JPH0520233U - Electronic trip device for circuit breakers - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide an electronic trip device for a circuit breaker capable of preventing malfunctions due to static electricity of the circuit breaker by always causing electrostatic discharge in a part of a ground pattern of a printed circuit board. [Structure] A discharge part 9 is provided in a part of a ground pattern 8 that is resistant to static electricity in the printed circuit board 4 and is close to a board mounting part 5 of a metal frame 3 for fixing the printed circuit board 4.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 This invention relates to an electronic trip device for a circuit breaker, and in particular to its electrostatic discharge.

[0002]

[Prior Art]

 The conventional electronic trip device for a circuit breaker is configured as shown in FIGS. In the figure, 1 is an insulating box that constitutes an electronic overcurrent trip device, 2 is its transparent cover, 3 is a metal frame installed in the insulating box 1, and 4 is fixed by the metal frame 3. It is a printed circuit board.

[0003]

[Problems to be solved by the device]

 Since the conventional electronic trip device of the rotary circuit breaker is configured as described above, electrostatic discharge occurs between the metal frame 3 and the printed circuit board 4. Silicone rubber was applied to the printed circuit board 4 to prevent this electrostatic discharge, but not only is it time-consuming to apply it, but also uneven coating causes static electricity to be generated in the thin part of the circuit breaker. There was a problem that it malfunctioned.

The present invention has been made in order to solve such a problem, and a circuit breaker capable of preventing a malfunction due to static electricity of a circuit breaker by always causing an electrostatic discharge in a part of a ground pattern of a printed circuit board. The purpose is to obtain an electronic tripping device for vessels.

[0005]

[Means for Solving the Problems]

 An electronic trip device for a circuit breaker according to the present invention is one in which a discharge part which is close to a board mounting part of a metal frame for fixing the printed circuit board is provided in a part of a ground pattern resistant to static electricity in the printed circuit board. Is.

[0006]

[Action]

 In this invention, static electricity is constantly discharged in a part of the ground pattern of the printed circuit board, so there is no influence on the other.

[0007]

【Example】

 An embodiment of this invention will be described with reference to FIGS. 1 is a front view showing a state where a printed circuit board is fixed to a metal frame, FIG. 2 is a view of FIG. 1 from the left, FIG. 3 is a cross-sectional view taken along line III-III of FIG. 1, and FIG. 4 is a line of FIG. FIG. 4 is a sectional view taken along the line IV-IV, in which the same or corresponding parts as those of the above-mentioned conventional one are designated by the same reference numerals, and the description thereof will be omitted. In the figure, 5 is a board mounting portion formed on the metal frame 3, 6 is a mounting screw, 7 is a spacer, 8 is a ground pattern formed on the printed board 4, and 9 is a discharge portion formed on a part of the ground pattern 8. Thus, the metal frame 3 is formed in a shape that is close to the board mounting portion 5 and has a sharp tip so as to easily discharge.

If the discharge part 9 is provided in a part of the ground pattern 8 of the printed circuit board 4 as described above, static electricity is always provided between the board mounting part 5 and the discharge part 9 which are closest to the metal frame 3. Since the discharge is generated, static electricity is constantly generated in the ground pattern 8 which is resistant to static electricity in the printed circuit board 4, and there is no influence on the other. Therefore, the circuit breaker does not malfunction due to the electrostatic discharge of the electronic trip device.

[0009]

[Effect of the device]

 As described above, according to the present invention, since static electricity is constantly generated in a part of the ground pattern of the printed circuit board, there is an effect that the circuit breaker does not malfunction due to the static electricity and high reliability is obtained.

[Brief description of drawings]

FIG. 1 is a front view of an essential part showing an embodiment of the present invention.

FIG. 2 is a diagram of FIG. 1 viewed from the left.

3 is a cross-sectional view taken along the line III-III in FIG.

4 is a cross-sectional view taken along the line IV-IV in FIG.

FIG. 5 is a perspective view showing a conventional electronic trip device.

FIG. 6 is a vertical cross-sectional view of FIG.

[Explanation of symbols]

 3 Metal frame 4 Printed circuit board 5 Board mounting part 8 Ground pattern 9 Discharge part

Claims (1)

[Scope of utility model registration request] 1. An electronic device for a circuit breaker, characterized in that a discharge part is provided in a part of a ground pattern resistant to static electricity in a printed circuit board, the discharge part being close to a board mounting part of a metal frame for fixing the printed circuit board. Tripping device.