JPS62193329A - Method for connecting communication equipment or the like with communication cord - Google Patents

Abstract

PURPOSE:To suppress the noise to the other communications to a small value and to move a communication equipment or the like freely along a communication cord in such a state by transmitting and receiving signals between the communication equipment or the like and the communication cord by the connection using a non-radioactive magnetic field generated in the vicinity of the communication cord. CONSTITUTION:When a signal current I is conducted to a conductor 1 in the direction of an arrow, magnetic fluxes B due to this current are generated in opposite directions of white arrows alternately. For the purpose of receiving efficiently these magnetic fluxes, coils are arranged at the intervals of a half of the twisting pitch of the conductor, and the winding directions of coils are inverted alternately, and coils are connected in series. Thus, voltages generated in coils are added to transmit and receive the signal of the communication cord with the high sensitivity.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for coupling a communication device or an information processing device to a communication cord.

(Prior Art) Conventionally, in wiring between communication devices and information processing devices, the method of attaching a connector to the terminal or intermediate part of the communication cord and connecting the communication device, etc. to the communication cord via the connector has been used in offices, residences, etc. It is being carried out in

However, with this method, when rearranging the communication device or the like, it is necessary to perform complicated operations such as replacing the communication cord and replacing the connector.

With the method of using connectors, it may be difficult to frequently change the arrangement of communication devices in an office or the like as necessary. Methods using wireless antennas or leaky cables have been developed to solve this problem.

When communicating within an office using a wireless antenna, there are two methods: using weak radio waves (15μV/m at a distance of 100m) and operating in an approved frequency band. Obstacles impede communication and shorten the transmission distance. Regarding the latter, since the frequency band is limited, there is a problem that multi-line communication becomes difficult.

In addition, both methods require a modulator/demodulator for modulating the carrier frequency, resulting in an expensive system.

In addition, in the method of using a leaky cable, the frequency range that can be used is limited, so in order to take advantage of the leaky cable's characteristics of efficiently generating an electromagnetic field and having little impact on the surrounding area, the frequency range that can be used is limited. There was a drawback that the signal band could not be widened.

(Kondo, Hori; “Characteristics of leaky coaxial cables”, Oguchi Nippon Cable Jiho, No. 60, September 1975, pp. 1-9)
(Problems to be Solved by the Invention) An object of the present invention is to provide a coupling method that enables coupling of a communication device or the like to a communication code at any point along the communication code.

(Means for Solving the Problems) The present invention provides electrical connection between a communication device, etc., and a communication cord made of insulated core wires twisted with a uniform pitch in the longitudinal direction of the insulated core wires. A coupler consisting of a plurality of coils connected in series that are alternately wound in reverse is installed near the communication cord,
The coils at both ends of the coupler are connected to the communication device, etc., and a non-radiative magnetic field is generated in the direction of the central axis of the coil.

The present invention differs substantially from prior art methods using radio antennas or leaky cables, which employ coupling using radiated electromagnetic fields.

(Example) Fig. 1 shows an example of the present invention when a pair of communication cords are used, 1 being an insulated core wire twisted with a uniform pinch, 2
is an index indicating the twisted position of the core wire and the position of the coil, 3
4 is a magnetic core, 4 is a coil, 5 is a communication device, 6 is a plastic insulator, and 7 is a connection cord.

Here, the centers of the coils 4 are arranged at an interval of 2 of the twist pitch of the core wires, and adjacent coils are wound in opposite directions and connected in series as shown in the figure.

Here, by matching the index added to the coupler consisting of the magnetic core 3 and coil 4 in Figure 1 with the index added to the communication cord, the electromagnetic coupling between the communication cord and the coupler is maximized, and the distance between the coupler and the communication cord is Send and receive signals.

Note that it is also possible to adjust the position of the coupler so that the transmission and reception sensitivity of the communication device etc. is maximized, and the index on the communication code may be omitted.

FIG. 2 is a diagram for explaining the principle of electromagnetic coupling between the communication cord and the coupler in the embodiment of FIG. 1.

Here, when the signal current ■ flows through the core wire 1 in the direction of the arrow, magnetic flux B due to this current is generated alternately in opposite directions as shown by the white arrows. In order to receive this magnetic flux efficiently, the coils are arranged at intervals of % of the twist pitch of the core wires, the winding directions of the coils are alternately reversed, and the coils are connected in series. As a result, the voltages generated in the coils can be added, and the communication code signal can be transmitted and received with high sensitivity.

FIG. 3 is a diagram showing an example of the core wire and coil of the communication cord projected onto a plane, and shows a state where the electromagnetic coupling is shifted in the longitudinal direction by A pitch from the state shown in FIG. 2 where the electromagnetic coupling is maximum. The ○ mark indicates an upward magnetic field perpendicular to the paper surface, and the ■ mark indicates a downward magnetic field perpendicular to the paper surface. In this case, the magnetic flux interlinking with the coil is 2
Since the magnetic fields that reverse at each pitch cancel each other out, there is almost no coupling between the coupler and the communication cord.

On the other hand, when transmitting from the coupler to the communication code, the second
The coupling efficiency is maximum when the positional relationship is as shown in the figure, and the third
When the positional relationship is as shown in the figure, there is almost no coupling between the coupler and the communication cord.

Furthermore, since the core wires of the communication cord are twisted, noise induced into the communication cord from surrounding electrical appliances can be suppressed. For example, the noise induced from the power supply line to the communication line during switch operation of an electrical product can be reduced by about 30 dB compared to a core wire without twist. (Eye, radish, valve outlet; “Characteristics of induced noise from power supply lines occurring in communication lines”, Institute of Electronics and Communication Engineers Technical Report, Vol. 85. m29
．． EMCJ85-7. pp.

17-22) Although the embodiment using four coils has been described above, the number of coils is not limited to four, and may be any number of two or more depending on the required coupling efficiency. Note that the number of coils is the same in the embodiments described below.

Example 2 FIGS. 4+2) and 5(a) are diagrams in which the core wires of an embodiment of a communication cord having a structure in which two pairs of twisted core wires are arranged in parallel are projected onto a plane.

In the example of FIG. 4(a), the pinch of #1 core wire is
By setting the number of core wires to 2, interference between the signals of #1 and #2 core wires is suppressed. The reason for this is that the magnetic flux generated from #1's AI+Az loop is greater than #2's 8. This is because they cancel each other out within the loop, and similarly the connection between #1 and #2 disappears in each loop.

Figure 5 (In the embodiment of al), interference between lines is reduced by making the twist pitches of #1 and #2 equal and shifting the twist positions of #1 and #2 by A pitch. Reason for this This is because the magnetic flux from the B1.BZ loop in #2 cancels out against the A loop in #1, and the same thing occurs in each loop. a)
In this embodiment, the crosstalk between the core wires is suppressed to a small level.

Further, FIGS. 4(a) and 5(bl) show projections of embodiments of the coil of the coupler that transmits and receives signals to and from the core wires shown in FIGS. 4(a) and 5(a).

As shown in Figures 4(a) and 4(b),
The relationship between the direction of the magnetic field of the coil of the #1 coupler in Fig. 4 (b) and the direction of the magnetic field of the coil of the #2 coupler in Fig. 4 (bl) is as follows: The relationship between the direction of the magnetic field caused by the current flowing in the wire and the direction of the magnetic field caused by the current flowing in the #2 core wire in Fig. 4(a) is the same. Also, Fig. 5+a) and Fig. 5fb)
As shown in Figure 5 (#1 and #2 in kll)
The relationship between the magnetic field directions of the coupler coil is shown in Figure 5(a).
This is similar to the relationship between the directions of the magnetic fields generated by the currents flowing through the #1 and #2 core wires in .

Therefore, if the number of coils in couplers #1 and #2 is an even number, the coupling between couplers #1 and #2 can also be kept small.

Although the embodiment in which two pairs of twisted core wires are installed in parallel has been described above, the number of pairs of twisted core wires in parallel may be any number of pairs greater than or equal to 2.

Figure 6 shows a plastic core 8 consisting of two copper tapes and an insulating flat plate in order to realize a flat cord suitable for floor wiring.
An example is shown in which the twisted pair core wire 1 is realized by winding the cable around the coil.The thickness of the communication cord is reduced and the area of the loop formed by the pair when projected onto a plane is increased, so that the communication cord and the coil are Bonds can be made larger.

Figure 7 shows an example in which the length of the conductor on the side surface of the insulator is made longer than in the example shown in Figure 6 in order to further increase the area of the loop formed by the pair when the core wires are projected onto a plane. shows.

A communication code having such a structure can be manufactured by applying printed circuit board manufacturing technology.

FIG. 8 is a diagram showing another embodiment of the present invention, in which four pairs of core wires wound around a plastic core 8 are arranged in a plane as shown in FIG. A mating part for fixing the coupler and the communication cord at the optimum position is shown in a fixed state, where 9 is the coupler, 10 is the mating notch, 11 is the mating pawl, 12 is the fixing metal fitting, 1
3 is a hole for attaching a fixing metal fitting.

Above we have shown a basic example using twisted pair core wires, but in order to further increase the coupling efficiency between the communication cord and the coupler, as shown in Figure 9fa) A sheet 14 made of a magnetic material such as ferrite is placed below the planar cord, and a magnetic core 15 made of ferrite or the like is further provided through which a loop formed by a pair of twisted core wires is passed.

Figure 9 (bl is an enlarged view of a part of the cross section taken along the plane passing through A and A' in Figure 9 (al) and a part of the cross section of the magnetic core and coil in Figure 1, showing the coupler. As shown in Figure 9(b), by inserting a ferrite sheet and a magnetic core into the communication cord, the magnetic flux shown by the dotted line in the figure increases, concentrating the magnetic flux, and coupling. It can increase efficiency.

It is also effective to make the part of the plastic insulator that fixes the core wire in a flat shape from a magnetic material such as ferrite.

In order to further reduce external interference and interference between core wires using this method, each line of the communication cord and the coil of the coupler must be shielded with an electrical material such as aluminum or copper. It is best to connect only the connection side of the coupler by removing the shield from the top of the communication cord.

Although the above embodiment shows an example in which pairs with different twist pitches are arranged side by side by 2, pairs with the same twist pitch may be arranged side by side with a shift of A pitch. Further, the number of pairs to be installed may be any number greater than or equal to one.

As explained above, the coupling method of the present invention performs signal transmission and reception between a communication device, etc. and a communication cord by coupling using a non-radiative magnetic field generated near the communication cord. In comparison, communication devices and the like can be moved freely along the communication cord while minimizing noise affecting other communications.

Furthermore, since twisted wires are used for the communication cord, noise from the outside and interference between lines can be reduced, and there is an advantage that multiple twisted wire pairs can be installed together in a compact manner if necessary.

[Brief explanation of drawings]

FIG. 1 is an embodiment of the present invention using a pair of communication cords, FIG. 2 is a diagram for explaining the principle of electromagnetic coupling between the communication cord of the embodiment of FIG. 1 and a coupler, FIG. 3 is a diagram showing an example of the core wire and coil of the communication cord projected onto a plane;
Fig. 4(a), Fig. 5 (al is a diagram in which the core wires of an embodiment of a communication cord having a structure in which two pairs of twisted core wires are arranged in parallel are projected onto a plane; Figure 5 (b) is a projected view of an embodiment of the coil of the coupler that transmits and receives signals with the core wires in Figures 4 (al and 5 (al), and Figures 6 and 7 are flat wires for floor wiring. FIG. 8 is a perspective view of another embodiment of the present invention, and FIG. 9(a) is a perspective view of a flat cord with improved coupling characteristics using a sheet made of magnetic material such as ferrite. , FIG. 9 (bl is an enlarged view of a part of the cross section taken along the plane passing through A and A' in FIG. 9 (al) and a part of the cross section of the magnetic core and coil in FIG. 1. 1... Core wire 2... Index 3... Magnetic core 4... Coil 5... Communication device
6...Plastic insulator 7...Connection cord
8... Plastic core 9... Coupler
10... Engagement notch 11... Engagement pawl 12... Fixing fitting 13... Hole 14... Sheet 15 made of magnetic material such as ferrite.
...Magnetic core patent applicant Nippon Telegraph and Telephone Corporation Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] 1. Electrical connection between a communication device, etc. and a communication cord consisting of insulated core wires twisted at a uniform pitch is achieved by connecting in series multiple coils that are alternately reversely wound in the longitudinal direction of the insulated core wires. A coupler made of the above is installed near the communication cord, coils at both ends of the coupler are connected to the communication device, etc., and a non-radiative magnetic field is generated in the direction of the central axis of the coil. A method of connecting a communication device, etc., and a communication cord.