JP3089896B2 - Capacitor unit for preventing noise in electric cookers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capacitor unit for preventing noise in an electric cooker using a commutator motor.

[0002]

2. Description of the Related Art In recent years, with the spread of electronic equipment, electric appliances with low noise have been demanded.

[0003] Hereinafter, a conventional capacitor for preventing noise in an electric cooker will be described. FIG. 4 is a schematic view of the actual wiring showing the noise prevention capacitor and its connection of the conventional electric cooker. In FIG. 4, reference numeral 1 denotes a capacitor molded with a filler 3 inside a resin case 2, and one lead wire 4, 5 is provided at each terminal of the capacitor.

[0004] Reference numeral 6 denotes a power cord, and one power cord 6a
Is connected to the terminal 7a of the switch 7. Switch 7
The other terminal 7b is connected to the commutator motor 9 by the power cord 8.
And the other terminal 9 of the commutator motor 9
b is connected to the power cord 6b to form a main circuit.

Also, lead wires 4 and 5 are connected to terminals 7b, respectively.
And the terminal 9b. Reference numeral 10 denotes a ground wire, which is connected to the commutator motor 9 via the auxiliary capacitors 11a and 11b.
Is grounded to the non-charging metal part.

[0006] The operation of the capacitor for preventing noise of the electric cooker configured as described above will be described below.
The capacitor 1 connected in parallel with the commutator motor 9 short-circuits a high-frequency noise current caused by a spark generated between the commutator and the brush of the commutator motor 9 in a closed circuit composed of the capacitor 1 and the commutator motor 9 to supply power. The noise transmitted to the code 6 is attenuated.

[0007]

However, in the above-described conventional configuration, the frequency of the noise terminal voltage of the power cord rises with a peak near 5 to 15 MHz as shown by the solid line graph in FIG. Had.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a capacitor for preventing noise in an electric cooker in which a peak does not occur in a noise terminal voltage of a power cord.

[0009]

SUMMARY OF THE INVENTION The present invention in order to achieve this purpose, the power supply by a branch pattern capacitors which are located remotely from the pattern of the power supply line on the print circuit board from the pattern of the power supply line When connecting to a line, a separating portion is provided at the center of the pattern branched from the power supply line pattern to reach the end face of the power supply line pattern.

[0010]

[Action] by this configuration, print connect a capacitor branch pattern from the pattern of the power line wiring board, an electric cooker having a separation portion extending to the end face of the center of the power supply line pattern of branching pattern also noise preventing capacitor unit, part of a main circuit branch pattern is composed of a power supply and a commutator motor for branching pattern is disconnected in the middle and Do Ri, the length of the pattern to route the capacitor to the power line Irrespective of this, the length of the branch path from the capacitor to the main circuit can be minimized, and the noise terminal voltage can be reduced.

[0011]

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 12 denotes a capacitor molded with a charging material 14 inside a resin case 13, and two lead wires 15, 2 are provided at both terminals of the capacitor.
16 and 17, 18 are provided.

Reference numeral 19 denotes a power cord.
9a is connected to the terminal 20a of the switch 20, and the other terminal 20b of the switch 20 is connected to the leads 15, 1
6 is connected to the terminal 21a of the commutator motor 21, and the other terminal 21b of the commutator motor 21 is connected to the lead wires 18,1.
7, the power supply cord 19b is connected by a connector 22 to form a main circuit.

Reference numeral 23 denotes a ground wire which is an auxiliary capacitor 2
It is grounded to the non-charging metal part of the commutator motor 21 via 4a and 24b.

The operation of the noise prevention capacitor of the electric cooker having the above-described structure will be described. The capacitor 12 connected in parallel with the commutator motor 21 short-circuits the spark noise generated between the commutator and the brush of the commutator motor 21 in a closed circuit formed by the capacitor 12 and the commutator motor 21 and transmits the noise to the power cord 19. Attenuate.

The main circuit formed by the power supply and the commutator motor 21 is as follows:
A part thereof is constituted by lead wires 15 to 18 of the capacitor 12, and the length of the branch path from the capacitor 12 to the main circuit, that is, the connection point between the lead wires 15, 16 and the connection point between the lead wires 17, 18 is as follows. It is not affected by the length of the lead wires 15 to 18 provided on the capacitor 21.

Generally, the noise terminal voltage transmitted to the power supply side of an electric cooker having a built-in commutator motor tends to be as shown in FIG. 5 and shows a peak at a frequency of 5 to 15 MHz. The magnitude of this peak becomes larger as the length of the wiring branched from the main circuit of the capacitor connected in parallel to the main circuit through which the main current flows, which is composed of the power supply and the commutator motor, becomes longer, and becomes larger in FIG. The graph shown by indicates the case where the branch road is 3 to 5 cm or more, and the graph shown by the broken line shows the case where the branch road is very short.

The magnitude of this peak is hardly influenced by the length of the lead wire connecting the commutator motor 21 and the capacitor 12. Therefore, in this embodiment, the branch point of the capacitor 21 from the main circuit is connected to the lead wires 15 and 1.
6 and the connection point of the lead wires 17 and 18, the length of the branch path is limited to only a very short portion inside the resin case 13, so that the noise terminal voltage can be reduced.

As described above, according to the present embodiment, for the sake of convenience of the wiring processing, the capacitor 12 is formed by using a mold type capacitor with a lead wire which is often used in an electric cooker.
Even if the length of the lead wires 15 to 18 becomes long, noise does not increase, so that the condenser can be freely arranged and a low-noise electric cooker can be obtained.

Embodiment 2 Hereinafter, a second embodiment of the present invention will be described with reference to the drawings.

In FIG. 2, reference numeral 25 denotes a printed wiring board having power supply line patterns 26 and 27, both ends of which are connected to a power supply and a commutator motor (not shown), respectively. Reference numeral 28 denotes a power line pattern 26, 2
7 are connected to patterns 29 and 30 branched from the pattern.
The branched patterns 29 and 30 are separated portions 3 reaching the end faces of the power supply line patterns 26 and 27 provided at the center.
29, 29b and 30a,
30b is divided into two parts.

The operation of the noise-preventing capacitor unit of the electric cooking machine configured as described above will be described. The circuit of the main current from the power supply to the commutator motor includes the power supply line patterns 26, 27, 29a, 29b and 30.
a, 30b, and the capacitor 2
The length of the branch path from 8 to the main current circuit is
Only the very short part of the eighth foot is needed.

The length of the branch path is determined by
Patterns 29, 3 branched because of the provision of 1, 32
Patterns 29 and 30 branched without being affected by the length of 0
, The noise terminal voltage can be reduced even if the length becomes longer.
On the other hand, in the case of FIG. 3 in which the separation portion is not provided, the length of the branch path becomes the same as the length of the branched patterns 33 and 34, and as this becomes longer, the noise terminal voltage increases.

As described above, according to the present embodiment, even when the capacitor 28 must be wired by the patterns 29 and 30 branched away from the power supply line patterns 26 and 27, the pattern in which the noise terminal voltage is branched is used. 2
This can be reduced regardless of the lengths of the capacitors 9 and 30, and the arrangement of the capacitor 28 can be freely performed.

[0025]

According to the present invention as described above, according to the present invention, the print wiring board by connecting a capacitor branch pattern from the pattern of the power supply lines, electric cooker noise having a cut-off portion at the center of the branch pattern preventing capacitor unit also can because branching pattern are separated in the middle, the length of the branch path from the capacitor main current to the commutator motor to branch pattern flows up circuit of the main current to the shortest, the noise The terminal voltage can be reduced.

[Brief description of the drawings]

FIG. 1 is a connection diagram of a capacitor unit for preventing noise of an electric cooker according to a first embodiment of the present invention.

FIG. 2 is a plan view of a main part of a capacitor unit for preventing noise of an electric cooker according to a second embodiment of the present invention.

FIG. 3 is a plan view of a main part of a noise preventing capacitor unit of a conventional electric cooking machine.

FIG. 4 is a connection diagram of a conventional capacitor unit for preventing noise of an electric cooker.

FIG. 5 is a graph showing the operation of the capacitor unit for preventing noise in the electric cooker.

[Explanation of symbols]

 12, 28 Capacitor 13 Resin case 15 to 18 Lead wire 25 Printed wiring board 26, 27 Power supply line 29, 30 Branched pattern 31, 32 Separation part

Claims (1)

(57) [Claims] 1. A method of connecting a capacitor between power supplies on a printed wiring board, wherein the capacitors are arranged at locations where the power supply line patterns are separated from each other, and the capacitors are arranged in a pattern branched from the power supply line pattern. A noise preventing capacitor unit for an electric cooker, wherein a connected portion is provided at a center of a pattern branched from the power supply line pattern to an end face of the power supply line pattern.