JPH10144536A - Transformer for power supply - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transformer for power supplies such that the bad effect on other electronic devices is suppressed to a minimum or zero by suppressing common mode noise current. SOLUTION: A transformer T for power supplies is driven by switching to interrupt the input voltage to a primary winding N1 and to generate output voltage with variation on a secondary winding NS. The primary windings 1 N1 which generate the same variation of voltage as that generated by the secondary winding NS are placed on both sides of the secondary winding NS of the transformer T so that the variation of voltage may be balanced between the primary winding N1 and the secondary winding NS.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transformer for a power supply device.

[0002]

2. Description of the Related Art An example of a conventional switching power supply device using a transformer T will be described with reference to FIG.

In a conventional switching power supply, a transformer T has a primary winding N indicated by reference numerals 1, 2, and 3,
1 and N2 and secondary windings Ns indicated by reference numerals 6 and 7 and auxiliary windings N3 indicated by reference numerals 4 and 5 for generating a driving voltage for switching drive are provided on the primary side. ing.

An input voltage is supplied to the primary windings N1 and N2 from a DC power supply E via a switching-driven MOS-FET Q1. The gate of the MOS-FET Q1 is supplied with a control signal from a control circuit 10 which takes in the drive voltage generated by the auxiliary winding N3 via a diode D, thereby switching the MOS-FET Q1. Thus, the input voltage supplied to the primary windings N1 and N2 is interrupted.

[0005] A rectifier diode D1 and a smoothing capacitor (electrolytic capacitor) C1 are connected to the secondary winding Ns of the transformer T so that the input voltage supplied to the primary windings N1 and N2 can be interrupted. Accordingly, the AC output voltage generated in the secondary winding Ns is rectified and smoothed and applied to the load resistor R.

Further, the terminal side of the secondary winding Ns indicated by reference numeral 6 shown in FIG. 5 is connected to ground ER, and the terminal side of the auxiliary winding N3 indicated by reference numeral 4 is connected to a capacitor C0. To the ground ER.

FIG. 6 shows the arrangement of the windings of the transformer T and the state of voltage fluctuation corresponding to this arrangement.

The transformer T is provided on both sides of a secondary winding Ns indicated by reference numerals 6 and 7 which generate an AC voltage fluctuation (0 to V2), and a numeral 1 with a large AC voltage fluctuation (0 to V1 / 2). 2 and a primary winding N2 also indicated by reference numerals 2 and 3 having large AC voltage fluctuations (V1 / 2 to V1), and further outside the primary winding N2. Auxiliary windings N3 indicated by reference numerals 4 and 5 are arranged.

[0009]

However, in the above-mentioned conventional example, the primary windings N1 and N2 having a large AC voltage fluctuation are directly arranged on both sides of the secondary winding Ns, so that the primary winding N1 is not used. , N2 and the AC voltage fluctuation of the secondary winding Ns become imbalanced, and as a result, the primary windings N1, N2
The common mode noise current IC flows to the secondary winding Ns side and further to the ground ER via the distributed capacitance Cx between the secondary winding Ns and the secondary winding Ns. Then, there is a problem that the common mode noise current IC returns to the commercial power supply and adversely affects other electronic devices (not shown) as a noise voltage.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a transformer for a power supply device capable of suppressing common mode noise current and minimizing or eliminating adverse effects on other electronic devices is provided. It is intended to provide.

[0011]

According to the first aspect of the present invention,
In a transformer for a power supply that generates an output voltage with voltage fluctuations in a secondary winding based on an input voltage to a primary winding, the secondary winding is provided on both sides of the secondary winding of the transformer. A primary winding which causes a voltage fluctuation similar to the voltage fluctuation is arranged.

According to a second aspect of the present invention, there is provided a transformer for a power supply device which is switched and intermittently inputs and outputs an input voltage to a primary winding and generates an output voltage with a voltage fluctuation in a secondary winding. Are arranged on both sides of the secondary winding described above, a primary winding which causes a voltage fluctuation similar to the voltage fluctuation caused by the secondary winding.

According to a third aspect of the present invention, there is provided a transformer for a power supply device which is switched and intermittently inputs and outputs an input voltage to a primary winding and generates an output voltage with a voltage fluctuation in a secondary winding. On both sides of the secondary winding, there is a part of the primary winding that causes a voltage fluctuation similar to the voltage fluctuation caused by the secondary winding, and a voltage fluctuation similar to the voltage fluctuation caused by the secondary winding. An auxiliary winding for generating a driving voltage for switching driving is arranged.

According to a fourth aspect of the present invention, there is provided a transformer for a power supply device which is switched and intermittently inputs and outputs an input voltage to a primary winding and generates an output voltage with a voltage fluctuation in a secondary winding. On both sides of the secondary winding, a part of a primary winding composed of multiple parallel wires causing a voltage variation similar to the voltage variation caused by the secondary winding, and a voltage variation caused by the secondary winding. Along with arranging an auxiliary winding composed of multiple parallel lines for generating a driving voltage for switching drive with a similar voltage fluctuation, a part of the primary winding and the outer side of each of the auxiliary windings, The remaining part of the primary winding is arranged.

According to the present invention having the above-described structure, the primary winding that causes a voltage fluctuation similar to the voltage fluctuation caused by the secondary winding is arranged on both sides of the secondary winding of the transformer. , AC voltage fluctuation of the primary winding and AC voltage fluctuation of the secondary winding are balanced, thereby suppressing common mode noise current and minimizing or eliminating adverse effects on other electronic devices Becomes In this case, the transformer is 1
The next winding is switched and the input voltage is intermittent,
The present invention can also be used for a switching power supply device that generates an output voltage with a voltage fluctuation in the next winding.

The primary windings disposed on both sides of the secondary winding include a part of the primary winding that causes a voltage fluctuation similar to the voltage fluctuation caused by the secondary winding, A configuration using an auxiliary winding that generates a driving voltage for switching driving accompanied by a voltage fluctuation similar to the voltage fluctuation caused by the next winding is also possible. According to this configuration, the auxiliary winding for switching driving can be used. It can be used as a primary winding that balances AC voltage fluctuations and suppresses common mode noise current.

Further, a part of the primary winding composed of multiple parallel lines that causes a voltage fluctuation similar to the voltage fluctuation caused by the secondary winding, and a voltage fluctuation similar to the voltage fluctuation caused by the secondary winding are generated. Auxiliary windings composed of multiple parallel wires for generating a driving voltage for switching drive are arranged on both sides of the secondary winding, and a part of the primary winding and an outer side of each of the auxiliary windings In addition, by arranging the rest of the primary winding, the influence of the electric field generated in the rest of the primary winding on the secondary winding can be reduced by one of the primary windings composed of multiple parallel wires. It can be eliminated by the electric field shielding action between the portion and the auxiliary winding composed of multiple parallel wires, and thereby, the common mode noise current can be more effectively suppressed.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows a switching power supply including a transformer according to an embodiment of the present invention. In this switching power supply, those having the same functions as those of the conventional switching power supply shown in FIG. 5 are denoted by the same reference numerals.

The switching power supply shown in FIG.
1 is substantially the same as the conventional switching power supply device shown in FIG. 1 except that the winding structure and the winding arrangement of the transformer T are different. This switching power supply is called a ringing system or a flyback system.

The transformer T in the switching power supply device shown in FIG. 1 has a primary winding N1 which generates a stepwise AC voltage fluctuation V as shown in FIG.
, The primary winding N4 and the numerals 3, 4
2 and a stepwise AC voltage fluctuation V as shown in FIG. A secondary winding Ns is provided.

Also, on the primary side, FIG.
The auxiliary winding N3 which generates a stepwise AC voltage fluctuation V as shown in FIG.

FIG. 2 shows the arrangement of the windings of the transformer T of the present embodiment and the state of voltage fluctuation according to the arrangement.

The transformer T has two parts indicated by reference numerals 7 and 8.
On both sides of the secondary winding Ns, the primary winding N1 which is a part of all the primary windings indicated by reference numerals 1 and 2, and the auxiliary winding N3 indicated by reference numerals 5 and 6 are arranged. , The primary winding N
Further outside of 1 is the number 2, which is the remainder of all the primary windings.
The primary winding N4 indicated by reference numeral 3 is arranged, and the primary winding N5 indicated by reference numerals 3 and 4, which is the rest of all the primary windings, is arranged further outside the auxiliary winding N3. is there.

The stepwise AC voltage fluctuation V of the primary winding N1 and the auxiliary winding N3 as shown in FIG.
The stepwise AC voltage fluctuation V of s as shown in FIG. 2 can be realized as an equilibrium of these by making the respective winding patterns the same.

By using the transformer T having such a configuration, the AC voltage fluctuation V of the primary winding N1 and the auxiliary winding N3 and the voltage fluctuation of the secondary winding Ns become similar and balanced. From the primary winding N1 through the distributed capacitor Cx, the secondary winding Ns
Further, the flow of the common mode noise current IC to the ground ER is suppressed or eliminated, thereby making it possible to minimize or eliminate adverse effects on other electronic devices.

FIGS. 3 and 4 show examples in which multiple parallel wires 11 are used as the primary winding N1 and the auxiliary winding N3. As shown in FIG. 4, the multiple parallel wires 11 are formed by bundling an arbitrary number of winding materials 12 at a time and joining their exposed ends with solder 13 to form a single winding conductor. is there.

The primary winding N1 and the auxiliary winding N3 using such multiple parallel wires 11 are arranged on both sides of the secondary winding Ns, and the primary winding N1 and the auxiliary winding N3 are arranged. N
The primary windings N4 and N5, which are the rest of the primary windings, are arranged outside each of the primary windings 3 and 3 so that the secondary windings of the electric field generated in the primary windings N4 and N5 are formed. The influence on Ns can be eliminated by the electric field shielding effect of the multiple parallel lines 11, whereby the common mode noise current IC can be more effectively suppressed. Although the present embodiment has been described with reference to the ringing system or the flyback system, a forward-type switching power supply device can be similarly configured.

[0029]

According to the present invention, it is possible to provide a transformer for a power supply device capable of suppressing a common mode noise current and minimizing or eliminating adverse effects on other electronic devices.
In addition, a transformer that can be used for a switching power supply device can be provided.

Further, the auxiliary winding for switching drive can be utilized as a primary winding for balancing AC voltage fluctuations and suppressing common mode noise current, and a transformer for a power supply device whose structure can be simplified can be provided.

Further, it is possible to provide a transformer for a power supply device capable of more effectively suppressing a common mode noise current by using multiple parallel lines.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a switching power supply including a transformer according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating a relationship between a winding arrangement of a transformer and a voltage fluctuation according to the embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a winding arrangement using multiple parallel wires according to the embodiment of the present invention.

FIG. 4 is a perspective view showing an example of multiple parallel lines according to the embodiment of the present invention.

FIG. 5 is a circuit diagram showing a conventional switching power supply device including a transformer.

FIG. 6 is an explanatory diagram showing a relationship between a winding arrangement of a conventional transformer and voltage fluctuation.

[Explanation of symbols]

 10 Control circuit E DC power supply ER Ground Q1 MOS-FET D Diode N1 Primary winding N3 Auxiliary winding N4 Primary winding N5 Primary winding Ns Secondary winding D1 Rectifying diode C1 Smoothing capacitor C0 Capacitor Cx Distributed capacitance R Load resistance IC Common mode noise current

Claims (4)

[Claims] 1. A transformer for a power supply device that generates an output voltage with a voltage fluctuation in a secondary winding based on an input voltage to a primary winding. A transformer for a power supply device, comprising a primary winding that causes a voltage fluctuation similar to a voltage fluctuation caused by a secondary winding. 2. A transformer for a power supply device, which is switched and intermittently inputs and outputs an input voltage to a primary winding and generates an output voltage with a voltage fluctuation in a secondary winding. A transformer for a power supply device, comprising a primary winding on both sides that causes a voltage fluctuation similar to the voltage fluctuation caused by the secondary winding. 3. A transformer for a power supply device which is switched and intermittently inputs and outputs an input voltage to a primary winding and generates an output voltage with a voltage fluctuation in a secondary winding. On both sides, a part of the primary winding that causes a voltage change similar to the voltage change caused by the secondary winding, and a drive voltage for switching drive that involves a voltage change similar to the voltage change caused by the secondary winding A transformer for a power supply device, wherein an auxiliary winding for generating a current is arranged. 4. A transformer for a power supply device which is switched and intermittently inputs and outputs an input voltage to a primary winding and generates an output voltage with voltage fluctuation in a secondary winding. On both sides, there is a part of a primary winding composed of multiple parallel wires that causes a voltage fluctuation similar to the voltage fluctuation caused by the secondary winding, and a voltage fluctuation similar to the voltage fluctuation caused by the secondary winding. An auxiliary winding composed of multiple parallel lines for generating a driving voltage for switching drive is disposed, and a remaining part of the primary winding is provided outside each of the primary winding and the auxiliary winding. A transformer for a power supply device, comprising: