CN1003759B - Automatic separator for subscribers in magnetotelephone party-line system - Google Patents

Abstract

The present invention belongs to the technical field of telecommunication, which is designed to realize the mutual confidentiality of the signals between two subscribers of magnet telephones on the same line. The present invention has the technical characteristic that a calling signal of one telephone can be automatically separated from a voice signal; when the two telephones on the same line transmit calling signals, one telephone uses a phantom line, and the other telephone uses a solid line so as to avoid the crosstalk between a ring action and a number plate action. During a call, any subscriber on the same line can automatically separate the other subscriber from the line first so as to ensure that the call is not interfered or eavesdropped, and a circuit theory is disclosed in the specification.

Description

Automatic separator for subscribers in magnetotelephone party-line system

The present invention relates to the multiplex technique of line telecommunications technical field magnetic telephone transmission line.

In existing technology, the fairly simple method of multiplexed communications circuit is to increase phantom line, and Ji Tezheng is: two kinds of signals (call signal and voice signal) of a phone are to use same circuit (phantom line or physical circuit) to transmit.Because the sound of crosstalking when this technology can not be eliminated conversation fully, security performance is poor, seldom uses now.(see " line telecommunications transmission basis " the 15th page, People's Telecon Publishing House March nineteen eighty-three the 1st edition.) utilize the technology of carrier telephone and time-division voice multiplex circuit because technology and reason economically are inconvenient in the little rural subscribers' use of conversation capacity.At present, the rural area away from post and telecommunications the place to increase a local battery apparatus user, generally all want a pair of transmission line of new frame.

The present invention is exactly for overcoming the shortcoming of phantom line when conversation security performance difference, designing for the multiplexed communications circuit provides a simple method of economy.

Feature of the present invention is: only, do not use phantom line during conversation at the biography of a phone of transmission use phantom line during signal, thereby cross-talk phenomenon can avoid conversation that phantom line brings the time.Its method is: in two collinear magnetic telephones, wherein there is one with phantom line call transmission signal, another is with two-wire physical circuit call transmission signal, and promptly the call signal transmission line of two phones establishes one's own system, and can accomplish that the action of jingle bell or number plate do not crosstalk mutually; All use physical circuit during two telephone relations, but wherein any one user can try to be the first and monopolize circuit, automatically cut off another user's circuit, another subsets are separated with transmission line, be not affected, do not eavesdropped to guarantee conversation, as seen, in two party-lines, have method that a phone uses during telephone signal in transmission unlike the prior art, it transmits the call signal of a phone respectively with two different circuits with voice signal.Particular circuit configurations is seen accompanying drawing 1.

Explanation to accompanying drawing 1

Entire circuit is divided into (A), (B), (C), (D) 4 unit by dotted line among the figure.(A) the switch place is represented in the unit, and (B represents the unit two users and multiplexel circuit bound fraction, (C), (D) two unit represent two users respectively.The a pair of line that connects (A), (B) two unit multiplexing transmission line of indicating connects (B) and represents the transmission line that two users are connected with multiplexel circuit separately respectively with two pairs of lines of (C), (D) unit.

A door among the figure, b door are represented the circuit unit of exchanger user door; A machine, representative of b machine and the corresponding subsets of swap gate.C1, c2, c3, c4, c7, c8, c9, c10 respectively are capacity for its effect of capacitor of 0.5 microfarad is for voice signal provides path, and the restriction call signal passes through.C5, c6, c11, c12, c13, c14 respectively are capacitors that capacity is 15 microfarads, and its effect is to provide path for call signal and voice signal, and cut off direct current signal.W1, w2, w3, w4, w5, w6, w7, w8 respectively are semiconductor device, select for use the voltage stabilizing value be about 3V as the 2cw22 silicon voltage regulator diode, its effect is the conducting call signal, the blocking-up voice signal.Ja, Jb are respectively the solenoid of two relays, and its inductance value is big as far as possible, and the low-frequency choke of can connecting in case of necessity is to reduce its shunting to call signal.JaK1, JaK2 and JbK1, JaK2 are respectively two groups of normally closed switchs that are subjected to Ja, Jb control.B1, B2, B3, B4, B5, B6 are repeating coils, just the connection difference.B1, B2, B3, B4 are used to increase phantom line, and B5, B6 are used to prevent that battery pack is with the voice signal short circuit.1/ 2 is ground connection symbols.

The circuit working principle

Physical circuit provides path for the call signal between a door and a machine.The c5 that connects in the circuit, c6, c11, c12 capacity be big (15 microfarad), and call signal is not had big influence.With B1, B2, B3, B4 is that phantom line that main element is formed is that call signal between b door and the b machine provides path.Crosstalk mutually for the call signal that prevents two phones, used by 8 capacitors and 4 four-terminal networks that semiconductor device is formed.Capacitor per 4 one group (c1, c2, c3, c4 are one group, and c7, c8, c9, c10 are one group) is as two tetrapolar series arms, and per two of semiconductor device is that one group (w1, w2 are one group, and w5, w6 are one group) is as two tetrapolar and arms.When calling out between a door and a machine, because the capacity less (0.5 microfarad) of c3, c4 and c7, c8, most of signal is by passing through in the physical circuit.The call signal that fraction seals in b door and b machine through c3, c4 and c7, c8 can be subjected to the attenuation of w1, w2 and w5, w6, and therefore, b door and b machine can misoperation or mistake jingle bells.When calling out between b door and the b machine, because the capacity less (0.5 microfarad) of capacitor c1, c2 and c9, c10, pass through in the phantom line that most of signal is made up of B1, B2, B3, B4.The call signal that fraction seals in a door and a machine through c1, c2 and c9, c10 can be subjected to the attenuation of w1, w2 and w5, w6, and therefore, a door and a machine can misoperation or mistake jingle bells.As can be seen, be series arm with 4 low value capacitors, with semiconductor device for and the four-terminal network formed of arm can be voice signal path be provided, but attenuation call signal again.The key here is that the also arm of network has used semiconductor device.In the prior art with Resistor-Capacitor Unit for and arm do not reach above-mentioned effect.

Semiconductor device w3, w4 and w7, w8 have connected at the ground connection place of phantom line.These two groups of semiconductor device conductings during calling are for call signal provides path.During conversation since signal voltage far below the conducting voltage of semiconductor device, semiconductor device can conducting, therefore can be considered phantom line earth point open circuit, therefore the ground wire cross-talk that voltage is lower also is restricted.Directly grounded method can not reach above-mentioned effect in the prior art.

More than be the callwork principle, during calling, two phones all connect with separately particular form and transmission line.

Operation principle during conversation is simpler, and two phones provide path by capacitor, can both connect with physical circuit.But any one user conversion circuit of can trying to be the first wherein.Suppose between a door and a machine call out after, a machine off-hook, closed ka simultaneously, so battery pack Dca powers to Jb, Jbk1 and Jbk2 disconnect, the b machine separates with circuit.Even this moment, the b machine Closing Switch kb of place was also of no avail.Talk-through, the on-hook of a machine disconnects ka, Jb simultaneously and discharges, and Jbk1 and Jbk2 connect, and circuit restores to the original state.If b machine elder generation off-hook, operation principle is same as described above.Switch ka, kb can be respectively and the off-hook on-hook Synchronization Control of a machine, b machine, with handled easily.Converse with the b machine if a is confidential, both sides do not want Closing Switch ka and kb gets final product.

The present invention compared with prior art have mutually do not crosstalk, advantage that security performance is good, and technology is simpler than carrier telephone and time-division phone, after the enforcement, can save and account for the track investment of gross investment more than 50 percent, at the low vast villages and towns in rural areas particularly suitable of line efficiency.

Embodiment and installing and using

With the villages and towns in rural areas is example, to the distant post and telecommunications institute (telephone exchange point) of distance a two-wire telephone circuit is arranged all generally from country government.If will install a local battery apparatus additional in not far unit of distance country government, as shown in Figure 2.

If can be in the time of between post and telecommunications institute (telephone exchange point) and country government, will installing a telephone set additional by installing shown in the accompanying drawing 3.

(A), (B), (C), (D4 circuit unit in (A) in accompanying drawing 2 and the accompanying drawing 3 in the square frame, (B), (C), (D) expression accompanying drawing 1.Wherein (C) represents original user, (D) represents the user of newly installing additional.

If have two or more circuit will use the present invention in a place, then should note the not shared working grounding cable of plurality of units, each unit should use a working grounding cable separately.Every working grounding cable all should be buried underground separately.Distance between per two ground wires are buried underground a little will be more than 20 meters even farther.The lead-out wire that each ground wire is buried underground is a little wanted mutual insulating, introduces each unit respectively.Can be referring to shown in the accompanying drawing 4.(A) unit in (A) expression accompanying drawing 1 in the accompanying drawing 4 in the square frame, each (A) unit is independent separately.If the shared earth connection of plurality of units, the phenomenon that then easy generation is crosstalked mutually.

During use, the method for operation and the prior art at switch place are just the same.The subscriber computer place except that when collinear two users converse mutually, note can not Closing Switch ka and kb, all the other do not have specific (special) requirements yet.

Claims (16)

1, a kind of telephone line multiplexing equipment, particularly a kind of magnetic telephone line sharing equipment, comprising:

A. two telephone users: (a machine) (or (a door)) and (b machine) (or (b machine));

B. two kinds of transmission lines: two-wire physical circuit and the phantom line that utilizes it to increase;

C. the line is busy automatically installs: (Ja) and (Jb);

It is characterized in that:

D. use be connected between the telephone set (b machine) (or (b door)) of phantom line and the physical circuit can be smoothly by the voice signal four-terminal network of attenuation call signal again.

2, a kind of telephone signal transmission method, particularly a kind of magnetic telephone method for transmitting signals, the practice is: utilize repeating coil to increase a phantom line on a pair of circuit that is equipped with telephone set (a door), (a machine), transmission line as another telephone set (b door) (b machine) is characterized in that: the voice signal of telephone set (b door), (b machine) and call signal use physical circuit and phantom line to transmit respectively.

3, equipment as claimed in claim 1, its tetrapolar feature comprises:

A. one group of capacitor that provides path and restriction call signal to pass through for voice signal is provided the series arm of network;

B. one of network and arm have one group of voice signal can not make its conducting, call signal can make the voltage stabilizing didoe of its conducting;

C. close telephone set (b door) (or (b machine)) end of network is parallel with a winding of transformer (B1) (or (B4)), and (B1) (or another winding of (B4) connects phantom line;

D. the ground connection of phantom line place is in series with one group of voice signal and can not makes its conducting, call signal can make the voltage stabilizing didoe of its conducting.

4, method as claimed in claim 2, comprising:

A. with can make voice signal smoothly by and the four-terminal network that passes through of restriction call signal the signal of telephone set (b door) (or (b machine)) is separated;

B. the call signal after separating is transmitted with phantom line, and voice signal transmits with physical circuit;

C. the one group of voice signal of ground connection place series connection at phantom line can not make its conducting, call signal can make the voltage stabilizing didoe of its conducting with the restriction cross-talk.

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