JPH0638063A - Flyback transformer protecting device - Google Patents

Abstract

PURPOSE:To protect a flyback transformer and peripheral parts by stopping the operation of the flyback transformer when external discharging is generated from the flyback transformer. CONSTITUTION:The flyback transformer protection circuit is constituted so that an external discharging detection board 31 is provided so as to cover a flyback transformer 1, and a judge circuit 32 and a relay 33 are connected to this external discharging detection board 31. The relay 33 is connected between the high voltage side of a low voltage coil 5 of the flyback transformer 1 and a ground 13. Thus, when external discharging is detected, the relay 33 is opened, the impression of flyback pulses to the low voltage coil 5 is halted, and the operation of the flyback transformer 1 is halted. Then, the flyback transformer 1 and the peripheral parts can be protected, and fire accidents caused by external discharging can be effectively prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flyback transformer protection device for protecting a flyback transformer and peripheral components by external discharge from the flyback transformer.

[0002]

2. Description of the Related Art Here, a high voltage generator including a flyback transformer and a horizontal deflection circuit according to the prior art is shown in FIGS.

In the figure, 1 is a flyback transformer mounted on a substrate A, 2 is a transformer case constituting the flyback transformer 1, and the transformer case 2 is formed of an insulating resin material in a cylindrical shape with a bottom. A low voltage coil 5, a high voltage coil 6, a high voltage diode 7 and the like, which will be described later, are housed inside and molded with an insulating resin. The flyback transformer 1 is fixed to a cylindrical anode lead wire insertion portion 2A into which an anode lead wire 8 to be described later is inserted, a chassis of a television picture tube (neither shown), etc. on the upper surface of the transformer case 2. A fixed portion 2B is provided so as to project, and a focus pack 3 is attached to the side surface.

Reference numeral 4 denotes a core formed by abutting "U" -shaped core members, one leg portion of the core 4 is inserted into the transformer case 2, and the other leg portion is the transformer case. It is arranged on the outer peripheral side of 2.

Reference numeral 5 denotes a low-voltage coil wound around a low-pressure bobbin (not shown) which is provided by being inserted into one leg of the core 4,
6, 6, ... Are high-voltage coils formed by coaxially winding or section winding a plurality of high-voltage windings on a high-voltage bobbin (not shown) provided on the outer peripheral side of the low-voltage coil 5, 7, 7 ,. ... showing a high-voltage diode alternately connected in series with each high-voltage winding constituting the high-voltage coil 6. The high-voltage diode 7A on the highest pressure side is connected to an anode lead wire 8, and the anode lead wire 8 is provided at an end portion. It is connected to the side surface of the cathode ray tube 10 via the anode cap 9 and is adapted to apply a DC high voltage.

Reference numerals 11 and 12 denote focus voltage resistors and screen voltage resistors, which are variable resistors and are provided in the focus pack 3, respectively. The focus voltage resistor 11 and the screen voltage resistor 12 are molded by resin. It is housed in the focus pack 3. Reference numerals 11A and 12A denote resistance adjusting knobs of the resistors 11 and 12, and the knobs 11A and 12A project from the focus pack 3.

A focus voltage resistor 11 and a screen voltage resistor 12 are connected in series between the high voltage diode 7A located on the highest pressure side and the ground 13.
The focus voltage resistor 11 is connected to the focus voltage lead wire 14, and the screen voltage resistor 12 is connected to the screen voltage lead wire 15.

Reference numeral 16 denotes a horizontal deflection circuit connected to the high voltage side end of the low voltage coil 5. The horizontal deflection circuit 16 includes a horizontal output transistor 17, which is an NPN transistor, a damper diode 18, a resonance capacitor 19, and a deflection yoke. It is composed of a horizontal deflection coil 20, an S-shaped correction capacitor 21, etc., the collector side of the transistor 17 is connected to the high voltage end side of the low voltage coil 5, and the emitter side is grounded by 13.
Grounded to. The low voltage end of the low voltage coil 5 is connected to a flyback power source 22 that applies a DC voltage to the low voltage coil 5.

In the high voltage generator thus constructed, a basic pulse is applied to the base of the transistor 17 from a horizontal driving circuit (not shown), so that the collector pulse (flyback) from the collector of the transistor 17 is applied. Pulse) is output to the low voltage coil 5. As a result, a high voltage determined by the number of coil turns is induced in the high-voltage coil 6, these high voltages are added and rectified by the high-voltage diode 7, and the anode lead wire 8 and the anode cap 9 are connected from the highest-voltage side high-voltage diode 7A. A DC high voltage is output to the cathode ray tube 10 via the.

[0010]

By the way, in the above-mentioned conventional technique, the insulation distance H is required around the flyback transformer 1 so that external discharge from the flyback transformer 1 does not occur. Even when it is mounted on the substrate A as described above, the peripheral component B such as the horizontal deflection circuit 16 is mounted at a position having an insulation distance H or more. The insulation distance H is described in the specifications, and the set maker mounts the flyback transformer 1 on the television receiver according to the description.

There is no problem when the user uses the television receiver under the operating conditions in accordance with the operating instructions, but the operating conditions differ from those in the operating instructions, such as a bathroom or a sauna with extremely high humidity. The humidity around the flyback transformer 1 is extremely high when it is used in an environment such as when a vase is placed on a television receiver and the vase collapses and water collects around the flyback transformer 1. As a result, external discharge easily occurs.

As a result, when the flyback transformer 1 is externally discharged under the above conditions, the peripheral component B is broken, the low voltage coil 5 and the high voltage coil 6 of the flyback transformer 1 are broken, and the high voltage diode 7 is broken. And so on.

Further, there is a risk that dust accumulated around the flyback transformer 1 will be ignited by this external discharge, causing a fire accident.

The present invention has been made in view of the above-mentioned problems of the prior art, and the present invention is a flyback transformer protection capable of stopping the application of a DC high voltage from the flyback transformer when an external discharge of the flyback transformer is detected. The purpose is to provide a device.

[0015]

A flyback transformer protection device adopted by the present invention to solve the above-mentioned problems includes a flyback transformer including a low-voltage coil, a high-voltage coil and a core, and a flyback transformer. External discharge detection means provided to be separated by a predetermined distance so as to cover, and detecting external discharge from the flyback transformer,
And a voltage application stopping means for stopping the voltage application to the flyback transformer when the external discharge detecting means detects an external discharge from the flyback transformer.

[0016]

With the above structure, when the external discharge detecting means detects the external discharge, the voltage applying means is activated to immediately stop the voltage application to the flyback transformer and continue the external discharge from the flyback transformer. To prevent.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In the embodiments, the same components as those of the above-described conventional technique are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, reference numeral 31 denotes an external discharge detecting plate as an external discharge detecting means provided on the substrate A so as to cover the flyback transformer 1 with a predetermined distance (insulation distance H) apart from it. The plate 31 is made of a conductive material and is configured to have a potential close to the ground potential, and the resistance adjusting knobs 11A and 12A of the focus voltage resistor 11 and the screen voltage resistor 12 described above can be adjusted from the outside on the side surface thereof. Thus, the through holes 31A and 31B are formed.

Reference numeral 32 denotes a determination circuit connected to the external discharge detection plate 31, and the determination circuit 32 outputs an excitation signal for closing a relay 33, which will be described later, when no external discharge is generated from the flyback transformer 1. If an external discharge occurs from the flyback transformer, relay 3
The output of the excitation signal to 3 is stopped and the relay 33 is opened.

Reference numeral 33 indicates a relay connected between the flyback power source 22 on the low voltage side of the low voltage coil of the flyback transformer 1 and the ground 13, and the relay 33 applies an excitation coil to the exciting coil from the judging circuit 32. The current is controlled to open and close internal switches (neither shown).

The determination circuit 32 and the relay 33 are specific examples of the voltage application stopping means according to this embodiment.

The operation of the high-voltage device of the present embodiment having the above-mentioned structure is the same as that of the flyback transformer 1 when there is no external discharge.

Therefore, in this embodiment, the external discharge detection plate 31 is provided around the flyback transformer 1, the determination circuit 32 and the relay 33 are connected to the external discharge detection plate 31, and the relay 33 is connected to the flyback transformer. Since the flyback transformer 1 is connected between the high voltage side of the low voltage coil 5 and the ground 13, the relay 33 is activated by the excitation signal from the determination circuit 32 when no external discharge is generated from the flyback transformer 1.
Is closed. As a result, a flyback pulse is applied from the horizontal deflection circuit 16 to the low voltage coil 5, a boost is achieved in the flyback transformer 1, and a high DC voltage is applied to the cathode ray tube 10 via the anode lead wire 8 and the anode cap 9. To do.

On the other hand, when an external discharge is generated from the flyback transformer 1, it is discharged to the external discharge detection plate 31 close to the ground potential, and the external discharge detection plate 31 outputs a remarkably high instantaneous voltage. Then, the determination circuit 32 compares whether or not the instantaneous voltage is higher than a predetermined voltage level, and when it determines that the instantaneous voltage is equal to or higher than the predetermined voltage level, the output of the excitation signal to the relay 33 is stopped. As a result, the relay 33 is opened, and the low voltage coil 5 and the ground 13 are disconnected. As a result, the application of the flyback pulse from the horizontal deflection circuit 16 to the low voltage coil 5 is stopped, and the operation of the flyback transformer 1 is prohibited. As a result, the output of the DC high voltage from the flyback transformer 1 is stopped.

Therefore, in this embodiment, the application of the flyback pulse from the horizontal deflection circuit 16 to the low voltage coil 5 of the flyback transformer 1 can be prohibited at the moment when the external discharge is generated from the flyback transformer 1. You can
The operation of the flyback transformer 1 is stopped. Then, the external discharge from the flyback transformer 1 is surely prevented from continuing, the low-voltage coil 5, the high-voltage coil 6 and the high-voltage diode 7 constituting the flyback transformer 1 are prevented from being destroyed, and the substrate A is It is possible to reliably prevent the mounted other peripheral components from being destroyed.

Furthermore, since the external discharge detection plate 31 is provided on the substrate A so as to cover the flyback transformer 1, it is possible to reduce the intrusion of dust and the like from the outside. Then, as described above, it is possible to effectively prevent a fire accident due to the synergistic effect of prohibiting continuous external discharge from the flyback transformer 1 and reducing dust and the like around the flyback transformer 1. .

On the other hand, in the television receiver using the flyback transformer protection device according to the present embodiment, the user performs a usage method that violates the instruction manual in a humid place such as a bathroom or a sauna. When an external discharge is generated from the flyback transformer 1, the protection circuit is activated to automatically stop the television receiver, thereby notifying the user that the usage conditions are not met.

In the above embodiment, the plate-shaped external discharge detecting plate 31 made of a conductive material is used as the external discharge detecting means, but the present invention is not limited to this, and a breathable net-like member is used. However, it may be in the form of a coil, and in short, it may be provided so as to cover the flyback transformer 1 at a predetermined distance (insulation distance H). Furthermore, the predetermined distance may be shorter than the insulation distance H.

Further, the connection position of the relay 33 is not limited to the position between the low voltage coil 5 and the ground 13, and may be connected between the emitter of the horizontal output transistor 17 of the horizontal deflection circuit 16 and the ground 13. , May be connected between the base of the horizontal output transistor 17 and the horizontal drive circuit,
The point is that it may be a position where the application of the flyback pulse to the low voltage coil 5 can be stopped.

Further, the voltage application stopping means is the determination circuit 32.
It is not limited to the relay 33 and the relay 33, but a fuse that blows or a breaker that opens when external discharge from the flyback transformer 1 is detected may be provided.

[0031]

As described above in detail, according to the present invention, the external discharge detecting means for detecting the external discharge from the flyback transformer is provided at a predetermined distance from the flyback transformer. When the external discharge is detected by the configuration, the voltage application to the flyback transformer is stopped by the voltage application stopping means, so that the external discharge from the flyback transformer can be prevented from continuing and the flyback transformer can be protected. In addition, it is possible to surely protect peripheral parts and to effectively prevent a fire accident due to external discharge.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an external discharge detection plate arranged to cover a flyback transformer as a flyback transformer protection device according to an exemplary embodiment of the present invention.

FIG. 2 is a cross-sectional view as seen from the direction of arrows II-II in FIG.

FIG. 3 is a circuit configuration diagram of a high voltage generator and a flyback transformer protection device according to the present embodiment.

FIG. 4 is an external view showing a flyback transformer and peripheral components according to a conventional technique.

FIG. 5 is a circuit configuration diagram of a conventional high voltage generator.

[Explanation of symbols]

 1 Flyback Transformer 5 Low Voltage Coil 6 High Voltage Coil 7 High Voltage Diode 31 External Discharge Detection Plate (External Discharge Detection Means) 32 Judgment Circuit (Voltage Application Stopping Means) 33 Relay (Voltage Application Stopping Means) A Board B Peripheral Parts H Insulation Distance ( (Predetermined distance)

Claims (1)

[Claims] 1. A flyback transformer including a low-voltage coil, a high-voltage coil, and a core, and an external device that is provided at a predetermined distance from the flyback transformer so as to cover the flyback transformer and detects external discharge from the flyback transformer. Flyback transformer protection comprising discharge detection means and voltage application stopping means for stopping voltage application to the flyback transformer when the external discharge detecting means detects an external discharge from the flyback transformer. apparatus.