CN2173483Y - Theft-proof device for telephone line - Google Patents

Abstract

The utility model relates to a theft-proof device for a telephone line, belonging to the terminal device of the telephone network. The theft-proof device for a telephone line is composed of a polarity protective circuit, an off/on hook testing circuit, a square wave oscillator, a strobing gate, a simulation electronic gate, a state indicator circuit, a voltage shortage indicator circuit, a power supply and a switch. The theft-proof device for a telephone line not only can make the off hook on the illegal doubling telephone, and the indication alarm on the open circuit, the short circuit and the battery voltage shortage of the telephone line but also can block the circuit to stop the number stealing on time when the illegal doubling telephone is in the off-hook state, and moreover, the normal use of the original telephone can not be influenced. The theft-proof device for a telephone line has simple structure, small size, low cost, high reliability, convenient installation and operation, and can be widely used for the family and the enterprise having telephones.

Description

Theft-proof device for telephone line

The utility model belongs to a kind of telephone network terminal equipment, especially relates to a kind of illegal doubling receiver off-book signal that passes through to detect, and in time the blockade line roadlock ends the anti-device of usurping of telephone line of steal-number.

In recent years, phone is accepted by increasing people as one of most important means of communication.Yet domestic call installation fee and Monthly Fee are all higher at present, and illegal doubling steal-number phenomenon happens occasionally, and is brought extra economic loss by the owner of steal-number phone.Though the telephone call office that has adopts program control password toll line bialing, expense is higher, and can not separate long-distance by no means steal-number problem, also has problems such as cryptocompromise and complicated operation simultaneously.People urgently seek a kind of anti-device of usurping of telephone line of the reliable cheapness as the telephone network terminal equipment.

The purpose of this utility model is the anti-device of usurping of the telephone line that provides a kind of reliable operation, cheap, easy to install, it can not only be reported to the police to illegal doubling receiver off-book, telephone wire open circuit and short circuit, battery is under-voltage indication, and can when illegal doubling receiver off-book, end steal-number by timely blockade line roadlock, do not influence the normal use of original phone simultaneously.

The purpose of this utility model can reach by following measure: the utility model is by polar protective circuit, picking/hanging machine detection circuit; square-wave oscillator; storbing gate; the analog electrical cervical orifice of uterus; condition indication circuit, under-voltage indicating circuit, power supply and switch are formed, and it is characterized in that: its storbing gate is by cmos nand gate IC ₁: B and CMOS inverter ic ₂: the A cascade is formed, and two inputs of storbing gate are connected with the output of picking/hanging machine detection circuit and the output of square-wave oscillator respectively, and the output of storbing gate links to each other with the input of analog electrical cervical orifice of uterus and the input of condition indication circuit.Its picking/hanging machine detection circuit is by high resistance measurement voltage divider R ₁, R ₂, the CMOS inverter ic ₁: A, integrator R ₃, C ₁Cascade is formed.The load of its analog electrical cervical orifice of uterus is by R ₉And C ₃Be formed in parallel.Its under-voltage indicating circuit is by diode D ₇～D ₁₀, light-emitting diode D ₆, resistance R ₁₀, R ₁₁With the CMOS inverter ic ₂: C forms.

Fig. 1 is an electrical schematic diagram of the present utility model.

Fig. 2 is an outline drawing of the present utility model.

(embodiment) is described in further detail the utility model below in conjunction with accompanying drawing:

With reference to Fig. 1, Fig. 2, the utility model is made up of polar protective circuit ［ 1 ］, picking/hanging machine detection circuit ［ 2 ］, square-wave oscillator ［ 3 ］, storbing gate ［ 4 ］, analog electrical cervical orifice of uterus ［ 5 ］, condition indication circuit ［ 6 ］, under-voltage indicating circuit ［ 7 ］, power supply ［ 8 ］ and switch ［ 9 ］.By D ₁～D ₄R in the output of the polar protective circuit of forming ［ 1 ］ and the picking/hanging machine detection circuit ［ 2 ］ ₁An end and analog electrical cervical orifice of uterus ［ 5 ］ in triode BG ₂Emitter be connected.R in the dislodging machine testing road ［ 2 ］ ₁The other end and IC ₁1 pin be connected IC with 2 pin ₁R with 3 pin and integrator ₃One end connects, R ₃The other end and IC ₁5 pin connect.IC in the square-wave oscillator ［ 3 ］ ₁11 pin and storbing gate ［ 4 ］ in IC ₁6 pin connect.IC in the storbing gate ［ 4 ］ ₂3 pin and analog electrical cervical orifice of uterus ［ 5 ］ in R ₆An end and condition indication circuit ［ 6 ］ in IC ₂5 pin be connected with 6 pin.Triode BG in the analog electrical cervical orifice of uterus ［ 5 ］ ₂Collector electrode and resistance R ₉One end and electrochemical capacitor C ₃Positive pole be connected.Light-emitting diode D in the condition indication circuit ［ 6 ］ ₅［ 10 ］ negative pole passes through resistance R ₅Meet IC ₂4 pin, D ₅Positive pole meet the V of switch SW ［ 9 ］ _CCEnd.Diode D in the under-voltage indicating circuit ［ 7 ］ ₇～D ₁₀Series connection, D ₇Positive pole meet R ₁₁An end and IC ₂8 pin and 9 pin, light-emitting diode D ₆［ 11 ］ negative pole passes through resistance R ₁₀Meet IC ₂10 pin, R ₁₁The other end and D ₆Positive pole meet the V of switch ［ 9 ］ _CCEnd.Switch ［ 9 ］ is the single-pole double throw self-lock switch, and one the tunnel imports line one end of answering the call, and another road input connects the positive pole of power supply ［ 8 ］, and corresponding output meets an end of polar protective circuit ［ 1 ］ and the V of each circuit respectively _CCEnd.

When each doubling phone was in hook state, voltage was added on the picking/hanging machine detection circuit ［ 2 ］ through polar protective circuit ［ 1 ］ on the telephone wire, and resitstance voltage divider is output as about 5V, inverter ic ₁: A is output as low level, and integrator output also is low level, storbing gate ［ 4 ］ sealing.At this moment, analog electrical cervical orifice of uterus ［ 5 ］ is input as low level, BG ₂End, simultaneously light-emitting diode D ₅［ 10 ］ extinguish.

As the doubling receiver off-book, drops is to the 7V on the telephone wire, resitstance voltage divider output is below 0.5V, integrator is output as high level, open storbing gate ［ 4 ］, the square-wave signal that square-wave oscillator ［ 3 ］ produces is by gating, and analog electrical cervical orifice of uterus ［ 5 ］ disconnects by the square wave breath-group and the closed blockade of having finished circuit, and the person can't pull out the number of taking on the telephone to make the off-hook.Square wave is about the 300ms high level, the 300ms low level, and the break-make of analog electrical cervical orifice of uterus ［ 5 ］ can be heard the sound that is similar to busy tone on phone, the person puts down phone thereby make illegal doubling usurp the circuit.Meanwhile, the light-emitting diode D in the condition indication circuit ［ 6 ］ ₅［ 10 ］ also press the flicker of square wave breath-group, inform the positive doubling off-hook of owner.As the on-hook of doubling phone, between the square wave low period, analog electrical cervical orifice of uterus ［ 5 ］ disconnects, picking/hanging machine detection circuit ［ 2 ］ output low level, and sealing storbing gate ［ 4 ］, telephone line prevents that usurping device gets back to monitored state.

When telephone set open circuit or short circuit, polar protective circuit ［ 1 ］ is output low level all, and the anti-device of usurping of telephone line this moment is worked when illegal doubling receiver off-book is arranged.

When phone was squeezed into, bell signal was through polar protective circuit ［ 1 ］ full-wave rectification, inverter ic in the picking/hanging machine detection circuit ［ 2 ］ ₁: A exports square-wave signal, output low level still behind integrator, and sealing storbing gate ［ 4 ］ is finished bell signal in the anti-filtering of usurping in the device of telephone line, thereby does not influence the normal ringer of original phone.

Usurp the growth of service time of battery in the device along with telephone line is anti-, voltage can reduce, but cell voltage all can operate as normal more than 3V, and the set thus alarm threshold of owing is about 3.2V.Under-voltage indicating circuit ［ 7 ］ utilizes four diode D ₇～D ₁₀The nonlinear resistance property that series connection is presented is by regulating resistance R ₁₁Resistance, work as V _CCDuring greater than 3.2V, inverter ic ₂: the C input is a low level relatively, is output as high level, light-emitting diode D ₆［ 11 ］ by (extinguishing); Work as V _CCDuring less than 3.2V, the inverter input is a high level relatively, is output as low level, light-emitting diode D ₆［ 11 ］ conducting (luminous).

When owner need outwards pull out phone or answer incoming call, only need connect the switch that makes a movement ［ 9 ］, disconnect the anti-power supply of usurping device of telephone line with being connected of phone.Press switch ［ 9 ］ again, recover monitored state.

The utility model has the advantages that simple in structurely, volume is little, and cost is low, and the reliability height is easy to install, and the power consumptive province can be widely used in the family and office that phone is housed.

Claims (4)

1, the anti-device of usurping of a kind of telephone line; it is made up of polar protective circuit [1], picking/hanging machine detection circuit [2], square-wave oscillator [3], storbing gate [4], analog electrical cervical orifice of uterus [5], condition indication circuit [6], under-voltage indicating circuit [7], power supply [8] and switch [9], it is characterized in that: its storbing gate [4] is by cmos nand gate IC ₁: B and CMOS inverter ic ₂: the A cascade is formed, two inputs of storbing gate [4] are connected with the output of picking/hanging machine detection circuit [2] and the output of square-wave oscillator [3] respectively, and the output of storbing gate [4] is connected with the input of analog electrical cervical orifice of uterus [5] and the input of condition indication circuit [6].

2, telephone line as claimed in claim 1 is anti-usurps device, and it is characterized in that: its picking/hanging machine detection circuit ［ 2 ］ is by high resistance measurement voltage divider R ₁, R ₂, the CMOS inverter ic ₁: A, integrator R ₃, C ₁Cascade is formed.

3, telephone line as claimed in claim 1 is anti-usurps device, it is characterized in that: by triode BG ₁, BG ₂, resistance R ₆～R ₈The load of the analog electrical cervical orifice of uterus of forming ［ 5 ］ is by R ₉And C ₃Be formed in parallel.

4, telephone line as claimed in claim 1 is anti-usurps device, and it is characterized in that: its under-voltage indicating circuit ［ 7 ］ is by diode D ₇～D ₁₀, light-emitting diode D ₆, resistance R ₁₀, R ₁₁With the CMOS inverter ic ₂: C forms.