CN1070309C - Adjustable saturable transformer - Google Patents

Abstract

The present invention relates to an adjustable saturable transformer which comprises an iron core, a magnetic saturation control coil and a linearity compensation coil, wherein the cross section of the iron core presents an E1 or an EE shape, and a gap is formed on one side of the iron core; the magnetic saturation control coil is positioned on a middle branch of the iron core; when direct current is switched to the magnetic saturation control coil, a magnetic loop saturation region can be formed between the middle branch of the iron core and the side of the iron core without a gap, and a magnetic loop saturable region is formed on the other side of the iron core; the linearity compensation coil is positioned on the side of the iron core without a gap, and an inner circle magnetic loop is formed between the linearity compensation coil and an intermediate stage of the iron core; an outer circle magnetic loop is formed between the linearity compensation coil and the side of the iron core with the gap. The adjustment of saturation points of the linearity compensation coil can be realized by adjusting the current of the magnetic saturation control coil.

Description

Adjustable saturable transformer

The present invention relates to a kind of adjustable saturable transformer, especially refer to a kind of linear compensation transformer that is applicable to the horizontal deflecting circuit of cathode ray tube, this transformer not only has concurrently to be revised the image left side and elongates outside the effect of distortion, has more adjustable saturation point and only need adjust the magnitude of current and be applicable to various horizontal frequencies and can overcome the magnetic interference problem that the open-flux path of conventional linear compensation transformer is derived.

In the prior art, disclose in clear 56-109074 number " adjustable saturable transformer " patent of invention as day disclosure special permission communique, a kind of adjustable saturable transformer that is used for the pincushion distortion of correcting TV receiver is disclosed, this transformer comprises that the cross section is the iron core of EI shape, and a magnetic saturation control coil is positioned at iron core middle branch place; Shown in Figure 1 as in this patent, it makes the E type be alignd with relative certain intervals lg with the easy saturable core 22,23 of I type, wherein the 24A of foot of E sections core 22 central authorities is wound with control coil 27, and the 24B of foot, the 24C at two ends is wound with Be Controlled coil 28B, 28C with mutual differential manner of execution again.

When side pinuchsion occurring, on control coil 27, pass to the electric current that the cycle changes, Be Controlled coil 28B, 28C horizontal yoke current are imposed Modulation and Amplitude Modulation, so that carry out the correction of horizontal deflection output.

In addition, the horizontal deflection coil of cathode ray tube makes horizontal scanning line by under the characteristic that scans to the right on the left of the screen now, because the deflection current of deflecting coil is complete impartible sawtooth waveform, cause being divided into the distortion that presents exponential curve corresponding to the impedance part of scan period, this promptly causes the display picture left side to generate the phenomenon of elongation, and this distortion can be by following formulate:

d(％)=(1/2)ts[(Ry+rs)/Ly]×100％

Ly: yoke inductance

Ts: sweep time

Ry: deflecting coil impedance

Rs: transistor internal driving

Also be to cause to generate and elongate district 42 as the left-hand portion distortion of the circular image 41 of Fig. 3 viewing area 40, cause image 41 to generate under the defective of elongating distortion, general settling mode, for shown in the horizontal deflecting circuit of the multifrequency display of Fig. 2 C, in the below of the horizontal deflection coil 50 of deflection circuit then for select anti-saturation coil 60 places of different induction reactance by the automatic switchover of multifrequency selector switch, reach the compensation of the varying level scanning frequency being carried out the image level distortion, why it can reach solves the characteristic that distortion is elongated in described image left side, be mainly each anti-saturation coil of utilization 60 for when the just reverse different current direction, can present different degree of saturation and reach according to this, when also being corresponding to Fig. 3 left-side images position, for making anti-saturation coil 60 be undersaturated condition, use the size of current of revising horizontal deflection coil, to revise foregoing problems.

But structure with the linear compensation of above-mentioned horizontal deflection, then must use many group anti-saturation coils 60 to carry out the level distortion compensation to different frequency, obviously, this structure is too complicated, in addition, the structure of each anti-saturation coil 60, for shown in the structural plan figure and equivalent circuit diagram of Fig. 2 A and Fig. 2 B, except twining on the iron core 62 the linear bucking coil 61, an end that more is iron core 62 is combined with permanent magnet 63, and this promptly belongs to a kind of open-flux path form basically, that is has the magnetic field interference problem, so, promptly influence cathode ray tube easily and cause colorimetric purity and the not good phenomenon of the look degree of convergence, and owing to the horizontal frequency of its anti-saturation coil 60 along with display constantly promotes, under the also proportional relation of usage quantity increases, foregoing problems then more becomes seriously, truly has necessity of being improved.

Main purpose of the present invention is: a kind of adjustable saturable transformer simple in structure is provided, for forming a kind of particular design that can change its saturation point by a control coil, reaching only needs single element can replace the fixed anti-saturation coil of known many groups, obtain outside the advantage of simplifying compensation circuit, this transformer more need not permanent magnet and Inside coil be the design of closed magnetic circuit, more can solve magnetic disturbance and the problem of deriving at all.

Of the present invention time a purpose is: the adjustable saturable transformer that provides a kind of non-electromagnetic field to disturb, being mainly with a cross section is that EE or EI and a side form gapped iron core, and twine a saturated control coil at the interpole of iron core, and be the linear bucking coil of winding in the no clearance side of iron core, form the saturable transformer of a closed magnetic circuit, and can see through the magnitude of current of adjusting by this saturated control coil, can adjust the saturation point of this linear compensation coil, replace outside the known fixed anti-saturation coil and can reach, more a kind of no permanent magnet and closed magnetic circuit, and non-electromagnetic field interference problem.

For achieving the above object, the present invention takes following scheme:

Adjustable saturable transformer of the present invention is one to be used for the linear compensation element of the horizontal deflecting circuit of multifrequency display or cathode ray tube, comprising:

One iron core, its cross section are EI shape or EE shape, form the gap in iron core one side;

One magnetic saturation control coil is positioned at iron core middle branch place;

When the magnetic saturation control coil passes to direct current, can between the interpole of iron core and its no clearance side, form the magnetic loop saturation region, between iron core middle branch and gapped side, then form the magnetic loop saturable region;

The side, no gap of iron core is provided with a linear compensation coil, forms an inner ring magnetic loop between itself and the iron core interpole, its with the gapped side of iron core between formation outer ring magnetic loop;

The adjustment of the mat magnetic saturation control coil magnitude of current is to adjust the full chalaza of linear compensation coil.

Further specify architectural feature of the present invention below in conjunction with drawings and Examples.

Brief Description Of Drawings:

Figure 1A is applied to the circuit diagram of the embodiment of horizontal deflecting circuit for the present invention.

Figure 1B is the deflection current waveform schematic diagram of Fig. 1.

Fig. 2 A is the schematic diagram of known multifrequency display horizontal deflecting circuit.

Fig. 2 B is the plane graph of known anti-saturation coil.

Fig. 2 C is the equivalent circuit diagram of known anti-saturation coil.

Fig. 3 is the schematic diagram of horizontal deflection distortion.

Fig. 4 A, B are the floor map of EI of the present invention and EE iron core.

Fig. 5 A, B are respectively schematic diagram and the magnetic loop schematic diagram that the present invention adds the magnetic saturation control coil.

Fig. 6 A, B are respectively schematic diagram and the magnetic loop schematic diagram that the present invention adds the linear compensation coil.

Fig. 7 A, B are respectively in the linear compensation coil and add in contrast to the schematic diagram and the magnetic loop schematic diagram of the electric current of Fig. 6 A.

Fig. 8 A, B are respectively schematic diagram and the magnetic loop schematic diagram that two groups of coils are paramagnetic.

Fig. 9 A, B are respectively schematic diagram and the magnetic loop schematic diagram that two groups of coils are contrary magnetic.

Figure 10 is a current waveform schematic diagram of the present invention.

Shown in Figure 1A, be mainly below the deflecting coil 50 of the horizontal deflecting circuit of cathode ray tube serial connection one and can adjust the linear compensation transformer T1 of saturation point, solve image left side elongation problem of dtmf distortion DTMF to reach, Figure 1B is the waveform of expression deflection current, and this linear compensation transformer T1 is by comprising that a linear compensation coil L1 who is connected in series with aforementioned deflecting coil 50 and a magnetic saturation control coil L2 are formed, connect one group of matrix current adjustment circuit that is constituted by transistor 32 and variable resistor 31 at magnetic saturation control coil L2 place, to supply the direct voltage that magnetic saturation control coil L2 one continues, and adjust size of current by magnetic saturation control coil L2 via the impedance that changes variable resistor 31, can change the saturation point of linear compensation coil L1, like this, through with the occasion of this structure applications in the multiple horizontal frequency of multifrequency display, can change the numerical value of variable resistor 31 and correspondingly adjust linear compensation coil L1, make it can under the varying level scanning frequency, form different compensation effects, form a kind of horizontal deflection compensation that this single linear compensator transformer T2 can reach each frequency range that only needs, need not to dispose complexity and inconvenience that too much fixed anti-saturation coil and solution are derived.

The structure of linear compensation transformer T1, more a kind of design that need not any permanent magnet, and be a kind of closed magnetic circuit, more do not have the magnetic field interference problem that known anti-saturation coil is caused, form a kind of particular design that can solve horizontal deflection distortion and magnetic field interference simultaneously.

As Fig. 4 A, shown in the B, the iron core position of linear compensation transformer of the present invention, the iron core that is EE or EI by the cross section all can be reached, if to use the EI iron core is example, then shown in Fig. 5 A, for the one side at the iron core that is combined into day font is to be formed with suitable gap 10, it is gapless asymmetric that opposite side then is, at the middle branch position of iron core is to twine magnetic saturation control coil L2 thereon, through as it just be with Fig. 5 A in the adding of the end points of this magnetic saturation control coil L2, negative (+,-) during direct current shown in the electrode, can form the state shown in Fig. 5 B, for form two magnetic loops 11 by the mediad both sides, 12, and because two magnetic loops 11,12 because of one is closed, and another has gap 10 events, forms a saturation region A and saturable region B respectively.

Shown in Fig. 6 A, B, then be at the gapless side position of aforementioned iron core wrap wire bucking coil L1, and under "on" position, be positioned at the outer ring magnetic loop 22 of the inner ring magnetic loop 21 of aforementioned saturation region A and the saturable region B that flows through for formation, shown in Fig. 7 A, B, when changing the sense of current of linear compensation coil L1, then can change the direction of aforementioned inside and outside circle magnetic loop 21,22.

Shown in Fig. 8 A and Fig. 9 A, the occasion that on iron core, adds linear compensation coil L1 and magnetic saturation control coil L2 simultaneously, and under the sense of current that does not change magnetic saturation control coil L2, shown in Fig. 8 A, when adding negative current in linear compensation coil L1 place, the relation of its magnetic loop is promptly shown in Fig. 8 B, magnetic loop 11 at the magnetic saturation control coil L2 at A position, the saturation region of iron core is in the same way (paramagnetism) for the inner ring magnetic loop 21 with linear compensation coil L1, and owing to this iron core zone presents under the phenomenon of extremely low magnetic resistance in the crack continuously, that is linear compensation coil L1 is under the negative current flow regime, only the little electric current of need can make iron core reach capacity easily under flowing, so linear compensation coil L2 presents the characteristic of general resistance, so deflection current is not had any restriction (deflection current is not subjected to image), on the contrary, be subjected to deflection current counter-rotating and when changing forward current flow into (shown in Fig. 9 A) in linear compensation coil L1, then corresponding magnetic loop changes promptly shown in Fig. 9 B, owing to linear compensation coil L1 inner ring magnetic loop 21 is under the state that diamagnetism presents high magnetic resistance for the magnetic loop 11 with magnetic saturation control coil L2, promptly with the magnetic loop that the be positioned at saturation region B 12 formation paramagnetic loops of outer ring magnetic loop 22 with magnetic saturation control coil L2, more since these magnetic circuits have gap 10 exist under (can't make it is saturated) with little electric current, can be by the magnetic saturation control coil L2 magnitude of current adjusting saturation point, that is the electric current of linear compensation coil L1 is subjected to the magnitude of current decision of magnetic saturation control coil L2.

And be relevant to aforementioned in the positive negative sense electric current of linear compensation coil L1 circulation and the waveform correlation of magnetic saturation control coil L2 circulating current variation, promptly as shown in figure 10, the solid line of drawing is to be shown in not apply the deflection current B that is presented under any compensating coefficient, the sawtooth waveform that indicates the dotted line formula of L1 is the output current of expression linear compensation coil L1, and the dotted line of the drawing stepped variation in top is the current value of magnetic saturation control coil L2, in this figure, can know discovery, when linear compensation coil L1 is negative current flow, promptly because aforementioned under saturated fully state, moving, for being synchronous variation with deflection current, and for the forward current aspect of linear compensation coil L1, the proportional relationship change of electric current that then applies the height of electric current and linear compensation coil L1 is circulated according to magnetic saturation control coil L2, so, the electric current that is promptly suitably proved magnetic saturation control coil L2 is bigger, then degree of saturation is higher, and the electric current adjustment by magnetic saturation control coil L2, can optionally change the position that its saturation point takes place, reach and revise the elongation distortion that each horizontal frequency generated.

The present invention has following effect:

Since above-mentioned linear compensation transformer T1 form asymmetric and only a side form the gap, can By the control of the magnic saturation and control coil L2 magnitude of current, make the linear compensation coil L1 can be just Form different saturation effect under the negative current situation, and have the characteristic of adjusting saturation point, so Not only can revise the characteristic of level distortion, more owing to wherein need not additional any permanent magnet, and Its magnetic loop also only is loop but not under the known open pattern, more can effectively solves habit Know that magnetic field unwarranted intervention that the anti-saturation coil generates derives to excitation and the look degree of convergence Harmful effect, the present invention have stronger practicality.

Claims (2)

1, a kind of adjustable saturable transformer is one to be used for the linear compensation element of the horizontal deflecting circuit of multifrequency display or cathode ray tube, comprising:

One iron core, its cross section is EI shape, forms the gap in iron core one side;

One magnetic saturation control coil is positioned at iron core middle branch place; It is characterized in that:

When the magnetic saturation control coil passes to direct current, can between the interpole of iron core and its no clearance side, form the magnetic loop saturation region, between iron core middle branch and gapped side, then form the magnetic loop saturable region;

The side, no gap of iron core is provided with a linear compensation coil, forms an inner ring magnetic loop between itself and the iron core interpole, its with the gapped side of iron core between formation outer ring magnetic loop;

The adjustment of the mat magnetic saturation control coil magnitude of current is to adjust the full chalaza of linear compensation coil.

2, adjustable saturable transformer according to claim 1 is characterized in that, the cross section of described iron core is EE shape.

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