temperature of the component parts mentioned in No. 4 to rise.

Moreover, the system? The il power supply circuit A4 is an LC series resonant circuit KY provided separately from the power supply path to the load LD.

The vibration TL'fLl+ is taken in from the drive/control circuit D.
Since the configuration is such that the current is supplied to the drive/control circuit DR, a sufficient amount of current can be supplied to the drive/control circuit DR.

[Example 2] A second embodiment of the invention will be described based on FIG.

As shown in FIG. 3, this impark device includes an inductance element L1 and a resonance capacitor C between the positive side of the DC power supply E and the connection point of the switching element QQ2.
I and capacitor C for DC component cut! The difference from the embodiment shown in FIG. 1 is that a series circuit is connected with the embodiment shown in FIG.

This embodiment has the same effects as the first embodiment.

[Embodiment 3] A third embodiment of the present invention will be described based on FIGS. 4 and 5. As shown in FIG. 4, this inverter device uses a discharge lamp as the load L D z and an inductance element constituting the LC series resonant circuit for the load, and an inductance element for the LC series resonant circuit KYt for the control power supply. An example in which the device is also used as an element is shown.

In Fig. 4, the rectifier/smoothing circuit SS is connected to the commercial power supply, A
Create a DC power supply voltage by rectifying and smoothing the voltage of C.

At the DC output end of this rectifier/smoothing circuit SS, there is a switching element Q made of a transistor.

A series circuit of Q2 is connected. Moreover, each switching element Q1. Between the collector and emitter of Qz,
Respectively, diode D5. D'+ are connected in antiparallel. A series circuit including a discharge lamp, which is a capacitor Ct for cutting a DC component, an inductance element Ct, and a load LD, is connected to both ends of the switching element Q2. Furthermore, a capacitor C3 for resonance is connected between the non-power supply side electrode terminals of both filaments f, , (,) of the main lamp t, which is the load LD. constitutes an LC series resonant circuit and supplies power to the load LD.

Capacitor C3 is an inductance element and is controlled by TL.
The series circuit of a capacitor C3 and a diode D constitutes an LC series resonant circuit KY for RI, and a series circuit of a capacitor C3 and a diode D is connected to the power supply side of the discharge lamp which is a load [, Dt, and a diode D2 has a diode D1 and a capacitor C0 The series circuits are connected in parallel, and these are connected to the rectifier/smoothing circuit S as before.
It constitutes HI. Further, a drive/control circuit DR and a Zener diode ZD are connected in parallel with the capacitor C6.
is connected. The above LC series resonant circuit KY2 and rectification/smoothing circuit B5H, and control 77! I 7i #Supply circuit A.

is configured.

The configuration of the drive/control circuit DR is similar to the circuit shown in FIG. Further, the configuration of the starting circuit ST is also the same as that shown in FIG.

The operation of the circuit shown in FIG. 4 will be explained below. When the commercial power supply AC is turned on, a DC i differential voltage is obtained which is rectified and smoothed by the rectification and smoothing circuit SS. A control power source with a voltage Vo and a current of 1° is supplied to the drive/control circuit DR from the DC power supply voltage through the startup circuit ST, and the drive/control circuit DR supplies the bases of the transistors, which are the switching elements Q, to Drive signals that alternately go high level are applied, and the switching elements Q+ and Qz alternately turn on and off. As a result, the voltage at point X becomes a rectangular wave voltage, and this voltage is applied to the inductance element L1. Capacitor C
, is applied to the LC series resonant circuit for the i part, and an oscillating current flows through the LC series resonant circuit for the load. Note that the capacitance of the DC component cutting capacitor C2 is set to be sufficiently larger than the capacitance of the resonance capacitor C2.

Similarly, an oscillating current flows through the [, C series resonant circuit KY2 for the control power supply.

Here, the oscillating current flowing through the resonance capacitor C1 is I
c+, and the oscillating current flowing through the resonance capacitor C3 is 1. Then, the oscillating current 11 is relative to the oscillating current tel,
Habo ■, ζ (C3/CI) ・ICI ・・・・・・
The relationship is as shown in (3), and the capacitance of the capacitor C3 is smaller than that of the capacitor C1, and the oscillating current * l + is a smaller current than the oscillating current ICI. Therefore, switching element Q1.
The I factor due to the oscillating current 11 of the transistor, which is Qz, is negligible.

On the other hand, the current I flowing through the resonance inductance element
LI is a composite current of the oscillating current 11 and the oscillating current ICI, and ILI"[1" (Ci /c+) 3
・ICI...(4) Represented by:

As explained in the embodiment of FIG. 1, when the oscillating current ■ flows in the direction of the arrow (that is, the current +1
flows in the direction of the arrow), the diode D becomes conductive, and the oscillating current 1 charges the capacitor C0 to DC through the diode D+, and is also consumed by the drive/control circuit DR. In this way, the voltage V0. A controlled power source with a current of 1° can be obtained.

Further, when the oscillating current I flows in the direction opposite to the direction of the arrow (that is, when the current ILI flows in the direction opposite to the arrow), the diode D2 conducts, and the series connection by the inductance element R and the capacitor C3 The resonance continues,
Capacitor C0 supplies control power to drive control circuit DR. In this case, the drive/control circuit DR
The charge in the capacitor C0 is consumed.

In the case of this embodiment, as in the embodiment of FIG. 1, the voltage ■
. , IN-1o, the farmer has no power from the controlled power supply circuit A.

Then, at the same time when control iX[l power is supplied from the control power supply circuit A to the drive/control circuit DR, the startup circuit I
The supply of ij control power from sT is stopped.

After this, when the frequency of the drive signal gradually approaches the resonant frequency, a large amount of oscillating current flows through the capacitor C1, the voltage across it increases, and the discharge lamp, which is the load LD, starts and lights up even after 0 lighting. , the oscillating current 11 that satisfies the equation (3) flows as before lighting, and similarly, a tn-controlled power source is obtained via the diode D due to the amount of oscillation lJI.

FIG. 5 is a time chart of each part in the embodiment of the inverter device shown in FIG. 4 after the discharge lamp (load LDt) is turned on. fa+ in the same figure is the voltage across the switching element Q, which is a transistor, ib) is the composite current I8 that combines the current flowing through the switching element Q2 and the current flowing through the diode D, and tel in the figure is the inductance element -F-. The oscillating current 11 flowing through +-+, +(1
1 is the oscillating current +1 flowing through the capacitor C1, the same figure (e
l is a load current flowing in a sinusoidal manner.

In such a configuration, the LC series resonant circuit KY, Since the oscillating current (1) is flowing through the oscillating current (1), there is also the effect that the control power source for the drive/control circuit DR can be obtained.

Furthermore, since the oscillating current 1 does not change much even with alternating current input fluctuations, the alternating current input voltage (commercial electricity? IIX voltage)
It can operate stably even in the face of fluctuations.

As mentioned above, in this embodiment ζ, the load LC
The inductance element of the series resonant circuit is also used as the inductance element constituting the LC series resonant circuit for the control power supply, and the vibration i of the LC series resonant circuit Yt for the control power supply is
ll current 11 to voltage ■. , ii, and a rectifying/smoothing circuit SH for obtaining the control power source I0, the number of parts is smaller than in the first and second embodiments, and the structure can be simple and inexpensive.

Other effects are similar to those of the first embodiment.

[Implementation example 4] A fourth embodiment of the invention will be described based on FIG. 6.

This inverter device, as shown in FIG.
The positive side of E and the switching element Q.

An inductance element Ll is connected between the connection point of Q2 and
The difference from the embodiment shown in FIG. 4 is that a series circuit consisting of a capacitor C1 for resonance and a capacitor C2 for cutting a DC component is connected, and other points are the same as the embodiment shown in FIG.

This embodiment has the same effects as the third embodiment.

[Implementation example 5] A fifth embodiment of this invention will be described based on FIG. 7.

In this embodiment, the present invention is applied to a half-bridge type inverter device, and the configuration and operation of the control power supply circuit A are the same as those described in the embodiment of FIG. 4.

In Fig. 7, C6 and C are each a capacitor, and the other parts have the same functions as those explained in Figs. are doing.

This embodiment has the same effects as the first embodiment.

In this embodiment, the inductance element L1 constituting the LC series resonant circuit for the load is also used as the inductance element of the LC series resonant circuit KY for the control power supply, but both inductance elements are They may be provided individually as in the embodiment.

Furthermore, the configuration of the inverter device may also be a full bridge type instead of a half bridge type.

In this case, capacitors C6 and C? in FIG. is replaced by a switching element.

Further, the inverter device may be of I'ri type.

[Example 6] A sixth embodiment of this invention will be described based on FIG.

This embodiment is applied to a discharge lamp lighting device that lights a large number of discharge lamps in parallel.

This inverter device has an inductance element L l l
n series circuits are connected in parallel from the series circuit of the load LD, , consisting of the inductance element Lln and the discharge lamp to the series circuit of the load LD, , consisting of the inductance element Lln and the discharge lamp, and this parallel circuit is used for cutting the DC component. It is connected in series with the capacitor C2 between the connection point of the switching elements Q, , Qt and the negative side of the DC power supply E. Also,
The non-TiE of each discharge lamp with loads LD, , ~LD, .
Resonant capacitors C11 to C between the side electrode terminals, respectively.
The series circuits from the series circuit of the resonance capacitor C31 and the diode D21 to the series circuit of the resonance capacitor C3n and the diode DLM are connected in parallel to the capacitors CI l to C1, respectively. Diode D Il is connected to the connection point of series circuit capacitor C31""' C1n and diode Df,%D,,1.
The anode of -D is connected to the other, and the cathodes of diodes D and -D are connected in common and connected to capacitor C0. Others are the same as those in FIG.

According to the circuit configuration of FIG. 8, the loads LDx to LDl,
, regardless of whether they are attached or detached, as long as at least one is connected, capacitor C0 is charged and a control power source can be obtained. In addition, all loads LDz~L
If DI- is removed and a completely unloaded state is reached, the power supply through the diodes D, ~Dln will disappear, so the control T1. The source is shut off and the oscillation operation stops, ensuring safety during no-load conditions.

Other effects are similar to those of the first embodiment.

〔Effect of the invention〕

According to the inverter device of this invention, the LC for control power supply
A series resonant circuit is provided, and a rectifier/smoothing circuit is provided that obtains control power from the oscillating current of the LC series resonant circuit after startup, so by appropriately setting the circuit constants of the LC series resonant circuit, the drive/control circuit can be It is possible to match the applied voltage with the input voltage to the control power supply circuit, thus eliminating the need for voltage matching transformers and current limiting resistors. As a result, it is lightweight, inexpensive, has little power loss, does not cause temperature rise in the components of the control power supply circuit, and is highly efficient.

Moreover, the control power supply circuit is configured to take in oscillating current from an LC series resonant circuit provided separately from the power supply path to the load and supply it to the drive/control circuit, so that the current is sufficiently supplied to the drive/control circuit. can be supplied.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing the configuration of a first embodiment of the present invention;
FIG. 2 is a time chart of each part of the inverter device shown in FIG. 1, FIG. 3 is a circuit diagram showing the configuration of a second embodiment of the invention, and FIG. 4 is a diagram showing the configuration of a third embodiment of the invention. 5 is a time chart of each part of the inverter device shown in FIG. 4, FIG. 6 is a circuit diagram showing the configuration of a fourth embodiment of the present invention, and FIG. 7 is a fifth embodiment of the present invention. 8 is a circuit diagram showing the configuration of the sixth embodiment of the present invention, FIG. 9 is a circuit diagram showing the configuration of the first conventional example, and FIG. 10 is the circuit diagram showing the configuration of the first conventional example. FIG. 11 is a circuit diagram showing the configuration of the second conventional example, and FIG.
FIG. 2 is a circuit diagram showing the configuration of a third conventional example. E...DC power supply, Q 1. Q2...Switching element, DR...Drive/control circuit, KY,...LC
Series resonant circuit, 38. ... Rectifier/smoothing circuit, A4...
・Control power supply circuit 2, ST...starting circuit EE line; Fig. Fig. Fig. 10

Claims (1)

[Claims] A switching element that converts the voltage of a DC power source into an AC voltage by switching and applies it to a load, a drive/control circuit that drives this switching element on and off, an LC series resonant circuit to which the AC voltage is applied, and this LC series resonant circuit. The oscillating current is rectified and smoothed to
An inverter device comprising: a control power supply circuit including a rectifier/smoothing circuit that supplies control power to a control circuit; and a startup circuit that supplies voltage of the DC power supply to the drive/control circuit at startup.