CN2177310Y - Telephone protector - Google Patents

Abstract

The utility model provides a telephone protector which is composed of a casing and a circuit arranged in the casing, wherein the circuit comprises an arrester, a polar fixing circuit, a low pass filter circuit, a variable divider circuit, an off-hook discrimination circuit, a latch circuit, a display circuit, a clamp circuit, a controlled oscillation circuit and an amplifying circuit. Once off-hook, the utility model can immediately send audio pulse signals to a telephone line so as to cause thieves not to communicate, so that others can not steal and use telephones without influence on normal use of the telephones by users.

Description

Telephone protector

The utility model relates to a kind of line protector, particularly relates to a kind of phone protector.

Along with popularizing of phone, the phenomenon of other people steal telephone wire has appearred in the society, and be about to telephone set and insert on the subscriber's telephone line, bring economically loss for this telephone wire user.For preventing other people steal telephone wire, at present commercially available a kind of " telephone wire prevent the steal device " inserts on the telephone wire steal phone afterwards though can prevent other people telephone set; but the protection poor effect, even be in the protection situation, the steal person is during as the side of answering the call; still can more clearly converse, moreover, because no latch function; after the steal person puts down microphone; whether indicator light extinguishes, and the user can't be distinguished when indicator light does not work, have people's steal to cross telephone wire; and do not have lightning protection measures, power consumption is big etc.

The purpose of this utility model is to provide a kind of protection effective, and can accurately discern the phone protector whether people's steal telephone wire is arranged.

The utility model phone protector is to realize like this; it is made up of housing and the circuit that is arranged in the housing; its circuit comprises lightning arrester, polarity permanent circuit, low-pass filter circuit, variable bleeder circuit, off-hook judging circuit, latch cicuit, power supply; display circuit, clamp circuit, controlled oscillation circuit and amplifying circuit.Its annexation is, the telephone wire tandem tap, connect polarity permanent circuit input behind the lightning arrester connected in parallel, it exports an end ground connection, another termination low-pass filter circuit input, low-pass filter circuit output connects variable bleeder circuit input, it exports termination off-hook judging circuit input, another output termination clamp circuit input, clamp circuit output connects power supply, and another of off-hook judging circuit exported termination latch cicuit input, latch cicuit output connects demonstration, another output of off-hook judging circuit is accepted control oscillating circuit input, its output termination amplifying circuit input, and amplifying circuit output connects the output of polarity permanent circuit.

Its Semi-polarity permanent circuit is made of the bridge circuit that diode D2～D5 forms, and telephone wire L1, L2 tandem tap K1-2 connect the bridge circuit input behind the lightning arrester connected in parallel RU, and it exports an end ground connection, and another output terminals A output positive voltage is given low-pass filter circuit; Low-pass filter circuit is made of resistance R 1 and capacitor C 1, and circuit filtering is dried scratches for this, and output dc voltage is given variable bleeder circuit; Variable bleeder circuit is made of resistance R 1, R2, R4 and voltage stabilizing didoe D6, and its output divides two-way, and one tunnel input off-hook judging circuit guarantees the off hook state input low level, and on-hook (putting down microphone) state input high level.Another road output connects the clamp circuit input; Clamp circuit is realized by diode D1, guarantees that the voltage of variable bleeder circuit input off-hook judging circuit is no more than Vcc+0.5V, and simultaneously to power source charges; The off-hook judging circuit is an inverter, is made of not gate M1 and M2, and during off-hook, because variable bleeder circuit is input as low level, this circuit is just exported high level and given the controlled oscillation circuit, exports high level simultaneously and triggers latch cicuit; Latch cicuit is by NAND gate M5 and M6, and resistance R 8 and R10 and capacitor C 2 and C4 constitute.This circuit output high level is given and is shown; Demonstration is made of light-emitting diode D7 and resistance R 9; The controlled oscillation circuit is by not gate M3, NAND gate M4, resistance R 6 and R7, and capacitor C 3 constitutes.When off-hook judging circuit input high level, this circuit produces audio signal, and send into telephone wire behind the input amplifying circuit, dried telephone set dialing signal and the spoken sounds of scratching, amplifying circuit is made of current-limiting resistance R5, R3 and transistor BG1, it exports to the polarity permanent circuit, through K switch 1-2 to telephone wire L1 and L2.

The operation principle of the utility model phone protector is, hook state telephone wire L1, the last voltage of L2 are 50～60V, is positive 50-60V voltage at the A point behind diode D2～D5, Vcc+0.5V voltage occurs at the B point again after low-pass filtering and variable dividing potential drop.This voltage divides two-way, one tunnel input clamp diode D1, and give power source charges; one tunnel input not gate M1 input, M1 output C point is a low level, this low level is blocked NAND gate M4; make the oscillating circuit failure of oscillations, the H point is a high level, and not gate M3 output I point is a low level; transistor BG1 is obstructed; output is high impedance, so when squeezing into phone, the telephone set normal ringer; the user only need disconnect the protector circuit, gets final product normal talking.The low level that C is ordered is also imported not gate M2, and making the D point is high level, and E point, G point are high level, and behind NAND gate M5, M6, the F point keeps original state, and light-emitting diode D1 still keeps original light on and off state.Off hook state: as on the telephone wire of this protector, inserting the steal telephone set; an as long as off-hook; voltage between L1, L2 two telephone wires is reduced to 7～10V by 50～60V; the A point becomes+7～10V, and the B point is 0V, and the C point is high level immediately; NAND gate M4 lifts a blockade immediately; oscillating circuit vibrates immediately, and audio pulse appears in the I point, after amplifying by diode D2～D5 and close K1-2 and be input on the telephone wire.When steal person off-hook dialing or off-hook were answered a call, this pulse signal made it can't use phone dried dialing signal or the voice signal of scratching.C point high level makes the D point be low level immediately simultaneously, and the F point is a high level, and light-emitting diode D7 is shinny immediately.The notice subscriber's telephone line is by people's steal.Have only when outage is switched on again, the F point just is a low level, and D7 just can extinguish.

After the advantage of the utility model phone protector was that the steal phone inserts on the subscriber's telephone line, the person can't put through phone or receive phone to make the steal, and can send signal, shows people's steal.This protector also has lightning protection measures, charge function, and long-term use need not changed battery.

Describe the utility model embodiment in detail below in conjunction with accompanying drawing.

Fig. 1: the utility model circuit block diagram

Fig. 2: the utility model circuit connection diagram

The circuit of the utility model phone protector is connected to, and diode D2～D5 constitutes the polarity permanent circuit, and telephone wire L1, L2 serial connection K switch 1-2 is connected to D2 and D4 respectively, the middle-end of D3 and D5, the middle-end ground connection of D4 and D5 behind the lightning arrester connected in parallel RU.Resistance R 1 and capacitor C 1 constitute low-pass filter circuit, the middle-end of R1 one termination D2 and D3, another termination C1 one end, C1 other end ground connection.Resistance R 1, R2, R4 and voltage stabilizing didoe D6 constitute variable bleeder circuit, the middle-end of R2 one termination R1 and C1, another termination D6 one end, another termination of D6 R4 one end, R4 other end ground connection.Clamp circuit is realized by clamp diode D1, meets the power input Vcc of integrated circuit behind the one end tandem tap K1-1, the middle-end of another termination D6 and R4.Not gate M1 and M2 constitute the off-hook judging circuit, the middle-end of M1 input termination D6 and R4, output termination M2 input.Resistance R 8 and R10, capacitor C 2 and C4, and NAND gate M5 and M6 formation latch cicuit, C2 one termination M2 output, another termination of C2 M5 input connects the M6 input behind its middle-end series connection R8 and the R10, the M6 input connects M5 output simultaneously, M6 output connects M5 input, the middle-end of C4 one termination R10 and M6 input, other end ground connection.Resistance R 9 and light-emitting diode D7 constitute display circuit, D7 one termination M5 output, ground connection behind the other end series connection R9.Resistance R 6 and R7, capacitor C 3, not gate M3, NAND gate M4 constitutes the controlled oscillation circuit, the M4 input connects the middle-end of M1 and M2, and its output connects the M3 input, R7 one termination M4 input, the middle-end of R6 one termination M3 and M4, the R6 and the R7 other end are connected to C3 one end, another termination of C3 M3 output.Resistance R 3 and R5, transistor BG1 constitutes amplifying circuit, the middle-end of R5 one termination M3 and C3, another termination BG1 base stage, grounded emitter is connected to the middle-end of D2 and D3 behind the collector electrode series connection R3.

Battery 1.5 * 200 anodes meet the power input Vcc of the integrated package of not gate and NAND gate behind K switch 1-1.

Claims (2)

1; a kind of phone protector; form by housing and the circuit that is arranged in the housing; it is characterized in that circuit comprises lightning arrester; the polarity permanent circuit; low-pass filter circuit; variable bleeder circuit; the off-hook judging circuit; latch cicuit; display circuit; clamp circuit; controlled oscillation circuit and amplifying circuit; its annexation is; the telephone wire tandem tap; connect polarity permanent circuit input behind the lightning arrester connected in parallel; it exports an end ground connection; another termination low-pass filtering input; the variable bleeder circuit input of low-pass filtering output termination; it exports a termination off-hook judging circuit input; another termination clamp circuit input; clamp circuit output connects power supply; the off-hook judging circuit is exported termination latch cicuit input, and latch cicuit output connects display circuit, and another output of off-hook judging circuit is accepted control oscillating circuit input; its output termination amplifying circuit input, amplifying circuit output connects the output of polarity permanent circuit.

2, phone protector as claimed in claim 1 is characterized in that the polarity permanent circuit is made of the bridge circuit that diode D2～D5 forms; Low-pass filter circuit is made of resistance R 1 and capacitor C 1; Variable bleeder circuit is made of voltage stabilizing didoe D6 and peripheral circuit thereof; The off-hook judging circuit is made of not gate M1 and M2, and latch cicuit is made of dual input NAND gate M5, M6 and peripheral circuit thereof; Clamp circuit is realized by diode D1; The controlled oscillation circuit is made of not gate M3, NAND gate M4 and peripheral circuit thereof; Amplifying circuit is made of transistor BG1 and peripheral circuit thereof.

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