JPH0946895A - Power supply - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a malfunction or damage to an element caused by external energy without making the body size larger or assembling cost higher, by tearing off at least one part of solder resist as a discharging path on a printed circuit board. SOLUTION: When electrostatic energy as outer energy is applied from an output terminal 6 or an output terminal 7, the electrostatic energy is carried through elements of Y-capacitance C3, T-capacitance C1 or Y-capacitance C2 to an input-side circuit. As a result, there is a difference in potential between input terminals 1 and 2 in a pair, and the output terminals 6 and 7, and almost all the voltage caused by the potential difference is applied across the input and output ends of an inductance L1. At the same time, a discharging path is formed between inductance a-c and between inductance b-d. In this way, a part of resist on a printed circuit board is torn off as a discharging path to discharge external energy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device having means for discharging external energy.

[0002]

2. Description of the Related Art Conventionally, when an external energy irrelevant to the circuit operation is applied to a power supply device, such as electrostatic noise being added by a charged person operating the device, the power supply If the ground terminal of the device is connected to the ground of the commercial power supply, the applied external energy will be released to the ground of the commercial power supply through a path with low impedance, which may cause malfunction of the power supply device or destruction of elements. There is no such thing.

However, in practice, the ground terminal of the power supply device is often not connected to the ground of the commercial power supply,
In that case, the external energy applied to the device is released to the input terminal of the commercial power source through the path with low impedance. Then, a potential difference depending on the magnitude of impedance and the magnitude of external energy is generated at both ends of the path, and discharge may occur between any of the lands on the printed board. In that case, if an element having a low withstand voltage is mounted on one or both of the lands, the element may be destroyed by the generated discharge.

In order to prevent the above-mentioned problems from occurring, for example, Spark Gap (registered trademark) is used.

FIG. 10 is a circuit block diagram of a conventional power supply device in which a spark gap is mounted.

In this conventional example, as shown in FIG. 10, an inductor L101 connected to AC input terminals 101 and 102 is used.
And Y capacitances C101 and C for noise reduction
102, an input rectifying / smoothing circuit 103 including a rectifying circuit, a filter circuit and a smoothing capacitor, and a Y capacitance C
101 and C102, a Y capacitance C103 for realizing double insulation between the input side and the output side, and a switching device Q including a power transistor and the like.
101, a control circuit 104 for controlling the switching device Q101 and the like, a transformer T101 having an insulating function between the input side and the output side, an output rectifying / smoothing circuit 105 including a rectifying circuit, a filter circuit and a smoothing capacitor, and a spark. And the gap 110.

The operation of the power supply device configured as described above will be described below.

When electrostatic energy, which is external energy not related to the operation of the power supply device, is applied from the output terminal 106 or the output terminal 107, and the ground terminal 110 of the power supply device is connected to the commercial power supply ground 109 (switch When 108 is in the ON state), the applied electrostatic energy is not released to the commercial power source and problems such as element destruction in the power source device do not occur.

On the other hand, when the ground terminal 110 is not connected to the commercial power source ground 109 (the switch 8 is OF
F state), electrostatic energy is Y capacitance C10
3 and Y capacitance C101 or Y capacitance C102 to reach the input side circuit. At this time, the input terminal pair 101, 102 and the output terminal pair 106, 1
07, a potential difference due to electrostatic energy is generated, and due to the nature of the inductor, most of the voltage due to the generated potential difference is applied to both ends of the input side and the output side of the inductor L101.

When a voltage is applied across the inductor L101, the applied voltage is discharged by the spark gap 110 and released to the commercial power source via the AC input terminal 102.

As described above, the spark gap 110 is
It has a role of preventing destruction of the element due to discharge from any land on the line to which the conductor L101 is connected to the land of another element, for example, the land of the switching device Q101 and the control circuit 104.

The two AC input terminals 101 and 102
Are connected via Y capacitances C101 and C102, and therefore have the same potential with respect to electrostatic energy applied from the outside. Therefore, the spark gap 110
With respect to the connection, the same effect can be obtained regardless of which side of the input terminals 101 and 102 is connected.

[0013]

However, in the conventional power supply device as described above, since the dedicated parts for preventing the destruction of the element by the external energy applied from the outside of the device are mounted, the mounting space for the dedicated parts is mounted. Therefore, there is a problem in that the power supply device becomes large in size, and the cost increases when adding dedicated parts.

The present invention has been made in view of the problems of the above-described conventional technique, and does not increase the size of the apparatus and does not increase the cost, and the external device is not used. It is an object of the present invention to provide a power supply device that does not cause malfunctions or destruction of elements even when energy is applied.

[0015]

To achieve the above object, the present invention comprises an inductor and a circuit element on a printed wiring board, and further prevents malfunction and element destruction due to application of external energy unrelated to circuit operation. In order to do so, a power supply device having a discharging means for discharging the external energy, wherein the discharging means has a discharge path formed by peeling off at least one solder resist on the printed wiring board. Characterize.

Further, the solder resist is peeled off at two points of a pattern on the printed wiring board on the input side and the output side of the same winding of the inductor.

Further, the place where the solder resist is peeled off is a pattern on the printer board of one terminal of the inductor, and the same winding as the one terminal of the inductor is provided near the pattern on the printed board of the one terminal of the inductor. Is characterized in that it has a heat sink whose potential is the same as that of the different terminals.

Further, the shape for peeling off the solder resist is a quadrangle.

Further, the shape for peeling off the solder resist is characterized in that the facing parts of the two solder resists have an acute angle.

Further, the heat dissipation plate has a shape having an acute angle or a corner at a position closest to the pattern.

Further, there is provided a power supply device having a discharging means for discharging the external energy in order to prevent malfunction and element destruction due to application of external energy irrelevant to the circuit operation, wherein the discharging means has at least one corner. And a discharge path formed by a land having

Further, the discharge path is composed of two points of lands on the printed wiring board on the input side and the output side of the same winding of the inductor.

The discharge path is provided in the vicinity of the pattern of the one terminal of the inductor on the printed wiring board and the pattern of the one terminal of the inductor on the printed circuit board, and has the same winding as the one terminal of the inductor. It is characterized in that it is composed of different terminals and heat sinks at the same potential.

(Operation) In the present invention configured as described above, the solder resist of the pattern on the printed board is peeled off to expose the metal layer. In the adjacent pattern, both metal layers are exposed to form a discharge path, and when external energy unrelated to circuit operation is applied from the outside, the external energy is discharged from the location where the solder resist is peeled off. Is done.

Further, the discharge efficiency is improved by changing the shape of peeling the solder resist or the shape of the land.

In this way, the external energy is discharged, and the malfunction of the device and the destruction of elements are prevented.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a circuit block diagram showing the overall configuration of an embodiment of the power supply device of the present invention.

As an embodiment, the power supply device is an inductor L1 connected to AC input terminals 1 and 2 as shown in FIG.
And Y capacitances C1 and C2 for noise reduction
An input rectifying / smoothing circuit 3 including a rectifying circuit, a filter circuit and a smoothing capacitor, a Y capacitance C3 for realizing double insulation between the input side and the output side together with the Y capacitances C1 and C2, and a power transistor. Switching device Q1, a control circuit 4 for controlling the switching device Q1 and the like, a transformer T1 having an insulating function between the input side and the output side, an output rectifying and smoothing circuit including a rectifying circuit, a filter circuit and a smoothing capacitor. It is composed of 5 and.

The operation of the power supply device configured as described above will be described below.

When electrostatic energy, which is external energy not related to the operation of the power supply device, is applied from the output terminal 6 or the output terminal 7, the electrostatic energy passes through the Y capacitance C3 and the Y capacitance C1 or the Y capacitance C2. Reach the input side circuit. At this time,
A potential difference due to electrostatic energy is generated between the input terminal pair 1 and 2 and the output terminal pair 6 and 7, and most of the voltage due to the generated potential difference is applied to both ends of the input side and the output side of the inductor L1 due to the nature of the inductor. To be done.

The present invention is characterized in that a discharge path for discharging the applied voltage as described above is formed without using a dedicated component.

Therefore, various examples in which a discharge path is formed in the power supply device shown in FIG. 1 will be given.

FIG. 2 is an example of a discharge path formed in the power supply device of FIG.

The discharge path shown in FIG. 2 is formed between the lands of the inductor, that is, between a and c and between b and d.

FIG. 3 is a diagram showing an example of a heat sink mounted on the power supply device of the present invention.

As shown in FIG. 3, the heat radiating plate mounted on the power supply device in this embodiment has a heat generating component mounting portion A to which heat generating components such as switching devices are mounted and a board connecting portion to be mounted on a printed circuit board. B, and the board connecting portion B is inserted into a hole formed in the printed board in advance, and is attached to the low impedance pattern by soldering on the pattern surface side.

FIG. 4 is a diagram showing a peripheral pattern when the heat sink shown in FIG. 3 is attached to the power supply device of the present invention.

In the example shown in FIG. 4, the point h, which is the portion to which the board connecting portion B of the heat dissipation plate is connected, is located near the mounting pattern and the portion g near the point h in the mounting pattern is The solder resist is peeled off and the copper foil is exposed. As a result, electric discharge is performed between the portion from which the solder resist has been peeled off and the heat sink.

FIG. 5 is a diagram showing an example in which the discharge path is formed by peeling the solder resist into a square shape.

In the example shown in FIG. 5, a part of the solder resist of the mounting pattern is peeled off in a square shape, and the copper foil is exposed from the peeled part, so that it is between the parts e and f where the solder resist is peeled off. Is discharged.

FIG. 6 is a diagram showing the shape of the discharge generating portion shown in FIG. 5 which is triangular.

In the example shown in FIG. 6, a part of the solder resist of the mounting pattern is peeled off so that a portion facing the mounting pattern where the discharge path is formed has an acute angle, and a copper foil is peeled off from the peeled portion. Discharging is performed between the portions e and f where the solder resist is peeled off due to the exposure. Here, since the portions facing each other have an acute angle, the charge density is increased and discharge is facilitated.

FIG. 7 is a diagram showing an example in which discharge occurrence points are set on lands.

In the example shown in FIG. 7, the shape of the land is such that the portion facing the land where the discharge path is formed has a corner, which increases the charge density and facilitates discharge.

FIG. 8 is a diagram showing an example in which the shape of the land is as shown in FIG. 7 and the shape of the portion of the heat dissipation plate connected to the substrate is an acute angle.

In the example shown in FIG. 8, as compared with the example shown in FIG. 4, the shape of the portion of the heat dissipation plate connected to the substrate has an acute angle, so the charge density increases and discharge becomes easier. ing.

FIG. 9 shows the shape of the land as shown in FIG. 7, and a part of the solder resist of the mounting pattern in which the land and the discharge path are formed is peeled off so that the portion facing the land becomes an acute angle. FIG.

In the example shown in FIG. 9, the shape of the land is such that the portion facing the mounting pattern on which the discharge path is formed has a corner, and the land and a part of the solder resist of the mounting pattern are formed. Since the portion facing the land is peeled off so as to form an acute angle, the charge density is increased and discharge is facilitated.

[0050]

Since the present invention is constructed as described above, it has the following effects.

(1) Since the copper foil is exposed by peeling off the solder resist on the printed board to form the discharge path, when the external energy is applied, the external energy is discharged from the formed discharge path. . Therefore, it is possible to prevent malfunction and destruction of elements even when external energy is applied from the outside without increasing the size of the device and increasing the cost.

(2) Since the shape for removing the solder resist is a quadrangle or a shape having an acute angle, the discharge efficiency of external energy can be further improved.

(3) The shape of the land on the printed circuit board is
Since the shape has a corner on at least one side, external energy can be discharged between the lands.
Therefore, it is possible to prevent malfunction and destruction of elements even when external energy is applied from the outside without increasing the size of the device and increasing the cost.

[Brief description of drawings]

FIG. 1 is a circuit block diagram showing an entire embodiment of a power supply device of the present invention.

FIG. 2 is an example of a discharge path formed in the power supply device of FIG.

FIG. 3 is a diagram showing an example of a heat dissipation plate mounted on the power supply device of the present invention.

FIG. 4 is a diagram showing a peripheral pattern when the heat sink shown in FIG. 3 is attached to the power supply device of the present invention.

FIG. 5 is a diagram showing an example of forming a discharge path by peeling a solder resist into a square shape.

FIG. 6 is a diagram showing a shape of a discharge generating portion shown in FIG. 5 which is triangular.

FIG. 7 is a diagram showing an example in which discharge occurrence points are set on a land.

FIG. 8 is a diagram showing an example in which the shape of the land is as shown in FIG. 7 and the shape of the portion of the heat dissipation plate connected to the substrate is an acute angle.

9 shows an example in which the shape of the land is as shown in FIG. 7, and a part of the solder resist of the mounting pattern in which the land and the discharge path are formed is peeled off so that a portion facing the land becomes an acute angle. FIG.

FIG. 10 is a circuit block diagram of a conventional power supply device in which a spark gap is mounted.

[Explanation of symbols]

 1, 2 AC input terminals 3 Input rectifying / smoothing circuit 4 Control circuit 5 Output rectifying / smoothing circuit 6, 7 Output terminals C1, C2, C3 Y capacitance L1 Inductor Q1 Switching device T1 Transformer A Heat generating component mounting part B Board connection part a, b, c, d, j, k land e, f, g solder resist stripped part h heat sink i printed circuit board pattern surface

Claims (9)

[Claims] 1. A power supply having an inductor and a circuit element on a printed wiring board, and further having a discharging means for discharging the external energy in order to prevent malfunction and element destruction due to application of external energy unrelated to circuit operation. The power supply device is characterized in that the discharge means has a discharge path formed by peeling off a solder resist at at least one location on the printed wiring board. 2. The power supply device according to claim 1, wherein the solder resist is peeled off at two points of a pattern on a printed wiring board on each of an input side and an output side of the same winding of the inductor. Power supply device characterized by. 3. The power supply device according to claim 1, wherein the portion where the solder resist is peeled off is a pattern on a printer board of one terminal of the inductor, and is located near a pattern on a printed board of the one terminal of the inductor. A power supply device having a heat sink having the same potential as one terminal of the inductor and a different terminal of the same winding. 4. The power supply device according to claim 2 or 3, wherein the shape for removing the solder resist is a quadrangle. 5. The power supply device according to claim 2, wherein the shape for peeling off the solder resist is a shape in which facing portions of the solder resists at the two points are acute angles. 6. The power supply device according to claim 3, wherein the heat dissipation plate has a shape having an acute angle or a corner at a position closest to the pattern. 7. A power supply device having discharge means for discharging the external energy in order to prevent malfunction and element destruction due to application of external energy irrelevant to circuit operation, wherein the discharge means has at least one corner. A power supply device comprising: a discharge path formed by a land having 8. The power supply device according to claim 7, wherein the discharge path includes two points of lands on the printed wiring board on the input side and the output side of the same winding of the inductor. Power supply. 9. The power supply device according to claim 7, wherein the discharge path is provided in the vicinity of the pattern of the one terminal of the inductor on the printed wiring board and the pattern of the one terminal of the inductor on the printed circuit board. A power supply device comprising one terminal of the inductor, a different terminal of the same winding, and a heat dissipation plate at the same potential.