JPS6056011B2 - turnout - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a splitter that is advantageously used, for example, in a public listening system for television receivers.

In the prior art, although it is possible to reduce the transmission loss of high-frequency signals by using a splitter, it is difficult to reduce the voltage standing wave ratio on the output side, and as a result, it is difficult to reduce the voltage standing wave ratio on the output side. Color bleeding, etc. has occurred.

An object of the present invention is to provide a splitter that makes it possible to reduce the output voltage standing wave ratio.

FIG. 1 is an electrical circuit diagram of an embodiment of the present invention. The input terminal 2 of the splitter 1 is connected to a high frequency signal source 3 such as an antenna.
is connected. The output terminal 4 is connected to a subsequent load 5 such as a branch switch or a television receiver having a similar configuration. A load 7 such as a television receiver is connected to the other branch output terminal 6. One end of a primary coil 9 of a transformer 8 is connected to the input terminal 2 . Output terminal 4
The other end of the primary coil 9 is connected to. One of the secondary coils 10 electromagnetically coupled to the primary coil 9 of the transformer 8.
The end is connected to the output terminal 6 for the other branch. The other end of the secondary coil 10 is grounded.

A resistor R is connected between the input terminal 2 and the other output terminal 6.
1 is connected. The other output terminal 6 is grounded via a resistor R2. The primary coil 9 and the secondary coil 10 are set to have opposite polarities. The high frequency signal from the high frequency signal source 3 is derived from the input terminal 2 through the primary coil 9 of the transformer 8 and output from the output terminal 4. The high frequency signal from this input terminal 2 is also guided to the output terminal 6 via a resistor R1. A voltage in the direction of arrow 12 is induced in the secondary coil 10 by a high frequency signal flowing in the direction of arrow 11 in primary coil 9 .

The signal induced in the secondary coil 10 and the signal via the resistor R1 are supplied from the output terminal 6 to the load 7. When a signal such as noise is applied to the output terminal 6 from the load 7, the noise flows in the direction of the arrow 11 via the resistor R1 and the primary coil 9.

At the same time, noise from the load 7 applied to the output terminal 6 flows into the secondary coil 10 in a direction opposite to the arrow 12.
Noise flowing in the direction opposite to the arrow 12 in the secondary coil 10 induces a voltage in the primary coil 9 in the opposite direction to the arrow 11. As a result, the noise applied from the load 7 to the output terminal 6 is canceled in the primary coil 9, thereby preventing noise from being applied from the output terminal 4 to the subsequent load 5 such as a branch or receiver. . In this way, the advantage that mutual interference between the output terminals 4 and 6 becomes extremely small is exhibited. The resistor R2 matches the impedance of the output terminal 6 and lowers the output voltage standing wave ratio of the output terminal 6.

A series circuit 13 consisting of a resistor RO and a coil LO is connected between the input terminal 2 and the output terminal 4.

This series circuit 13 can correct the phase delay of the current flowing from the output terminal 4 to the branching device 1. Therefore, the voltage standing wave ratio at the output terminal 4 can be reduced. However, according to the inventor's study, when the series circuit 13 is not provided, leakage inductance of the transformer 8, coupling due to stray capacitance between the primary coil 9 and the secondary coil 10, resistance Rl, Due to the effect of R2 as an inductance, the phase of the current flowing from the output terminal 4 to the branching device 1 lags behind the voltage of the signal source connected to the output terminal 4.

Therefore, the voltage standing wave ratio at the output terminal 4 increases. According to the embodiment described above, it is possible to correct the phase delay of the current from the output terminal 4 to the branching device 1, so that the television receiver as the load 5 that receives the high frequency signal from the output terminal 4 can be corrected. It is possible to reduce color bleeding in images. In FIG. 2, the results of an experiment conducted by the inventor of the present invention in one embodiment of the present invention are shown by a solid line.

In the electrical circuit shown in Figure 1, R1=240Ω, R2=1
20Ω and RO=47Ω, the coil LO is configured with 4 turns on an air-core bobbin of 4Tmφ, and in the transformer 8, the turns ratio between the primary coil 9 and the secondary coil 10 is 1:4. The experimental results show that even when the frequency is relatively high, the voltage standing wave ratio at the output terminal 4 can be suppressed to 2 or less. For comparison, the experimental results when the series circuit 13 is removed are shown in broken lines in FIG. As described above, according to the present invention, it is possible to reduce the voltage standing wave ratio of the high frequency signal from the output terminal of the branching device.

[Brief explanation of drawings]

FIG. 1 is an electrical circuit diagram of an embodiment of the present invention, and FIG. 2 is a graph showing experimental results by the inventor. 1... Branch, 2... Input terminal, 4,
6... Output terminal, 8... Transformer, 9
...Primary coil, 10...Secondary coil, 13...Series circuit, Rl, R2, RO...
...Resistance, LO... Coil.

Claims (1)

[Claims] 1 Connect one end of the primary coil of the transformer to the input terminal,
Connect the other end of the primary coil to one output terminal, connect one end of the secondary coil of the transformer to the other branch output terminal, ground the other end of the secondary coil, and connect the primary coil and The secondary coils have their polarities reversed, resistors are connected between the input terminal and the other output terminal and between the other terminal and ground, and between the input terminal and the one output terminal, A turnout characterized by connecting a series circuit consisting of a resistor and a coil.