JP2009253994A - Mobile phone system with av equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the following problem encountered when an output cord is carried together with a portable terminal device: to cope with high-frequency noise, a ferrite core is attached to the output cord and this degrades the portability of the terminal device. <P>SOLUTION: A mobile phose system with AV equipment is so constructed that a toroidal core is installed at an output end in the substrate of a switching power supply (hereafter, referred to as AC adaptor) that supplies power to a portable terminal device with a television. Thus television screen noise can be reduced in the portable terminal when a battery is charged or power is supplied with the AC adaptor. A mobile phone system with AV equipment is equipped with an LC filter and a toroidal core. Thus television screen noise can be reduced in the portable terminal when a battery is charged or power is supplied with the AC adaptor. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a system in which an AC adapter that supplies a predetermined direct current voltage and direct current to an electronic device and a portable terminal device with a television are combined.

  A conventional switching power supply is shown in FIG. 3 and will be described.

  In FIG. 3, 1 is an AC adapter, 2 is an output cord, 3 is a portable terminal with a TV, and 4 is a ferrite core for noise removal.

  Generally, it is known that high frequency noise mixed into an electronic device from an AC adapter that supplies power can be reduced by attaching a ferrite core to the output cord 2.

  In order to remove noise, for example, a filter circuit for normal mode and common mode noise is employed in a combination of an inductor element (for example, a choke coil) and a capacitor element (for example, a noise absorbing capacitor).

  Further, when the above filter is employed, the inductor element becomes large in order to ensure the attenuation amount of noise in the low frequency range.

This content can be understood from, for example, the drawing of Patent Document 1.
JP 2004-297551 A

  However, in the countermeasure against the high frequency noise as described above, since the ferrite core is attached to the output cord, it is not portable when being carried with the portable terminal device, and the ferrite core is not an inexpensive part in terms of manufacturing cost. It can be said that the ratio of the adapter to the material cost is relatively large.

  The present invention solves the above-described problems. By mounting a toroidal core on the output end of the AC adapter without attaching a ferrite core, high-frequency noise is reduced, and the AV device is excellent in portability and low cost. A portable terminal system can be realized.

  The present invention has a toroidal core mounted on the output end of a substrate of a switching power supply (hereinafter referred to as an AC adapter) that supplies power to a mobile terminal device with a TV, and the mobile phone TV screen when the battery is charged or supplied with the AC adapter. This is a mobile phone system with AV equipment that can reduce noise.

  According to the present invention, in a mobile terminal system with a TV, a toroidal core is mounted on the output end in the substrate of the AC adapter to reduce high-frequency noise generated from the secondary output of the AC adapter. As a result, even when a TV screen is displayed on the portable terminal when power is supplied from the AC adapter, it is possible to suppress power beat noise and flickering of the screen caused by high frequency noise.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

(Embodiment)
FIG. 1 is a circuit configuration diagram according to an embodiment of the present invention.

  An AC / DC conversion circuit 7 is provided inside an AC adapter 1 for AC input, and is connected to a portable terminal 3 with a TV through an output cord 2 from this power source.

  Normally, when connecting a power supply system such as the AC adapter 1 and a system such as an AV device, noise from the outside or noise from the connected side often jumps into the output cord 2 or the like and is affected by the noise. Cheap.

  In recent years, the frequency handled as a system tends to be high, and high frequency components are high, which makes it easy to cause an unstable power supply state.

  As a countermeasure against the noise, when connecting the AC adapter 1 to a system-side television such as a portable television, a certain amount of noise can be eliminated with the ferrite core 4 for noise removal between the portable terminal 3 with a television. .

  In general, this ferrite component is called a toroidal core.

  However, although the noise can be reduced, there is a case where the margin amount is not sufficient for the system, and there is a limit between the output codes 2 between the power source and the system.

  Therefore, this time, a configuration for removing noise is produced in the AC adapter 1 by the coil 5 and the capacitor and the filter of the coil.

  This configuration is referred to as the LC filter 6.

  This is on the output side of the AC adapter 1, and if installed after the AC / DC conversion circuit 7, there is an effect that noise can be further reduced.

  In this case, rather than configuring the filter with the output cable 2, for example, if it is fabricated on the circuit board inside the device of the AC adapter 1, the parts are physically stable and the effect of noise removal is large. In TV reception or the like, even video with high frequency components can be sufficiently reproduced without being disturbed.

  This component is a coil and a capacitor and can be made relatively small in scale.

  FIG. 2 shows a configuration in which the LC filter 6 portion is deleted inside the AC adapter 1.

  Even in this case, although the effect is smaller than that of the configuration of FIG. 1, there are cases where measures against noise can be taken by inserting the coil 5 after the AC / DC conversion circuit 7 in terms of reducing the number of components or mounting area.

  In the electronic device according to the present invention, it is useful to eliminate noise of a system in which an AC adapter that supplies a predetermined DC voltage and DC current and a portable terminal device with a television are combined.

Circuit configuration diagram shown in the embodiment of the present invention Simplified configuration diagram of a circuit shown in an embodiment of the present invention Configuration diagram of conventional switching power supply

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 AC adapter 2 Output cord 3 Mobile terminal with TV 4 Ferrite core for noise removal 5 Coil 6 LC filter 7 AC / DC conversion circuit

Claims (2)

A toroidal core is mounted on the output terminal in the substrate of a switching power supply (hereinafter referred to as an AC adapter) that supplies power to a mobile terminal device with a TV to reduce the TV screen noise of the mobile terminal when the battery is charged or supplied with the AC adapter. A mobile phone system with an AV device characterized by the above. An LC filter and a toroidal core are mounted on the output end in the substrate of the AC adapter that supplies power to the mobile terminal device with TV, and the TV screen noise of the mobile terminal is reduced when the battery is charged or power is supplied by the AC adapter. The cellular phone system with an AV device according to claim 1,

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