JPS6211103Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a printed board for horizontal deflection paths used in television receivers and the like.

For example, the horizontal deflection circuit of a typical television receiver is constructed as shown in Figure 1, and this circuit
It is designed to be incorporated into a printed board as shown in the figure. That is, in FIG. 2, A is a conductive foil pattern to which the collector of the horizontal output transistor 1, the primary coil 2 of the flyback transformer, one end of each horizontal deflection coil 3, etc. of FIG. is a similar pattern to which the other end of the deflection coil 3 and one end of the horizontal width coil 4 are connected, C is the pattern for the intermediate tap of the width coil 4, and D is the other end of the width coil and the pincushion distortion correction transformer. The pattern to which one end of the horizontal coil 5 is connected, E is the other end of the horizontal coil and the DC blocking capacitor 6
F is a pattern to which one end of the capacitor 6 is connected, and F is a grounding pattern to which the other end of the capacitor 6 is connected, and these correspond to the portions indicated by thick lines in FIG. 1, respectively.

In such a printed board, if the closed loop shown by the broken line in FIG. 1 is broken due to poor soldering between one of the patterns A to F and the lead wire of a component connected thereto, A high voltage of about 1 KV is generated at the open end of the cut portion on the high potential side, that is, the side close to the collector of the horizontal output transistor 1. At this time, since the impedance of each component in the closed loop is relatively low, the high voltage causes arc discharge to occur at the disconnected part, and the heat generated at that time carbonizes the surrounding printed circuit board. Since arc tracking (that is, a path for arc discharge) is formed and the arc current flows through this path, this condition progresses and eventually the printed board burns out.

However, since the arc current in such a case still flows through the aforementioned closed loop (broken line in Figure 1), the current value is almost unchanged from that during normal operation. For this reason, it has been extremely difficult to detect changes in the current flowing in the closed loop, that is, the deflection current, and take circuit measures against the above situation.

Therefore, the present invention has been devised in view of this point, and the details thereof will be explained below.

FIG. 3 shows an embodiment of a printed board according to the present invention, and parts corresponding to those in FIG. 2 are given the same figure numbers. In the printed board shown in FIG. 3, the horizontal deflection current flows adjacent to each of the conductive foil patterns A to F corresponding to the thick lines shown in FIG. The device is characterized in that a protective conductive foil pattern F is provided with a gap in between and that this pattern F is connected to a ground point inside the receiver.

In such a printed board, for example, conductive foil pattern B
When the solder connection between the wire and the lead wire of the horizontal width coil 4 connected thereto comes off, an arc discharge occurs as in the case of Fig. 2, and the board around the pattern B is carbonized, and this carbonized Patterns B and F will be short-circuited through this part. Then, a closed loop is formed with the power supply (+B) through the primary coil 2 of the flyback transformer → pattern A → horizontal deflection coil 3 → pattern B → pattern F → ground, and the above coils 2 and 3 Since the DC impedance of is small, a large current will flow through this closed loop. As a result, the fuse (not shown) provided in the power supply (+B) blows out, cutting off the power supply to the horizontal deflection circuit.
This prevents accidents such as printed board fires. This is true no matter where arc discharge occurs in the conductive foil patterns A to E.

Although the conductive foil pattern F has been described as being for grounding, it is not limited to this.
When an arc discharges, it is connected to the conductive foil pattern in the area where the arc discharge occurs, thereby connecting the power supply (+
It is sufficient if it forms a closed loop with sufficiently low impedance for B).

Since the printed board of the present invention is constructed as described above, if arc discharge occurs due to poor connection between the conductive foil pattern and the deflection circuit components connected thereto, the printed board will ignite. Accidents such as combustion can be prevented, and the manufacturing cost does not increase due to this, making it practical.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing a horizontal deflection circuit of a general television receiver, Fig. 2 is a plan view showing the back side of a conventional printed board for horizontal deflection circuit, and Fig. 3 is an implementation of the printed board of the present invention. FIG. 2 is a diagram showing an example similar to FIG. 2; A to E: conductive foil pattern through which horizontal deflection current flows; F: protective conductive foil pattern forming a closed loop with respect to the power source;

Claims (1)

[Scope of utility model registration request] When an arc discharge occurs in a conductive foil pattern through which a horizontal deflection current flows in a printed circuit board in which a horizontal deflection circuit of a television receiver or the like is installed, the horizontal deflection circuit is connected to the above pattern by the arc discharge. 1. A printed board for a horizontal deflection circuit, characterized in that a protective conductive foil pattern is provided in close proximity to the pattern to form a low impedance closed circuit with respect to a power source of the deflection circuit.