JPH04285475A - Power source - Google Patents

Abstract

PURPOSE:To reduce in size and weight by using an LC composite element in a resonance switching power source. CONSTITUTION:An LC composite element in which dielectric elements 21, 22 and conductor foils 23, 24 are alternately superposed, electrode lead conductors 25, 26 are provided from starting and finishing ends of a winding to be wound in a cylindrical shape and a magnetic element 27 is passed inside, is used as a resonance element of a resonance inverter. The size and the weight are reduced, and the efficiency is enhanced as compared with the case of using discrete elements.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switching power supply and to reducing the size and weight of electrical equipment incorporating the same.

0002

[Prior Art] Inverter circuits generate alternating current or pulsed power by periodically turning on and off switching elements from a direct current power supply, and converter circuits that rectify the alternating current or pulsed power to obtain controlled direct current power. As a type of this, a resonant switching power supply has been put into practical use that uses the electric vibrations of an inductor L and a capacitor C to facilitate the on/off operation of the switching element, thereby suppressing the generation of electromagnetic noise and power loss associated with switching. ing. (“
'89 Switching Power Supply System Symposium, edited by Japan Management Association, etc.)

Conventional resonant switching power supplies have separate electric elements, an inductor L and a capacitor C, as a resonant circuit that stores alternating current or pulsed power generated by periodically turning on and off switching elements. However, the problems are that these inductors and capacitors necessarily have a large volume and weight, and that power loss due to resistance as a parasitic element is large.

0004

SUMMARY OF THE INVENTION An object of the present invention is to reduce the volume, weight, and power losses of inductors and capacitors in resonant circuits.

[0005]

[Means for Solving the Problems] In the power supply device of the present invention,
It has a switching element, a control means for turning it on and off periodically, and an LC composite element as an electric element that stores alternating current or pulse power generated by these elements. The LC composite element has the following structure. (1) A dielectric and a conductor foil, or (2) a metallized dielectric, or (3) a dielectric and a metallized dielectric, or (4) a conductor foil, a dielectric, and a metallized dielectric, in one sheet or in one piece. A set or multiple sets are stacked, wound into a cylindrical shape, and a magnetic core made of a magnetic material is passed inside the core, and an electrode lead-out conductor is placed at the end of the conductor foil or metallized dielectric material or at a suitable intermediate position. A device with a current extraction section consisting of a conductor layer or by spraying a conductor.

That is, in the resonant switching power supply of the present invention, the inductor L and the capacitor C are combined by giving part or all of the conductor of the capacitor the same function as the inductor winding.

[0007]

[Operation] The operation of the present invention will be explained using a power supply device having a resonant inverter circuit which is an embodiment of the present invention shown in FIG. FIG. 1(a) is a circuit diagram configuring a so-called full bridge. 1 is an LC composite element, and 4 to 7 are switching elements, which are turned on and off by being driven by a control means that operates as described below.

As a first step, when switching elements 4 and 7 are turned on and switching elements 5 and 6 are turned off, switching element 4 is
Through the primary side of the transformer 2, the LC composite element 1, and the switching element 7, a current flows with a waveform close to a sinusoidal vibration with a period mainly determined by the inductance component L and capacitance component C of the LC composite element 1. When half a cycle of this current waveform has passed and the current value has become 0, as a second step, switching elements 5 and 6 are turned on, and switching elements 4 and 7 are turned off. , the LC composite element 1 , the primary side of the transformer 2 , and the switching element 5 . By repeating the first step and the second step, AC power is stored in the LC composite element 1, and the AC power is supplied to the AC load 3 via the transformer 2.

FIG. 1(b) and FIG. 1(c) are L in FIG. 1(a).
It is a structural diagram of an example of the C composite element 1, in which dielectric thin films 21 and 22 and conductor foils 23 and 24 are stacked, and the conductor foil 23 is
An electrode lead-out conductor 25 is provided at the end of the winding end of the conductor foil 24, and an electrode lead-out conductor 26 is provided at the end of the conductor foil 24 on the winding start side, which is wound into a cylindrical shape. Electrode lead conductors 25 and 26 are drawn out as terminals of the present LC composite element 1, and between these terminals there are dielectric thin films 21 and 22 sandwiched between conductor foils 23 and 24, which absorb electrostatic energy. It constitutes a storage capacitor C. In addition, the current flowing through this capacitor forms a cylindrical current path when flowing from one terminal to the other terminal, and acts as an inductor L that stores magnetic energy.From the above, this LC composite element 1 It can be seen that is electrically equivalent to an inductor L and a capacitor C connected in series.

0010

[Embodiment] Fig. 1 is an explanatory diagram of the first embodiment of the present invention, and its operation is as explained above. Magnetic material 2
A magnetic circuit is provided using a magnetic core made of 7 and a gap spacer 28 to increase the inductance value of the inductor L.

FIG. 2 is an explanatory diagram of a second embodiment of the present invention, showing an example of a power supply applicable to a pulse load such as a flash lamp. FIG. 2(a) is a circuit diagram, and constitutes a so-called half bridge. 20 is the primary side (
It has an LC series circuit on the secondary side (between C and D).
This is an example of an LC composite element that has an LC parallel circuit and constitutes a transformer so that the inductors on both sides have magnetic coupling. 4 and 5 are switching elements, which are driven by a control means and turned on and off alternately. As a result, electric vibrations are excited on the primary side of the LC composite element 20, energy is stored, and the energy is transmitted to the secondary side via the above-mentioned magnetic coupling. In this example, there is a rectifier 1 on the secondary side.
A pulse discharge capacitor 15 is connected through a full-wave rectifier circuit 4, and when a suitable amount of energy is stored therein, the switch 16 is closed to provide the energy to the pulse power load 13.

FIGS. 2(b) and 2(c) are structural diagrams of an LC composite element in a second embodiment of the present invention. Figure 2
(b) The right half of (c) is the primary side (terminal A- in Fig. 1(a)).
B) has exactly the same structure as the first embodiment, and is as explained in FIGS. 1(b) and 1(c) above. The left half will be explained below. dielectric thin films 31 and 32;
The conductor foils 33 and 34 are overlapped, and an electrode lead-out conductor 37 is provided at the end of the conductor foil 33 on the winding start side and winding end side, respectively.
and 35, and an electrode lead-out conductor 36 is provided at the end of the conductor foil 34, which is wound into a cylindrical shape. The electrode lead conductor 35 is connected to the terminal C of the present LC composite element 20, and the electrode lead conductors 36 and 37 are collectively connected to the terminal D of the present LC composite element 20. Between these terminals CD are dielectric thin films 31 and 32 sandwiched between conductor foils 33 and 34, forming a capacitor C that stores electrostatic energy. The conductor foil 33 also extends from the electrode lead conductor 35 (terminal C) to the electrode lead conductor 37 (
When flowing to terminal D), it forms a cylindrical current path and acts as an inductor L that stores magnetic energy.From the above, the secondary side of this LC composite element is connected in series with an inductor L and a capacitor C. It can be seen that it is electrically equivalent to the In this example, the conductor foil 33 functions as an inductor, and the current value flowing here is greater than that of the conductor foil 34. Therefore, using a conductor foil 33 that is thicker than the conductor foil 34 is effective in reducing the loss due to resistance. It is effective as a means to reduce

FIG. 3 is an explanatory diagram of a third embodiment of the present invention, which is an embodiment of a power supply device using a resonant converter circuit that obtains an insulated DC output from a DC power supply 12 and supplies it to a DC load 18. be. FIG. 3(a) is a circuit diagram, which can be considered as a modification of a so-called half bridge, with 30 having an LC series circuit on the primary side (between A and B) and a secondary side (between C and B).
This is an example of an LC composite element in which an LC parallel circuit is provided between D and E, and inductors on both sides are magnetically coupled to form a transformer. 4 and 5 are switching elements, which are driven by a control means and turned on and off alternately. As a result, electric vibrations are excited on the primary side of the LC composite element, energy is stored, and the energy is transmitted to the secondary side via the above-mentioned magnetic coupling. In this example, power is supplied to the DC load 18 on the secondary side through a full-wave rectification circuit including a rectifier 14 .

FIGS. 3(b) and 3(c) are structural diagrams of an LC composite element in a third embodiment of the present invention. Figure 3
(b) The right half of (c) is the primary side (terminal A- in Fig. 1(a)).
B), a bypass core 29 for adding leakage inductance and a gap spacer 28 for adjusting the value of the leakage inductance are added to increase the degree of freedom in design and manufacturing. It has exactly the same structure as
This is as explained in FIG. 1(b) and FIG. 1(c) above. The left half will be explained below. Dielectric thin films 31 and 32 and conductor foils 33 and 34 are stacked, and electrode lead conductors 37 and 35 are placed at the ends of the conductor foil 33 at the start and end sides, respectively, and at the ends of the conductor foil 34 at the start and end of the winding. Electrode lead conductors 38 and 3 are provided at the end of the winding end, respectively.
6 is wound into a cylindrical shape. The electrode lead conductor 36 is connected to the terminal C of the present LC composite element, the electrode lead conductors 5 and 38 are collectively connected to the terminal D of the present LC composite element, and the electrode lead conductor 37 is connected to the terminal E of the present LC composite element. connected to. Between these terminals C and D,
Dielectric thin films 31 and 3 sandwiched between conductor foils 33 and 34
2, which constitutes a capacitor C that stores electrostatic energy. Further, the conductor foil 34 has an electrode lead-out conductor 36 (
When flowing from the terminal C) to the electrode lead conductor 38 (terminal D), it forms a cylindrical current path and acts as an inductor L that stores magnetic energy. Based on the above, this LC
It can be seen that the secondary side terminal C-D of the composite element is electrically equivalent to an inductor L and a capacitor C connected in parallel. Further, the same holds true between terminals DE and E of the present LC composite element, and the equivalent circuit becomes as shown in FIG. 3(a).

In this embodiment, an electrode lead-out conductor can be provided at the center of the wound conductor foil in order to take out the center tap on the secondary side. Also, on the secondary side,
There is also a method of using insulated conductor wires (so-called magnet wires such as enamelled wires) conventionally used in transformers, or Litz wires made by bundling and twisting a large number of conductor wires.

FIG. 4 is an explanatory diagram of a fourth embodiment of the present invention, which is an embodiment of a power supply device using a resonant converter circuit that supplies alternating current power from a direct current power supply 12 to an alternating current load 3 by switching. Figure 4(a) is a circuit diagram, which can be thought of as a variation of a so-called half bridge, and 40 is 2
This is an example of an LC composite element having an equivalent circuit in which two capacitors are connected in series and one terminal of an inductor is connected to the connection point. 4 and 5 are switching elements, which are driven by a control means and turned on and off alternately. As a result, a substantially sinusoidal current determined by the resonance period of the LC composite element 40 can be passed through the AC load 3 .

FIGS. 4(b) and 4(c) are structural diagrams of an LC composite element in a fourth embodiment of the present invention. In this example, dielectrics 41, 42, 43, 44, conductor foil 51,
52, 53, and 54 are stacked alternately, and electrode lead-out conductors 49, 50 are provided from the ends of the conductor foils 52, 54 on the winding start side, respectively, and electrode lead conductors 49, 50 are provided from the ends of the conductor foils 51, 52, 53, and 54 on the winding end side, respectively. Each electrode lead conductor 45, 46, 47, 48 is provided and wound. The electrode lead conductors 45 and 47 are each connected to a main LC.
Connected to terminals A and B of the composite element, electrode lead conductor 46,
48 is connected, and electrode lead conductors 49 and 50 are collectively connected to terminal C of the present LC composite element. Book LC
Terminal C of the composite element and the electrode lead-out conductors 46 and 48
A cylindrical current path is formed between the conductor foils 52 and 54 and an inductor is formed between the connection point and the connection point. Also,
A conductor foil 51 and a conductor foil 52 or 54 face each other with the dielectric 41 or 44 in between, forming a capacitor between the terminal A of the present LC composite element and the connection point of the electrode lead-out conductors 46 and 48. are doing. Similarly, between the terminal B of the present LC composite element and the connection point of the electrode lead-out conductors 46 and 48, a conductor foil 53 and a conductor foil 52 or 54 are opposed to each other with the dielectric 42 or 43 in between, and a capacitor is connected. It consists of Therefore, this LC composite element has an equivalent circuit in which two capacitors are connected in series and one terminal of an inductor is connected to the connection point.

In these examples, the edges of the conductor foil in the winding width direction (FIGS. 1(b), (c) and 2(b), (
In the side view of c), this corresponds to the upper and lower edges of the conductor foils 23, 24 and 33, 34. ), the electric field strength is high, causing partial discharge to occur and deteriorating dielectric materials, etc. Also, when high-frequency alternating current is passed, there is a loss due to current concentration at the edges of the conductor foil. As a countermeasure to these problems, we applied the technology used in foil-wound capacitors and increased the curvature of the edges of the conductor foil by using bent foil. It is effective to alleviate the concentration of electric fields and currents. In this case, by shifting the positions of the plurality of folded foils in the winding width direction so that the folded portions do not overlap each other, it is possible to suppress an increase in the winding height. A similar problem can also occur when using metallized dielectrics, but an application of the technique used in metallized film capacitors is to increase the thickness of the metal deposited on the dielectric to be thicker at the edges. The so-called heavy
A similar effect can be obtained by using an edge.

Furthermore, in these embodiments, in addition to winding a conductor or dielectric material for the purpose of storing and transmitting energy, it is also possible to monitor the current flowing through the LC composite element and send a signal to the control means. For this purpose, it may be advantageous to provide an auxiliary winding on the magnetic core constituting the LC composite element.

[0020]

[Effects of the Invention] In the resonant switching power supply of the present invention, the conductive foil, which was used only as the electrode of the capacitor in the conventional LC resonant circuit using individual components, is also used as the inductor conductor, and the function as an electric element is multiplied. It has been realized. As a result, the volume, weight, and power loss of the power supply device can be reduced compared to the conventional case using individual parts, and effects such as smaller size, lighter weight, and higher efficiency can be obtained.

[Brief explanation of the drawing]

FIG. 1 shows the main parts of a power supply device according to a first embodiment of the present invention (
(a) is a resonant inverter circuit diagram, (b) is a cross-sectional view of the LC composite element, and (c) is a side view of the LC composite element.

FIG. 2 shows the main parts of the power supply device according to the second embodiment of the present invention (
(a) is a resonant converter circuit diagram, (b) is a cross-sectional view of the LC composite element, and (c) is a side view of the LC composite element.

FIG. 3 shows main parts of a power supply device according to a third embodiment of the present invention (
(a) is a resonant converter circuit diagram, (b) is a cross-sectional view of the LC composite element, and (c) is a side view of the LC composite element.

FIG. 4 shows main parts of a power supply device according to a fourth embodiment of the present invention (
(a) is a resonant converter circuit diagram, (b) is a cross-sectional view of the LC composite element, and (c) is a side view of the LC composite element.

[Explanation of symbols]

1 LC composite element 2　Transformer 3 AC load 4 First switching element 5 Second switching element 6 Third switching element 7 Fourth switching element 8 First protection diode 9 Second protection diode 10 Third protection diode 11 Fourth protection diode 12 DC power supply 13 Pulse power load 14 Rectifier 15 Pulse discharge capacitor 16 Switch 17 Capacitor 18 DC load 20 LC composite element 21 First dielectric 22 Second dielectric 23 First conductor foil 24 Second conductor foil 25 First electrode lead conductor 26 Second electrode lead conductor 27 Magnetic material 28 Gap spacer 29 Bypass core 30 LC composite element 31 Third dielectric 32 Fourth dielectric 33 Third conductor foil 34 Fourth conductor foil 35 Third electrode lead conductor 36 Fourth electrode lead conductor 37 Fifth electrode lead conductor 38 Sixth electrode lead conductor 40 LC composite element 41 First dielectric 42 Second dielectric 43 Third dielectric 44 Fourth dielectric 45 First electrode lead conductor 46 Second electrode lead conductor 47 Third electrode lead conductor 48 Fourth electrode lead conductor 49 Fifth electrode lead conductor 50 Sixth electrode lead conductor 51 First conductor foil 52 Second conductor foil 53 Third conductor foil 54 Fourth conductor foil

Claims (1)

[Claims] 1. A power supply device comprising a switching element and a control means for periodically turning on and off the switching element, and having an LC composite element as an electric element for storing alternating current or pulsed power generated by the switching element, wherein the LC composite element (
1) a dielectric material and a conductive foil, or (2) a metallized dielectric material, or (3) a dielectric material and a metalized dielectric material, or (4) a conductive foil, a dielectric material, and a metalized dielectric material, one sheet or a set. Alternatively, multiple pairs are stacked, wound into a cylindrical shape, and a magnetic core made of a magnetic material is passed inside the core, and an electrode lead conductor or conductor layer is placed at the end of the conductor foil or metallized dielectric material or at a suitable intermediate position. What is claimed is: 1. A power supply device characterized in that a current extraction section is provided.