JPS58281Y2 - power transformer - Google Patents

Description

[Detailed explanation of the invention] This invention & 6) Concerning a power transformer using a loidal core.

A power transformer using a toroidal core has the advantage of being able to easily obtain a power transformer that is small and has low internal impedance due to the core's high maximum magnetic flux density, etc. Therefore, this is used as a power transformer for DC power supplies. In this way, a high-performance DC power supply with low internal impedance can be obtained.

By the way, when this toroidal core type power transformer is used to configure a DC power supply device that obtains DC output from an AC power supply, a smoothing choke coil may be used in addition to the power transformer.

However, in a type of DC power supply that uses a choke coil for smoothing, it is necessary to install two types of parts: a power transformer and a choke coil, which requires a considerable amount of storage space. This obviated the advantage of the core-type power transformer's small size and hindered miniaturization of the device.

In particular, choke coils require consideration to ensure that the leakage magnetic flux or induced noise emitted from them does not have a negative impact on others, so a storage space greater than the actual space occupied is required, making the overall device more compact. It was making it difficult.

This idea was made in view of the above problems, and its purpose is to effectively suppress the leakage magnetic flux and induction noise mentioned above, and to take advantage of the small size advantage of the toroidal core type power transformer. This enables the miniaturization of DC power supplies,
Another object of the present invention is to provide a toroidal core type power transformer that enables rational assembly and cost reduction.

In other words, the power transformer according to this invention has a power transformer section formed by winding a toroidal core and a choke coil section formed by winding a toroidal core coaxially stacked together in a common shielding case. Examples thereof will be described below in detail based on the drawings.

Figure 1 shows the power transformer according to this invention! This shows an example in which a power transformer section 2 and a choke coil 3 are housed in a stacked state in a cylindrical shield case 1.

The power transformer section 2 has a toroidal core with primary and secondary transformer windings, and has a cylindrical shape with a diameter larger than the length of the cylinder.

Further, the choke coil section 3, like the power transformer section 2, is a toroidal core with a choke winding, and its outer shape is an annular shape having approximately the same outer diameter as the transformer section 2. ing.

Thereby, the transformer section 2 and the choke coil section 3 are coaxially stacked on top of each other and efficiently housed in the shield case 1.

The gap in the case 1 is filled with a suitable insulating material to seal the transformer section 2 and the choke coil section 3.

Lead wires 21, 22, 23, 24 from the primary and secondary windings of the transformer section 20 shown in FIG. 2, and lead wires 31, 32 from the choke winding of the choke coil section 3.
are led out from the bottom of the case 1 in a bundle as shown in FIG.

As shown in FIG. 3, the transformer section 2 and the choke coil section 3
The case 1 containing the holder can be attached as if it were a single component through its attachment parts 11 and 12.

FIG. 3 shows a choke input type DC power supply circuit constituted by the power transformers shown in FIGS. 1, 2, and 3. After being full-wave rectified by a rectifier, it is smoothed by a choke coil section 3 inserted in series and a capacitor C connected in parallel, and then supplied to a load R.

Here, as mentioned above, the choke coil section 3 has the following features:
A toroidal core is used, but this toroidal core exhibits a very steep magnetization curve because its magnetic path is closed and there is no gigang.

Therefore, the choke coil section 3 exhibits high inductance when the current is small, but the inductance decreases as the current increases.

Therefore, it is possible to provide a DC power supply device in which the DC output voltage is significantly reduced when the current is small, the voltage drop is small when the current is large, and the voltage fluctuation rate is good.

A toroidal core type power supply in which a choke coil part 3 having such properties and the above power transformer part which also uses a toroidal core are housed in a common shield case 1 in a coaxially laminated state. By effectively utilizing the advantages of the transformer's small size and low internal impedance, leakage magnetic flux and induction noise can be effectively suppressed, and a high-performance DC power supply with a small size and low voltage fluctuation rate can be obtained. Become.

As described above, the power transformer according to this invention has a power transformer section formed by winding a toroidal core, and a choke coil section formed by winding a toroidal core, which are coaxially stacked. By housing the power supply in a shielded case, leakage magnetic flux and induced noise are effectively suppressed, and the advantages of the toroidal core type power transformer can be effectively utilized, making it possible to downsize the DC power supply. It is also possible to rationalize the assembly and reduce costs.

[Brief explanation of the drawing]

Figure 1 is a location diagram of the power transformer according to this invention, Figure 2 is a schematic perspective view showing the arrangement of the power transformer and choke coil section, and Figure 3 is an external view of the power transformer according to this invention. The perspective view and FIG. 4 are circuit diagrams of a DC power supply device configured with the above power transformer. 1... Shield case, 2... Power transformer section, 3... Choke coil section, D...
... Bridge rectifier, C ... Capacitor, R
······load.

Claims (1)

[Scope of utility model registration request] A power transformer section formed by winding a toroidal core,
A power transformer that consists of a toroidal core and a choke coil section with wire wound on them, stacked coaxially and housed in a common shield case.