JPH021984Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a communal listening distributor used in a two-way signal transmission system using a communal reception system.

Conventionally, a distribution amplifier for amplifying and distributing television (TV) radio waves received by a receiving antenna to a required level and supplying the same to a plurality of terminals has been constructed, for example, as shown in FIG. 1. This distribution amplifier 1 has an input terminal 2 and four output terminals 3a to 3d.
It consists of an amplifier 4 and a 4-way divider 5 connected in series between them. The amplifier 4 amplifies the TV signal input from the receiving antenna through the input terminal 2 to a predetermined level, and the 4-way divider 5 divides the amplified signal into 4
It is something to be distributed.

Incidentally, recently, two-way signal transmission systems in the home, such as home security, using home public listening have been used.

However, in the conventional distribution amplifier 1, the four-way divider 5 has directionality, and the signal amplified by the amplifier 4 is output from the output terminals 3a to 3d, but conversely, for example, from the output terminal 3a. When a signal is input, it is reversely coupled to the other output terminals 3b to 3d and the coupling loss is large, so the output terminals 3b to 3d
No output can be obtained by output to 3d or attenuated. For example, a signal source such as a security sensor is connected to a terminal connected to the output terminal 3a, and a monitoring device for monitoring the security sensor etc. is connected to the output terminal 3b. In this case, the signal input from the security sensor etc. to the output terminal 3a is transmitted to the input terminal 2 side via the 4-way divider 5, but since the coupling loss of the 4-way divider 5 is large, the signal is sent to the output terminal 3b. is not output. Therefore, the signal does not reach the monitoring device, and it cannot perform its security role. In this manner, in the conventional distribution amplifier 1, there was no coupling between the output terminals 3a to 3d.

This idea was made in view of the above circumstances,
The purpose is to provide a public listening distributor that can easily perform two-way signal transmission in terminals such as home security using a home public listening system.

An embodiment of this invention will be described below with reference to the drawings. FIG. 2 shows the configuration of the distribution amplifier 11. This distribution amplifier 11 has an input terminal 12
It is composed of a blocking filter 14, an amplifier 15, and a non-directional four-way divider 16 connected in series between the output terminals 13a and 13d. TV radio waves received by a receiving antenna are input to the input terminal 12 . The amplifier 15 is for correcting distribution loss and amplifying the input signal to a required level.

FIG. 3 shows a specific configuration of the non-directional four-way distributor 16. This non-directional 4-way divider 16 is configured using resistors 17a to 17d, and when a signal is input from the output terminal 13a, the other output terminal 1
3b to 13d are coupled only through distribution loss, and therefore outputs can be obtained at the output terminals 13b to 13d, respectively. Incidentally, it is also possible to use a transformer in place of the resistors 17a to 17d, and a specific configuration thereof is shown in FIG. In the figure, 19a is an input terminal, and 19b to 19e are output terminals. Since this transformer 19 has no directionality, the output terminal 1
Even if the signal is input from 9b, the signal is transmitted to input terminal 19a and output terminals 19c, 19d, and 19e.
For example, output terminal 1 among the output terminals 13a to 13d
A signal source such as a security sensor is connected to 3a, and a monitoring device for monitoring a signal from the security sensor is connected to output terminal 13b, for example.

The concrete circuit configuration of the blocking filter 14 is shown in FIG. 6, for example. The figure shows a well-known blocking filter circuit that is most commonly used. Capacitor 14a, variable capacitor 14b, and inductance 14c constitute one blocking filter, and similarly capacitor 14e, variable capacitor 14f, and inductance 14g constitute another blocking filter. These two blocking filters are connected by a coaxial cable 14d of λ/4 of the bidirectional signal frequency used to form the main blocking filter 14.
Configure. When transmitting a home two-way signal, this blocking filter 14 is used because high frequency waves may be used in the home, and this high frequency signal passes through the amplifier 15 in the opposite direction and leaks to the input terminal 12, and this leaked radio wave is sent to the receiving antenna. This is to prevent unnecessary radiation, which is not desirable.

In the distribution amplifier 11 having such a configuration, the TV signal supplied to the input terminal 12 is transmitted to the amplifier 15.
After being amplified to the required level at
3d to the terminal's TV receiver.

Further, the signal from the security sensor is supplied to the non-directional 4-way distributor 16 via the output terminal 13a. Since this non-directional 4-way divider 16 has no directionality, the input signal is supplied to the output terminal 13b with only distribution loss, and is further transmitted to the monitoring device.

By using the distribution amplifier 11 in this manner, home bidirectional signal transmission can be easily performed.

In the above embodiment, since the amplifier 15 is built-in, it is used as the distribution amplifier 11, but the amplifier 15 is not necessary in a strong electric field area, and as shown in FIG. Instead of the distributor 16 alone, a four-way non-directional distributor 18 with a blocking filter may be used.

As described above, by using the public listening distributor of this invention, bidirectional signal transmission at the terminal can be easily performed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional distribution amplifier, and FIG. 2 is a block diagram of a distribution amplifier according to an embodiment of this invention.
FIG. 3 is a circuit diagram of a non-directional 4-way divider used in the distribution amplifier of FIG. 2, and FIG. 4 is a diagram of a 4-way omni-directional divider with a blocking filter according to another embodiment of this invention. , FIG. 5 is a diagram showing another circuit configuration of the non-directional four-way divider, and FIG. 6 is a diagram showing a specific circuit configuration of the blocking filter. 11...Distribution amplifier, 12...Input terminal, 13
a to 13d... Output terminal, 14... Blocking filter, 15... Amplifier, 16... Non-directional 4-way divider, 17a-17d... Resistor, 18... Non-directional 4-way divider with blocking filter.

Claims (1)

[Claims for Utility Model Registration] (1) Community distribution used in a system that performs two-way signal transmission between terminals using a community reception system that branches and distributes signals received by a receiving antenna to multiple terminals. The device includes a blocking filter that blocks radiation of a signal used between the terminals from the receiving antenna, and a nondirectional distributor that has nondirectionality and distributes and outputs the input signal from a plurality of output terminals. A public listening distributor that is characterized by: (2) A public hearing system according to claim 1 of the utility model registration claim, which includes a built-in amplifier for correcting the distribution loss of the input signal and amplifying the input signal to a required level in the preceding stage of the omnidirectional distributor. distributor.