JPH088676A - Distributor and booster device using the same - Google Patents

Abstract

(57) [Summary] [Purpose] It is an object of the present invention to suppress a bad influence between output terminals of a distributor used for a TV, a VTR, etc. and to provide a good output signal. [Structure] Distribution transformer 14 and this distribution transformer 14
The resistor 17 and the capacitor 18 are connected in series between the distributed output terminals 15 and 16. Therefore, the inductance of the distribution transformer 14 and the capacitance of the capacitor 18 form a resonance circuit, and the insulation between the output terminals is improved, so that signals output from the other terminals of the distribution transformer 14 are not interfered with each other. Various signals can be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distributor for distributing high frequency signals and a booster device using the distributor.

[0002]

2. Description of the Related Art A conventional distributor and a booster circuit using this distributor will be described below.

As a conventional distributor, a distribution transformer 1 as shown in FIG. 4 has been used. In this distribution transformer 1, the first coil 1a and the second coil 1b are wound in series and connected to the ferrite core. Then, one terminal was connected to the first output terminal 4 and the other terminal was connected to the second output terminal 5. Also, the connection point between the first coil 1a and the second coil 1b was connected to the input terminal 3. The resistor 2 is connected between the first output terminal 4 and the second output terminal 5. In this distributor, theoretically, the insulation loss between the first output terminal 4 and the second output terminal 5 is infinite, but the insulation between the first output terminal 4 and the second output terminal 5 of the distributor is large. The loss does not become infinity as shown by the characteristic A in FIG. 2 (here, the horizontal axis of FIG. 2 is the frequency (MHz), and the vertical axis is the attenuation amount (d
B). ).

Therefore, in the distributor for distributing the high frequency signal, in order to increase the insulation between the output 4 and the output 5,
It is used as a booster device as shown in FIG. That is, the input terminal 6, the amplifier 7 connected to the input terminal 6, the distribution transformer 1 having the input terminal 3 connected to the output of the amplifier 7, and the one output 4 of the distribution transformer 1 are connected. An amplifier 8, an output terminal 10 to which the output of the amplifier 8 is connected, an amplifier 9 connected to the other output 5 of the distribution transformer 1, and an output terminal 11 to which the output of the amplifier 9 is connected, Output 4 and Output 5
And a resistor 2 connected between and.

Here, the amplifier 8 is inserted not for the purpose of amplifying the signal to the output terminal 10, but for the purpose of increasing the insulation between the one output terminal 10 and the other output terminal 11. It is what

[0006]

Therefore, the insulation between the output 4 and the output 5 cannot be increased only by the conventional configuration as shown in FIG. 4, and the booster device merely increases the insulation. There was a problem that the amplifier 8 had to be inserted for the purpose of.

An object of the present invention is to solve the above problems and to provide a distributor having a large insulation performance between outputs.

[0008]

In order to achieve this object, the distributor of the present invention has a structure in which a resistor and a capacitor are connected in series between the distribution output terminals of the distribution transformer.

[0009]

With this configuration, since the parallel resonant circuit is formed by the inductance of the distribution transformer and the capacitance of the capacitor connected between the distribution output terminals, the impedance between the distribution output terminals becomes high, and as a result, the first output And the insulation performance between the second output and the second output is improved.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram of a distributor according to an embodiment of the present invention. In FIG. 1, 14 is a distribution transformer in which a first coil 14a and a second coil 14b are connected in series and wound around a ferrite core. The distribution coil 14 includes a first coil 14a and a second coil 14a. Output terminal 15 to which one terminal of the coil 14b is respectively connected
A resistor 17 and a capacitor 18 are provided between the output terminal 16 and the output terminal 16.
And are connected in series. Also, the first coil 14a
The connection point between the second coil 14b and the second coil 14b is connected to the input terminal 19.

The operation of the distributor 20 configured as described above will be described below. A parallel resonance circuit is configured by the instance of the coils 14a and 14b wound around the ferrite core of the distribution transformer 14 and the capacitance of the capacitor 18 connected between the output terminal 15 and the output terminal 16 of the distribution transformer 14. ing.
In this embodiment, the inductance of the coils 14a and 14b is 900 nH, and the capacitance of the capacitor connected between the output terminals 15 and 16 of the distribution transformer 14 is 4 pF. At this time, the resonance frequency is about 8 which is the VHF band frequency of the television broadcast wave in the European region.
The frequency is 4 MHz, and the insulation loss between the output terminal 15 and the output terminal 16 of the distribution transformer 14 in this frequency band can be greatly improved as shown in B of FIG.

That is, what is important here is that in a VHF band distributor, the insulation from about 45 MHz to about 150 MHz inevitably lowers. Therefore, in order to improve the insulation performance during this period, the center frequency is set to about 84 MHz. The insulation performance is improved from 45 MHz to about 150 MHz.

Next, FIG. 3 shows a booster device using the distributor 20 according to the present invention. The input terminal 21 is connected to the first amplifier circuit 22. The output of this amplifier circuit 22 is connected to the input terminal 19 of the distributor 20 according to the invention, one output 15 of this distributor 20 being connected to the output terminal 23 of the booster circuit. The other output terminal 16 of the distributor 20 is connected to the second amplifier circuit 24, and the output of the amplifier circuit 24 is connected to the output terminal 25.

The operation of the booster device configured as described above will be described below. After the signal input from the input terminal 21 is amplified by the first amplifier circuit 22,
It is distributed by the distributor 20. The signal distributed by the distributor 20 is output from one output terminal 23 and connected to an external tuner such as a VTR. The signal output from the other output terminal 16 of the distributor 20 is
The signal amplified by the second amplifier circuit 24 is output from the output terminal 25 and connected to an external television.

Here, as in the conventional example shown in FIG. 5, the tuning of the tuner connected to the output terminal 10 causes a large change in the impedance of the output terminal 5 of the distributor.
It is a well-known fact. When the insulation characteristic between the output terminals 4 and 5 of the distributor is small as shown in the conventional example, the signal output from the other output terminal 5 of the distributor is affected, and The level fluctuation of the output signal will occur.

However, by using the distributor 20 of the present invention, the insulation characteristic for the other output terminal 16 of the distributor 20 is high, so that the influence thereof can be suppressed, and the signal output from the output terminal 25 has a level fluctuation. It can be supplied to the TV as a good output.

As described above, according to this embodiment, the distributor 2
By connecting the resistor 17 and the capacitor 18 in series between the output terminal 15 and the output terminal 16 of 0, the insulation characteristic between the output terminal 15 and the output terminal 16 of the distributor 20 can be significantly improved. . Therefore, even if the impedance connected to one output terminal 15 of the distributor 20 fluctuates, a good signal with less interference can be supplied to the signal output from the other output terminal 16. it can.

Further, in the case of the booster device, the amplifier 8 shown in the conventional example is unnecessary, so that the booster device can be downsized and the cost can be reduced.

[0019]

As described above, according to the present invention, since the parallel resonant circuit is constituted by the inductance of the distribution transformer and the capacitance of the capacitor connected between the distribution output terminals, the impedance between the distribution output terminals is high. As a result, the insulation performance between the first output and the second output is improved.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a distributor according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram of insulation characteristics of the same.

FIG. 3 is a circuit diagram of a booster device using the distributor of the present invention.

FIG. 4 is a circuit diagram of a conventional distributor.

FIG. 5 is a circuit diagram of a booster device using a conventional distributor.

[Explanation of symbols]

 14 Distribution Transformer 15 Output Terminal 16 Output Terminal 17 Resistor 18 Capacitor 19 Input Terminal

Claims (3)

[Claims] 1. A distributor comprising an input terminal, a distribution transformer connected to the input terminal, and a resistor and a capacitor connected in series between distribution output terminals of the distribution transformer. 2. The resonance frequency of the resonator formed by the inductance of the distribution transformer and the capacitance of the capacitor is in the range of 45 MHz to 150 MHz.
Distributor as described. 3. An input terminal, a first amplifier connected to this input terminal, a distributor whose input terminal is connected to the output of this first amplifier, and one output signal of this distributor. A first output terminal to be supplied, a second amplifier connected to the other output of the distributor, and a second output terminal to which an output signal of the second amplifier is supplied. The booster device as a distributor according to claim 1.