JPH0427283A - Power source circuit device - Google Patents

Abstract

PURPOSE:To prevent a fact that influence is exerted on a deflecting coil of a TV receiver by providing in parallel plural same transformers for forming a power source circuit by putting the terminals is order, and connecting a primary side terminal so that a primary side terminal current becomes the reverse direction. CONSTITUTION:A power source circuit is formed by providing in parallel plural pieces such as two pieces, etc., of transformers 20, 30, respectively to which windings of a primary side and a secondary side are wound in the same direction by putting in order primary side input terminals 21 and 22, 31 and 32, and secondary side output terminals 23 and 24, and 33 and 34 in the same line. In such a state, when each of the terminals 21 and 32, and 22 and 31 is connected to common input terminals 41, 42, a current flowing to a primary coil of the transformers 20, 30 becomes the reverse direction, and a leakage magnetic flux generated in a primary winding of the transformers 20, 30 becomes the reverse direction and cancels each other. As a result, even if a home terminal equipment for using this power source circuit as a power source is placed on a CATV receiver, the power source circuit device which exerts no influence on a deflecting coil of the receiver is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a power supply circuit device suitable for home terminal equipment of a CATV system.

2. Description of the Related Art Conventionally, a power supply circuit device in a home terminal equipment of a CATV system uses one power transformer and adopts a circuit configuration in which the primary side input voltage is stepped up or down to a required secondary side output voltage. Furthermore, home terminal equipment for CATV systems is generally installed on top of the television receiver that is used at the same time, and due to lack of design consideration for this usage method, various problems can occur. was giving.

FIG. 3 shows a schematic partial cross-sectional view of such a conventional power supply circuit device, in which 1 is a power transformer 1, which inputs power supply voltage from primary side input terminals 2 and 3, and transforms the primary side winding. A required output voltage is taken out from the secondary output terminals 6 and 7 by the wire 4 and the secondary winding 5. Note that 8 is an iron core, which is entirely covered by a case (not shown). 9 is a fixing member for fixing the power transformer 1, and 10 is a magnetic flux generated from the power transformer 1.

Such a power supply circuit device, as shown in FIG.
It will be used by being incorporated into a home terminal device 12 installed on the top surface of a television receiver 11 of a TV system.

Problems to be Solved by the Invention However, CA employing such a power supply circuit device
The household terminal device 12 of the TV system has a problem in that the deflection coil of the television receiver 11 is affected by the magnetic flux 10 generated from the power transformer, causing image disturbance.

The present invention solves these conventional problems, and aims to provide a power supply circuit device for home terminal equipment in a CATV system that does not cause disturbances in television images.

Means for Solving the Problems In order to achieve the above object, the present invention provides a primary side and a secondary side.
A plurality of power transformers whose secondary windings are wound in the same direction are arranged in parallel with their primary input terminals and secondary output terminals aligned in the same row, and the primary side of each power transformer is The primary input terminals of each power transformer are connected so that currents in opposite directions flow through the input terminals.

According to the present invention, with the above-described configuration, magnetic fluxes generated from a plurality of power transformers can be canceled out, and disturbances in television images in a CATV system can be prevented.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic partial plan view of a power supply circuit device according to an embodiment of the present invention. 20 and 30
are power transformers in which the primary and secondary windings are wound in the same direction, and each has a primary side input terminal 21.
．． 22 and 31.32 and secondary output terminal 23.24
and 33 and 34 are arranged in parallel on opposite sides and in the same row. Primary input terminal 21 of power transformer 20 and primary input terminal 3 of power transformer 30
2 are connected to form a common input terminal 41, and the other primary input terminal 22 of the power transformer 2o and the other primary input terminal 31 of the power transformer 30 are connected to form a common terminal 42. There is. It is assumed that power transformers 20 and 30 are placed as close as possible. 50 is a fixing member for fixing the power transformers 20 and 30.

FIG. 2 is a schematic partial cross-sectional view of the power supply circuit device shown in FIG. It is a line. 35 is the iron core of the power transformer 30, 36 is the primary winding of the power transformer 30, and 37 is the power transformer 3.
0 secondary winding. The primary winding 26 and the secondary winding 27 of the power transformer 20 and the primary winding 36 and the secondary winding 37 of the power transformer 30 are wound in the same direction as described above. 60 is a magnetic flux generated by the power transformer 20, and 70 is a magnetic flux generated by the power transformer 30.

Next, the operation of the above embodiment will be explained. When the power supply voltage is applied manually to the common input terminals 41 and 42, the primary winding 26, 36 and the secondary winding 27 of each power transformer 20, 30
．． 37 are wound in the same direction, and the primary input terminal 21 of the power transformer 2o and the input terminal 32 on the opposite side of the power transformer 30 are connected, and the other input terminal 22 of the power transformer 20 and the power supply Since the other input terminal 31 of the transformer 30 is connected, the power transformer 20
The primary winding 26 of the power transformer 30 and the primary winding 36 of the power transformer 30
Since currents in opposite directions flow through the devices, magnetic fluxes 60 and 70 in opposite directions are generated and cancel each other out, allowing other devices to be affected by the magnetic flux.

In this way, according to the embodiment, a plurality of power transformers 2
Since magnetic fluxes 60 and 70 in opposite directions are generated by the oppositely directed currents flowing through the primary windings 26 and 36 of 0 and 30, the generated magnetic fluxes 60 and 7o cancel each other out, reducing the influence of the magnetic flux on other devices. can be eliminated.

Effects of the Invention As is clear from the above embodiments, according to the power supply circuit device of the present invention, a plurality of power transformers whose primary and secondary windings are wound in the same direction can be connected to the primary side input. Align the terminals and the secondary output terminals in the same row and place them in parallel, and connect the primary input terminals of each power transformer so that current flows in the opposite direction to the primary input terminal of each power transformer. Therefore, the magnetic fluxes generated by the primary windings of each power transformer go in opposite directions and cancel each other out, so that even if the CATV home terminal equipment containing this power supply circuit device is installed on top of the television receiver, , it does not affect the deflection coil of the television receiver (and can prevent disturbances in the television image).

[Brief explanation of the drawing]

FIG. 1 is a schematic partial plan view of a power supply circuit device showing an embodiment of the present invention, FIG. 2 is a schematic partial cross-sectional view of FIG. 1, and FIG. 3 is a schematic partial cross-sectional view of a conventional power supply circuit device. FIG. 4 is a front view showing the installed state of home terminal equipment and a television receiver in which a conventional power supply circuit device is housed. 20.30...Power transformer, 21.22.31.3
2...Primary side input terminal, 23.24.33.34...
・Secondary side output terminal, 25.35... Iron core, 26.36
...Primary winding, 27.37...Secondary winding, 1, 2...Common input terminal, 50...Fixing member, 60°70...Magnetic flux.

Claims (1)

[Claims] A plurality of power transformers with primary and secondary windings wound in the same direction are arranged in parallel with the primary input terminals and secondary output terminals aligned in the same row, and each power source A power supply circuit device in which the primary input terminals of each power transformer are connected so that currents flow in opposite directions to the primary input terminals of the transformers.