JPH01286647A - Alternating current branching circuit - Google Patents

Abstract

PURPOSE:To individually suppress the spread of a trouble and to increase the reliability of a circuit by building the switching circuit of an alternating current due to doubling into individual branching units. CONSTITUTION:For a branching unit 3 to input two pairs of present-use and preliminary alternating current signal outputs with a transmission part 1 and a modulating part 2 as a pair, the necessary number of branchings is connected in parallel and further, a terminal station circuit 4 is connected in order to execute the impedance joining. To respective units 3, two present-use and preliminary alternating current signals are inputted and either of signals is outputted by a switching signal SEL. In the unit 3, a switching circuit 6 is an analog switching element due to a fixed element, has an amplifying circuit 5 respectively for an input output and a signal is selectively outputted from lines LINE 1 and 2 with a switching signal SEL. Thus, a 1:N transmission system is obtained.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention provides a method for branching one data transmission circuit into multiple locations.
This invention relates to an AC branch circuit in the :N transmission system, and particularly to an AC branch circuit in which the transmitter and modulator are duplicated.

[Conventional technology]

Conventional commonly used AC branch circuits in which the transmitter and modulator are duplicated use a mechanical switching unit such as a relay or switch to select between the output signals from each modulator. Then, this output signal is passed in parallel to a branching unit for branching to multiple locations.

[Problem to be solved by the invention]

The above-mentioned conventional AC branch circuits use mechanical operating parts such as relays and switches as switching units, and have a drawback of being less reliable than solid-state devices.

In addition, since there is only one switching unit, if any failure occurs in this switching unit, it has the disadvantage that it will affect all branch circuits, even though the transmitter and modulator are duplicated. .

SUMMARY OF THE INVENTION An object of the present invention is to provide an AC branch circuit in which a transmitting section and a modulating section are duplicated in order to eliminate the above-mentioned obstacles and minimize their influence.

[Means to solve the problem]

The AC branch circuit of the present invention includes a duplex transmitting section and a modulating section, and the transmitting section includes a branching unit incorporating a switching circuit that inputs two output signals and selects and outputs one of the two systems using a switching signal from the outside. A 1:N transmission system is configured by connecting a plurality of modulators in parallel to the modulator.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention. Transmitter (P
/S>1 and modulation unit (MOD) 2 of 1 m, the branch unit 3 which inputs two sets of AC signal outputs, one for current use and the other for backup, is connected in parallel as many as the branch, and furthermore, a termination circuit (T) 4 is connected for impedance connection. is connected. Each branch unit 3 has a current one.

Two spare AC signals are input, and one of the signals is output according to the switching signal SEL.

FIG. 2 is a detailed configuration diagram of the branching unit 3.

In FIG. 2, the switching circuit 6 is an analog switching element using a solid state element, and has an amplifier circuit 5 at each input and output.
The signal from the line LINE1.2 is selectively output by the switching signal SEL.

〔Effect of the invention〕

As explained above, according to the present invention, by incorporating a redundant AC signal switching circuit into each branch unit, there is an effect that the propagation of a fault is stopped individually and does not affect the entire system. Furthermore, by using solid-state elements in the switching circuit, a more reliable AC branch circuit can be provided.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the AC branch circuit of the present invention, and FIG. 2 is a detailed block diagram of the branch unit. DESCRIPTION OF SYMBOLS 1... Transmission part, 2... Modulation part, 3... Branch unit, 4... Termination circuit, 5... Amplification circuit, 6... Switching circuit.

Claims (1)

[Claims] A branching unit including a duplexed transmitting section and a modulating section, and incorporating a switching circuit that inputs two output signals and selects and outputs one of the two systems using a switching signal from an external device, is connected to the transmitting section and the modulating section. An AC branch circuit characterized in that a 1:N transmission system is configured by connecting a plurality of them in parallel.