Typical electrical product creepage distance and electrical gap capability verification sample

Abstract

The utility model provides a typical electrical product creepage distance and electrical gap capability verification sample, the middle parts of a first printed circuit board and a second printed circuit board are provided with triangular hollows, the vertex angle of the triangular hollows of the first printed circuit board is 75 degrees, and the vertex angle of the triangular hollows of the second printed circuit board is 85 degrees. A first conducting strip, a second conducting strip, a third conducting strip and a fourth conducting strip are arranged on one side of the triangular hollowed-out part, a rectangular groove and a fifth conducting strip are arranged on the other side of the triangular hollowed-out part, the distance between the first conducting strip and the vertex angle of the triangular hollowed-out part is 10 mm, and the distance between the first conducting strip, the second conducting strip and the third conducting strip is 1.3 mm; according to the utility model, the two printed circuit board samples are designed, the creepage distance lengths of the two samples under the pollution level II and the pollution level III are the same, but the paths are different, mathematical statistics is facilitated, the device can be used for laboratory proficiency verification test activities and laboratory internal quality control, and experimental personnel are prevented from being communicated with test data.

Description

Technical Field

[0001] The utility model relates to the technical field of safety testing of electrical products, in particular to a sample for verifying the creepage distance and clearance ability of typical electrical products. Background Technique

[0002] The creepage distance and clearance tests are two basic tests for the safety testing of electronic and electrical products, which are closely related to factors such as working voltage, insulation type, pollution degree, etc. The creepage distance is the shortest distance along the surface of solid insulating material between two conductive parts, and the size of the creepage distance should ensure that there will be no insulation flashover or breakdown (tracking) under the given working voltage and pollution degree.

[0003] The clearance is the shortest distance in air between two conductive parts, and the size of the clearance should ensure that the transient overvoltage entering the equipment and the peak voltage generated inside the equipment will not break down the clearance. The creepage distance shall not be less than the relevant clearance. Therefore, the minimum creepage distance may be equal to the required clearance. However, except for this selected dimensional limit, there is no physical connection between the minimum clearance in air and the allowable minimum creepage distance.

[0004] As a key test item of electrical products, the creepage distance and clearance are involved in almost all electrical products, such as audio and video equipment, information electronic equipment, household electrical appliances products, lamps, medical devices. For the creepage distance or clearance of equipment or products relative to their working voltage, insulation type, and environmental pollution level, if they are too small, it will cause equipment breakdown and electric shock to people, bringing serious product safety problems and endangering people's lives and property safety.

[0005] Therefore, this test item has always been the focus of product supervision and product quality control. Summary of the Invention

[0006] The purpose of the utility model is to provide a sample for verifying the creepage distance and clearance ability of typical electrical products.

[0007] In order to achieve the above purpose, the technical solution of the utility model is:

[0008] A sample for verifying the creepage distance and clearance ability of typical electrical products, characterized in that it includes a first printed circuit board and a second printed circuit board. The first printed circuit board and the second printed circuit board are rectangular plates. There are triangular cutouts in the middle of the first printed circuit board and the second printed circuit board. The apex angle of the triangular cutout of the first printed circuit board is 75°, and the apex angle of the triangular cutout of the second triangular cutout is 85°.

[0009] On one side of the triangular hollow, a first conductive sheet, a second conductive sheet, a third conductive sheet, and a fourth conductive sheet are successively arranged from the top angle to the bottom angle. The first conductive sheet, the second conductive sheet, the third conductive sheet, and the fourth conductive sheet extend perpendicular to one side of the triangular hollow. On the other side of the triangular hollow, a rectangular groove and a fifth conductive sheet are successively arranged from the top angle to the bottom angle. The rectangular groove and the fifth conductive sheet extend perpendicular to the other side of the triangular hollow.

[0010] The distance between the first conductive sheet and the top angle of the triangular hollow is equal to the distance between the rectangular groove and the top angle of the triangular hollow. The first conductive sheet, the second conductive sheet, and the third conductive sheet are arranged in close contact at equal intervals. The width of the rectangular groove is equal to the distance between the first conductive sheet, the second conductive sheet, and the third conductive sheet. The distance between the fourth conductive sheet and the third conductive sheet is equal to the distance between the first conductive sheet and the top angle of the triangular hollow. The distance between the fifth conductive sheet and the rectangular groove is equal to the distance between the rectangular groove and the top angle of the triangular hollow.

[0011] The distance between the first conductive sheet and the top angle of the triangular hollow is 10 mm, and the distance between the first conductive sheet, the second conductive sheet, and the third conductive sheet is 1.3 mm.

[0012] Further, the first printed circuit board and the second printed circuit board are rectangular plates.

[0013] The present utility model designs two printed circuit board samples. The creepage distance lengths of the two samples are the same under pollution degree II and pollution degree III, but the paths are different, which is convenient for mathematical statistics and can be used for laboratory proficiency testing activities and internal quality control of the laboratory to avoid experimenters colluding with test data. Description of the Drawings

[0014] Figure 1 It is a schematic structural diagram of the second printed circuit board of the verification sample of the present utility model;

[0015] Figure 2 It is an example diagram of the creepage distance and electrical clearance of the groove;

[0016] Figure 3 It is another example diagram of the creepage distance and electrical clearance of the groove;

[0017] Figure 4 It is an example diagram of the creepage distance and electrical clearance of the V-shaped groove;

[0018] Figure 5 It is an example diagram of the creepage distance and electrical clearance of the continuous conductor;

[0019] Figure 6 It is a schematic diagram of the creepage distance of the first printed circuit board of the present utility model under pollution degree II;

[0020] Figure 7This is a schematic diagram of the creepage distance of the first printed circuit board of the present utility model under pollution degree III;

[0021] Figure 8 This is a schematic diagram of the clearance of the first printed circuit board of the present utility model under pollution degrees II and III;

[0022] Figure 9 This is a schematic diagram of the creepage distance of the second printed circuit board of the present utility model under pollution degree II;

[0023] Figure 10 This is a schematic diagram of the creepage distance of the second printed circuit board of the present utility model under pollution degree III;

[0024] Figure 11 This is a schematic diagram of the clearance of the second printed circuit board of the present utility model under pollution degree II;

[0025] Figure 12 This is a schematic diagram of the clearance of the second printed circuit board of the present utility model under pollution degree III.

[0026] Reference numerals:

[0027] 1 First printed circuit board, 2 Second printed circuit board, 3 Triangular hollow,

[0028] 4 First conductive sheet, 5 Second conductive sheet, 6 Third conductive sheet, 7 Fourth conductive sheet, 8 Fifth conductive sheet, 9 Rectangular groove. Detailed implementation manners

[0029] Next, the technical solutions of the present utility model will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0030] The present utility model discloses a sample for verifying the creepage distance and clearance capabilities of a typical electrical product, including a first printed circuit board 1 and a second printed circuit board 2. The first printed circuit board 1 and the second printed circuit board 2 are rectangular plates. A triangular hollow 3 is provided in the middle of the first printed circuit board 1 and the second printed circuit board 2. The triangular hollow 3 is an isosceles triangle. The apex angle of the triangular hollow 3 of the first printed circuit board 1 is 75°, and the apex angle of the triangular hollow 3 of the second triangular hollow 3 is 85°. Refer to Figure 1 .

[0031] On one side of the triangular hollow 3, a first conductive sheet 4, a second conductive sheet 5, a third conductive sheet 6, and a fourth conductive sheet 7 are successively arranged from the top corner to the bottom corner. The first conductive sheet 4, the second conductive sheet 5, the third conductive sheet 6, and the fourth conductive sheet 7 extend perpendicular to one side of the triangular hollow 3. On the other side of the triangular hollow 3, a rectangular groove 9 and a fifth conductive sheet 8 are successively arranged from the top corner to the bottom corner. The rectangular groove 9 and the fifth conductive sheet 8 extend perpendicular to the other side of the triangular hollow 3.

[0032] The distance between the first conductive sheet 4 and the top corner of the triangular hollow 3 is equal to the distance between the rectangular groove 9 and the top corner of the triangular hollow 3. The first conductive sheet 4, the second conductive sheet 5, and the third conductive sheet 6 are arranged in close contact at equal intervals. The distance between the fourth conductive sheet 7 and the third conductive sheet 6 is equal to the distance between the first conductive sheet 4 and the top corner of the triangular hollow 3. The distance between the fifth conductive sheet 8 and the rectangular groove 9 is equal to the distance between the rectangular groove 9 and the top corner of the triangular hollow 3.

[0033] The design of the verification sample of the present utility model considers the following rules;

[0034] Rule 1: The paths considered include grooves with parallel or converging sides having a width less than X mm and an arbitrary depth. The creepage distance and the electrical clearance are measured directly across the groove as shown. Figure 2 shown, measured directly across the groove.

[0035] X is the minimum value specified according to the corresponding pollution degree, as shown in Table 1 for details.

[0036] Table 1 Minimum value of dimension X under different pollution degrees

[0037] Pollution degree Minimum value of dimension X 1 0.25 mm 2 1.0 mm 3 1.5 mm

[0038] Rule 2: The paths considered include grooves with parallel sides having an arbitrary depth and a width equal to or greater than X mm. The electrical clearance is the "dotted line" distance, and the creepage distance follows the contour of the groove. Refer to Figure 3 .

[0039] Rule 3: The paths considered include a V-shaped groove with a width greater than X mm, as shown in Figure 4 shown;

[0040] When the groove angle is less than 80 degrees, the electrical clearance is the "dotted line" distance, and the creepage path follows the contour of the groove but is "short-circuited" at the bottom of the groove by an X mm connection;

[0041] When the groove angle is greater than or equal to 80 degrees, both the electrical clearance and the creepage distance path follow the boundary of the groove.

[0042] Rule 4: For the continuous conductor as shown in Figure 5 shown, where C is the conductor, both the creepage distance and the electrical clearance are d + D.

[0043] The statistical analysis of the verification samples of this utility model adopts the Robust statistical technique for processing. The value reported by the laboratory is used as the laboratory test result, the median value is used as the designated value, and the normalized interquartile range (NIQR) is used as the variability measurement value (target standard deviation). The Z value is calculated according to the following formula for statistical evaluation:

[0044] Z = (x - X) / σ

[0045] Where: x - the test result of the participating laboratory;

[0046] X - the designated value;

[0047] σ - the variability measurement value (target standard deviation);

[0048] When The result is satisfactory;

[0049] When The result is suspect;

[0050] When The result is unsatisfactory.

[0051] Following the above Rules 1 to 4, the correct paths for creepage distance and clearance under Pollution Degree 2 and Pollution Degree 3 are obtained.

[0052] In the design of the verification samples of this utility model, the distance between the first conductive sheet 4 and the vertex of the triangular hollow 3 is 10 mm, and the distance between the first conductive sheet 4, the second conductive sheet 5 and the third conductive sheet 6 is 1.3 mm.

[0053] As Figure 6 shown, for the creepage distance of the first printed circuit board 1 under Pollution Degree 2, it first moves along one side of the triangular hollow 3. According to Rule 1, X under Pollution Degree 2 is 1.0 mm, and the distance between the first conductive sheet 4, the second conductive sheet 5 and the third conductive sheet 6 is 1.3 mm which is greater than 1.0 mm, so it cannot cross the slot for measurement. The path is the bottom end of the fourth conductive sheet 7 - the bottom end of the third conductive sheet 6 - the bottom end of the second conductive sheet 5 - the bottom end of the first conductive sheet 4;

[0054] According to the situation where the slot angle is less than 80 degrees in Rule 3, it moves horizontally 1 mm across the vertex at the upper part of one side of the triangular hollow 3, continues to move horizontally to the top end of the rectangular slot 9, and finally to the top end of the fifth conductive sheet 8.

[0055] As Figure 7 shown, for the creepage distance of the first printed circuit board 1 under Pollution Degree 3, it first moves along one side of the triangular hollow 3. According to Rule 1, X under Pollution Degree 3 is 1.5 mm, and the distance between the first conductive sheet 4, the second conductive sheet 5 and the third conductive sheet 6 is 1.3 mm which is less than 1.5 mm, so it can cross the slot for measurement. The path is the bottom end of the fourth conductive sheet 7 - the bottom end of the third conductive sheet 6 - the bottom end of the first conductive sheet 4;

[0056] According to the case where the groove angle in Rule 3 is less than 80 degrees, move horizontally 1 mm across the top corner on the upper side of one side of the triangular hollow 3, and continue to move along the other side of the triangular hollow 3. The path is from the bottom end of the rectangular groove 9 to the bottom end of the fifth conductive sheet 8.

[0057] As Figure 8 shown, the electrical clearance of the first printed circuit board 1 under pollution degree II and pollution degree III is from the bottom end of the fourth conductive sheet 7 to the bottom end of the fifth conductive sheet 8.

[0058] As Figure 9 shown, for the creepage distance of the second printed circuit board 2 under pollution degree II, first move along one side of the triangular hollow 3. According to Rule 1, X is 1.0 mm under pollution degree II. The distance between the first conductive sheet 4, the second conductive sheet 5, and the third conductive sheet 6 is 1.3 mm which is greater than 1.0 mm, so it cannot be measured across the groove. The path is from the bottom end of the fourth conductive sheet 7 to the bottom end of the third conductive sheet 6 to the bottom end of the second conductive sheet 5 to the bottom end of the first conductive sheet 4;

[0059] According to the case where the groove angle in Rule 3 is greater than 80 degrees, move along the boundary of the triangular hollow 3 to the top corner, continue to move horizontally to the top of the rectangular groove 9, and finally to the top of the fifth conductive sheet 8.

[0060] As Figure 10 shown, for the creepage distance of the second printed circuit board 2 under pollution degree III, first move along one side of the triangular hollow 3. According to Rule 1, X is 1.5 mm under pollution degree III. The distance between the first conductive sheet 4, the second conductive sheet 5, and the third conductive sheet 6 is 1.3 mm which is less than 1.5 mm, so it can be measured across the groove. The path is from the bottom end of the fourth conductive sheet 7 to the bottom end of the third conductive sheet 6 to the bottom end of the first conductive sheet 4;

[0061] According to the case where the groove angle in Rule 3 is greater than 80 degrees, move along the boundary of the triangular hollow 3 to the top corner, and continue to move along the other side of the triangular hollow 3. The path is from the bottom end of the rectangular groove 9 to the bottom end of the fifth conductive sheet 8.

[0062] The creepage distance paths of the first printed circuit board 1 and the second printed circuit board 2 are different under pollution degree II and pollution degree III, but the lengths are equal.

[0063] As Figure 11 shown, the electrical clearance of the second printed circuit board 2 under pollution degree II is from the bottom end of the fourth conductive sheet 7 to the bottom end of the fifth conductive sheet 8.

[0064] As Figure 12 shown, the electrical clearance of the second printed circuit board 2 under pollution degree III is from the bottom end of the fourth conductive sheet 7 to the bottom end of the third conductive sheet 6 to the bottom end of the first conductive sheet 4 to the bottom end of the fifth conductive sheet 8.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A verification sample for the creepage distance and clearance of a typical electrical product, characterized in that, It includes a first printed circuit board and a second printed circuit board. A triangular hollow is provided in the middle of the first printed circuit board and the second printed circuit board. The triangular hollow is an isosceles triangle. The apex angle of the triangular hollow of the first printed circuit board is 75°, and the apex angle of the triangular hollow of the second triangular hollow is 85°. On one side of the triangular hollow, a first conductive sheet, a second conductive sheet, a third conductive sheet, and a fourth conductive sheet are sequentially provided from the apex angle to the base angle. The first conductive sheet, the second conductive sheet, the third conductive sheet, and the fourth conductive sheet extend perpendicular to one side of the triangular hollow. On the other side of the triangular hollow, a rectangular groove and a fifth conductive sheet are sequentially provided from the apex angle to the base angle. The rectangular groove and the fifth conductive sheet extend perpendicular to the other side of the triangular hollow. The distance between the first conductive sheet and the apex angle of the triangular hollow is equal to the distance between the rectangular groove and the apex angle of the triangular hollow. The first conductive sheet, the second conductive sheet, and the third conductive sheet are arranged in close contact at equal intervals. The width of the rectangular groove is equal to the distance between the first conductive sheet, the second conductive sheet, and the third conductive sheet. The distance between the fourth conductive sheet and the third conductive sheet is equal to the distance between the first conductive sheet and the apex angle of the triangular hollow. The distance between the fifth conductive sheet and the rectangular groove is equal to the distance between the rectangular groove and the apex angle of the triangular hollow. The distance between the first conductive sheet and the apex angle of the triangular hollow is 10 mm, and the distance between the first conductive sheet, the second conductive sheet, and the third conductive sheet is 1.3 mm.

2. The verification sample for the creepage distance and clearance ability of the typical electrical product according to claim 1, wherein The first printed circuit board and the second printed circuit board are rectangular plates.

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