JPS5941815A - High-frequency leakage transformer - Google Patents

Abstract

PURPOSE:To reduce the total loss of the transformer by fitting a path core to a core, converging leakage flux, reducing high-frequency flux passing through a winding and limiting the relationship of path core length (x) and path core gap length (y). CONSTITUTION:With the cross-shaped core 21, a vertical section constitutes a main core 22 and sections projected in the horizontal direction from the center of the vertical section constitute the path core 23. A primary winding 25 is wound on a section upper than the path core 23 of the main core 22 and a secondary winding 26 on a section lower than that. The total loss of the high- frequency leakage transformer is minimized when the projecting size of the path core, path core length (x), and the gap size of the path core, gap length (y), are approximately equal, but core loss increases when (x) is larger than (y), copper loss increases when (x) is smaller than (y), and total loss increases in either case. Accordingly, the relationship of path core length (x) and gap length (y) is brought to formula 0.4<=y/(x+y)<=0.8 (0.4<=y/(x+y)<=0.6 is preferable).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lower loss high frequency leakage I lance.

Conventionally, a high frequency leakage transformer having the configuration shown in FIG. 1 is known. Such a high frequency leakage transformer is used in a ballast for lighting a discharge lamp at a high frequency using a voltage induced in the secondary winding of a high frequency voltage'. In FIG. 1, reference numerals 1a and 1b are E-shaped cores, which face each other at intervals, and have three gaps 2.
3.4 is formed. In addition, the middle legs 5 a and 5 b of the cores 1 a and 1 b constitute the main core (leg portion) of this leakage transformer, and are connected to the primary windings 6 and 2 , respectively.
The next winding 7゛ is wound. Side legs 8a, 8b, 9a, 9b #3. J: base 1'o
a and iob constitute a rhizo core (yoke) for forming a main magnetic path together with the main core.

By the way, in such a one-cage transformer, leakage magnetic flux flows from the middle legs 5a, 5b of the E-shaped cores la, 1b to the side legs 8a, 8b, 9a, 9b, as shown by the arrow φ, for example, through the windings. 6 and 7, the copper loss caused by the eddy current is large, especially at high frequencies of 10 Ktlz or higher, and therefore the total loss is also large.

The purpose of the present invention is to solve the above-mentioned problems in the conventional type.
An object of the present invention is to reduce total loss in a high frequency leakage transformer based on the concept of providing a bus core for magnetic flux leakage and limiting the relative dimensions of this bus core.

The present invention includes a primary winding to which a high frequency voltage is applied, a secondary winding that supplies the induced voltage of this high frequency voltage to a load, and a winding system in which these primary windings and secondary windings are divided and wound. A magnetic core consisting of a main core and a sub-core that connects both ends of this main core via the outside of the primary winding a3 and the secondary winding to form a main magnetic path together with the main core is shell II.
5. In the high frequency leakage 1-lance, a bus 11a protrudes between the primary winding and the secondary winding of the main core or from the sub-core toward the main core. In addition, the relationship between the protrusion dimension X of this bass core and the gillage dimension y from the tip of this bass core to the sub core or main core is set to 0.4≦V/(X+V)≦0.8. Zuru.

The present invention is applied to high frequencies, and the term "high frequency" here means a frequency of 10 K +-, I 7 or more.

At frequencies below 10 KI-(z), losses such as eddy current loss are not so large as to become a problem, so the sufficient effect of the present invention cannot be obtained.

In the present invention, materials known for use in high frequencies, such as ferrite and amorphous, can be used as the material for the magnetic core. Furthermore, the shape of the magnetic core before the present invention is applied (conventional shape) is such that it is possible to provide a protrusion between the primary winding and secondary winding of the main core and between the rib core, and the capacitance is Any shape can be used as long as it is of sufficient quality.

The total loss of the high frequency leakage transformer in this defense is
A protruding dimension, that is, bass core length X and bass core gear I7
When the diameter of the shaft and the shaft length y are almost equal, the minimum value is reached, but when x > y, the iron loss increases, and when x < y, the copper loss increases, and in either case, the total loss increases. . In order to keep the input condition fl of the primary winding and the output condition of the secondary winding constant, the main gap length and It is necessary to keep the excitation inductance and leakage inductance constant by changing the number of turns.For this reason, reducing the bus core gap length y reduces the main gap length and also reduces the number of turns of the primary and secondary windings. will decrease, and the maximum magnetic flux density [3m will increase U t, the loss will increase,
On the other hand, in order to obtain the same coupling constant by increasing the bus core length y, it is necessary to increase the main gap length and the number of turns L, which decreases iron loss but increases copper loss. It is. Based on the above knowledge, in the present invention, the relationship between the bass core length )≦0.6.

Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 2 shows the configuration of a high frequency leakage transformer according to an embodiment of the present invention. In the figure, a vertical portion of a cross-shaped core 21 is a main core 22, and a portion projecting horizontally from the center of this vertical portion constitutes a bass core 23.

A primary winding 25 is wound above the bus core 23 of the main core 22, and a secondary winding 26 is wound below the main core 22.

U-shaped cores 27a and 27b are each cross-shaped core 21
Both ends of the main core 22 are connected via the outside of the primary winding 25 and the secondary winding 26 to constitute a subcore 27 for forming a main magnetic path together with the main core 22. Note that the ()-shaped cores 27a and 27b and the cross-shaped core 2
1, main gaps 28 are provided at 48 locations.

FIG. 3 shows the shape and dimensions (mm) of a magnetic core for a leakage transformer according to another embodiment of the present invention.

The magnetic cores shown in FIG. 2 are one I-shaped core (main core 22) and two U-shaped cores 27a.

The above-mentioned I type 2 J was created by changing the r day J type consisting of 27b to the conventional shape.
Two U-shaped cores 27a from the central part of A.

Two protrusions, that is, bass cores 23 are provided on the left and right sides in the figure toward the center 29 of the bottom of the base 27b.
Regarding the conventional shape of ``Japanese'' type, this time we will use two U-shaped cores 27.
one protrusion inward from the bottom central portion 29 of each of a and 27b toward the central portion of the I-shaped core, that is, the bass core 2;
3.

FIG. 4 shows a high-frequency leakage 1-lance using the magnetic core shown in FIG. Iron loss Pi, high-frequency copper loss pcu(+-IF), Pcu(oc), and total loss pt when excitation inductance and leakage inductance are kept constant by changing the winding length and the number of turns of the primary and secondary windings. shows.

Kikomei can be applied to magnetic cores of various shapes such as EE type, El type, UL type, medium heat round foot type EE type, and bot type, and the shape of the bass core can also be rectangular, oval, circular, etc. However, it is particularly preferable to use a bus core in which the gap dimension y is uniform in most of the joints at the tip of the bus, that is, the shape is similar to the cross section of the main core or the inner surface of the sub core. .

FIG. 5 shows an example of the dimensions (mm) of each part of the magnetic core used in the high frequency leakage transformer shown in FIG. Using magnetic cores with different bus core lengths X and gear V-tube lengths y, the number of turns and main gap 28 are adjusted so that the input/output characteristics, that is, the excitation inductance, leakage, and inductance are constant at 4T. The iron loss Pi of the high frequency leakage transformer, the high frequency copper loss Pcu (T+F), 1
) cu (o c ) and total loss pt are as shown in FIG.

From the graphs of FIG. 4 and FIG. 6, the total loss becomes the minimum when x=y, regardless of whether the magnetic core of FIG. 3 a3 or FIG. 5 is used. In addition, for those using the magnetic core shown in Figure 3, y/(x + y) < 0.4 or 0.8 < y /
At (X + V), the total loss pt is the conventional example, that is, y/(
x+y)=1. Furthermore, for those using the magnetic core shown in Figure 5, 0.4≦V/(X+l'
It can be seen that when )≦0.6, the total loss [)] is reduced by 23 to 25% compared to the conventional example. Therefore, the relationship between the bass core length X and the bass core length y is 0.4≦V/(X+V)≦
0.8 is preferable, and 0.4≦V/(X←
It is particularly preferable that y)≦0.6.

FIG. 7 shows an example of a discharge lamp lighting device to which the high frequency leakage transformer of the present invention is applied.

In the same figure, the power supply 30 includes an AC type 11131, and a rectifier circuit, for example, a full-wave rectifier circuit 32 is connected to this AC IU source 31, and the subsequent circuits are supplied with non-resistance signals from the rectifier circuit 32.
fJ supplies DC (rectified output). A capacitor 33 is connected between the rectified output terminals a and b, and a die A for
A high-frequency generator, for example, a high-frequency inverter 40, is connected via a constant current inductor 35 together with the series circuit of the - field 31. Note that the varistor 36, the capacitor 37, and the balanced transformer 38 constitute a noise prevention circuit.

This inverter 40 uses a push-pull type inverter, and includes a pair of transistors 41 and 42, bias resistors 43 and 44, a resonant capacitor 45, and an output transformer 46. In the discharge lamp lighting device shown in FIG. 7, the high frequency leakage transformer of the present invention is used as the output transformer 46. In this case, the inverter 40 has an output transformer 4 connected to the rectified output positive terminal a.
The center tap (center tap) of the primary winding 461 of the transistor 6 is connected, and the transistor 4
1 and the base of the transistor 42 via the bias resistor 44, and also connect the emitters of the rectified output negative terminals 1 to 41 and 42 via the inductor 35, respectively. The collectors of the transistors 41 and 42 are connected to both ends of the primary winding 461 of the output transformer 46, and a resonant winding 4J45 is connected between both ends of the primary winding 461. 3, next winding 463
is connected to the bases of the transistors 41 and 42.

On the other hand, the midpoint C of the primary winding 461 of the output transformer 46
Intermediate taps d and e are provided between and both ends, respectively. A high frequency rectifier circuit such as a tie auto 48. is connected to these taps d and e via a current limiting transformer/17.
A full-wave rectifier circuit consisting of 49 is connected, and this rectifier circuit is further connected to the connection point between the capacitor 33 and the diode 34 to form a feedback circuit.

Then, f' is applied to the secondary winding 462 of the output transformer 46 of C1.
Connect the discharge lamp 50 as J. Note that this secondary winding 462 has a tap for supplying filament current to the filament electrode of the discharge lamp 50.

There is a Q.

Next, the operation of the apparatus constructed as described in Section J below will be described.

Now, when the AC power supply 31 is turned on, the gold wave rectifier circuit 32, J
A full-wave rectified output is generated, which is applied to the inverter 40 via the inductor 35. As a result, in the inverter 40, the rectified output is applied as a base current to the transistors 41 and 42 via the bias resistors 43 and 44. In other words, one of the transistors 41 and 42 turns on first due to a slight imbalance, but if the transistor 41 turns on first, the primary winding 46 of the output transformer 46
A current flows through 1. Therefore -C1 In this state, the primary winding 46
An oscillating voltage is generated by the inductance of 1 and the resonance capacitor 45, which generates an electromotive force in the tertiary winding 463, which in turn turns on transistors 1 to 42.

Therefore, in the same manner, the C1 registers 41 and 42 are turned on and off alternately. In this case, a rectified output is generated by the induced output of the primary winding 461 of the output transformer/16 through a rectifier circuit consisting of diodes 4, 8, and 49, and this output is given to the feedback output C capacitor 33. . As a result, the capacitor 33 is charged in a predetermined direction.

Further, this capacitor 33 is discharged when the rectified output of the rectifier circuit 32 becomes equal to or less than a predetermined voltage every half cycle, that is, the charging voltage of the capacitor 33 in this embodiment, and provides this discharge output to the inverter 40.

As a result, a high frequency output with no rest period is generated on the secondary winding @ 462 side of the output transformer 46 of the inverter 40, and the discharge lamp 37 is lit with good luminous efficiency using this high frequency output.

As described above, according to the present invention, a bus core is attached to the core of a high frequency leakage transformer to converge leakage magnetic flux,
By reducing the high-frequency magnetic flux passing through the windings, the high-frequency copper loss due to high-frequency eddy currents can be reduced, and by limiting the relationship between bus core length x and bus core gap length y, when excitation inductance and leakage inductance are constant. Since the sum of iron loss a3 J and resistance loss is reduced, the total loss of the lance can be reduced.

[Brief explanation of the drawing]

Figure 1 shows the windings of a conventional high frequency leakage transformer.
1b-J-plane C; FIG. 2 is a diagram of a high-frequency leakage 1 Herance winding according to one embodiment of the present invention cut at the upper surface of the magnetic core; FIG. A perspective view of the high frequency leakage 1 to lance magnetic core according to the example, FIG. 4 is a graph showing the relationship between the relative path XI agap length V/(X+V) and various losses in the transformer of FIG.
The figure is a perspective view of the magnetic core for the high frequency leakage transformer in Figure 2, Figure 6 is a graph showing the relationship between the relative pass core top length y/(x+y) and various losses in the transformer in Figure 5, and The figure is a circuit diagram of a discharge lamp lighting device to which the high frequency League-Sitrans of the present invention is applied. 21...Cross-shaped '1 Noah, 22...Main core,
23...Bass core, 25,461...Primary winding,
26.462...Secondary winding, 27...Zabcore,
46... Output lamp, 60... Discharge lamp. Patent applicant Tokyo Denki Kagaku Co., Ltd. Patent applicant Toshiba Electric Materials Co., Ltd. Agent Patent attorney 4P Tatsuo Tatsuo Patent attorney Tetsuya Ito 1st! 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] 1. A primary winding to which a high frequency voltage is applied, a secondary winding that supplies the induced voltage of this high frequency voltage to a load;
A main core in which the primary winding and the secondary winding are wound separately and both ends of this main core are connected via the outside of the primary winding d3 and the secondary winding, and the main core and the main core are connected together with the main core. In a high frequency leakage lance comprising a magnetic core consisting of a single core and a magnetic core forming a path, between the primary winding and the secondary winding of the main core or from the subcore to these one knob core. Alternatively, a bass core protruding toward the main core is provided, and the relationship between the protruding dimension x of this bass core and the gear cutting y from the tip of the bass core to the sub core or main core is 0.4≦y/(x
+y)≦0.8. 2. The high frequency leakage transformer according to claim 1, wherein the relationship between the path core protrusion dimension x and the gap dimension y is 0.4≦y, /(x + y)≦0.6.