JPH0845763A - Flyback transformer with control circuit - Google Patents

Abstract

PURPOSE:To provide a flyback transformer with a control circuit wherein malfunction of a high voltage control circuit caused by radiation noise is not generated and response to high voltage correction is excellent. CONSTITUTION:In a flyback transformer 1 built in one body by arranging a sub-case 15 accommodating and installing a high voltage control circuit 7 on a transformer case 14, the high voltage control circuit 7 is positioned on the opposite side of a coil member 5 to a high voltage film capacitor 9. The high voltage film capacitor 9 is formed by once surrounding the outermost winding with an earth conductor film 6 as an earth electrode. The earth conductor film 6 absorbs radiation noize generated from a high voltage coil of the coil member 5, and prevents the radiation noize from reaching the high voltage control circuit 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flyback transformer with a control circuit for applying a high voltage to the anode of a cathode ray tube such as a television receiver or a display device.

[0002]

2. Description of the Related Art FIG. 2 shows an example of a circuit of a flyback transformer 1 incorporated in a television receiver, a display device or the like. Flyback transformer 1
Is a core 4 into which a low voltage coil 2 and a high voltage coil 3 are fitted. The flyback pulse generated in the horizontal deflection output circuit is boosted and output from the high voltage output end of the high voltage coil 3 to smooth the high voltage output voltage. A high voltage is applied to the anode 28 of the cathode ray tube 27 via the high-voltage film capacitor 9 that operates. Further, a high-voltage control circuit 7 is provided in order to constantly supply a stable high-voltage output voltage from the high-voltage coil 3 to the anode 28. The high-voltage control circuit 7 detects the high-voltage output voltage and, for example, lowers the high-voltage output voltage. At this time, the crest value of the flyback pulse generated in the horizontal deflection output circuit is controlled to increase according to this amount of drop, and the high voltage output voltage is stabilized.

As shown in FIG. 4, the flyback transformer 1 is installed on a set substrate 26 on which the horizontal deflection output circuit, conductor patterns (not shown), etc. are formed.
A high voltage is applied to the anode 28 of the cathode ray tube 27 via the anode lead 29. The high voltage control circuit 7 is installed near the flyback transformer 1.

[0004]

By the way, the high voltage coil 3 radiates radio waves (including harmonics) of the flyback pulse to the periphery of the flyback transformer 1 as radiation noise, and this radiation noise causes a high voltage control circuit. There is a problem that the malfunction of No. 7 occurs and the stabilization control of the high voltage output voltage is hindered.

Further, since the high-voltage control circuit 7 is arranged away from the flyback transformer 1, the lead for detecting the high-voltage output voltage of the flyback transformer 1 and leading it to the high-voltage control circuit 7 becomes long, and a large impedance is produced. Since it has, the radiation noise emitted from the flyback transformer 1 will be carried, and there is a problem that it is difficult to detect an accurate high voltage output voltage.

The flyback transformer 1 circuit and the high voltage control circuit 7 are manufactured by different manufacturers,
Since the circuit constant of the flyback transformer 1 and the circuit constant of the high-voltage control circuit 7 are apt to be mismatched because they are incorporated into the set substrate 26 when the television receiver is assembled as separate and independent electronic parts, this mismatching is likely to occur. When the high voltage output voltage drops, even if the high voltage control circuit 7 controls the high voltage stabilization, the high voltage output voltage does not actually increase to compensate for the high voltage drop. There is a problem that the feedback control operation of the transformer 1 and the high voltage control circuit 7 does not cooperate well, the response of the high voltage correction is bad, and the setting of the high voltage output voltage value cannot be easily changed.

The present invention has been made to solve the above-mentioned problems, and an object thereof is to manufacture a high-voltage control circuit integrally with a flyback transformer to improve the response of high-voltage correction and to detect it with the high-voltage control circuit. It is to provide a flyback transformer with a control circuit that prevents noise of the high-voltage output voltage and that does not cause the high-voltage control circuit to malfunction due to radiation noise, and that accurately controls the stabilization of the high-voltage output voltage.

[0008]

In order to achieve the above object, the present invention is constructed as follows. That is, the flyback transformer with a control circuit of the first invention is a control circuit in which a coil body in which a high voltage coil is fitted to the outside of a low voltage coil and a circuit forming portion of a high voltage control system are integrally mounted in a transformer case. A flyback transformer having a grounding conductor member provided outside the high-voltage coil for blocking radiation noise radiated from the high-voltage coil. The ground conductor member serves as a radiation noise blocking member on the opposite side of the high-voltage coil. A circuit forming portion of a high voltage control system is provided at a position, and a second invention has a configuration of a flyback transformer with a control circuit of the first invention, and an output side of a high voltage coil. Is connected to a high-voltage film capacitor that smoothes the high-voltage output voltage. Is configured as characterized in that a grounding conductor portion which cross.

[0009]

In the present invention having the above-mentioned structure, when the flyback transformer is driven and the radiation noise is radiated from the high voltage coil, the radiation noise traveling in the direction of the circuit forming portion of the high voltage control system becomes It is absorbed by the ground conductor between the coils and the progress of radiation noise is cut off without reaching the circuit formation part. Even if the circuit formation part is close to the high voltage coil, it is not affected by radiation noise and the high voltage output voltage The flyback transformer applies a stable high voltage output voltage to the anode.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. In the description of the present embodiment, the same reference numerals will be given to the same names as those in the conventional example, and detailed description thereof will be omitted.

FIG. 1 shows the structure of a flyback transformer 1 with a control circuit according to this embodiment. In the figure,
The transformer case 14 has an accommodating chamber 17 for the coil body 5 and an accommodating chamber 18 for the high voltage film capacitor 9 in which the high voltage coil 3 is fitted on the outside of the low voltage coil 2. Are installed in the accommodating chambers 17 and 18, respectively, and the sub case 15 is arranged at a position opposite to the coil body 5 with respect to the high-voltage film capacitor 9, and the sub case 15 is provided in the concave claw 31 of the transformer case 14. The convex claw 32 of the sub case 15 is slidably fitted and is detachably or adhesively fixed to be integrated with the transformer case 1. The high voltage control circuit 7 is housed and installed in the sub case 15. Further, the focus case 13 of the focus pack 11 is fitted to the fitting claw 16 of the transformer case 14, and the focus pack 11 is mounted to the flyback transformer 1.

The equivalent circuit of the high voltage film capacitor 9 is
For example, as shown in FIG.
22 includes a capacitor body 24 formed in series. As shown in FIG. 3A, the capacitor body 24 includes two films 20 provided with a plurality of capacitor conductor films 21 at intervals, and an insulating film ( (Not shown). In the present embodiment, the film 20 is wound from the high-voltage end side, is flatly wound into an elliptical shape, and is wound around the outermost circumference of the earth conductor film 6 serving as an earth electrode. The high voltage control circuit 7 is provided between the coil body 5 and the coil body 5 to protect it from radiation noise. The ground conductor film 6 is connected to the ground point of a circuit board such as a television receiver and has the same potential as the ground potential of the circuit board.

When the flyback transformer 1 is driven and radiation noise is radiated from the high-voltage coil 3, the ground conductor film 6 drops the radiation noise reaching the high-voltage film capacitor 9 to the ground and absorbs it. Radiation noise is prevented from advancing to 7, and the high voltage control circuit 7 performs the stabilization control of the high voltage output voltage without being affected by the radiation noise.

According to the present embodiment, the radiation noise radiated from the high voltage coil 3 is absorbed and removed when it reaches the ground conductor film 6, and the progress of the radiation noise to the high voltage control circuit 7 is blocked. The malfunction of the high voltage control circuit 7 can be prevented, and even if the high voltage control circuit 7 and the high voltage coil 3 are close to each other, the stable control of the high voltage output voltage can be performed without any trouble.

Further, since the flyback transformer 1 is provided with the high-voltage control circuit 7 and integrated, the length of the lead for guiding the high-voltage output voltage of the flyback transformer 1 to the high-voltage control circuit 7 is shortened, and the impedance is reduced. The noise of the high voltage output voltage detection signal due to radiation noise is reduced,
The high voltage control circuit 7 can accurately detect the high voltage output voltage.

Further, as in the prior art, the flyback transformer 1 circuit and the high-voltage control circuit 7 are manufactured by separate manufacturers, respectively, and are not incorporated in the set substrate 26 when assembling the television receiver, but in the flyback. Since the transformer 1 is provided with the high-voltage control circuit 7 and is integrated and manufactured by the manufacturer of the flyback transformer, no mismatch occurs between the circuit constant of the flyback transformer 1 and the circuit constant of the high-voltage control circuit 7, and the high voltage The response of correction can be improved. Further, it is possible to flexibly change the response speed of the high voltage correction and the circuit constants of the flyback transformer 1 and the high voltage control circuit 7.

Further, as described above, since the flyback transformer 1 is provided with the high voltage control circuit 7, the set substrate 26
Since the conductor pattern for electrically connecting the flyback transformer 1 and the high voltage control circuit 7 is not required, the design of the conductor pattern and the like of the set board 26 is simplified, and the high voltage control circuit 7 is installed on the set board 26. Work can be omitted, and set board 26
Saves labor in installing electronic components in

The present invention is not limited to this embodiment, and various modes can be adopted. For example, in the above-described embodiment, the earth conductor member (earth conductor film 6) is formed on the outermost periphery of the high voltage film capacitor 9, but the high voltage control serves as a means for blocking radiation noise from the high voltage coil 3 (coil body 5). Similar effects can be obtained by forming a ground conductor member at a position for protecting the circuit 7, for example, at A or B shown in FIG.

Further, in the above embodiment, the high-voltage control circuit 7 is housed and installed in the sub case 15, and the convex claw 32 of the sub case 15 is fitted and integrated with the concave claw 31 of the transformer case 14. Instead of using 15, the coil body 5 and the high-voltage film capacitor 9 may be integrally housed in the transformer case 14, and at this time, the high-voltage control circuit 7 may be provided at a position opposite to the coil body 5 with respect to the high-voltage film capacitor 9. To place.
Further, instead of using the concave claw 31, for example, a mounting port is provided on the transformer case 14, and another mounting means such as inserting and mounting the convex claw 32 into the mounting port is used. May be attached.

Furthermore, in the above embodiment, the high voltage control circuit 7 is used as the circuit forming portion of the high voltage control system, but the same effect can be obtained by using other control circuits.

[0021]

According to the present invention, a ground conductor member is provided outside a coil body in which a high voltage coil is fitted on the outside of a low voltage coil, and a high voltage is provided at a position opposite to the coil body with respect to the ground conductor member. Since the circuit forming part of the control system is arranged, the ground conductor member absorbs the radiation noise radiated from the high-voltage coil, and blocks the progress of the radiation noise to the circuit forming part of the high-voltage control system, and the coil body and the circuit forming part. Even if and are brought close to each other, it is possible to prevent malfunction of the circuit forming portion of the high voltage control system due to radiation noise, and the flyback transformer can output a stable high voltage output voltage.

Further, since the flyback transformer is provided with the high voltage control system circuit forming portion to form one electronic component, the lead for guiding the high voltage output voltage output from the coil body to the circuit forming portion is shortened and the impedance is reduced. Noise due to radiation noise of the high-voltage output voltage detection signal can be reduced. Furthermore, the circuit constant of the flyback transformer and the circuit constant of the circuit forming portion of the high voltage control system can be matched, and the response of the high voltage control can be improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a flyback transformer with a control circuit according to an embodiment.

FIG. 2 is an explanatory diagram showing a circuit example of a flyback transformer.

FIG. 3 is an explanatory diagram showing an example of a high voltage film capacitor.

FIG. 4 is an explanatory diagram showing a conventional example.

[Explanation of symbols]

 1 Flyback Transformer 2 Low Voltage Coil 3 High Voltage Coil 4 Core 5 Coil 6 Earth Conductor Film 7 High Voltage Control Circuit 9 High Voltage Film Capacitor

Claims (2)

[Claims] 1. A flyback transformer with a control circuit, wherein a coil body having a high-voltage coil fitted to the outside of a low-voltage coil and a circuit forming portion of a high-voltage control system are integrally mounted to a transformer case, the high-voltage coil comprising: A ground conductor member for blocking radiation noise radiated from the high-voltage coil is provided outside the coil, and a circuit forming portion of the high-voltage control system is provided at a position opposite to the high-voltage coil by using this ground conductor member as a shield for radiation noise. Flyback transformer with control circuit provided. 2. A high-voltage film capacitor for smoothing a high-voltage output voltage is connected to the output side of the high-voltage coil, and an outer peripheral electrode of this high-voltage film capacitor is used as a ground conductor portion for blocking radiation noise of the high-voltage coil. A flyback transformer with a control circuit according to claim 1.