JPH0732463B2 - Anomaly detection and protection equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to an abnormality detection device for detecting the occurrence of an abnormal state in a horizontal deflection circuit used in a television receiver, a television monitor, a CRT display device, and the like. And when such an abnormal condition is detected, the power supply to the horizontal deflection circuit or the power supply to the entire device such as a television receiver is cut off to prevent the occurrence of disasters such as smoke and fire. The present invention relates to a protection device for doing so.

[Prior Art] Generally, a horizontal deflection circuit used in a television receiver or the like is incorporated in a printed circuit board, but this horizontal deflection circuit has a high frequency and a large amount of current flows. The value of the inductance of the horizontal deflection circuit is large, and this portion has a constant current characteristic. Therefore, if there is a contact failure such as a soldering failure or a half-breakage in this portion, excessive power consumption occurs between the portion where the contact failure occurs and the pattern of the substrate, and the arc causes the portion to be carbonized. , Resistance is created in the contact failure accident part. Here, since the horizontal deflection circuit has a constant current characteristic, carbonization progresses and the resistance value increases, and even when the resistance value increases in this way, the flowing current is much less than before the accident. This did not change, and as a result, the area that caused the accident accelerated heat generation, the board burned out, and this often caused smoke and fire. Moreover, as described above, since this circuit has a constant current characteristic, it is difficult to detect such an accident with the overcurrent detection circuit, and there is no effective means to solve this problem until now, and smoke is emitted. It became a social problem as a color TV (for example, the Yomiuri Shimbun,
(See the column "Life Safety Notes" in August 1981).

[Object] Therefore, an object of the present invention is to provide an abnormality detection device capable of appropriately detecting an abnormal current (or an unsteady current) generated in a horizontal deflection circuit to detect an abnormality in the circuit. .

Another object of the present invention is to appropriately detect an abnormal current (or an unsteady current) generated in the horizontal deflection circuit, and to properly cut off the power supply to the horizontal deflection circuit by the detection output. To provide a protection device.

[Structure of the Invention] When the above-described contact failure accident occurs, the present inventor has found that an abnormal current (or an unsteady current) flows between the component causing the accident and the horizontal deflection circuit due to this current. The present invention has been completed on the basis of the recognition of the fact that noise appears in the current flowing through the coil inside the coil, and the present invention utilizes such noise to detect the occurrence of an accident. By shutting off the power supply to the horizontal deflection circuit before the accident becomes serious, it is possible to prevent a major disaster from occurring due to the accident.

That is, the abnormality detection device of the present invention comprises a noise current detecting means electromagnetically coupled to the horizontal deflection current path of the horizontal deflection circuit and detecting a noise current component superimposed on the current flowing through the horizontal deflection circuit at the time of abnormality, and the noise current. Rectification means for passing only a component having a polarity opposite to the retrace pulse of the retrace pulse and noise current detection signal being output from the detection means, and the horizontal deflection circuit according to the output from the rectification means. And an output means for detecting an abnormality in the electric current in the inside.

Here, the output means has a capacitor that stores the rectified output from the rectifying means, and a semiconductor element that operates according to the output of the capacitor, and obtains the detection output of the current abnormality from the semiconductor element. You can

The protection device of the present invention comprises a noise current detecting means electromagnetically coupled to a horizontal deflection current path of a horizontal deflection circuit, and a noise current detecting means for detecting a noise current component superimposed on a current flowing through the horizontal deflection circuit when an abnormality occurs, and the noise current detecting means. Of the retrace pulse and the noise current detection signal in the output of the rectifying means for passing only the component having the opposite polarity to the retrace pulse, and the current in the horizontal deflection circuit according to the output from the rectifying means. And an interrupting device for interrupting the supply of electric power to the horizontal deflection circuit by the detection output from the output device.

Here, the output means has a capacitor that stores the rectified output from the rectifying means, and a semiconductor element that operates according to the output of the capacitor, and obtains the detection output of the current abnormality from the semiconductor element. You can

The interrupting means can supply the abnormality detection output to the horizontal drive circuit of the horizontal deflection circuit to stop the generation of the horizontal drive signal.

The abnormality detection output from the semiconductor element can be supplied to the X-ray radiation prevention circuit of the horizontal deflection circuit to operate the X-ray radiation prevention circuit.

[Examples] The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic diagram of a horizontal deflection circuit used in a general television receiver or the like. Here, Q1 is a transistor as a switching element of the horizontal deflection output stage, D1 is a damper diode, C1 is a resonance capacitor, and T1 is a horizontal output transformer or a flyback transformer. The coil L1 is a horizontal deflection yoke, the coil L2 is a horizontal amplitude adjustment coil, and the coil L3 is a horizontal linearity correction reactor. C2 is a capacitor for S-shaped distortion correction and DC blocking. Components L1 to L3 and C2 mentioned above, plus transistor Q1 and diode D
1, capacitor C1 and transformer T1 are printed circuit board PB
It is placed on top. Further, Vcc is a power supply, HD is a horizontal drive pulse from a horizontal drive circuit (not shown), and Id is a horizontal deflection current.

The present invention is based on the circuit components L1, L2, L3, C1, C2, T1 shown in FIG.
The present invention is intended to prevent heat generation, smoke ignition, and the like due to increased loss of the component or its mounting portion caused by half-breakage or poor contact such as, and the basic configuration of the abnormality detection and protection device of the present invention for that purpose is shown in FIG. . Here, the same parts as those in FIG. 1 are designated by the same reference numerals.

In FIG. 2, reference numeral 1 is a horizontal drive circuit capable of forming, for example, a horizontal oscillation circuit, a drive circuit, an AFC circuit and an X-ray radiation prevention circuit in the form of an integrated circuit. Q1 is a horizontal deflection output stage switching element corresponding to the transistor Q1 of the horizontal deflection circuit shown in FIG. L is a horizontal deflection yoke
It is a coil as a generic term representatively showing L1, horizontal amplitude adjusting coil L2, linearity correcting coil L3, and the like.

Reference numeral 2 is a detection coil that is electromagnetically coupled to the current path of the horizontal deflection current Id to detect this current Id. The detection signal S1 extracted by the detection coil 2 is supplied to the abnormality detection circuit 3,
The horizontal deflection drive circuit 1 is shut off by the abnormality detection output S2 from the abnormality detection circuit 3.

For example, when a contact failure occurs in the connection part of the coil L or the capacitor C2, the output voltage S2 is generated in the abnormality detection circuit 3, and as a result, the horizontal drive output HD from the horizontal drive circuit 1 is stopped and the contact failure part is detected. The applied power also becomes zero, and it is possible to prevent smoking and the like.

Next, a more specific embodiment of the present invention is shown in FIG. Here, the horizontal drive circuit 1 has an X-ray radiation prevention circuit, and 1A is its X-ray radiation prevention voltage input terminal. The horizontal deflection current extracted by the detection coil 2 is supplied to the abnormality detection circuit 3.

The abnormality detection circuit 3 has a rectifying diode D2, a capacitor C3 that stores the rectified output, and a discharge resistor R1 connected in parallel with the capacitor C3. The terminal 34 is grounded or the detection voltage from the X-ray radiation preventing voltage detection circuit 4 is applied thereto. Here, the voltage extracted from the detection coil 2 by appropriately setting the polarity and the coupling degree of the detection coil 2.
With respect to the terminal 32, the waveform of S1 causes the retrace pulse to appear in the negative polarity at the terminal 31 and the slight level of the positive polarity appear in the normal state at the terminal 31, as shown in FIG. 4A. In FIG. 4A, H is a horizontal deflection period, and FB is a horizontal deflection retrace line period.

Then, as the output S2 of the abnormality detection circuit 3, in the normal state, a voltage of almost zero appears between the terminals 33 and 34,
The voltage at which the X-ray radiation prevention circuit in the horizontal drive circuit 1 operates has not been reached. Therefore, the horizontal deflection circuit PB operates perfectly normally.

On the other hand, if a non-steady current flows in the horizontal deflection circuit substrate PB due to contact failure or the like in the circuit PB as described above, spike-shaped noise voltage as shown in FIG. Occurs. The peak voltage of this voltage is diode D2
Is rectified, and further charged in the capacitor C3 so as to have a voltage and a voltage holding time sufficient to operate the X-ray radiation prevention circuit. As a result, the X-ray radiation prevention circuit operates, the horizontal drive output HD is stopped, the horizontal deflection is stopped, and heat generation in the defective contact portion is prevented.

Next, FIG. 5 shows another specific example that operates in the same manner as the circuit shown in FIG. Here, L2 is a width coil, L3 is a linearity coil, L1 is a horizontal deflection yoke, and SPCT is a side pin cushion transformer. SC1 is an anomaly detection output thyristor, and the charge output of the capacitor C3 is applied to its gate as a gate voltage. R2 is a resistance for overload protection of the thyristor SC1, and a series connection of the thyristor SC1 and this resistance R2 is connected to both ends of a zener diode DZ for determining the operating voltage of the X-ray radiation prevention voltage detection circuit 4. The X-ray radiation preventing voltage detection circuit 4 has a conventional configuration and is arranged separately from the horizontal drive circuit 1 in this example.
Of course, it may be incorporated in the horizontal drive circuit 1.

The collector voltage of the horizontal output transistor Q1 is changed to the capacitor C4.
The output obtained by dividing the voltage with C5 and C5 is further divided with a resistor R3 and a variable resistor VR, and then rectified with a diode D4. The rectified output is supplied to the integrating circuit of the resistor R4 and the capacitor C6,
The output is compared with the blocking voltage of Zener diode DZ. The comparison output is taken out through the resistor R5 and the capacitor C7, and the voltage input terminal for X-ray radiation prevention of the horizontal drive circuit 1
Apply to 1A. Then, when the collector voltage of the horizontal output transistor Q1 is abnormally high, the horizontal output transistor Q1 conducts to cut off the HD output of the horizontal drive circuit 1 to prevent the generation of X-rays.

The gate voltage of the thyristor SC1 is a direct current of about 0.2 to 0.4 V in the steady state as shown in FIG. 4B, and the thyristor SC1 is in the non-conducting state. On the other hand, when an unsteady current is generated and a large positive spike is generated as shown in FIG. 4A, only the spike component is charged in the capacitor C3. Then, this charging voltage rises to a gate voltage sufficient to make the thyristor SC1 conductive.

When the thyristor SC1 becomes conductive, the Zener diode DZ is short-circuited via the small resistance R2. When the Zener diode DZ is short-circuited in this manner, the horizontal deflection circuit is stopped by the X-ray radiation prevention circuit in the horizontal drive circuit 1 in the same manner as when abnormal radiation of X-rays occurs.
It is possible to prevent burnout accidents.

A transistor can be used instead of the thyristor SC1, but as these semiconductor elements, those which are insensitive in a short time are used, and also, as the diode D2, which has a slow speed is used, discharge in the tube of the cathode ray tube is performed. It is preferable not to respond to.

FIG. 6 shows a modification of the embodiment of the present invention shown in FIG. This embodiment is an example of application to a horizontal drive circuit 1'which does not have an X-ray radiation prevention circuit. The circuit shown in FIG.
2 is added, and the anode of this thyristor SC2 is connected to the power supply terminal of the horizontal drive circuit 1'or in the drive circuit, and the anode and cathode of the thyristor SC2 are caused by the unsteady current generated by the contact failure of the parts in the horizontal deflection circuit. The operation of the horizontal deflection circuit 1'is stopped by short-circuiting between the and. The rest of the configuration is the same as that in FIG. 5, and the X-ray radiation preventing effect can be provided as in the example in FIG.

The present invention is not limited to the above-described embodiments, but the spike current can be detected in various forms, and the abnormality can be detected in various forms based on the detection signal. For example, as the current detection coil 2, a part of existing parts, for example, a secondary winding may be provided on the coils L2 and L3 as shown in FIG.
Alternatively, the transformer T1 may be provided with a secondary winding. Alternatively, it is also possible to provide a detection coil outside and detect the spike current by electromagnetically coupling with an existing component.

Further, instead of rectifying the detected spike current as in the above-described example and then charging the capacitor C3, the number of pulses of the spike current can be counted and an abnormality can be determined from the count value.

Alternatively, as shown in FIG. 8, the voltage charged in the capacitor C3 causes a switching element, for example, a thyristor SC3 to conduct when an abnormality occurs, and the conduction output cuts off the interrupted circuit 5 such as a horizontal drive circuit or a power supply circuit. Then
Alternatively, by reducing the supply voltage, it is possible to cut off the horizontal deflection current Id and prevent accidents such as smoking.

[Effects] As is apparent from the above, according to the present invention, it is possible to effectively and proactively prevent accidents such as smoking without degrading or impairing the performance and functions of the conventional horizontal deflection circuit. it can. Moreover, since the power consumed by the device of the present invention itself is almost zero, there is an advantage that the total power consumption does not increase. In addition, the present invention has the advantage that it can be easily applied to existing devices.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an example of a general horizontal deflection circuit, FIG. 2 is a block diagram showing the basic configuration of the present invention, FIG. 3 is a circuit diagram showing a more concrete embodiment thereof, FIG. 4A and FIG. FIG. 4B is a signal waveform diagram for explaining its operation, and FIGS. 5, 6, 7, and 8 are circuit diagrams showing four modified examples of the present invention. 1, 1 '... Horizontal drive circuit, 1A ... X-ray radiation prevention voltage input terminal, 2 ... Current detection coil, 3 ... Abnormality detection circuit, 4 ... X-ray radiation prevention voltage detection circuit, 5 ... … Cut off circuit, Q1… Horizontal output transistor, D1… Damper diode, C1… Resonance capacitor, T1… Horizontal output transformer or flyback transformer, L1… Horizontal deflection yoke, L2… Horizontal amplitude adjustment coil , L3: Horizontal linearity correction coil, C2: S-shaped distortion correction and DC blocking capacitor, PB: Horizontal deflection circuit printed circuit board, Vcc ... Power supply, HD ... Horizontal drive pulse, Id ... Horizontal Deflection current, L ... L1, L2, L3 etc. as representative coil, S1 ... Current detection signal, S2 ... Abnormality detection output, D2 ... Rectification diode, C3 ... Rectification output charging capacitor, R1 …… Discharge resistance, X …… Ground terminal or X Radiation-prevention voltage application terminals, 31 to 34 ... Terminals, H ... Horizontal deflection period, FB ... Horizontal return period, SPCT ... Side pin cushion transformer, SC1 ... Abnormality detection output thyristor, R2 ... Excess Load protection resistance, DZ ... Zener diode for operating voltage determination, C4 to C7 ... Capacitor, R3 to R6 ... Resistance, D3, D4 ... Diode, VR ... Variable resistance, SC2 ... Horizontal drive cutoff thyristor, FS ... Fuse with switch, SW ... Fuse FS switch, SC3 ... Thyristor as switching element.

Claims (6)

[Claims] 1. A noise current detection means for electromagnetically coupling to a horizontal deflection current path of a horizontal deflection circuit to detect a noise current component superimposed on a current flowing through the horizontal deflection circuit at the time of an abnormality, and a noise current detection means from the noise current detection means. Of the retrace pulse in the output and the noise current detection signal, a rectifying means that passes only a component having a polarity opposite to that of the retrace pulse, and a current in the horizontal deflection circuit according to the output from the rectifying means. An abnormality detection device, comprising: an output unit for detecting an abnormality. 2. The abnormality detecting device according to claim 1, wherein the output means includes a capacitor that stores the rectified output from the rectifying means, and a semiconductor element that operates according to the output of the capacitor. An abnormality detecting apparatus having the above-mentioned semiconductor element and obtaining the detection output of the abnormality of the current. 3. A noise current detecting means for electromagnetically coupling to a horizontal deflection current path of a horizontal deflection circuit, for detecting a noise current component superimposed on a current flowing through the horizontal deflection circuit at the time of abnormality, and a noise current detecting means from the noise current detecting means. Of the retrace pulse in the output and the noise current detection signal, a rectifying means that passes only a component having a polarity opposite to that of the retrace pulse, and a current in the horizontal deflection circuit according to the output from the rectifying means. A protection device comprising: output means for detecting an abnormality; and cut-off means for cutting off the supply of electric power to the horizontal deflection circuit by a detection output from the output means. 4. The protection device according to claim 3, wherein the output means has a capacitor that stores the rectified output from the rectifying means, and a semiconductor element that operates according to the output of the capacitor. Then, the protection device is characterized in that the detection output of the abnormality of the current is obtained from the semiconductor element. 5. The protection device according to claim 3 or 4, wherein the cutoff means supplies the abnormality detection output to a horizontal drive circuit of the horizontal deflection circuit and outputs the horizontal drive signal. The protection device is characterized in that the generation of is stopped. 6. The protection device according to claim 5, wherein the X-ray radiation prevention circuit of the horizontal deflection circuit is supplied with the abnormality detection output from the semiconductor element to prevent the X-ray radiation prevention circuit from operating. A protective device characterized by being operated.