CN2138861Y

CN2138861Y - Enciphered device of telephone wire

Info

Publication number: CN2138861Y
Application number: CN 92238603
Authority: CN
Inventors: 李伟; 郭军生; 安文河
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-10-29
Filing date: 1992-10-29
Publication date: 1993-07-21
Anticipated expiration: 2002-10-29

Abstract

The utility model discloses an enciphered device of telephone wire which can be connected between telephone exchange circuit and customer station set circuit. The circuit adopts differential system to process two-four line conversion, internal connecting with two branches of delivery and receiving. The components of the two branches are essentially same, which are all composed of a magnify filter circuit, a modem and a frequency dividing circuit. Voice signals from the station set are modulated and enciphered in sending circuit, and enciphered signals from the station set are demodulated and deciphered in receiving circuit; a cipher key converting switch is arranged on the frequency dividing circuit, which can choose different frequencies to process modulation-demodulation to encipher and decipher; the encipheror is provided with an encipher / decipher converting switch in order to select the mode of enciphered talking or common talking.

Description

Enciphered device of telephone wire

The utility model belongs to telephone communication unit.

The application of the various phones of China at present is very universal, has been penetrated in all trades and professions and the personal lifestyle, and Content of Communication relates to military affairs, national defence, public security, economy, science and technology and family's various aspects.But because China's telecommunications industry is started late, communication equipment is comparatively backward, often causes the phenomenon of giving away secrets, as the automatic magnetic field exposure of phone, and situations such as line cord cross-talk, the inner wrong number cross-talk of portion's machine, exchange monitoring.Current, though the existing secret phone equipment of China, its complex structure, volume be big, involve great expense, and can not satisfy the needs of social all trades and professions and personal lifestyle.

The utility model applicant was 92234580.5 at application number once, name is called in the patent of " acoustical coupling has, radio telephone encryption equipment ", proposed a kind of simple in structurely, easy to use, be beneficial to universal telephone encryption device, this device is the portable phone encryption device that a kind of on-fixed is installed.And for general organ and private home, often wish the formula that installs and fixes again, and can encrypt and common talking mode between the device that select arbitrarily, for this reason, the utility model proposes a kind of telephone line encryption equipment on the basis of the system secret skill art of aforementioned patent.

The purpose of this utility model is to propose a kind of telephone line encryption equipment that is installed between telephone exchange and the user's unit, can select to encrypt or common talking mode for the user.

Another purpose of the present utility model provides the telephone line encryption equipment of the alternative cipher key switch of a kind of 8-16 of having kind, to improve the communication security degree.

Another purpose of the present utility model provides a kind of telephone line encryption equipment with integrated circuit component, and to reduce volume, saves energy strengthens reliability.

The utility model telephone line encryption equipment comprises a casing and is loaded on encryption/non-encrypted change over switch and cipher key switch on the casing, and is used for the binding post (as shown in Figure 2) that is connected respectively with exchange, substation, is equiped with the encryption equipment circuit in the casing.This circuit is pressed two in the regular phone path--and four line conversion regimes are formed.Promptly between exchange and substation, be connected with receiving branch with encrypting to send by differential system, between exchange and phone and differential system, be respectively the two wires and be connected, differential system respectively is connected (totally four lines) for the two wires with transmission again with receiving branch.This differential system that utilizes carries out two--the usefulness of four lines conversions is as follows: at exchange to all being to adopt the TW two wire connection between user's unit, after entering encryption equipment, directly be connected if will send with two lines that two pairs of line parallels of receiving branch circuit get up with exchange comes, " receiving the back retransmits " phenomenon then can appear, will produce singing in the circuit, can't communicate by letter, will adopt differential system to carry out two for this reason, four conversions, make the two wires of exchange and user's unit convert four lines to through differential system, be connected with receiving branch with transmission respectively, differential system claims " two; four line transducers " again in the regular phone talking path, and the utility model is applied to encrypting the conversion of transmission and receiving lines.

The basic composition of circuit is: exchange links to each other with differential system respectively with phone, be connected between two differential systems and send and receiving branch, transmitting branch is encrypted by amplification filtering, modulation and filter amplification circuit is formed, receiving branch goes close by amplification filtering, demodulation and filter amplification circuit is formed, and sees Fig. 3.

The link encryption device is switched on or switched off by change over switch and exchange circuit, and during connection, the line of exchange and substation cuts off; During disconnection, exchange and substation are directly connected, and see Fig. 5.

Below, in conjunction with the embodiments the utility model telephone line encryption equipment is elaborated with reference to accompanying drawing.

Fig. 1 is the utility model telephone line encryption equipment profile schematic diagram.

Fig. 2 is the utility model telephone line encryption equipment schematic side view.

Fig. 3 is the utility model telephone line encryption equipment circuit block-diagram.

Fig. 4 is the utility model telephone line encryption equipment schematic circuit.

Fig. 5 is that the utility model telephone line encryption equipment uses connection layout.

As shown in Figure 1, the utility model telephone wire encryption equipment comprises casing 1 and interior wiring road thereof, and encryption/non-encrypted change over switch 2 is housed on the casing 1, and key change over switch 3 is used for the binding post 4 that links to each other with exchange, the binding post 5 that links to each other with phone; The composition of internal wiring such as Fig. 3, shown in 4, phone binding post 5 is connecting differential system circuit 6, exchange binding post 4 connection differential system circuit 6 ', identical in the composition of differential system circuit and the general speaking circuit loop, constitute by the version of pure resistance by T type network, differential system 6 and 6 ' between be connected to transtation mission circuit 7 and receiving circuit 8, wherein transtation mission circuit 7 is by amplification filtering circuit 9, modulator-demodulator 10 and crystal oscillator and frequency dividing circuit 11 are formed, also being connected to frequency-changeover switch 3(on the frequency dividing circuit 11 is the key change over switch), wherein an input of amplification filtering circuit 9 links to each other with the output of phone differential system 6, voice signal from phone is exported and is delivered to modulation 10 and modulate encryption from circuit 9 after amplification and low-pass filtering, another input that the coded signal of being exported is sent circuit 9 back to carries out low-pass filtering and power amplification, then output deliver to differential system 6 ', thereby the voice signal that will encrypt is sent to exchange, wherein the output of frequency dividing circuit 11 links to each other with modulator-demodulator 10 with circuit 9 respectively, so that filtering gating frequency and modulation frequency signal to be provided; The composition of the composition of receiving circuit 8 and above-mentioned transtation mission circuit 7 is basic identical, comprise amplification filtering circuit 9 ', modulator-demodulator 10 ' and crystal oscillator and frequency dividing circuit 11 ', frequency dividing circuit 11 ' on be connected to frequency-changeover switch 3(cipher key switch); Wherein, amplification filtering circuit 9 ' an input and exchange differential system 6 ' output link to each other; modulator-demodulator 10 ' the coded signal from exchange is carried out demodulation go close; deliver to differential system 6 from the close signal that goes of circuit 9 ' output, thereby the signal that will be reduced to normal speech is sent to phone.

One encryption/non-encrypted change over switch 2 also is housed, K promptly shown in Figure 5 in the circuit encryption equipment _1-1With K _1-2, work as K _1-1Closure, K _1-2During disconnection, encryption equipment and talking path disconnect, and can carry out non-encrypted mode and converse, and work as K _1-1Disconnect K _1-2When closed, insert encryption equipment in the circuit, can carry out secret telephony.

In order to improve communication and privacy degrees, frequency dividing circuit 11 is through the switching of key change over switch 3, the close signal of system of exportable 8-16 kind different frequency.

In order to reduce equipment volume, above-mentioned encryption equipment circuit adopts integrated circuit to form, two adjustable lowpass sampled data filter--the MC145414 of described circuit 9 and 9 ' employing, modulator-demodulator adopts three groups of two-way analog switching ics--and CD4053, frequency divider adopt ten tetrads serial counter/frequency divider integrated circuit--CD4060.

The utility model telephone wire encryption equipment has following outstanding advantage:

1. easy to install and use, utilize the binding post of encryption equipment encryption equipment can be connected between the circuit of telephone exchange and substation; Switching encryption/non-encrypted change over switch can select arbitrarily to encrypt and common talking mode.

2. phone adopts integrated circuit, and volume is little, economize on electricity.

3. simple in structure, cost is low, can be widely used in all trades and professions and the personal lifestyle.

Claims

1, a kind of telephone wire encryption equipment, chartered plane shell 1 and its internal circuit is characterized in that: encryption/non-encrypted change over switch 2 is housed, two pairs of posts 4 and 5 that key change over switch 3 and being used for links to each other respectively with exchange and substation on the casing 1;

Internal circuit comprises: the differential system circuit 6 and 6 that communicates respectively with described binding post 4 and 5 ', differential system circuit 6 and 6 ' between the transtation mission circuit 7 and the receiving circuit 8 that connect, wherein transtation mission circuit 7 is by amplification filtering circuit 9, modulator-demodulator 10 and crystal oscillator and frequency dividing circuit 11 are formed, wherein circuit 9 joins with the output of differential system 6, make from the voice signal of phone and deliver to modulator-demodulator 10 through amplification and low-pass filtering, encrypt another input of sending road 9 again back to through modulation, again through low-pass filtering and power amplification and export, this output and differential system 6 ' link to each other, thereby coded signal is delivered to the exchange circuit, described frequency dividing circuit 11 links to each other with modulator-demodulator 10 with circuit 9 respectively, to supply with filtering gating frequency and modulation frequency signal; The composition of described receiving circuit 8 is identical with transtation mission circuit 7, wherein amplification filtering circuit 9 ' with differential system 6 ' output link to each other, decrypted signal is delivered to the phone circuit, frequency dividing circuit 11 ' supply gating frequency and frequency, demodulation frequency signal;

Described encryption/non-encrypted change over switch 2 when speech scrambling, will be encrypted circuit and exchange circuit and connect, and phone and exchange disconnect; When non-encrypted conversation, will encrypt circuit and exchange and disconnect, phone and exchange are connected.

2, telephone wire encryption equipment as claimed in claim 1, it is characterized in that: described amplification filtering circuit 9 and 9 ' be adjustable lowpass sampled data filter-MC145414, modulator-demodulator 10 and 10 ' be integrated circuit CD4053, frequency divider 11 and 11 ' be integrated circuit CD4060.

3, as claim 1,2 described telephone wire encryption equipments, it is characterized in that: described frequency divider 11 and 11 ' be connected to cipher key switch 3, to change the modulation frequency that frequency divider is exported.