JPS63133511A - Current transformer - Google Patents

Abstract

PURPOSE:To contrive miniaturization, lightweightedness and low cost of production of the title current transformer by a method wherein a magnetic core is formed using the amorphous magnetic material having specific characteristics in squareness ratio in such a manner that it has no air-gap in its magnetic path. CONSTITUTION:In the current transformer 43 having a light-emitting diode 44 as a secondary load, a magnetic core 31 is formed using the amorphous magnetic material, having the DC magnetic characteristics of 0.7 or more in squareness ratio, in the form having no air-gap. Also, a gapless magnetic core can be formed using a toroidal-shaped tape-wound magnetic core 31, a tape- wound magnetic core having no oval-shape cut, or a ring core and the like which is punched out and laminated in ring shape. As a result, the optical output of the light-emitting diode 44 can be increased sharply, and the current zone of the switching device of pilot lamp built-in type can be made wider. As above-mentioned, the secondary winding current I0 against the primary winding current I1 can be increased when compared with the current transformer using other magnetic material.

Description

[Detailed Description of the Invention] [Technical Field] The present invention is used for an energization display device, in which a primary winding is inserted into a energization path to a load, a light emitting diode is connected to a secondary winding, and a light emitting diode is connected to a energization path to a load. This relates to a current transformer that detects energization and lights up a light emitting diode.

[Background technology]

A switch device with a built-in pilot lamp, used in household wiring equipment, etc., which uses the switch itself to turn on/off power from a commercial power source to a load such as an incandescent lamp or fluorescent lamp, and indicates that power is being applied to the load by lighting a light emitting diode. There is.

Such a switch device is used for a load having a load current of 0.05 A to 15 A, and is particularly used for indoor monitoring of power supply to gatepost lights and entrance lights.

FIG. 12 is a circuit diagram showing the connection relationship between the above-mentioned switch device and the commercial power supply and the load. and a load (incandescent lamp, fluorescent lamp, electric appliance, etc.) 3 are connected in series to a commercial power source 4, and a light emitting diode 5 is connected to the secondary winding of the current transformer 2.

In this circuit, when switch body 1 is turned on,
1 of the current transformer 2 through the load 3 from the commercial power supply 4
The primary current 11 flows through the next winding, and the 2 of the current transformer 2
The light emitting diode 5 connected to the secondary winding is turned on by the secondary current I2.

The light output of the light emitting diode 5 is proportional to the current flowing through the light emitting diode 5, but this characteristic depends on the amount of load current, the characteristics of the current transformer 2, and the characteristics of the light emitting diode 5.

Gatepost lights and entrance lights that are often used have a load of I.
Since it is smaller than OW, the load current is small, and the light emitting diode current and light output are small.

However, from the user's perspective, since it is used to confirm energization, it is necessary to obtain a light output of a certain level or higher, no matter what the load value is.

Although the current transformer 2 is designed taking the above points into consideration, its dimensions and electrical characteristics are limited, particularly depending on the magnetic core material and characteristics.

Fig. 13 shows an external perspective view of a switch device (-N5241 manufactured by Matsushita Electric Works) with a load current rating of 0.1 A to 4 A, Fig. 14 shows a sectional view of the lower housing, and Fig. 15 shows a cross-sectional view of the lower housing. The figure shows a plan view of the lower housing. This switch device has a lower housing 11 and an upper housing 12.
The current transformer 13 is housed on one side of the internal space of the lower housing 11, and the contact section, spring, etc. (not shown) are housed on the other side, and the upper housing 12 has a seesaw-shaped structure. A knob 14 is attached, and the contacts are opened and closed by rotating the knob 14. The knob 14 is provided with a window, and the light emitting diode 1
Light emitting diode 1 with the light emitting part of 5 exposed through the window
5 are integrally fixed.

As shown in FIG. 16, the current transformer 13 consists of a substantially E-shaped core 21 and a substantially L-shaped core 22 made of ferrite, which are divided into two, a primary winding 23, and a secondary @WA24. The primary winding 23 and the secondary winding 24 are fitted concentrically into the winding housing recess 21a of the core 22.
0 cylindrical central leg and both side layers with adhesive, core 2
1.22 constitutes a closed magnetic path. External dimensions of this current transformer 13 an') + CI + cx
are 16.5m, 15n, 3.75m, respectively.
It is 3.75m.

Although there is a strong demand for such a switch device to be smaller and lighter, the current transformer 13 cannot currently be made smaller than the above dimensions.

Further, in the shape of the cores 21 and 22 shown in FIG. 16, the mold structure is complicated due to the manufacturing method, and the shape and dimensions vary widely due to shrinkage during ferrite sintering.
There is a drawback that the cost is high due to the necessity of polishing the abutting surfaces in order to improve the bonding between the parts 22 and 22. In order to miniaturize switch devices, miniaturization of current transformers has been a major challenge.

As a material used as the magnetic core of current transformer,
There are amorphous magnetic materials. This amorphous magnetic material has physical, mechanical, and magnetic properties that are significantly different from ferrite and other magnetic materials.

The amorphous ribbon made using the ultra-quenching method has a thickness of 50 μm.
m or less, has a Vickers hardness of about 1000, has no crystal structure, and has small magnetic anisotropy. Its composition can be broadly divided into Fe, which exhibits magnetism.

The main elements are Co, Ni, and Si, B, P, and C.

Contains Ge etc. as an amorphous forming element, for example F
eves l+tB+o+ F eaoN 155M0
4BIIl+F fl@+B+3. ss +3. s C
There are t+F6*tCO+sB+aS+1, etc.

When an alloy with the above composition is melted and rapidly cooled at a cooling rate of about 300'C/sec or more, the alloy does not become crystalline.
Solidifies in an amorphous state. That is, a ribbon-shaped amorphous magnetic material can be obtained in an extremely short time.

According to the conventional manufacturing method of silicon steel strip, it is possible to obtain a steel plate with a thickness of about 100 μm, but it requires many rolling steps, takes a long time, and has high running costs, so the material is expensive. It had become a thing. Ferrite cores also had similar drawbacks due to the long sintering process.

On the other hand, amorphous magnetic materials have a short manufacturing process and can be produced at low cost. However, because it is a hard, thin, strip-shaped material that is difficult to process, its practical use as a transformer has been delayed.

Current transformers for switch devices need to be housed in a limited space, requiring miniaturization, and there have been no examples in the past of using amorphous magnetic materials as the magnetic core for current transformers that light up light-emitting diodes. However, its behavior and characteristics are completely unknown.

[Purpose of the invention]

An object of the present invention is to provide a current transformer that can increase the light output of a light emitting diode connected to a secondary winding, and can also be made smaller, lighter, and lower in cost.

[Disclosure of the invention]

The current transformer of the present invention is a current transformer in which a primary winding wound around a magnetic core is inserted into a conduction detection circuit, and a light emitting diode is connected to a secondary winding wound around the magnetic core. , is characterized in that it is made of an amorphous magnetic material having magnetic properties with a ratio of residual magnetic flux density to saturation magnetic flux density (squareness ratio) of 0.7 or more and is formed in a shape with no gaps in the magnetic path.

The amorphous magnetic material having a squareness ratio of 0.7 or more has the following compositional formula (atomic %).

XI@@-F Yp In the formula, P: 5<P≦40 X: Fe, Co, Ni, Cr, Mn, Zr.

One or two of Ti, V, Nb, Hf, Ta, Mo, W
Y containing at least one of Fe and CO in a mixed composition of more than one species: containing at least one of B and P in a mixed composition of one or more of St, B, C, ACGe, P, and Sn The amorphous magnetic material having the above composition is simply annealed at a temperature below the crystallization temperature, or annealed at a temperature below the crystallization temperature and in a magnetic field, or annealed at a temperature below the crystallization temperature and under stress. be done.

According to the configuration of this invention, the magnetic core of the current transformer is
The magnetic path is made of amorphous magnetic material with magnetic properties such that the ratio of residual magnetic flux density to saturation magnetic flux density (squareness ratio) is 0.7 or more, and the magnetic path is formed in a shape with no air gaps. The line current can be increased compared to current transformers using other magnetic materials, and the light output of the light emitting diode connected to the secondary winding can be increased.

Further, since an amorphous magnetic material is used as the magnetic core, the magnetic core can be made smaller and lighter, and the cost can be reduced, and the overall size, weight, and cost can be reduced.

Examples Examples of the present invention will be described in detail. Composition Fed@B+
sSi* (260552 manufactured by Allied), thickness approximately 25μ
m1 width d+-4 Tsuru's amorphous ribbon to inner diameter d□-7
A toroidal-shaped wound magnetic core with N and an outer diameter d3 of 14 m was prepared. The material properties announced by the manufacturer are shown in Table 1.

(The following is a margin) Table 1, Figure 1 fa) shows the shape of the wound magnetic core 31. In this state, in order to improve the characteristics, the wound magnetic core 31 was annealed in a 400°C annealing furnace for 2 hours, and then 5
The wound magnetic core 31 was cooled at a cooling rate of °C/+win.

Thereafter, in order to maintain the wound magnetic core 31 fixed, powder coating with resin was performed using Aron powder (EL-3000 manufactured by Toagosei ■). Figure 1 fbl is s after powder coating.
Since the core edge corner is covered with resin, there is no risk of wire breakage during winding in post-processing.

Figure 1 (C1 is the S magnetic core 31 using a toroidal winding machine.
Figure 1 (d) shows the state after winding the secondary winding 32.
1 indicates a state in which a primary winding 33 is further wound thereon, that is, a completed current transformer.

In this way, the shape of a current transformer made using an amorphous ribbon is quite different from that of a current transformer using a conventional ferrite core.

While the ferrite core is divided into two parts and has an abutting part, in this wound magnetic core 31, the magnetic path is continuous and has no gaps, and moreover, the longitudinal direction of the amorphous ribbon coincides with the magnetic path direction. Therefore, it has the characteristic that magnetic flux can easily pass through it.

Table 2 shows the difference in structure between a current transformer using conventional ferrite and a current transformer using amorphous ribbon.

(Leaving space below) Table 2 As is clear from Table 2, when comparing current transformers using amorphous ribbons and current transformers using ferrite, those using amorphous ribbons are superior to those using ferrite. In comparison, the core weight is about 50% and the external volume is about 60%, making the current transformer smaller and lighter.

After creating the current transformer, an electrical circuit for actual use was formed and the electrical characteristics of both current transformers were compared. Figure 2 shows the measurement circuit, where 41 is a 60Hz commercial power supply, 42 is a load, 43 is a current transformer, and 44 is a 60Hz commercial power supply.
is a bidirectional light emitting diode. light emitting diode 4
4, a GaP-based light emitting diode (LN-02ORCP manufactured by Kagoshima Denshi Corporation) was used, and was connected to the secondary side of the current transformer 43. In addition, as the load 42, 6
Using a 0W incandescent lamp, 1 of 43 current transformers
Next t! connected in series to the wire. Then, while changing the load current (primary current!1), the light emitting diode current ■. (
Secondary current) and light emitting diode voltage V were measured.

When the light emitting diode current (effective value) tD is measured while changing the primary current (effective value) r+ from 0.1 A to IA, the current transformer using an amorphous ribbon shows the solid line A in Figure 3. Therefore, a current transformer using ferrite is as shown by the solid line Ax in Figure 3, and a current transformer using an amorphous ribbon has a light emitting diode current I, for the same primary current I, than one using ferrite.
increased.

On the other hand, the relationship between the light emitting diode current ID and the light output of the light emitting diode depends on the composition of the light emitting diode.

Although it varies depending on the shape of the reflector, in the case of this light emitting diode, in order to visually confirm whether the light is on or off, the light emitting diode current! . Rikizuki requires more than 5m.

In order for the light emitting diode current Iゎ to be 1.5 mA or more in the current transformer 43 using conventional ferrite, the primary current! 1 is required to be 0.1 A or more, and this determines the minimum value of the primary current I.

On the other hand, in the current transformer 43 using an amorphous ribbon, the minimum value of the primary current (■) at which the light emitting diode current I becomes 1.5 mA or more is 0.08 A, which is smaller than that using ferrite. It has become. That is,
For those using amorphous ribbon, the primary current is small.
1, the lighting of the light emitting diode 44 can be visually confirmed, and the band of the primary current 11 is expanded accordingly. This 4A current transformer uses ferrite. It is IA to 4A, whereas that using an amorphous ribbon is 0.08A to 4A.

From the above, it can be seen that the current transformer 43 using an amorphous ribbon has better characteristics than the conventional transformer using ferrite, despite its small size.

Next, the light emitting diode voltage ■ when the primary current 11 is 0.2 A. and light emitting diode current I.

The waveform of
The structure using ferrite is shown in FIG. 5, fal, (b). As is clear from these figures, when using ferrite, the light emitting diode voltage VD rises slowly and the energization time is short, whereas when using an amorphous ribbon, the light emitting diode voltage VD rises quickly. , the effective current is large.

Therefore, the light output of the light emitting diode 44 increases.

In this way, the current transformer 43 using an amorphous ribbon exhibits characteristics that those using ferrite do not have.

Next, when examining the magnetic core material characteristics using AC B-H characteristics at 60 Hz, the current transformer 43 using an amorphous ribbon is as shown in Figure 6+81, and the one using ferrite is as shown in Figure 6+81). From this figure, the current transformer using an amorphous ribbon 43
It was found that the magnetic flux density and residual magnetic flux density are high, the coercive force is low, and the magnetization is steep. This fact and the composite circuit of the current transformer 43 and the light emitting diode 44 seem to have resulted in the above-mentioned light emitting diode current characteristics.
They discovered that this effect could only be achieved with amorphous magnetic materials, and could not be achieved with conventional magnetic materials such as ferrite and silicon steel sheets.

Returning to Figure 3 again, the light emitting diode current ■ when the primary current ■1 becomes 0.1. The ferrite is 1.5 m
Compared to A, the amorphous has an increase of 2.2 mA, but this can also be considered as an increase in the light output of the light emitting diode 44.

The current transformer 43 using an amorphous ribbon in this embodiment has high performance, with a core weight ratio of 50%, external dimension ratio of 60%, and optical output ratio of 150% compared to the conventional one using ferrite. Ta.

Next, we experimentally investigated which of the various magnetic properties affected the electrical properties by fabricating prototype current transformers using amorphous materials with various compositions.

As a result, it was discovered that there is a correlation between the squareness ratio (DC magnetic characteristics) Br/Bs, which is the ratio of the saturation magnetic flux density Bs to the residual magnetic flux density Br, and the light emitting diode current characteristics.

Figure 7 shows the squareness ratio B when the primary current 11 is 0.08A.
r/B s and light emitting diode current■. This shows the relationship: As the squareness ratio B r /B s increases, the light emitting diode current Iゎ increases. The conditions for human visual confirmation, that is! , ≧1.5+wA, the squareness ratio B r / B s must be B r
/Bs≧0.7.

The squareness ratio B r / B s of the amorphous magnetic material is
Although it depends on the composition, annealing conditions, etc. and is not uniform, the composition F'! of this example is F'! Using an amorphous magnetic material of 1ysB+ss4, annealing conditions under which the squareness ratio B r /B s is 0.7 or more were experimentally derived.

The annealing conditions include annealing temperature, annealing time, atmosphere of the annealing furnace, magnitude of applied magnetic field, cooling rate, etc. this house,
An experimental investigation was conducted on the annealing temperature, annealing time, and magnetic field size. The annealing furnace atmosphere is nitrogen atmosphere, and the cooling rate is 5℃.
/'s+in, the temperature inside the furnace is uniform.

First, the annealing time was set to 2 hours without applying a magnetic field.
Annealing was performed by varying the annealing temperature. As a result, the relationship between annealing temperature and squareness ratio B r / 133 is as shown in Fig. 8, real IB,
The squareness ratio B r /B s became larger than 0.7 when the annealing temperature ranged from 390°C to 450°C.

Next, when the annealing temperature is set to 410°C and the annealing time is changed, the relationship between the annealing time and the squareness ratio B r / B s becomes like the actual W c t in Fig. 9, and the annealing time is 410°C.
The squareness ratio B r / B S is 0 in the range of 0 minutes to 3 hours.
．． It's thicker than 7.

In other words, in order to satisfy the squareness ratio B r / B s of Br/Bs > 0.7 in non-magnetic annealing, annealing should be performed at an annealing temperature of 390°C to 450°C and an annealing time of 30 minutes to 3 hours. is the condition.

Next, an experiment was conducted under the above annealing temperature range and annealing time with a DC magnetic field of 10 oe applied in the magnetic path direction of the magnetic core. Showing the relationship between temperature and squareness ratio B r / B s,
Dashed line C in Figure 9! shows the relationship between the annealing time and the squareness ratio B r /B s when the annealing temperature is 390°C. From these figures, it can be seen that when annealing is performed in a magnetic field, the squareness ratio Br/Bs is generally larger than when annealing is performed without a magnetic field.

In addition, an experiment similar to the above was conducted with the magnetic field size set to 2 oe, and the same tendency was observed in this case, indicating that the application of a magnetic field is extremely effective in improving the squareness ratio B r / B s. Ta.

From this experiment, the composition F e? In sB++sig, the annealing temperature is 390°C to 450°C, and the annealing time is 30 minutes to 3
It is effective to anneal under the condition of time, and by applying a magnetic field during annealing, the squareness ratio B r /
It was found that 333 was improved.

In the above example, the composition FeysBtssig was shown, but we conducted experiments on other compositions and found a range of compositions that can be amorphous and have good electrical characteristics. That is, the conditions are expressed by the compositional formula % in atomic %.

however )l　Fe, Co, Ni, Cr, Mn, Zr.

One or two of Ti, V, Nb, Hf, Ta, Mo, W
A mixed composition of at least one species, Y that always includes at least one of F and Co: St, B, C, AJ, Go, P, S
A mixed composition of one or more types of n, which always includes at least one of B and P, and annealing is performed in this composition range, but the annealing temperature is low (both must be below the crystallization temperature). Furthermore, we discovered that magnetic field annealing, in which a magnetic field is applied during annealing, is very effective.

In addition, amorphous materials with positive magnetostriction (e.g. FeBSt system)
We have also found that it is effective to anneal under tensile stress in the case of annealing, and under compressive stress in the case of an amorphous material with negative magnetostriction (for example, CoB51 type).

In this example, a magnetic core made of an amorphous magnetic material was created by winding a thin strip to create a wound core with no gaps in a toroidal magnetic path. Similarly, laminated core or cut core shapes can also be created.

The laminated core is, for example, a magnetic plate punched out in an E shape in the thickness direction and stacked in multiple layers.

Moreover, a cut core is obtained by cutting a part of the magnetic path after creating a wound magnetic core. A feature of the laminated core and the cut core is that since both have divided magnetic paths, they have butt portions (gap surfaces) to form closed magnetic paths.

However, as a result of trial production and experiments, it has been discovered that a toroidal-shaped wound core is superior to laminated cores, cut cores, etc. as the magnetic core shape of the current transformer of the present invention.

The prototypes were made with the same core magnetic path cross-sectional area and magnetic path length, but with different shapes (toroidal, E-shaped cores, etc.).

cut core).

Figure 10+111 shows an external perspective view of a laminated core (E-shaped core), Figure 10 1bl shows an external perspective view of a cut core, and Figure 11 shows light emitting diode current characteristics corresponding to the core shape. . From this figure, it can be seen that the toroidal core exhibits extremely excellent characteristics regarding the light emitting diode current value. The reason for this is not clear, but because E-shaped cores and cut cores have gaps, magnetic flux crosses at the butt part.

This is thought to be because leakage flux and eddy current occur, and toroidal cores do not have such problems. This experiment revealed that a core with a gap is inappropriate as the magnetic core of the current transformer of the present invention.

In addition to a toroidal-shaped wound core, the gap-free magnetic core can be formed by a wound core without an elliptical cut, or a ring core made by punching a ring shape and stacking them.
The same effects as in the above embodiment can be obtained.

Here, the effects of this embodiment will be summarized. In a current transformer that uses a light emitting diode as a secondary load, the magnetic core is made of an amorphous magnetic material with direct current magnetic properties with a squareness ratio of 0.7 or more and is formed in a shape with no gaps in the magnetic path, which greatly increases the light output of the light emitting diode. can be increased to,
The current band of a switch device with a built-in pilot lamp is expanded, and the switch device can be made smaller and lighter. Furthermore, the switch device using this device can also be made smaller, and the cost of amorphous material is low, so it is possible to achieve significant cost reductions. .

Note that, since the present invention is based on the discovery of a special combination of a light emitting diode and an amorphous magnetic material, there are no limitations on the composition of the light emitting diode and the amorphous magnetic material.

〔Effect of the invention〕

According to the current transformer of the present invention, the magnetic core of the current transformer is made of an amorphous magnetic material having a magnetic property with a ratio of residual magnetic flux density to saturation magnetic flux density (squareness ratio) of 0.7 or more, and has a shape with no gaps in the magnetic path. , the secondary winding current can be increased for the same primary winding current compared to current transformers using other magnetic materials, and the light output of the light emitting diode connected to the secondary winding can be increased. can be increased. Further, since an amorphous magnetic material is used as the magnetic core, the magnetic core can be made smaller and lighter, and the cost can be reduced, and the overall size, weight, and cost can be reduced.

[Brief explanation of the drawing]

Fig. 1 ta+ is a perspective view of the winding core of a current transformer according to an embodiment of the present invention, 1st opening) is a perspective view of the winding core after powder coating; Figure 1 +dl is a perspective view of the primary winding after winding; Figure 2 is a circuit for measuring the relationship between the primary current of the current transformer and the light emitting diode current. Figure 3 is a characteristic diagram showing the relationship between the primary current of the current transformer and the light emitting diode current. Figure 4 shows the light emitting diode voltage and light emitting diode voltage when using a current transformer whose magnetic core is an amorphous magnetic material. Current waveform diagram, 5th
The figure shows waveform diagrams of light-emitting diode voltage and light-emitting diode current when a current transformer with a ferrite core is used. Figure 6 shows AC B-H characteristics of amorphous magnetic material and ferrite. Figure 7 shows squareness ratio and light emission. A characteristic diagram of diode current, FIG. 8 is a characteristic diagram showing the relationship between annealing temperature and squareness ratio, and FIG. 9 is a characteristic diagram showing the relationship between annealing time and squareness ratio.
Fig. 10 is a perspective view of the E-shaped core and cant core;
The figure is a graph showing the relationship between core type and light emitting diode current, Figure 12 is a circuit diagram of a conventional switch device with a built-in pilot lamp, and Figure 13 is a perspective view of the switch device.
FIG. 14 is a sectional view of the main part, FIG. 15 is a plan view of the main part, and FIG. 16 is an exploded perspective view of the conventional current transformer. 31...S magnetic core, 32...secondary winding, 33...1
Next winding Figure 11 = Primary electric washing, +1 (j! value) Figure 3 Figure 4 Figure 5 Figure 16 Figure 7 Figure 8 rl! J Figure 9 (a) (b) Figure 10 a Figure 11

Claims (5)

[Claims] (1) In a current transformer in which a primary winding wound around a magnetic core is inserted into a conduction detection circuit, and a light emitting diode is connected to a secondary winding wound around the magnetic core, the residual magnetic flux density A current transformer characterized in that it is made of an amorphous magnetic material having a magnetic property in which the ratio of the magnetic flux density and the saturation magnetic flux density is 0.7 or more and is formed in a shape with no gaps in the magnetic path. (2) The current transformer according to claim (1), wherein the amorphous magnetic material has the following compositional formula (atomic %). X_1_0_0_-_PY_P In the formula, P:5<P≦40 X: Fe, Co, Ni, Cr, Mn, Zr, Ti, V,
Y: One or two of Si, B, C, Al, Ge, P, and Sn with a mixed composition of one or more of Nb, Hf, Ta, Mo, and W and at least one of Fe and Co A mixed composition of more than one species containing at least one of B and P (3) The current transformer according to claim (2), wherein the amorphous magnetic material is annealed at a temperature below its crystallization temperature. (4) The amorphous magnetic material is annealed in a magnetic field at a temperature below the crystallization temperature.
Current transformer described in section 2). (5) The amorphous magnetic material is annealed at a temperature below the crystallization temperature and under stress.
Current transformer described in section 2).